Develop Reference

Deploy java spring-boot app *.jar to heroku with other files in root folder

I have a spring boot app as qsysprereg2-1.0.jar. I pushed into heroku git already compiled jar file + Procfile + folder "config" with files for my app as "config/config.properties". Just some properties.
In Gradle I have only:
apply plugin: 'java'
task stage() {
println("Go stage...")
}
All compiled and deployed successfully.
In result I have error:
java.io.FileNotFoundException: config/config.properties (No such file or directory)
Of course, because:
Running bash on ⬢ qprereg... up, run.9546 (Free)
~ $ ls
Procfile qsysprereg2-1.0.jar system.properties
Where is no folder "config" from git. But "config/config.properties" had been pushed into git.
How to add the folder with files to deploy artifacts?

Sorry, but I did not find a nice solution. I made some tricks. I put all my config files in jar as resources. During starting the app I am checking the files outside jar on dick then coping from resources to dist. New files are keeping on disk without problems. Code for that:
public static void main(String[] args) {
try {
prepareConfig();
} catch (IOException ex) {
log.error("Config prepare fail.", ex);
log.throwing(ex);
throw new RuntimeException(ex);
}
SpringApplication.run(Application.class, args);
}
private static void prepareConfig() throws IOException {
File dir = new File("config");
if (!dir.exists() || !dir.isDirectory()) {
log.info("Create config directory");
Files.createDirectory(dir.toPath());
}
makeReady("config/config1.properties");
makeReady("config/config2.properties");
makeReady("config/config3.properties");
makeReady("config/configN.properties");
}
private static void makeReady(String fileName) throws IOException {
File file = new File(fileName);
if (!file.exists()) {
log.info("Create config file '{}'", file.getName());
try (final InputStream stream = Application.class.getResourceAsStream("/" + fileName)) {
Files.copy(stream, file.toPath());
}
}
}

Launch JavaFX project using reflection

I have a program, that downloads a Git repository, builds it and launches defined Main class. It works properly with ordinary projects, but when I want to launch a JavaFX project, I get strange errors like:
Exception in thread "main" java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at Main.main(Main.java:31)
Caused by: java.lang.RuntimeException: java.lang.ClassNotFoundException: app.UI_Main
at javafx.application.Application.launch(Application.java:260)
at app.UI_Main.main(UI_Main.java:31)
... 5 more
Caused by: java.lang.ClassNotFoundException: app.UI_Main
at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at javafx.application.Application.launch(Application.java:248)
... 6 more
My Main class is:
public class Main {
private static final String GIT_ADDRESS = "https://github.com/lerryv/CheckCheckerDesktop";
private static final String MAIN_PATH = "app/";
private static final String MAIN_CLASS = "app.UI_Main";
public static void main(String[] args) throws GitAPIException, IOException, ClassNotFoundException, NoSuchMethodException, InvocationTargetException, IllegalAccessException {
Git.cloneRepository().setURI(GIT_ADDRESS).setDirectory(Paths.get("./dir/").toFile()).call();
Collection<String> result = compile(Paths.get("./dir/src/").toFile());
String command = System.getProperty("java.home") + "/../bin/javac -d dirOut -cp \".:json-simple-1.1.jar\" " + result.join(" ");
Runtime.getRuntime().exec(command);
URLClassLoader urlClassLoader = URLClassLoader.newInstance(
new URL[]{
new File("dirOut/").toURI().toURL()
}
);
Class clazz = urlClassLoader.loadClass(MAIN_CLASS);
Method main = clazz.getDeclaredMethod("main", String[].class);
assert Modifier.isStatic(main.getModifiers());
main.invoke(null, (Object) args);
}
private static Collection<String> compile(File directory) {
assert directory.isDirectory();
Collection<String> result = new Collection<>();
boolean hasFiles = false;
for (File file: directory.listFiles()) {
if (file.isDirectory()) {
result.addAll(compile(file));
} else {
if (!hasFiles) {
String path = file.getAbsolutePath();
String extension = path.substring(path.lastIndexOf(".") + 1);
if (extension.equals("java")) hasFiles = true;
}
}
}
if (hasFiles) result.add(directory.getAbsolutePath() + "/*.java");
return result;
};
}
At first I thought it cannot find the class, but when I removed the method.invoke statement, errors disappeared. Why does it happen and are there any workarounds?

