With Spring 4 and Hibernate 4, I was able to use Reflection to get the Hibernate Configuration object from the current environment, using this code:
#Autowired LocalContainerEntityManagerFactoryBean lcemfb;
EntityManagerFactoryImpl emf = (EntityManagerFactoryImpl) lcemfb.getNativeEntityManagerFactory();
SessionFactoryImpl sf = emf.getSessionFactory();
SessionFactoryServiceRegistryImpl serviceRegistry = (SessionFactoryServiceRegistryImpl) sf.getServiceRegistry();
Configuration cfg = null;
try {
Field field = SessionFactoryServiceRegistryImpl.class.getDeclaredField("configuration");
field.setAccessible(true);
cfg = (Configuration) field.get(serviceRegistry);
} catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException e) {
e.printStackTrace();
}
SchemaUpdate update = new SchemaUpdate(serviceRegistry, cfg);
With Hibernate 5, I must use some MetadataImplementor, which doesn't seems to be available from any of those objects. I also tried to use MetadataSources with the serviceRegistry. But it did say that it's the wrong kind of ServiceRegistry.
Is there any other way to get this working?
Basic idea for this problem is:
implementation of org.hibernate.integrator.spi.Integrator which stores required data to some holder. Register implementation as a service and use it where you need.
Work example you can find here https://github.com/valery-barysok/spring4-hibernate5-stackoverflow-34612019
create org.hibernate.integrator.api.integrator.Integrator class
import hello.HibernateInfoHolder;
import org.hibernate.boot.Metadata;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.service.spi.SessionFactoryServiceRegistry;
public class Integrator implements org.hibernate.integrator.spi.Integrator {
#Override
public void integrate(Metadata metadata, SessionFactoryImplementor sessionFactory, SessionFactoryServiceRegistry serviceRegistry) {
HibernateInfoHolder.setMetadata(metadata);
HibernateInfoHolder.setSessionFactory(sessionFactory);
HibernateInfoHolder.setServiceRegistry(serviceRegistry);
}
#Override
public void disintegrate(SessionFactoryImplementor sessionFactory, SessionFactoryServiceRegistry serviceRegistry) {
}
}
create META-INF/services/org.hibernate.integrator.spi.Integrator file
org.hibernate.integrator.api.integrator.Integrator
import org.hibernate.boot.spi.MetadataImplementor;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.hibernate.tool.hbm2ddl.SchemaUpdate;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
#SpringBootApplication
public class Application implements CommandLineRunner {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
#Override
public void run(String... args) throws Exception {
new SchemaExport((MetadataImplementor) HibernateInfoHolder.getMetadata()).create(true, true);
new SchemaUpdate(HibernateInfoHolder.getServiceRegistry(), (MetadataImplementor) HibernateInfoHolder.getMetadata()).execute(true, true);
}
}
I would like to add up on Aviad's answer to make it complete as per OP's request.
The internals:
In order to get an instance of MetadataImplementor, the workaround is to register an instance of SessionFactoryBuilderFactory through Java's ServiceLoader facility. This registered service's getSessionFactoryBuilder method is then invoked by MetadataImplementor with an instance of itself, when hibernate is bootstrapped. The code references are below:
Service Loading
Invocation of getSessionFactoryBuilder
So, ultimately to get an instance of MetadataImplementor, you have to implement SessionFactoryBuilderFactory and register so ServiceLoader can recognize this service:
An implementation of SessionFactoryBuilderFactory:
public class MetadataProvider implements SessionFactoryBuilderFactory {
private static MetadataImplementor metadata;
#Override
public SessionFactoryBuilder getSessionFactoryBuilder(MetadataImplementor metadata, SessionFactoryBuilderImplementor defaultBuilder) {
this.metadata = metadata;
return defaultBuilder; //Just return the one provided in the argument itself. All we care about is the metadata :)
}
public static MetadataImplementor getMetadata() {
return metadata;
}
}
In order to register the above, create simple text file in the following path(assuming it's a maven project, ultimately we need the 'META-INF' folder to be available in the classpath):
src/main/resources/META-INF/services/org.hibernate.boot.spi.SessionFactoryBuilderFactory
And the content of the text file should be a single line(can even be multiple lines if you need to register multiple instances) stating the fully qualified class path of your implementation of SessionFactoryBuilderFactory. For example, for the above class, if your package name is 'com.yourcompany.prj', the following should be the content of the file.
com.yourcompany.prj.MetadataProvider
And that's it, if you run your application, spring app or standalone hibernate, you will have an instance of MetadataImplementor available through a static method once hibernate is bootstraped.
Update 1:
There is no way it can be injected via Spring. I digged into Hibernate's source code and the metadata object is not stored anywhere in SessionFactory(which is what we get from Spring). So, it's not possible to inject it. But there are two options if you want it in Spring's way:
Extend existing classes and customize all the way from
LocalSessionFactoryBean -> MetadataSources -> MetadataBuilder
LocalSessionFactoryBean is what you configure in Spring and it has an object of MetadataSources. MetadataSources creates MetadataBuilder which in turn creates MetadataImplementor. All the above operations don't store anything, they just create object on the fly and return. If you want to have an instance of MetaData, you should extend and modify the above classes so that they store a local copy of respective objects before they return. That way you can have a reference to MetadataImplementor. But I wouldn't really recommend this unless it's really needed, because the APIs might change over time.
