Main class in a Jar File

Hi
I have created a ja file containing my whole project.
the jar file contains a java class which contains a main method.
now i want to run this java class present in my jar file from the command prompt. is it possible to do it. can we run a java file which is inside the jar file.
i don't want to extract the jar file to run the java class.
Please let me know what needs to be done in this case.
Thanks & Regards
Vikeng

now i want to run this java class present in my jar
file from the command prompt. is it possible to do
it. can we run a java file which is inside the jar
file.
java -jar MyJar.jarYou need to set the Main-Class attribute in the manifest, though.

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How to Invoke a main class in a jar file from my project

Hi
I am a new user of the Sun Java Studio enterprise. I would like to know how i can invoke a main method in a jar file associated to the project.
regards
Nisanth

Could you please clarify: do you want to run your project or a project from an independent jar?
In the first case just select Run Project from the project context menu or select a class with main method and click Run File in the class context menu.
Regarding the second case:
- I don't think there is such a feature in the IDE (running third party jars is not an IDE function). Could you explain why you need this?

Don't know how to make my main class import a jar file

OK, the title doesn't make much sense but here are my create-jar.bat and manifest files:
create-jar.bat:
jar cvmf manifest.txt dassimul-admin.jar player/ admin/ com/ connector/ common/ *.class
manifest.txt:
Main-Class: admin.DASAdmin
the problem is that in connector/ folder there is the jdbc mysql connector driver (.jar file).
in Eclipse I can add this jar to the Java Build Path, so the program runs.
When I double-click the dassimul-admin.jar file, I get a Class Not Found Exception
C:\MYWORK\dassimul>java -jar dassimul-admin.jar
FATAL ERROR WHILE LOADING SQL DRIVER: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
I think that the problem lies in the fact that admin.DASAdmin can't see and import the jar file in connector/ folder... am I right?

It looks like you are putting the mysql jar file inside the dassimul jar. That won't work unless you write custom code. You should use the Class-Path attribute of the manifest to define a relative path(s) to the other jar(s) that you need to use.
[http://java.sun.com/docs/books/tutorial/deployment/jar/index.html]

Is it possible to call a class in a jar file from JNI environment?

Hi
Is it possible to call a class in a jar file from JNI environment?
Thanks in advance.

Could you explain a bit more what you are trying to do? (In other words, your question is vague.)
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Could not find the main class (with every jar)

This isn't a developer question. I get the error Could not find the main class with every jar I try to open (for example the jar downloaded from https://gjar.dev.java.net/ gives the same problems - and I don't think there is something wrong with that JAR). It isn't a problem with the jar or MANIFEST because the same jar works fine on my laptop. So there is something wrong with my JRE installation, but what?
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hai T.B.M ... Sorry to post here... I know that i posted my question in wrong thread..but i dont have another solution to contact with you.. I had seen your answers which are really excellent and helped to do my project..
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import javax.media.*;
import java.awt.*;
import javax.swing.*;
import java.util.*;
import java.awt.event.*;
import javax.media.protocol.*;
import java.io.*;
import javax.media.control.StreamWriterControl;
public class webcam implements ActionListener,ControllerListener
boolean eomReached = false;
boolean realized = false;
JFrame f;
BorderLayout bd1;
CaptureDeviceInfo device;
MediaLocator m1;
Player player;
Component videoScreen;
JButton b1,b2;
Processor processor;
DataSource ds=null;
DataSink fileWriter=null;
JLabel status=new JLabel("");
public webcam()
try
JFrame f=new JFrame();
JPanel p =new JPanel();
JPanel p1=new JPanel();
device=CaptureDeviceManager.getDevice("vfw:Microsoft WDM Image Capture (Win32):0");
m1=device.getLocator();
System.out.println("1");
processor.configure();
processor = Manager.createProcessor(m1);
processor.setContentDescriptor(new
FileTypeDescriptor(FileTypeDescriptor.MSVIDEO));
ds=processor.getDataOutput();
player.addControllerListener(this);
MediaLocator dest = new MediaLocator("file://foo.avi");
fileWriter = Manager.createDataSink(ds, dest);
fileWriter.open();
ds.connect();
ds.start();
player=Manager.createPlayer(m1);
player.addControllerListener(this);
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b2=new JButton("STOP");
bd1=new BorderLayout();
p.setLayout(bd1);
p1.add(b1);
p1.add(b2);
p.add("South",p1);
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f.setVisible(true);
f.setSize(500,500);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
b1.addActionListener(this);
b2.addActionListener(this);
catch(Exception e){}
public void actionPerformed(ActionEvent e)
if(e.getSource()==b1)
try{
processor.start();
player.start();
fileWriter.start();
catch(Exception e1){}
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processor.stop();
processor.close();
fileWriter.close();
catch(Exception e2){}
public static void main(String args[])
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player.realize();
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try {
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realized = true;
notify();
} else if (event instanceof EndOfMediaEvent) {
eomReached = true;
}

