Develop Reference

JavaFX app overwriting files while being open causes exception

I have a runnable jar file (with a lib folder housing all the dependency jars). This is located on a network share which anyone that has access can run from. This works great except one huge caveat. If I want to deploy a new version of the software, I have to ask everyone to exit the application first. This is because if I overwrite the jars with new versions (or if there is a network blip), the running program stays open but as soon as they do an action that requires code in of the dependencies (jar file in lib folder), it will cause an exception:
Exception in thread "JavaFX Application Thread" java.lang.NoClassDefFoundError
The program will not produce an error, but certain actions will break, like communicating with an API etc.
Is there a way that I can resolve this so that I can publish updates while the user's are working or at least produce a prompt that will force them to close/and reopen the app etc.

One approach:
Provide a script which launches the application from a local copy of the remote code.
Store a version number with your app.
The script checks if there is a local copy of the app on the machine.
If no local version exists, the script copies the jars from your network share to a local copy.
If there is already a local copy, it checks the version against the network version.
If the network version is updated, it overwrites the local copy with the new remote version before launching the app,
otherwise it just launches the local copy.
If you want the users to be alerted that they are currently running an outdated copy, you could create a JavaFX task which polls the remote version number and checks it against the currently running version number. If they differ, you can alert and (if you wish) shutdown the app and re-trigger the launcher script.

I was able to create a scheme in which I have multiple server folder locations that house the jar distributable. And this jar basically checks these locations for the latest copy of the application and runs that latest copy. I was able to get it working for both Mac and Windows (didn't test Linux) by detecting the OS.
So now, I can publish an update over the oldest app, and the next time the user opens the app, it will be the latest copy.
process.properties
location.a=Application/A
location.b=Application/B
app=app.jar
You can add folders A-Z but just add them into the properties.
Main.java
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
import java.util.TreeMap;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.apache.commons.io.FileUtils;
import org.apache.commons.lang3.StringUtils;
public class Main
{
public static Properties properties;
private static final String DEFAULT_PROPERTY_FILE_LOCATION = Paths.get("").toAbsolutePath().toString() + File.separator + "process.properties";
private static final String JAVE_EXEC;
static
{
String os = System.getProperty("os.name");
if (StringUtils.containsIgnoreCase(os, "win"))
{
JAVA_EXEC = "java";
} else if (StringUtils.containsIgnoreCase(os, "mac"))
{
JAVA_EXEC = "/usr/bin/java";
} else if (StringUtils.containsIgnoreCase(os, "nux") || StringUtils.containsIgnoreCase(os, "nix"))
{
JAVA_EXEC = "/usr/bin/java";
} else
{
JAVA_EXEC = "java";
}
}
/**
* #param args the command line arguments
*/
public static void main(String[] args)
{
Main.properties = new Properties();
try
{
InputStream in = new FileInputStream(DEFAULT_PROPERTY_FILE_LOCATION);
Main.properties.load(in);
System.out.println("Loaded property file: " + DEFAULT_PROPERTY_FILE_LOCATION);
TreeMap<Long, String> locations = new TreeMap<>();
String appName = Main.properties.getProperty("app");
if (validateProperties(properties))
{
for (int letter = 'a'; letter <= 'z'; ++letter)
{
String location = "location." + (char) letter;
if (Main.properties.getProperty(location) != null)
{
String networkLocation = Paths.get("").toAbsolutePath() + File.separator + Main.properties.getProperty(location);
File file = new File(networkLocation + File.separator + appName);
if (file.exists())
{
locations.put(FileUtils.lastModified(file), networkLocation);
}
}
}
if (!locations.isEmpty())
{
Runtime.getRuntime().exec(new String[]
{
JAVA_EXEC, "-jar", locations.lastEntry().getValue() + File.separator + appName
}, null, new File(locations.lastEntry().getValue()));
}
}
} catch (IOException ex)
{
Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
}
}
private static boolean validateProperties(Properties properties)
{
List<String> mandatoryProperties = new ArrayList<>();
mandatoryProperties.add("app");
for (String mandatoryProperty : mandatoryProperties)
{
if (properties.get(mandatoryProperty) == null)
{
System.out.println("Failed - Property: " + mandatoryProperty + " doesn't exist.");
return false;
}
}
return true;
}
}

How to run a JMeter JMX file in Java code?