On the other hand, if you don't mind building a MetaDataImplemetor from SessionFactory, the following code will help you:
EntityManagerFactoryImpl emf=(EntityManagerFactoryImpl)lcemfb.getNativeEntityManagerFactory();
SessionFactoryImpl sf=emf.getSessionFactory();
StandardServiceRegistry serviceRegistry = sf.getSessionFactoryOptions().getServiceRegistry();
MetadataSources metadataSources = new MetadataSources(new BootstrapServiceRegistryBuilder().build());
Metadata metadata = metadataSources.buildMetadata(serviceRegistry);
SchemaUpdate update=new SchemaUpdate(serviceRegistry,metadata); //To create SchemaUpdate
// You can either create SchemaExport from the above details, or you can get the existing one as follows:
try {
Field field = SessionFactoryImpl.class.getDeclaredField("schemaExport");
field.setAccessible(true);
SchemaExport schemaExport = (SchemaExport) field.get(serviceRegistry);
} catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException e) {
e.printStackTrace();
}
Take a look on this one:
public class EntityMetaData implements SessionFactoryBuilderFactory {
private static final ThreadLocal<MetadataImplementor> meta = new ThreadLocal<>();
#Override
public SessionFactoryBuilder getSessionFactoryBuilder(MetadataImplementor metadata, SessionFactoryBuilderImplementor defaultBuilder) {
meta.set(metadata);
return defaultBuilder;
}
public static MetadataImplementor getMeta() {
return meta.get();
}
}
Take a look on This Thread which seems to answer your needs
Well, my go to on this:
public class SchemaTranslator {
public static void main(String[] args) throws Exception {
new SchemaTranslator().run();
}
private void run() throws Exception {
String packageName[] = { "model"};
generate(packageName);
}
private List<Class<?>> getClasses(String packageName) throws Exception {
File directory = null;
try {
ClassLoader cld = getClassLoader();
URL resource = getResource(packageName, cld);
directory = new File(resource.getFile());
} catch (NullPointerException ex) {
throw new ClassNotFoundException(packageName + " (" + directory + ") does not appear to be a valid package");
}
return collectClasses(packageName, directory);
}
private ClassLoader getClassLoader() throws ClassNotFoundException {
ClassLoader cld = Thread.currentThread().getContextClassLoader();
if (cld == null) {
throw new ClassNotFoundException("Can't get class loader.");
}
return cld;
}
private URL getResource(String packageName, ClassLoader cld) throws ClassNotFoundException {
String path = packageName.replace('.', '/');
URL resource = cld.getResource(path);
if (resource == null) {
throw new ClassNotFoundException("No resource for " + path);
}
return resource;
}
private List<Class<?>> collectClasses(String packageName, File directory) throws ClassNotFoundException {
List<Class<?>> classes = new ArrayList<>();
if (directory.exists()) {
String[] files = directory.list();
for (String file : files) {
if (file.endsWith(".class")) {
// removes the .class extension
classes.add(Class.forName(packageName + '.' + file.substring(0, file.length() - 6)));
}
}
} else {
throw new ClassNotFoundException(packageName + " is not a valid package");
}
return classes;
}
private void generate(String[] packagesName) throws Exception {
Map<String, String> settings = new HashMap<String, String>();
settings.put("hibernate.hbm2ddl.auto", "drop-create");
settings.put("hibernate.dialect", "org.hibernate.dialect.PostgreSQL94Dialect");
MetadataSources metadata = new MetadataSources(
new StandardServiceRegistryBuilder()
.applySettings(settings)
.build());
for (String packageName : packagesName) {
System.out.println("packageName: " + packageName);
for (Class<?> clazz : getClasses(packageName)) {
System.out.println("Class: " + clazz);
metadata.addAnnotatedClass(clazz);
}
}
SchemaExport export = new SchemaExport(
(MetadataImplementor) metadata.buildMetadata()
);
export.setDelimiter(";");
export.setOutputFile("db-schema.sql");
export.setFormat(true);
export.execute(true, false, false, false);
}
}
Related
I was practicing to access properties from property file using a singleton class called PropertyLoader but however my maven project is not able to locate the file in resources and giving null pointer excepiton.
Here is the class code.
import java.io.IOException;
import java.util.Properties;
import org.apache.log4j.Logger;
public class PropertyLoader {
private static PropertyLoader instance = null;
private Properties properties;
private final static Logger LOGGER = Logger.getLogger(PropertyLoader.class.getName());
protected PropertyLoader() throws IOException {
//TODO: Fix problem with loading properties file below
properties = new Properties();
properties.load(PropertyLoader.class.getResourceAsStream("app.properties"));
}
public static PropertyLoader getInstance() {
if(instance == null) {
try {
instance = new PropertyLoader();
} catch (IOException ioe) {
LOGGER.error("Error Occurred while creating Property Loader instance: " + ioe.getMessage());
}
}
return instance;
}
public String getValue(String key) {
LOGGER.info("Getting property value for: " + key);
return properties.getProperty(key);
}
}
Error I am getting:
Exception in thread "main" java.lang.NullPointerException: inStream
parameter is null at
java.base/java.util.Objects.requireNonNull(Objects.java:247) at
java.base/java.util.Properties.load(Properties.java:404) at
in.net.sudhir.evernote.client.batchjob.PropertyLoader.(PropertyLoader.java:16)
at
in.net.sudhir.evernote.client.batchjob.PropertyLoader.getInstance(PropertyLoader.java:23)
at
in.net.sudhir.evernote.client.batchjob.EvernoteClient.(EvernoteClient.java:51)
at
in.net.sudhir.evernote.client.batchjob.BatchProcess.main(BatchProcess.java:33)
Here is the Screen shot of Project Structure.
Project Structure in IntelliJ IDEA
properties = new Properties();
try(InputStream inputStream = PropertyLoader.class.getClassLoader().getResourceAsStream("app.properties")) {
if(inputStream == null)
throw new FileNotFoundException("File not found in classpath");
properties.load(inputStream);
}
NOTE: It's bad practice to do computations in the constructor. It's better to create some method that load a resource file.
In a Java servlet container (preferably Tomcat, but if this can be done in a different container then say so) I desire something which is theoretically possible. My question here is whether tools exist to support it, and if so what tools (or what names I should research further).
Here is my problem: in one servlet container I want to run a large number of different WAR files. They share some large common libraries (such as Spring). At first blush, I have two unacceptable alternatives:
Include the large library (Spring, for example) in each WAR file. This is unacceptable because it will load a large number of copies of Spring, exhausting the memory on the server.
Place the large library in the container classpath. Now all of the WAR files share one instance of the library (good). But this is unacceptable because I cannot upgrade the Spring version without upgrading ALL of the WAR files at once, and such a large change is difficult verging on impossible.
In theory, though, there is an alternative which could work:
Put each version of the large library into the container-level classpath. Do some container level magic so that each WAR file declares which version it wishes to use and it will find that on its classpath.
The "magic" must be done at the container level (I think) because this can only be achieved by loading each version of the library with a different classloader, then adjusting what classloaders are visible to each WAR file.
So, have you ever heard of doing this? If so, how? Or tell me what it is called so I can research further.
Regarding Tomcat, for the 7th version you can use VirtualWebappLocader like so
<Context>
<Loader className="org.apache.catalina.loader.VirtualWebappLoader"
virtualClasspath="/usr/shared/lib/spring-3/*.jar,/usr/shared/classes" />
</Context>
For the 8th version Pre- & Post- Resources should be used instead
<Context>
<Resources>
<PostResources className="org.apache.catalina.webresources.DirResourceSet"
base="/usr/shared/lib/spring-3" webAppMount="/WEB-INF/lib" />
<PostResources className="org.apache.catalina.webresources.DirResourceSet"
base="/usr/shared/classes" webAppMount="/WEB-INF/classes" />
</Resources>
</Context>
Don't forget to put the corresponding context.xml into the META-INF of your webapp.
For the jetty as well as other containers the same technique may be used.
The only difference is in how to specify extra classpath elements for the webapp.
UPDATE
The samples above does not share the loaded classes, but the idea is the same - use custom classloader. Here is just the pretty ugly sample that also tries to prevent classloader leaks during undeployment.