Runtime.getRuntime().exec(command)
This is starting another process, so after this line is executed compilation is not yet finished, you need to wait for this process to end, and probably you should also handle output/error stream of process to check if it succeed or not.
Process compileProc = Runtime.getRuntime().exec(command);
compileProc.waitFor();
Also I don't know what are you trying to do, but remember that not everyone might have compiler available and configured java.hame property, or configured it to different java version. (like older one and your code will not compile or newer one and you code will not run)

The program opens a new thread to start the project, but it executes the next line without monitoring its completion, so the thread can be removed if it is not necessary. If necessary, you need to write a monitoring thread to monitor and schedule all threads so that it can continue to execute after it has finished its work. Tasks of the main thread.

Project throwing IOException (File Not Found) when jar is run

I've made a project in java, using Eclipse.
Here is the project structure:
When I'm running the project in Eclipse as a java application, it runs perfectly fine.
Now, I need to export it as a jar. So, I created the jar using the method described in 3rd answer on this link (answered by Fever):
Failing to run jar file from command line: “no main manifest attribute”
Here is the output of jar tf EventLogger.jar:
META-INF/MANIFEST.MF
com/
com/project/
com/project/eventLogger/
com/project/eventLogger/KafkaConsumerGroup.class
com/project/eventLogger/KafkaProducer.class
com/project/eventLogger/ConsumeConfig.class
com/project/eventLogger/ConsumerThread.class
com/project/eventLogger/Formatter.class
com/project/eventLogger/Execute.class
com/project/eventLogger/Config.class
com/project/eventLogger/package-info.class
com/project/eventLogger/ProdConfig.class
com/project/eventLogger/FormatConfig.class
resources/
resources/Config.properties
resources/ConsumerConfig.properties
resources/FormatterConfig.properties
resources/ProducerConfig.properties
resources/log4j.properties
Here is the manifest file:
Manifest-Version: 1.0
Built-By: vishrant
Class-Path: lib/json-simple-1.1.1.jar lib/junit-4.10.jar lib/hamcrest-
core-1.1.jar lib/kafka_2.9.2-0.8.2.2.jar lib/jopt-simple-3.2.jar lib/
kafka-clients-0.8.2.2.jar lib/log4j-1.2.16.jar lib/lz4-1.2.0.jar lib/
metrics-core-2.2.0.jar lib/slf4j-api-1.7.6.jar lib/snappy-java-1.1.1.
7.jar lib/slf4j-log4j12-1.6.1.jar lib/zkclient-0.3.jar lib/zookeeper-
3.4.6.jar lib/jline-0.9.94.jar lib/netty-3.7.0.Final.jar lib/scala-li
brary-2.9.2-RC3.jar
Build-Jdk: 1.8.0_74
Created-By: Maven Integration for Eclipse
Main-Class: com.project.eventLogger.Execute
and, here is the exception:
java.io.FileNotFoundException: ConsumerConfig.properties (No such file or directory)
at java.io.FileInputStream.open0(Native Method)
at java.io.FileInputStream.open(FileInputStream.java:195)
at java.io.FileInputStream.<init>(FileInputStream.java:138)
at java.io.FileInputStream.<init>(FileInputStream.java:93)
at com.project.eventLogger.ConsumeConfig.loadPropertiesFile(ConsumeConfig.java:34)
at com.project.eventLogger.ConsumeConfig.<clinit>(ConsumeConfig.java:42)
at com.project.eventLogger.Execute.main(Execute.java:18)
Exception in thread "main" java.lang.ExceptionInInitializerError
at com.project.eventLogger.Execute.main(Execute.java:18)
Caused by: java.lang.NullPointerException
at com.project.eventLogger.ConsumeConfig.<clinit>(ConsumeConfig.java:47)
... 1 more
Seeing the exception, it is clear that it is not able to load ConsumerConfig.properties which is being done in ConsumeConfig.java.
Here is ConsumeConfig.java:
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Properties;
/**
* #author vishrant
*
*/
public class ConsumeConfig {
public static String zookeeper;
public static String balance;
public static String bootstrap_servers;
public static String zk_session_to;
public static String zk_sync;
public static String auto_commit;
public static String[] topics;
private static String kafka_bin;
private static final String PROPERTIES_FILE_PATH = "src/main/resources/ConsumerConfig.properties";
private static Properties loadPropertiesFile() throws IOException {
Properties properties = new Properties();
InputStream in = new FileInputStream(PROPERTIES_FILE_PATH);
properties.load(in);
return properties;
}
static {
Properties property = null;
try {
property = loadPropertiesFile();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
zookeeper = property.getProperty("ZOOKEEPER");
balance = property.getProperty("BALANCE");
bootstrap_servers = property.getProperty("BOOTSTRAP_SERVERS");
zk_session_to = property.getProperty("ZK_SESSION_TO");
zk_sync = property.getProperty("ZK_SYNC_TIME");
auto_commit = property.getProperty("AUTO_COMMIT_INTERVAL");
topics = property.getProperty("CONSUMER_TOPICS").split(",");
kafka_bin = property.getProperty("KAFKA_BIN_PATH");
}
}
Can someone tell me what is the problem and how to resolve this?
This runs perfectly well when run in Eclipse itself.
EDIT1:
Now, the exception is:
Exception in thread "main" java.lang.ExceptionInInitializerError
at com.project.eventLogger.Execute.main(Execute.java:18)
Caused by: java.lang.NullPointerException
at java.util.Properties$LineReader.readLine(Properties.java:434)
at java.util.Properties.load0(Properties.java:353)
at java.util.Properties.load(Properties.java:341)
at com.project.eventLogger.ConsumeConfig.loadPropertiesFile(ConsumeConfig.java:35)
at com.project.eventLogger.ConsumeConfig.<clinit> (ConsumeConfig.java:42)
... 1 more
line no 35:
props.load(resourceStream);
This is the code now:
private static final String PROPERTIES_FILE_PATH = "ConsumerConfig.properties";
private static Properties loadPropertiesFile() throws IOException {
ClassLoader loader = Thread.currentThread().getContextClassLoader();
Properties props = new Properties();
InputStream resourceStream = loader.getResourceAsStream(PROPERTIES_FILE_PATH);
props.load(resourceStream);
return props;
}