I am trying to run a JMeter MS SQL database test plan from Java code through my Spring Boot app but it's showing the following errors:
I have loaded the plugin manager in JMeter and put that in jmeter/lib/ext folder and installed all required plugins.
Java code to run JMeter test case:
package com.example.demofin;
import java.io.File;
import org.apache.jmeter.engine.StandardJMeterEngine;
import org.apache.jmeter.reporters.ResultCollector;
import org.apache.jmeter.reporters.Summariser;
import org.apache.jmeter.save.SaveService;
import org.apache.jmeter.util.JMeterUtils;
import org.apache.jorphan.collections.HashTree;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.stereotype.Component;
import com.example.demofin.config.Properties;
#Component
public class Demofin implements CommandLineRunner {
#Autowired
private Properties properties;
private Summariser result;
#Override
public void run(String... args) throws Exception {
for(String i : args)
System.out.println(i);
// String j = properties.getPropertyByKey("JMETER_HOME");
String j="D:\\apache-jmeter-4.0";
// System.out.println(j);
//System.out.println("Jmeter home path: " + properties.getPropertyByKey("JMETER_HOME"));
StandardJMeterEngine jmeter = new StandardJMeterEngine();
// // Initialize Properties, logging, locale, etc.
JMeterUtils.setJMeterHome(j);
JMeterUtils.loadJMeterProperties(j+"/bin/jmeter.properties");
//
// // you can comment this line out to see extra log messages of i.e. DEBUG level
JMeterUtils.initLogging();
JMeterUtils.initLocale();
// Initialize JMeter SaveService
SaveService.loadProperties();
// Load existing .jmx Test Plan
HashTree testPlanTree = SaveService.loadTree(new File("D:\\apache-jmeter-4.0\\" + "bin\\JDBC Connection Configuration.jmx"));
Summariser summer = null;
String summariserName = JMeterUtils.getPropDefault("summariser.name", "summary");
if (summariserName.length() > 0) {
summer = new Summariser(summariserName);
}
ResultCollector logger = new ResultCollector(summer);
testPlanTree.add(testPlanTree.getArray()[0], logger);
// Run JMeter Test
jmeter.configure(testPlanTree);
jmeter.run();
result = summer;
}
}

Usually, we compile java code to jar and push it to jmeter/lib/ext and use it in Jmeter.
If you attempt to using Jmeter in java, I suggest downloading source code of JMeter and merge to your project.

How do I include Xtext generator in my Maven project?

I am currently building a framework which would benefit from having a DSL for creating a configuration file, so I created one using Xtext.
Now I want to add a dependency to the classes that I have created so that I can generate configurations at runtime, but on Xtext's site it looks like the only two cases for integration are:
When I want CI for the language itself;
When I want to include a plugin that would generate code at build time.
How can I use the generator that I wrote in Xtext at runtime in my Maven project?

For CI for Xtext itself simpy use the new project wizard and select Maven as build system on the second page of the project. To build your model files have a look that the xtext-maven-plugin e.g. as used here https://github.com/xtext/maven-xtext-example/blob/master/example-project/pom.xml or here https://github.com/cdietrich/xtext-maven-example/blob/master/org.xtext.example.mydsl.model/pom.xml
If you simply want to read a model file and call the generator
package org.eclipse.xtext.example.domainmodel;
import java.util.ArrayList;
import java.util.List;
import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.xtext.generator.GeneratorContext;
import org.eclipse.xtext.generator.GeneratorDelegate;
import org.eclipse.xtext.generator.IGeneratorContext;
import org.eclipse.xtext.generator.JavaIoFileSystemAccess;
import org.eclipse.xtext.util.CancelIndicator;
import org.eclipse.xtext.validation.CheckMode;
import org.eclipse.xtext.validation.IResourceValidator;
import org.eclipse.xtext.validation.Issue;
import com.google.common.collect.Lists;
import com.google.inject.Injector;
/**
* #author dietrich - Initial contribution and API
*/
public class Main {
public static void main(String[] args) {
// TODO traverse directory
List<String> files = Lists.newArrayList("model/a.dmodel", "model/b.dmodel");
Injector injector = new DomainmodelStandaloneSetup().createInjectorAndDoEMFRegistration();
ResourceSet rs = injector.getInstance(ResourceSet.class);
ArrayList<Resource> resources = Lists.newArrayList();
for (String file : files) {
Resource r = rs.getResource(URI.createFileURI(file), true);
resources.add(r);
}
IResourceValidator validator = injector.getInstance(IResourceValidator.class);
for (Resource r : resources) {
List<Issue> issues = validator.validate(r, CheckMode.ALL, CancelIndicator.NullImpl);
for (Issue i : issues) {
System.out.println(i);
}
}
GeneratorDelegate generator = injector.getInstance(GeneratorDelegate.class);
JavaIoFileSystemAccess fsa = injector.getInstance(JavaIoFileSystemAccess.class);
fsa.setOutputPath("src-gen-code/");
GeneratorContext context = new GeneratorContext();
context.setCancelIndicator(CancelIndicator.NullImpl);
for (Resource r : resources) {
generator.generate(r, fsa, context);
}
}
}