SharedWebappLoader
package com.foo.bar;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.loader.WebappLoader;
public class SharedWebappLoader extends WebappLoader {
private String pathID;
private String pathConfig;
static final ThreadLocal<ClassLoaderFactory> classLoaderFactory = new ThreadLocal<>();
public SharedWebappLoader() {
this(null);
}
public SharedWebappLoader(ClassLoader parent) {
super(parent);
setLoaderClass(SharedWebappClassLoader.class.getName());
}
public String getPathID() {
return pathID;
}
public void setPathID(String pathID) {
this.pathID = pathID;
}
public String getPathConfig() {
return pathConfig;
}
public void setPathConfig(String pathConfig) {
this.pathConfig = pathConfig;
}
#Override
protected void startInternal() throws LifecycleException {
classLoaderFactory.set(new ClassLoaderFactory(pathConfig, pathID));
try {
super.startInternal();
} finally {
classLoaderFactory.remove();
}
}
}
SharedWebappClassLoader
package com.foo.bar;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.loader.ResourceEntry;
import org.apache.catalina.loader.WebappClassLoader;
import java.net.URL;
public class SharedWebappClassLoader extends WebappClassLoader {
public SharedWebappClassLoader(ClassLoader parent) {
super(SharedWebappLoader.classLoaderFactory.get().create(parent));
}
#Override
protected ResourceEntry findResourceInternal(String name, String path) {
ResourceEntry entry = super.findResourceInternal(name, path);
if(entry == null) {
URL url = parent.getResource(name);
if (url == null) {
return null;
}
entry = new ResourceEntry();
entry.source = url;
entry.codeBase = entry.source;
}
return entry;
}
#Override
public void stop() throws LifecycleException {
ClassLoaderFactory.removeLoader(parent);
}
}
ClassLoaderFactory
package com.foo.bar;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
public class ClassLoaderFactory {
private static final class ConfigKey {
private final String pathConfig;
private final String pathID;
private ConfigKey(String pathConfig, String pathID) {
this.pathConfig = pathConfig;
this.pathID = pathID;
}
#Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
ConfigKey configKey = (ConfigKey) o;
if (pathConfig != null ? !pathConfig.equals(configKey.pathConfig) : configKey.pathConfig != null)
return false;
if (pathID != null ? !pathID.equals(configKey.pathID) : configKey.pathID != null) return false;
return true;
}
#Override
public int hashCode() {
int result = pathConfig != null ? pathConfig.hashCode() : 0;
result = 31 * result + (pathID != null ? pathID.hashCode() : 0);
return result;
}
}
private static final Map<ConfigKey, ClassLoader> loaders = new HashMap<>();
private static final Map<ClassLoader, ConfigKey> revLoaders = new HashMap<>();
private static final Map<ClassLoader, Integer> usages = new HashMap<>();
private final ConfigKey key;
public ClassLoaderFactory(String pathConfig, String pathID) {
this.key = new ConfigKey(pathConfig, pathID);
}
public ClassLoader create(ClassLoader parent) {
synchronized (loaders) {
ClassLoader loader = loaders.get(key);
if(loader != null) {
Integer usageCount = usages.get(loader);
usages.put(loader, ++usageCount);
return loader;
}
Properties props = new Properties();
try (InputStream is = new BufferedInputStream(new FileInputStream(key.pathConfig))) {
props.load(is);
} catch (IOException e) {
throw new RuntimeException(e);
}
String libsStr = props.getProperty(key.pathID);
String[] libs = libsStr.split(File.pathSeparator);
URL[] urls = new URL[libs.length];
try {
for(int i = 0, len = libs.length; i < len; i++) {
urls[i] = new URL(libs[i]);
}
} catch (MalformedURLException e) {
throw new RuntimeException(e);
}
loader = new URLClassLoader(urls, parent);
loaders.put(key, loader);
revLoaders.put(loader, key);
usages.put(loader, 1);
return loader;
}
}
public static void removeLoader(ClassLoader parent) {
synchronized (loaders) {
Integer val = usages.get(parent);
if(val > 1) {
usages.put(parent, --val);
} else {
usages.remove(parent);
ConfigKey key = revLoaders.remove(parent);
loaders.remove(key);
}
}
}
}
context.xml of the first app
<Context>
<Loader className="com.foo.bar.SharedWebappLoader"
pathConfig="${catalina.base}/conf/shared.properties"
pathID="commons_2_1"/>
</Context>
context.xml of the second app
<Context>
<Loader className="com.foo.bar.SharedWebappLoader"
pathConfig="${catalina.base}/conf/shared.properties"
pathID="commons_2_6"/>
</Context>
$TOMCAT_HOME/conf/shared.properties
commons_2_1=file:/home/xxx/.m2/repository/commons-lang/commons-lang/2.1/commons-lang-2.1.jar
commons_2_6=file:/home/xxx/.m2/repository/commons-lang/commons-lang/2.6/commons-lang-2.6.jar
I was able to implement this for Tomcat (Tested on Tomcat 7.0.52). My solution involves implementing custom version of WebAppLoader which extends standard Tomcat's WebAppLoader. Thanks to this solution you can pass custom classloader to load classes for each of web application.
To utilize this new loader you need to declare it for each application (either in Context.xml file placed in each war or in Tomcat's server.xml file). This loader takes an extra custom parameter webappName which is later passed to LibrariesStorage class to determine which libraries should be used by which application.
<Context path="/pl-app" >
<Loader className="web.DynamicWebappLoader" webappName="pl-app"/>
</Context>
<Context path="/my-webapp" >
<Loader className="web.DynamicWebappLoader" webappName="myApplication2"/>
</Context>
Once this is defined you need to install this DynamicWebappLoader to Tomcat. To do this copy all copiled classes to lib directory of Tomcat (so you should have following files [tomcat dir]/lib/web/DynamicWebappLoader.class, [tomcat dir]/lib/web/LibrariesStorage.class, [tomcat dir]/lib/web/LibraryAndVersion.class, [tomcat dir]/lib/web/WebAppAwareClassLoader.class).
You need also to download xbean-classloader-4.0.jar and place it in Tomcat's lib dir (so you should have [tomcat dir]/lib/xbean-classloader-4.0.jar. NOTE:xbean-classloader provides special implementation of classloader (org.apache.xbean.classloader.JarFileClassLoader) which allowes to load needed jars at runtime.
Main trick is made in LibraryStorgeClass (full implementation is at the end). It stores a mapping between each application (defined by webappName) and libraries which this application is allowed to load. In current implementation this is hardcoded, but this can be rewritten to dynamically generate list of libs needed by each application. Each library has its own instance of JarFileClassLoader which ensures that each library is only loaded one time (the mapping between library and its classloader is stored in static field "libraryToClassLoader", so this mapping is the same for every web application because of static nature of the field)
class LibrariesStorage {
private static final String JARS_DIR = "D:/temp/idea_temp_proj2_/some_jars";
private static Map<LibraryAndVersion, JarFileClassLoader> libraryToClassLoader = new HashMap<>();
private static Map<String, List<LibraryAndVersion>> webappLibraries = new HashMap<>();
static {
try {
addLibrary("commons-lang3", "3.3.2", "commons-lang3-3.3.2.jar"); // instead of this lines add some intelligent directory scanner which will detect all jars and their versions in JAR_DIR
addLibrary("commons-lang3", "3.3.1", "commons-lang3-3.3.1.jar");
addLibrary("commons-lang3", "3.3.0", "commons-lang3-3.3.0.jar");
mapApplicationToLibrary("pl-app", "commons-lang3", "3.3.2"); // instead of manually mapping application to library version, some more intelligent code should be here (for example you can scann Web-Inf/lib of each application and detect needed jars
mapApplicationToLibrary("myApplication2", "commons-lang3", "3.3.0");
(...)
}
In above example, suppose that in directory with all the jars (defined here by JARS_DIR) we have only a commons-lang3-3.3.2.jar file. This would mean that application identified by "pl-app" name (the name comes from webappName attribute in tag in Context.xml as mentioned above) will be able to load classes from commons-lang jar. Application identified by "myApplication2" will get ClassNotFoundException at this point because it has access only to commons-lang3-3.3.0.jar, but this file is not present in JARS_DIR directory.