I see the following problems to be the cause:
The jar file is not created correctly for a maven project because the directory resources will normally be not copied to the target directory as is, i.e., instead of
resources/Config.properties
it should look like without the resources directory:
Config.properties
directly under the root directory of the jar file.
The second point is you are using the following in your code
private static final String PROPERTIES_FILE_PATH = "src/main/resources/ConsumerConfig.properties";
This path will not be seen outside of your IDE (in this case Eclipse) because src/main/resources should not exist in the jar file as you could see in the list of your jar file.
The last point is, you should use getResourceAsStream() of the class loader as Vikrant Kashyap already pointed.

try this
// Change Your File Path First.
private static final String PROPERTIES_FILE_PATH = "ConsumerConfig.properties";
private static Properties loadPropertiesFile() throws IOException {
Properties properties = new Properties();
// First way to load ResourceAsStream.
// ClassLoader loader = Thread.currentThread().getContextClassLoader();
// InputStream resourceStream = loader.getResourceAsStream(PROPERTIES_FILE_PATH);
// Second way to load ResourceAsStream.
InputStream resourceStream = ConsumeConfig.class.getResourceAsStream(PROPERTIES_FILE_PATH);
properties.load(resourceStream);
return properties;
}

Java make class available from JAR

I am making a program that operates as multiple JAR file dependencies. Basically, the thing loops through the .class files in a JAR file and gets a Class object for each of them. Each JAR has a Plugin.class file that I don't want to be available, but I want all the Classes to be accessible by other JAR dependencies as well as the main program. For example, in one JAR I have the class something.somethingelse.SomeClass, and from a second one (I made sure it is loaded second) I want to be able to import (at execution because it's in a separate JARfile) something.somethingelse.SomeClass and use it. I Have tried this after loading it into a Class object but it gives me ClassNotFound errors. I am using the newest java update and the newest version of eclipse IDE. I have three projects, "main", "aaa", and "aab". I have aaa and aab exported to JARs of which the contents are loaded into Class objects by main. aaa is loaded before aab, and I want aab to be able to access the classes from aaa through import aaa.Class. How can I (from main) make the classes of both jarfiles available to each other?
Here is my load plugin function:
public static void load(File file) throws Exception
{
JarFile jarFile = new JarFile(file);
Enumeration e = jarFile.entries();
URL[] urls = new URL[] { file.toURI().toURL() };
ClassLoader cl = new URLClassLoader(urls);
while (e.hasMoreElements()) {
JarEntry je = (JarEntry) e.nextElement();
if(je.isDirectory() || !je.getName().endsWith(".class") || je.getName() == "Plugin.class"){
continue;
}
// -6 because of .class
String className = je.getName().substring(0,je.getName().length()-6);
className = className.replace('/', '.');
Class c = cl.loadClass(className);
}
ClassLoader loader = new URLClassLoader(urls);
Class c = loader.loadClass("Plugin");
Object cobj = c.newInstance();
Method[] allMethods = c.getDeclaredMethods();
Method method = null;
boolean found = false;
for (Method m : allMethods) {
String mname = m.getName();
if (mname == "startPlugin"){
method = m;
found = true;
}
}
if(found)
{
method.invoke(cobj);
}
else
{
//skip class
}
}
And then my first JAR (aaa.jar) declares a class called hlfl.ui.UserInterface.
My second JAR's Plugin class is as follows:
import hlfl.ui.*;
public class Plugin {
//THIS DEPENDENCY EXPORTS TO: aab.jar
public void startPlugin()