External library not available when deploy with fat-jar

I'm using in my program the bluecove library.
While running the program via eclipse, all works smooth. I'm now trying to deploy my program, and following this post i'm using fat-jar.
When i run the jar file (created by fat-jar), the library can't be located, and i'm getting the exception BlueCove libraries not available as result of this line local = LocalDevice.getLocalDevice();.
In the fat-jar window i tried also to add bluecove-2.1.0.jar to the Class-Path place, and also with the path \src\JoJoServer\bluecove-2.1.0.jar.
I tried also to place the bluecove's jar file in different folders, such as the src, or an external folder.
Although i know it's not recommended, i tried the option of One-Jar, nevertheless it didn't help.
To run the jar (the one created by fat jar) i simply double click the file.
What i'm missing?
This is the entire code:
import java.io.IOException;
import javax.bluetooth.BluetoothStateException;
import javax.bluetooth.DiscoveryAgent;
import javax.bluetooth.LocalDevice;
import javax.bluetooth.UUID;
import javax.microedition.io.Connector;
import javax.microedition.io.StreamConnection;
import javax.microedition.io.StreamConnectionNotifier;
#Override
public void run() {
// retrieve the local Bluetooth device object
LocalDevice local = null;
StreamConnectionNotifier notifier;
StreamConnection connection = null;
// setup the server to listen for connection
try {
local = LocalDevice.getLocalDevice();
local.setDiscoverable(DiscoveryAgent.GIAC);
UUID uuid = new UUID("0000110100001000800000805F9B34FB", false);
System.out.println(uuid.toString());
String url = "btspp://localhost:" + uuid.toString() + ";name=RemoteBluetooth";
notifier = (StreamConnectionNotifier)Connector.open(url);
} catch (BluetoothStateException e) {
System.out.println("Bluetooth is not turned on.");
e.printStackTrace();
return;
}
// ...
}

I have no clue what could be your problem, but I've tried the process and everything works, so just a summary of what I've did. Maybe you will figure it out by following it...
I don't understand how the posted code could be the entire, I see no class definition. :)
So I've modified it to the main method and it works both from the Eclipse and also by running the JAR generated by the FatJar.
The modified code of the BTTest class:
package test;
import java.io.IOException;
import javax.bluetooth.BluetoothStateException;
import javax.bluetooth.DiscoveryAgent;
import javax.bluetooth.LocalDevice;
import javax.bluetooth.UUID;
import javax.microedition.io.Connector;
import javax.microedition.io.StreamConnection;
import javax.microedition.io.StreamConnectionNotifier;
public class BTTest {
public static void main(String[] args) throws Exception{
// retrieve the local Bluetooth device object
LocalDevice local = null;
StreamConnectionNotifier notifier;
StreamConnection connection = null;
// setup the server to listen for connection
try {
local = LocalDevice.getLocalDevice();
local.setDiscoverable(DiscoveryAgent.GIAC);
UUID uuid = new UUID("0000110100001000800000805F9B34FB", false);
System.out.println(uuid.toString());
String url = "btspp://localhost:" + uuid.toString()
+ ";name=RemoteBluetooth";
notifier = (StreamConnectionNotifier) Connector.open(url);
} catch (BluetoothStateException e) {
System.out.println("Bluetooth is not turned on.");
e.printStackTrace();
return;
}
// ...
}
}
To run or produce it, I have just put the bluecove library in the build path and created the fat jar with a simple way:
http://oi60.tinypic.com/vg1jpt.jpg
Starting the generated jar from command line:
D:\testProjects\bttest>java -jar bttest_fat.jar
BlueCove version 2.1.0 on winsock
0000110100001000800000805f9b34fb
BlueCove stack shutdown completed
Can you post a difference to your process?

embedded ApacheDS in my application, it fails on service.startup() -> DefaultSchemaService.getSchemaManager() returns null