Full implementation here:
package web;
import org.apache.catalina.loader.WebappLoader;
import org.apache.xbean.classloader.JarFileClassLoader;
import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class DynamicWebappLoader extends WebappLoader {
private String webappName;
private WebAppAwareClassLoader webAppAwareClassLoader;
public static final ThreadLocal lastCreatedClassLoader = new ThreadLocal();
public DynamicWebappLoader() {
super(new WebAppAwareClassLoader(Thread.currentThread().getContextClassLoader()));
webAppAwareClassLoader = (WebAppAwareClassLoader) lastCreatedClassLoader.get(); // unfortunately I did not find better solution to access new instance of WebAppAwareClassLoader created in previous line so I passed it via thread local
lastCreatedClassLoader.remove();
}
// (this method is called by Tomcat because of Loader attribute in Context.xml - <Context> <Loader className="..." webappName="myApplication2"/> )
public void setWebappName(String name) {
System.out.println("Setting webapp name: " + name);
this.webappName = name;
webAppAwareClassLoader.setWebAppName(name); // pass web app name to ClassLoader
}
}
class WebAppAwareClassLoader extends ClassLoader {
private String webAppName;
public WebAppAwareClassLoader(ClassLoader parent) {
super(parent);
DynamicWebappLoader.lastCreatedClassLoader.set(this); // store newly created instance in ThreadLocal .. did not find better way to access the reference later in code
}
#Override
public Class<?> loadClass(String className) throws ClassNotFoundException {
System.out.println("Load class: " + className + " for webapp: " + webAppName);
try {
return LibrariesStorage.loadClassForWebapp(webAppName, className);
} catch (ClassNotFoundException e) {
System.out.println("JarFileClassLoader did not find class: " + className + " " + e.getMessage());
return super.loadClass(className);
}
}
public void setWebAppName(String webAppName) {
this.webAppName = webAppName;
}
}
class LibrariesStorage {
private static final String JARS_DIR = "D:/temp/idea_temp_proj2_/some_jars";
private static Map<LibraryAndVersion, JarFileClassLoader> libraryToClassLoader = new HashMap<>();
private static Map<String, List<LibraryAndVersion>> webappLibraries = new HashMap<>();
static {
try {
addLibrary("commons-lang3", "3.3.2", "commons-lang3-3.3.2.jar"); // instead of this lines add some intelligent directory scanner which will detect all jars and their versions in JAR_DIR
addLibrary("commons-lang3", "3.3.1", "commons-lang3-3.3.1.jar");
addLibrary("commons-lang3", "3.3.0", "commons-lang3-3.3.0.jar");
mapApplicationToLibrary("pl-app", "commons-lang3", "3.3.2"); // instead of manually mapping application to library version, some more intelligent code should be here (for example you can scann Web-Inf/lib of each application and detect needed jars
mapApplicationToLibrary("myApplication2", "commons-lang3", "3.3.0");
} catch (MalformedURLException e) {
throw new RuntimeException(e.getMessage(), e);
}
}
private static void mapApplicationToLibrary(String applicationName, String libraryName, String libraryVersion) {
LibraryAndVersion libraryAndVersion = new LibraryAndVersion(libraryName, libraryVersion);
if (!webappLibraries.containsKey(applicationName)) {
webappLibraries.put(applicationName, new ArrayList<LibraryAndVersion>());
}
webappLibraries.get(applicationName).add(libraryAndVersion);
}
private static void addLibrary(String libraryName, String libraryVersion, String filename)
throws MalformedURLException {
LibraryAndVersion libraryAndVersion = new LibraryAndVersion(libraryName, libraryVersion);
URL libraryLocation = new File(JARS_DIR + File.separator + filename).toURI().toURL();
libraryToClassLoader.put(libraryAndVersion,
new JarFileClassLoader("JarFileClassLoader for lib: " + libraryAndVersion,
new URL[] { libraryLocation }));
}
private LibrariesStorage() {
}
public static Class<?> loadClassForWebapp(String webappName, String className) throws ClassNotFoundException {
System.out.println("Loading class: " + className + " for web application: " + webappName);
List<LibraryAndVersion> webappLibraries = LibrariesStorage.webappLibraries.get(webappName);
for (LibraryAndVersion libraryAndVersion : webappLibraries) {
JarFileClassLoader libraryClassLoader = libraryToClassLoader.get(libraryAndVersion);
try {
return libraryClassLoader.loadClass(className); // ok current lib contained class to load
} catch (ClassNotFoundException e) {
// ok.. continue in loop... try to load the class from classloader connected to next library
}
}
throw new ClassNotFoundException("Class " + className + " was not found in any jar connected to webapp: " +
webappLibraries);
}
}
class LibraryAndVersion {
private final String name;
private final String version;
LibraryAndVersion(String name, String version) {
this.name = name;
this.version = version;
}
#Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if ((o == null) || (getClass() != o.getClass())) {
return false;
}
LibraryAndVersion that = (LibraryAndVersion) o;
if ((name != null) ? (!name.equals(that.name)) : (that.name != null)) {
return false;
}
if ((version != null) ? (!version.equals(that.version)) : (that.version != null)) {
return false;
}
return true;
}
#Override
public int hashCode() {
int result = (name != null) ? name.hashCode() : 0;
result = (31 * result) + ((version != null) ? version.hashCode() : 0);
return result;
}
#Override
public String toString() {
return "LibraryAndVersion{" +
"name='" + name + '\'' +
", version='" + version + '\'' +
'}';
}
}
JBoss has a framework called Modules that solves this problem. You can save the shared library with its version and reference it from your war-file.
I have no idea if it works on Tomcat, but it works as a charm on Wildfly.
please see my requirement: using SchemaExport to export database schema that appiled BeanValidation constraints(eg, #Length(32) will create DB constraints: column(32)).
In Hibernate 4.1.x, i can using the hack code post here: https://forum.hibernate.org/viewtopic.php?f=1&t=1024911&view=previous
but the Ejb3Configuration class that required in above hack code was removed in Hibernate 4.3.5.
so how can i export database schema that appiled BeanValidation constraints without using Ejb3Configuration?
Something like this should work:
PersistenceUnitDescriptorAdapter pu = new PersistenceUnitDescriptorAdapter() {
#Override
public List<String> getManagedClassNames() {
return Arrays.asList( MyClass.class.getName(), ... );
}
};
Map<Object, Object> settings = new HashMap<Object, Object>();
settings.put( "javax.persistence.schema-generation.scripts.action", "create" );
settings.put( "javax.persistence.schema-generation.scripts.create-target", "<path-to-export-file>" );
EntityManagerFactoryBuilderImpl factoryBuilder = new EntityManagerFactoryBuilderImpl( pu, settings );
factoryBuilder.generateSchema();
It relies on Hibernate internal classes, but so did your earlier solution. You could create a issue here - https://hibernate.onjira.com/browse/HHH - explaining your use case. Maybe a solution using a public API can be made available.
i found an temporary solution by using HibernationConfiguration build by EntityManagerFactoryBuilderImpl. it uses the JPA configuration to emit the schema script（with bean-validator constraints).