{
System.out.println("Plugin Loading Interface Loaded [AAB]");
UserInterface c = new UserInterface();
}
}
But when I run it it gives me the following:
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun. reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at sf.htmlguy.hlaunch.PluginLoader.load(PluginLoader.java:58)
at sf.htmlguy.hlaunch.PluginLoader.loadAll(PluginLoader.java:22)
at sf.htmlguy.hlaunch.HLaunch.main(HLaunch.java:14)
Caused by: java.lang.NoClassDefFoundError: hlfl/ui/UserInterface
at Plugin.startPlugin(Plugin.java:7)
... 7 more
Caused by: java.lang.ClassNotFoundException: hlfl.ui.UserInterface
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 8 more
Just in case, the code is on SourceForge (the three projects are in subdirectories, "hlaunch for linux" is the main one.):
https://sourceforge.net/p/hlaunch/code

As far as I can tell your load method is creating a URLClassLoader containing just one JAR file. So you're going to end up with a classloader structure like this
main
/ \
/ \
UCL with aaa.jar UCL with aab.jar
thus classes in aaa and in aab can both see classes in main, but aaa and aab cannot see each other. If you want each plugin to be able to see the classes of those plugins that were loaded before it, then you need to arrange things so that each plugin you load uses the classloader of the previous plugin as its parent
main
|
UCL with aaa.jar
|
UCL with aab.jar
To do this you'd have to cache the loader you create when you load one plugin, and then pass that as a parameter when you create the next plugin's classloader.
private static ClassLoader lastPluginClassLoader = null;
public static void load(File file) throws Exception {
//...
ClassLoader loader = null;
if(lastPluginClassLoader == null) {
loader = new URLClassLoader(urls);
} else {
loader = new URLClassLoader(urls, lastPluginClassLoader);
}
lastPluginClassLoader = loader;
// ...
}
But all this (a) is not thread safe unless synchronized and (b) makes the behaviour critically dependent on the order in which the plugins are loaded. To do things properly you'd need some way to declare which plugins depend on which other plugins, and set up the classloader tree appropriately, etc. etc.
... and if you go too far down that road you've just re-invented OSGi.

Running java program from another java program

I'm trying to run a Java program from another Java application. Here is my code:
public class Main {
public static int Exec() throws IOException {
Process p = Runtime.getRuntime().exec("javac -d C:/Users/Dinara/Desktop/D/bin "
+ "C:/Users/Dinara/Desktop/D/src/test.java");
Process p1 = Runtime.getRuntime().exec("java -classpath C:/Users/Dinara/Desktop/D/bin test");
return 0;
}
public static void main(String[] args) throws IOException {
Exec();
}
}
javac works fine and creates test.class file in bin directory. However java -classpath C:/Users/Dinara/Desktop/D/bin test does not run the test.class file.
the content of the test.java:
import java.io.*;
class test {
public static void main(String args[]) {
try {
FileWriter fstream = new FileWriter("out.txt");
BufferedWriter out = new BufferedWriter(fstream);
out.write("Hello Java");
out.close();
} catch (Exception e) {
System.err.println("Error: " + e.getMessage());
}
}
}
I suppose that something wrong with recognizing Java command. Could you please give me a sample code for fixing this problem or share idea? I'm using Netbeans to run Main class and the location of the application folder is C:\Users\Dinara\Main

Use
System.getProperty("java.home") + "/bin/java -classpath C:/Users/Dinara/Desktop/D/bin test"
instead of
"java -classpath C:/Users/Dinara/Desktop/D/bin test"

You need to supply the full path to the javac, exec won't use the ath to find it for you