I'm trying to run an embedded ApacheDS in my application. After reading: Running Apache DS embedded in my application
and http://directory.apache.org/apacheds/1.5/41-embedding-apacheds-into-an-application.html
Using the last stable version 1.5.7,
this simple example fails when executing "service.startup();"
Exception in thread "main" java.lang.NullPointerException
at org.apache.directory.server.core.schema.DefaultSchemaService.initialize(DefaultSchemaService.java:380)
at org.apache.directory.server.core.DefaultDirectoryService.initialize(DefaultDirectoryService.java:1425)
at org.apache.directory.server.core.DefaultDirectoryService.startup(DefaultDirectoryService.java:907)
at Test3.runServer(Test3.java:41)
at Test3.main(Test3.java:24)
that is, DefaultSchemaService.getSchemaManager() returns null.
source code:
import java.util.Properties;
import javax.naming.Context;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.Attributes;
import javax.naming.directory.DirContext;
import javax.naming.directory.InitialDirContext;
import javax.naming.directory.SearchControls;
import javax.naming.directory.SearchResult;
import org.apache.directory.server.core.DefaultDirectoryService;
import org.apache.directory.server.core.partition.Partition;
import org.apache.directory.server.core.partition.impl.btree.jdbm.JdbmPartition;
import org.apache.directory.server.ldap.LdapServer;
import org.apache.directory.server.protocol.shared.transport.TcpTransport;
import org.apache.directory.shared.ldap.entry.ServerEntry;
import org.apache.directory.shared.ldap.name.DN;
public class Test3 {
public static void main(String[] args) throws Exception {
runServer();
testClient();
}
static void runServer() throws Exception {
DefaultDirectoryService service = new DefaultDirectoryService();
service.getChangeLog().setEnabled(false);
Partition partition = new JdbmPartition();
partition.setId("apache");
partition.setSuffix("dc=apache,dc=org");
service.addPartition(partition);
LdapServer ldapService = new LdapServer();
ldapService.setTransports(new TcpTransport(1400));
ldapService.setDirectoryService(service);
service.startup();
// Inject the apache root entry if it does not already exist
try {
service.getAdminSession().lookup(partition.getSuffixDn());
} catch (Exception lnnfe) {
DN dnApache = new DN("dc=Apache,dc=Org");
ServerEntry entryApache = service.newEntry(dnApache);
entryApache.add("objectClass", "top", "domain", "extensibleObject");
entryApache.add("dc", "Apache");
service.getAdminSession().add(entryApache);
}
DN dnApache = new DN("dc=Apache,dc=Org");
ServerEntry entryApache = service.newEntry(dnApache);
entryApache.add("objectClass", "top", "domain", "extensibleObject");
entryApache.add("dc", "Apache");
service.getAdminSession().add(entryApache);
ldapService.start();
}
static void testClient() throws NamingException {
Properties p = new Properties();
p.setProperty(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
p.setProperty(Context.PROVIDER_URL, "ldap://localhost:1400/");
p.setProperty(Context.SECURITY_PRINCIPAL, "uid=admin,ou=system");
p.setProperty(Context.SECURITY_CREDENTIALS, "secret");
p.setProperty(Context.SECURITY_AUTHENTICATION, "simple");
DirContext rootCtx = new InitialDirContext(p);
DirContext ctx = (DirContext) rootCtx.lookup("dc=apache,dc=org");
SearchControls sc = new SearchControls();
sc.setSearchScope(SearchControls.SUBTREE_SCOPE);
NamingEnumeration<SearchResult> searchResults = ctx.search("", "(objectclass=*)", sc);
while (searchResults.hasMoreElements()) {
SearchResult searchResult = searchResults.next();
Attributes attributes = searchResult.getAttributes();
System.out.println("searchResult.attributes: " + attributes) ;
}
}
}
It seems that ApacheDS versions 1.5.x are not backward compatible.
In ApacheDS 1.5.4 the call "service.startup();" works ok (but it fails somewhere else).
Any idea how to make this example work?

this version of ApacheDS needs to explicitely define the working directory:
service.setWorkingDirectory(new File("data"));

I recently face the similar problem, and after long googling, finally find something useful
Example for Embedded Apache Directory using 1.5.7
http://svn.apache.org/repos/asf/directory/documentation/samples/trunk/embedded-sample/src/main/java/org/apache/directory/seserver/EmbeddedADSVer157.java
and also have a look the pom.xml
Pom.xml Example for Embedded Apache Directory using 1.5.7
http://svn.apache.org/repos/asf/directory/documentation/samples/trunk/embedded-sample/pom.xml
Hope is help!