public final class JpaSchemaExporter
{
public JpaSchemaExporter(String utilName, String packageName, Properties properties, DialectType dialect,
Path outputPath) throws Exception
{
this.dialect = dialect;
this.outputPath = outputPath;
if (Files.exists(outputPath) && !Files.isDirectory(outputPath)) {
throw new IllegalArgumentException(
"Given path already exist and is not a directory! the path:" + outputPath);
}
Files.createDirectories(outputPath);
pud = new ParsedPersistenceXmlDescriptor(Resources.getResourceURL("META-INF"));
pud.setName(utilName);
pud.addClasses(Resources.getClasseNames(packageName));
pud.addMappingFiles("META-INF/orm.xml");
properties.setProperty("hibernate.dialect", dialect.getDialectClass());
ValidatorFactory validatorFactory = Validation.buildDefaultValidatorFactory();
factoryBuilder = new EntityManagerFactoryBuilderImpl( pud, properties );
factoryBuilder.withValidatorFactory(validatorFactory).build().close(); // create HibernateConfiguration instance
this.injectBeanValidationConstraintToDdlTranslator();
validatorFactory.close();
}
private void injectBeanValidationConstraintToDdlTranslator() {
try {
Configuration hibernateConfiguration = factoryBuilder.getHibernateConfiguration();
ValidatorFactory validatorFactory = (ValidatorFactory) factoryBuilder.getConfigurationValues().get(AvailableSettings.VALIDATION_FACTORY);
// private class in hibernate
Method applyRelationalConstraints = Class.forName("org.hibernate.cfg.beanvalidation.TypeSafeActivator")
.getMethod("applyRelationalConstraints",
ValidatorFactory.class,
java.util.Collection.class,
Properties.class,
Dialect.class);
applyRelationalConstraints.setAccessible(true);
Dialect dialectInstance = (Dialect) Class.forName(dialect.getDialectClass()).newInstance();
applyRelationalConstraints.invoke(null, validatorFactory,
Arrays.asList(Iterators.toArray(hibernateConfiguration.getClassMappings(), PersistentClass.class)) ,
hibernateConfiguration.getProperties(),
dialectInstance);
}
catch (Exception e) {
throw new RuntimeException(e);
}
}
#SuppressWarnings("unchecked")
public void create() throws IOException {
Configuration cfg = factoryBuilder.getHibernateConfiguration();
cfg.setProperty("hibernate.hbm2ddl.auto", "create");
SchemaExport export = new SchemaExport(cfg);
export.setDelimiter(";");
export.setOutputFile(Paths.get(outputPath.toString(), "ddl_create_" + dialect.name().toLowerCase() + ".sql").toString());
export.execute(true, false, false, true);
if (!export.getExceptions().isEmpty()) {
System.out.println();
System.out.println("SOME EXCEPTIONS OCCURED WHILE GENERATING THE UPDATE SCRIPT:");
for (Exception e : (List<Exception>) export.getExceptions()) {
System.out.println(e.getMessage());
}
}
}
#SuppressWarnings("unchecked")
public void update() throws IOException {
Configuration cfg = factoryBuilder.getHibernateConfiguration();
cfg.setProperty("hibernate.hbm2ddl.auto", "update");
SchemaUpdate updater = new SchemaUpdate(cfg);
updater.setDelimiter(";");
updater.setOutputFile(Paths.get(outputPath.toString(), "ddl_update_" + dialect.name().toLowerCase() + ".sql").toString());
updater.execute(true, false);
if (!updater.getExceptions().isEmpty()) {
System.out.println();
System.out.println("SOME EXCEPTIONS OCCURED WHILE GENERATING THE UPDATE SCRIPT:");
for (Exception e : ((List<Exception>) updater.getExceptions())) {
System.out.println(e.getMessage());
}
}
}
public void validate() {
Configuration hibernateConfiguration = factoryBuilder.getHibernateConfiguration();
hibernateConfiguration.setProperty("hibernate.hbm2ddl.auto", "validate");
SchemaValidator validator = new SchemaValidator(hibernateConfiguration);
validator.validate();
}
public static void main(String[] args) throws Exception {
Properties prop = new Properties(System.getProperties());
prop.setProperty("hibernate.connection.driver_class", "value in your env");
prop.setProperty("hibernate.connection.url", "value in your env");
prop.setProperty("hibernate.connection.username", "value in your env");
prop.setProperty("hibernate.connection.password", "value in your env");
Path path = Paths.get("schema output path in your env");
String packageName = prop.getProperty("package names of jpa classes");
String unitName = prop.getProperty("jpa Unit Name");
String[] dialects = "HSQL,MYSQL".split(",");
for(String dialect : dialects){
DialectType dialectType = DialectType.valueOf(dialect);
JpaSchemaExporter ddlExporter = new JpaSchemaExporter(unitName, packageName, prop, dialectType, path);
ddlExporter.update();
ddlExporter.create();
}
}
}
I'm trying to create a simple webapp without any XML configuration using Spring 3.1 and an embedded Jetty 8 server.
However, I'm struggling to get Jetty to recognise my implementaton of the Spring WebApplicationInitializer interface.
Project structure:
src
+- main
+- java
| +- JettyServer.java
| +- Initializer.java
|
+- webapp
+- web.xml (objective is to remove this - see below).
The Initializer class above is a simple implementation of WebApplicationInitializer:
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import org.springframework.web.WebApplicationInitializer;
public class Initializer implements WebApplicationInitializer {
#Override
public void onStartup(ServletContext servletContext) throws ServletException {
System.out.println("onStartup");
}
}
Likewise JettyServer is a simple implementation of an embedded Jetty server:
import org.eclipse.jetty.annotations.AnnotationConfiguration;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.webapp.Configuration;
import org.eclipse.jetty.webapp.WebAppContext;
public class JettyServer {
public static void main(String[] args) throws Exception {
Server server = new Server(8080);
WebAppContext webAppContext = new WebAppContext();
webAppContext.setResourceBase("src/main/webapp");
webAppContext.setContextPath("/");
webAppContext.setConfigurations(new Configuration[] { new AnnotationConfiguration() });
webAppContext.setParentLoaderPriority(true);
server.setHandler(webAppContext);
server.start();
server.join();
}
}
My understanding is that on startup Jetty will use AnnotationConfiguration to scan for
annotated implementations of ServletContainerInitializer; it should find Initializer and wire it in...
However, when I start the Jetty server (from within Eclipse) I see the following on the command-line:
2012-11-04 16:59:04.552:INFO:oejs.Server:jetty-8.1.7.v20120910
2012-11-04 16:59:05.046:INFO:/:No Spring WebApplicationInitializer types detected on classpath
2012-11-04 16:59:05.046:INFO:oejsh.ContextHandler:started o.e.j.w.WebAppContext{/,file:/Users/duncan/Coding/spring-mvc-embedded-jetty-test/src/main/webapp/}
2012-11-04 16:59:05.117:INFO:oejs.AbstractConnector:Started SelectChannelConnector#0.0.0.0:8080
The important bit is this:
No Spring WebApplicationInitializer types detected on classpath
Note that src/main/java is defined as a source folder in Eclipse, so should be on the classpath. Also note that the Dynamic Web Module Facet is set to 3.0.
I'm sure there's a simple explanation, but I'm struggling to see the wood for the trees! I suspect the key is with the following line:
...
webAppContext.setResourceBase("src/main/webapp");
...
This makes sense with a 2.5 servlet using web.xml (see below), but what should it be when using AnnotationConfiguration?
NB: Everything fires up correctly if I change the Configurations to the following:
...
webAppContext.setConfigurations(new Configuration[] { new WebXmlConfiguration() });
...
In this case it finds the web.xml under src/main/webapp and uses it to wire the servlet using DispatcherServlet and AnnotationConfigWebApplicationContext in the usual way (completely bypassing the WebApplicationInitializer implementation above).
This feels very much like a classpath problem, but I'm struggling to understand quite how Jetty associates itself with implementations of WebApplicationInitializer - any suggestions would be most appreciated!
For info, I'm using the following:
Spring 3.1.1
Jetty 8.1.7
STS 3.1.0
The problem is that Jetty's AnnotationConfiguration class does not scan non-jar resources on the classpath (except under WEB-INF/classes).
It finds my WebApplicationInitializer's if I register a subclass of AnnotationConfiguration which overrides configure(WebAppContext) to scan the host classpath in addition to the container and web-inf locations.
Most of the sub-class is (sadly) copy-paste from the parent. It includes:
an extra parse call (parseHostClassPath) at the end of the configure method;
the parseHostClassPath method which is largely copy-paste from
AnnotationConfiguration's parseWebInfClasses;
the getHostClassPathResource method which grabs the first non-jar URL
from the classloader (which, for me at least, is the file url to my
classpath in eclipse).
I am using slightly different versions of Jetty (8.1.7.v20120910) and Spring (3.1.2_RELEASE), but I imagine the same solution will work.
Edit: I created a working sample project in github with some modifications (the code below works fine from Eclipse but not when running in a shaded jar) - https://github.com/steveliles/jetty-embedded-spring-mvc-noxml
In the OP's JettyServer class the necessary change would replace line 15 with:
webAppContext.setConfigurations (new Configuration []
{
new AnnotationConfiguration()
{
#Override
public void configure(WebAppContext context) throws Exception
{
boolean metadataComplete = context.getMetaData().isMetaDataComplete();
context.addDecorator(new AnnotationDecorator(context));
AnnotationParser parser = null;
if (!metadataComplete)
{
if (context.getServletContext().getEffectiveMajorVersion() >= 3 || context.isConfigurationDiscovered())
{
parser = createAnnotationParser();
parser.registerAnnotationHandler("javax.servlet.annotation.WebServlet", new WebServletAnnotationHandler(context));
parser.registerAnnotationHandler("javax.servlet.annotation.WebFilter", new WebFilterAnnotationHandler(context));
parser.registerAnnotationHandler("javax.servlet.annotation.WebListener", new WebListenerAnnotationHandler(context));
}
}
List<ServletContainerInitializer> nonExcludedInitializers = getNonExcludedInitializers(context);
parser = registerServletContainerInitializerAnnotationHandlers(context, parser, nonExcludedInitializers);
if (parser != null)
{
parseContainerPath(context, parser);
parseWebInfClasses(context, parser);
parseWebInfLib (context, parser);
parseHostClassPath(context, parser);
}
}
private void parseHostClassPath(final WebAppContext context, AnnotationParser parser) throws Exception
{
clearAnnotationList(parser.getAnnotationHandlers());
Resource resource = getHostClassPathResource(getClass().getClassLoader());
if (resource == null)
return;
parser.parse(resource, new ClassNameResolver()
{
public boolean isExcluded (String name)
{
if (context.isSystemClass(name)) return true;
if (context.isServerClass(name)) return false;
return false;
}
public boolean shouldOverride (String name)
{
//looking at webapp classpath, found already-parsed class of same name - did it come from system or duplicate in webapp?
if (context.isParentLoaderPriority())
return false;
return true;
}
});
//TODO - where to set the annotations discovered from WEB-INF/classes?
List<DiscoveredAnnotation> annotations = new ArrayList<DiscoveredAnnotation>();
gatherAnnotations(annotations, parser.getAnnotationHandlers());
context.getMetaData().addDiscoveredAnnotations (annotations);
}
private Resource getHostClassPathResource(ClassLoader loader) throws IOException
{
if (loader instanceof URLClassLoader)
{
URL[] urls = ((URLClassLoader)loader).getURLs();
for (URL url : urls)
if (url.getProtocol().startsWith("file"))
return Resource.newResource(url);
}
return null;
}
},
});
Update: Jetty 8.1.8 introduces internal changes that are incompatible with the code above. For 8.1.8 the following seems to work:
webAppContext.setConfigurations (new Configuration []
{
// This is necessary because Jetty out-of-the-box does not scan
// the classpath of your project in Eclipse, so it doesn't find
// your WebAppInitializer.
new AnnotationConfiguration()
{
#Override
public void configure(WebAppContext context) throws Exception {
boolean metadataComplete = context.getMetaData().isMetaDataComplete();
context.addDecorator(new AnnotationDecorator(context));
//Even if metadata is complete, we still need to scan for ServletContainerInitializers - if there are any
AnnotationParser parser = null;
if (!metadataComplete)
{
//If metadata isn't complete, if this is a servlet 3 webapp or isConfigDiscovered is true, we need to search for annotations
if (context.getServletContext().getEffectiveMajorVersion() >= 3 || context.isConfigurationDiscovered())
{
_discoverableAnnotationHandlers.add(new WebServletAnnotationHandler(context));
_discoverableAnnotationHandlers.add(new WebFilterAnnotationHandler(context));
_discoverableAnnotationHandlers.add(new WebListenerAnnotationHandler(context));
}
}
//Regardless of metadata, if there are any ServletContainerInitializers with #HandlesTypes, then we need to scan all the
//classes so we can call their onStartup() methods correctly
createServletContainerInitializerAnnotationHandlers(context, getNonExcludedInitializers(context));
if (!_discoverableAnnotationHandlers.isEmpty() || _classInheritanceHandler != null || !_containerInitializerAnnotationHandlers.isEmpty())
{
parser = createAnnotationParser();
parse(context, parser);
for (DiscoverableAnnotationHandler h:_discoverableAnnotationHandlers)
context.getMetaData().addDiscoveredAnnotations(((AbstractDiscoverableAnnotationHandler)h).getAnnotationList());
}
}
private void parse(final WebAppContext context, AnnotationParser parser) throws Exception
{
List<Resource> _resources = getResources(getClass().getClassLoader());
for (Resource _resource : _resources)
{
if (_resource == null)
return;
parser.clearHandlers();
for (DiscoverableAnnotationHandler h:_discoverableAnnotationHandlers)
{
if (h instanceof AbstractDiscoverableAnnotationHandler)
((AbstractDiscoverableAnnotationHandler)h).setResource(null); //
}
parser.registerHandlers(_discoverableAnnotationHandlers);
parser.registerHandler(_classInheritanceHandler);
parser.registerHandlers(_containerInitializerAnnotationHandlers);
parser.parse(_resource,
new ClassNameResolver()
{
public boolean isExcluded (String name)
{
if (context.isSystemClass(name)) return true;
if (context.isServerClass(name)) return false;
return false;
}
public boolean shouldOverride (String name)
{
//looking at webapp classpath, found already-parsed class of same name - did it come from system or duplicate in webapp?
if (context.isParentLoaderPriority())
return false;
return true;
}
});
}
}
private List<Resource> getResources(ClassLoader aLoader) throws IOException
{
if (aLoader instanceof URLClassLoader)
{
List<Resource> _result = new ArrayList<Resource>();
URL[] _urls = ((URLClassLoader)aLoader).getURLs();
for (URL _url : _urls)
_result.add(Resource.newResource(_url));
return _result;
}
return Collections.emptyList();
}
}
});
I was able to resolve in an easier but more limited way by just providing explicitly to the AnnotationConfiguration the implementation class (MyWebApplicationInitializerImpl in this example) that I want to be loaded like this:
webAppContext.setConfigurations(new Configuration[] {
new WebXmlConfiguration(),
new AnnotationConfiguration() {
#Override
public void preConfigure(WebAppContext context) throws Exception {
MultiMap<String> map = new MultiMap<String>();
map.add(WebApplicationInitializer.class.getName(), MyWebApplicationInitializerImpl.class.getName());
context.setAttribute(CLASS_INHERITANCE_MAP, map);
_classInheritanceHandler = new ClassInheritanceHandler(map);
}
}
});
Jetty 9.0.1 contains an enhancement which allows for scanning of annotations of non-jar resources (ie classes) on the container classpath. See comment #5 on the following issue for how to use it:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=404176#c5
Jan
The code below did the trick in my maven project:
public static void main(String[] args) throws Exception {
Server server = new Server();
ServerConnector scc = new ServerConnector(server);
scc.setPort(Integer.parseInt(System.getProperty("jetty.port", "8080")));
server.setConnectors(new Connector[] { scc });
WebAppContext context = new WebAppContext();
context.setServer(server);
context.setContextPath("/");
context.setWar("src/main/webapp");
context.getMetaData().addContainerResource(new FileResource(new File("./target/classes").toURI()));
context.setConfigurations(new Configuration[]{
new WebXmlConfiguration(),
new AnnotationConfiguration()
});
server.setHandler(context);
try {
System.out.println(">>> STARTING EMBEDDED JETTY SERVER, PRESS ANY KEY TO STOP");
System.out.println(String.format(">>> open http://localhost:%s/", scc.getPort()));
server.start();
while (System.in.available() == 0) {
Thread.sleep(5000);
}
server.stop();
server.join();
} catch (Throwable t) {
t.printStackTrace();
System.exit(100);
}
}
Based on my testing and this thread http://forum.springsource.org/showthread.php?127152-WebApplicationInitializer-not-loaded-with-embedded-Jetty I don't think it works at the moment. If you look in AnnotationConfiguration.configure:
parseContainerPath(context, parser);
// snip comment
parseWebInfClasses(context, parser);
parseWebInfLib (context, parser);
it seems coupled to a war-like deployment rather than embedded.
Here is an example using Spring MVC and embedded Jetty that might be more useful:
http://www.jamesward.com/2012/08/13/containerless-spring-mvc
It creates the Spring servlet directly rather then relying on annotations.
To those experiencing this lately, it appears this gets around the issue:
#Component
public class Initializer implements WebApplicationInitializer {
private ServletContext servletContext;
#Autowired
public WebInitializer(ServletContext servletContext) {
this.servletContext = servletContext;
}
#PostConstruct
public void onStartup() throws ServletException {
onStartup(servletContext);
}
public void onStartup(ServletContext servletContext) throws ServletException {
System.out.println("onStartup");
}
}
To make it work on Jetty 9 set attribute AnnotationConfiguration.CLASS_INHERITANCE_MAP on WebAppContext
webAppContext.setAttribute(AnnotationConfiguration.CLASS_INHERITANCE_MAP, createClassMap());
And here is how to create this map:
private ClassInheritanceMap createClassMap() {
ClassInheritanceMap classMap = new ClassInheritanceMap();
ConcurrentHashSet<String> impl = new ConcurrentHashSet<>();
impl.add(MyWebAppInitializer.class.getName());
classMap.put(WebApplicationInitializer.class.getName(), impl);
return classMap;
}
I placed that solution on gitHub
What about just setting the context attribute that tells the scanner which things belong on the container classpath that need to be scanned?
context attribute:
org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern
./servlet-api-[^/].jar$
It is designed to be used with jar names, but you could just match everything.
You'd need to use the WebInfConfiguration as well as the AnnotationConfiguration classes.
cheers
Jan
In our case these lines helped in Jetty startup code:
ClassList cl = Configuration.ClassList.setServerDefault(server);
cl.addBefore("org.eclipse.jetty.webapp.JettyWebXmlConfiguration", "org.eclipse.jetty.annotations.AnnotationConfiguration");
Jetty 9 version of "magomarcelo" answer:
context.setConfigurations(
new org.eclipse.jetty.webapp.Configuration[] { new WebXmlConfiguration(), new AnnotationConfiguration() {
#Override
public void preConfigure(WebAppContext context) throws Exception {
final ClassInheritanceMap map = new ClassInheritanceMap();
final ConcurrentHashSet<String> set = new ConcurrentHashSet<>();
set.add(MyWebAppInitializer.class.getName());
map.put(WebApplicationInitializer.class.getName(), set);
context.setAttribute(CLASS_INHERITANCE_MAP, map);
_classInheritanceHandler = new ClassInheritanceHandler(map);
}
} });
For Jetty 9, if you have webjars, the solution provided does not work straight away as those Jars need to be on the classpath and the JAR contents need to be available as resources for your webapp. So, for that to work together with webjars, the config would have to be:
context.setExtraClasspath(pathsToWebJarsCommaSeparated);
context.setAttribute(WebInfConfiguration.WEBINF_JAR_PATTERN, ".*\\.jar$");
context.setAttribute(WebInfConfiguration.CONTAINER_JAR_PATTERN, ".*\\.jar$");
context.setConfigurations(
new org.eclipse.jetty.webapp.Configuration[] {
new WebInfConfiguration(), new MetaInfConfiguration(),
new AnnotationConfiguration() {
#Override
public void preConfigure(WebAppContext context) throws Exception {
final ClassInheritanceMap map = new ClassInheritanceMap();
final ConcurrentHashSet<String> set = new ConcurrentHashSet<>();
set.add(MyWebAppInitializer.class.getName());
map.put(WebApplicationInitializer.class.getName(), set);
context.setAttribute(CLASS_INHERITANCE_MAP, map);
_classInheritanceHandler = new ClassInheritanceHandler(map);
}
} });
The order here is important (WebInfConfiguration has to come before MetaInf).
Solution that worked for me and does not involve scanning, but uses WebApplicationInitializer class that you provide. Jetty version: 9.2.20
public class Main {
public static void main(String... args) throws Exception {
Properties properties = new Properties();
InputStream stream = Main.class.getResourceAsStream("/WEB-INF/application.properties");
properties.load(stream);
stream.close();
PropertyConfigurator.configure(properties);
WebAppContext webAppContext = new WebAppContext();
webAppContext.setResourceBase("resource");
webAppContext.setContextPath(properties.getProperty("base.url"));
webAppContext.setConfigurations(new Configuration[] {
new WebXmlConfiguration(),
new AnnotationConfiguration() {
#Override
public void preConfigure(WebAppContext context) {
ClassInheritanceMap map = new ClassInheritanceMap();
map.put(WebApplicationInitializer.class.getName(), new ConcurrentHashSet<String>() {{
add(WebInitializer.class.getName());
add(SecurityWebInitializer.class.getName());
}});
context.setAttribute(CLASS_INHERITANCE_MAP, map);
_classInheritanceHandler = new ClassInheritanceHandler(map);
}
}
});
Server server = new Server(Integer.parseInt(properties.getProperty("base.port")));
server.setHandler(webAppContext);
server.start();
server.join();
}
}
The source (in russian) of this code snippet is here: https://habrahabr.ru/post/255773/
did a simple maven project to demonstrate how it can be done cleanly.
public class Console {
public static void main(String[] args) {
try {
Server server = new Server(8080);
//Set a handler to handle requests.
server.setHandler(getWebAppContext());
//starts to listen at 0.0.0.0:8080
server.start();
server.join();
} catch (Exception e) {
log.error("server exited with exception", e);
}
}
private static WebAppContext getWebAppContext() {
final WebAppContext webAppContext = new WebAppContext();
//route all requests via this web-app.
webAppContext.setContextPath("/");
/*
* point to location where the jar into which this class gets packaged into resides.
* this could very well be the target directory in a maven development build.
*/
webAppContext.setResourceBase("directory_where_the_application_jar_exists");
//no web inf for us - so let the scanning know about location of our libraries / classes.
webAppContext.getMetaData().setWebInfClassesDirs(Arrays.asList(webAppContext.getBaseResource()));
//Scan for annotations (servlet 3+)
final AnnotationConfiguration configuration = new AnnotationConfiguration();
webAppContext.setConfigurations(new Configuration[]{configuration});
return webAppContext;
}
}
and that's all - the spring WebApplicationInitializer that you use will get detected without explicitly letting jetty server know about the existence of such an app initializer.
Lets say I have a java package commands which contains classes that all inherit from ICommand can I get all of those classes somehow? I'm locking for something among the lines of:
Package p = Package.getPackage("commands");
Class<ICommand>[] c = p.getAllPackagedClasses(); //not real
Is something like that possible?
Here's a basic example, assuming that classes are not JAR-packaged:
// Prepare.
String packageName = "com.example.commands";
List<Class<ICommand>> commands = new ArrayList<Class<ICommand>>();
URL root = Thread.currentThread().getContextClassLoader().getResource(packageName.replace(".", "/"));
// Filter .class files.
File[] files = new File(root.getFile()).listFiles(new FilenameFilter() {
public boolean accept(File dir, String name) {
return name.endsWith(".class");
}
});
// Find classes implementing ICommand.
for (File file : files) {
String className = file.getName().replaceAll(".class$", "");
Class<?> cls = Class.forName(packageName + "." + className);
if (ICommand.class.isAssignableFrom(cls)) {
commands.add((Class<ICommand>) cls);
}
}
Below is an implementation using the JSR-199 API, i.e. classes from javax.tools.*:
List<Class> commands = new ArrayList<>();
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
StandardJavaFileManager fileManager = compiler.getStandardFileManager(
null, null, null);
StandardLocation location = StandardLocation.CLASS_PATH;
String packageName = "commands";
Set<JavaFileObject.Kind> kinds = new HashSet<>();
kinds.add(JavaFileObject.Kind.CLASS);
boolean recurse = false;
Iterable<JavaFileObject> list = fileManager.list(location, packageName,
kinds, recurse);
for (JavaFileObject classFile : list) {
String name = classFile.getName().replaceAll(".*/|[.]class.*","");
commands.add(Class.forName(packageName + "." + name));
}
Works for all packages and classes on the class path, packaged in jar files or without. For classes not explicitly added to the class path, i.e. those loaded by the bootstrap class loader, try setting location to PLATFORM_CLASS_PATH instead.
Here is an utility method, using Spring.
Details about the pattern can be found here
public static List<Class> listMatchingClasses(String matchPattern) throws IOException {
List<Class> classes = new LinkedList<Class>();
PathMatchingResourcePatternResolver scanner = new PathMatchingResourcePatternResolver();
Resource[] resources = scanner.getResources(matchPattern);
for (Resource resource : resources) {
Class<?> clazz = getClassFromResource(resource);
classes.add(clazz);
}
return classes;
}
public static Class getClassFromResource(Resource resource) {
try {
String resourceUri = resource.getURI().toString();
resourceUri = resourceUri.replace(esourceUri.indexOf(".class"), "").replace("/", ".");
// try printing the resourceUri before calling forName, to see if it is OK.
return Class.forName(resourceUri);
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}
If you do not want to use external depencies and you want to work on your IDE / on a JAR file, you can try this:
public static List<Class<?>> getClassesForPackage(final String pkgName) throws IOException, URISyntaxException {
final String pkgPath = pkgName.replace('.', '/');
final URI pkg = Objects.requireNonNull(ClassLoader.getSystemClassLoader().getResource(pkgPath)).toURI();
final ArrayList<Class<?>> allClasses = new ArrayList<Class<?>>();
Path root;
if (pkg.toString().startsWith("jar:")) {
try {
root = FileSystems.getFileSystem(pkg).getPath(pkgPath);
} catch (final FileSystemNotFoundException e) {
root = FileSystems.newFileSystem(pkg, Collections.emptyMap()).getPath(pkgPath);
}
} else {
root = Paths.get(pkg);
}
final String extension = ".class";
try (final Stream<Path> allPaths = Files.walk(root)) {
allPaths.filter(Files::isRegularFile).forEach(file -> {
try {
final String path = file.toString().replace('/', '.');
final String name = path.substring(path.indexOf(pkgName), path.length() - extension.length());
allClasses.add(Class.forName(name));
} catch (final ClassNotFoundException | StringIndexOutOfBoundsException ignored) {
}
});
}
return allClasses;
}
From: Can you find all classes in a package using reflection?
Start with public Classloader.getResources(String name). Ask the classloader for a class corresponding to each name in the package you are interested. Repeat for all classloaders of relevance.
Yes but its not the easiest thing to do. There are lots of issues with this. Not all of the classes are easy to find. Some classes could be in a: Jar, as a class file, over the network etc.
Take a look at this thread.
To make sure they were the ICommand type then you would have to use reflection to check for the inheriting class.
This would be a very useful tool we need, and JDK should provide some support.
But it's probably better done during build. You know where all your class files are and you can inspect them statically and build a graph. At runtime you can query this graph to get all subtypes. This requires more work, but I believe it really belongs to the build process.
Using Johannes Link's ClasspathSuite, I was able to do it like this:
import org.junit.extensions.cpsuite.ClassTester;
import org.junit.extensions.cpsuite.ClasspathClassesFinder;
public static List<Class<?>> getClasses(final Package pkg, final boolean includeChildPackages) {
return new ClasspathClassesFinder(new ClassTester() {
#Override public boolean searchInJars() { return true; }
#Override public boolean acceptInnerClass() { return false; }
#Override public boolean acceptClassName(String name) {
return name.startsWith(pkg.getName()) && (includeChildPackages || name.indexOf(".", pkg.getName().length()) != -1);
}
#Override public boolean acceptClass(Class<?> c) { return true; }
}, System.getProperty("java.class.path")).find();
}
The ClasspathClassesFinder looks for class files and jars in the system classpath.
In your specific case, you could modify acceptClass like this:
#Override public boolean acceptClass(Class<?> c) {
return ICommand.class.isAssignableFrom(c);
}
One thing to note: be careful what you return in acceptClassName, as the next thing ClasspathClassesFinder does is to load the class and call acceptClass. If acceptClassName always return true, you'll end up loading every class in the classpath and that may cause an OutOfMemoryError.
You could use OpenPojo and do this:
final List<PojoClass> pojoClasses = PojoClassFactory.getPojoClassesRecursively("my.package.path", null);
Then you can go over the list and perform any functionality you desire.