Accessing classes in external jar files

I have a jar file called main. I want it to be able to acces the classes in another jar file say test.jar how do i do this.
Thank you

ok, if i have this right...
you have 2 directories that hold 2 .jars, right?
plugins/ -------- build/plugins .jar
systemModuals/ ------- DiaryUI and Loader .jar
Your main JAR is diary?
Diary.jar
you want Diary to run with the jars inside plugins and systemmoduals?
you set the "class-path:" tag like this....
write this manifest file. save it as Manifest.txt and put it in your home dir.
Main-Class: YourMainClass
Class-Path: Diary.jar plugins/this.jar systemmoduals/diaryui.jar
<make sure to hit enter, go to the next line>
command line to your parent directory.
jar cmf Manifest.txt Diary.jar build/main/*.class
you should be set to go.
use
jar xf META-INF/MANIFEST.MF
to read the present manifest that netbeans has created
if necessary

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how to say to netbeans ide that it has to include the
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with two inner classes that show up
in the build/classes file but not in the jar).
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First, please stop posting the same question multiple times:
Duplicate of http://forum.java.sun.com/thread.jspa?threadID=5269782&messageID=10127496#10127496
with an answer.
Second, If your problem is that you can't do this in NetBeans, you need to post to somewhere that provides NetBeans support - like the NetBeans website's mailing list. These forums do not support NetBeans (or any other IDE) - they are Java language forums.

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Is it possible to load classes from a jar file

Using ClassLoader is it possible to load the classes from a jar file?

URL[] u = new URL[1] ;
u[0] = new URL( "file://" + jarLocation + jarFileName + "/" );
URLClassLoader jLoader = new URLClassLoader( u );
Object clsName = jLoader.loadClass( clsList.elementAt(i).toString() ).newInstance();
I get this error message.
java.lang.ClassNotFoundException: ExceptionTestCase
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:297)
at java.lang.ClassLoader.loadClass(ClassLoader.java:253)
// "file://" + fileLocation + fileName + "/" This works fine from a browser.
Is there anything I am missing? Thanks for the reply.

How to combine the classes from 2 jar files into 1?

Hi there
I have got 2 jar files with the same name but the classes that they contain are different. So, I want to combine those 2 files into 1. Could anyone please tell me how to add the classes in a jar file to another jar file?
Thanks for your help!
From
Edmund

The jar utility allows you to extract files as well as put them into a jar. This is in the java docs.
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-Copy files from one dir to another.
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How do I list all classes in a Jar file?

How do I list all classes in a Jar file?

Its no problem if the jar file contains classes, but I have an EAR file, which contains a jar-file, and I want to list all classes in that jar-file.
I would like to do something like this:
java.util.jar.JarFile jarfile = new java.util.jar.JarFile( new File("/meYear.ear"), true );
java.util.jar.JarEntry jar = jarfile.getJarEntry( "myJar.jar" );
// Cast it to a new JarFile:
java.util.jar.JarFile newJar = (java.util.jar.JarFile)jar;
But the method getEntry returns something like jarFile$JarEntry, if I try to class cast it I get an classCastException.

JRE doesn't find the main class inside a JAR archive file

Hello everybody,
I've written a small application in Java, using NetBeans. Running my application inside NetBeans works fine, but I can't run it from the console or by double clicking the jar file.
Running it from the console I get the following error message:
java -jar TestApplication.jar
Exception in thread "main" java.lang.NoClassDefFoundError: tst.Benchmark
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Caused by: java.lang.ClassNotFoundException: tst.Benchmark not found in gnu.gcj.runtime.SystemClassLoader{urls=[file:TestApplication.jar], parent=gnu.gcj.runtime.ExtensionClassLoader{urls=[], parent=null}}
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Greetings JavanianGuy

This line
at gnu.java.lang.MainThread.run(libgcj.so.81)says that you're using GNU's Java, not Sun's Java. They are not the same. GNU Java is incomplete.
You'll need to ask this question at the GNU Java site.
Recommendation: Use Sun's Java

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Hi there,
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I noticed the MANIFEST.INF file that eclipse generated looks like:
Manifest-Version: 1.0
Main-Class: Automobile
When I tried to run my other classes not specify in the MANIFEST.INF it failed and only look for the Automobile class:
java -jar /tmp/Auto.jar TestMe

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Dinamyc class loading and jar files

I'm new to java. I would like to load some plugins in my application (it's going to be packaged as a jar at the end). I managed to find some dinamyc class loading examples but they search for the classes to load in a directory.
This is the code:
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System.out.println("Loading: " + pluginFiles[i].substring(0, pluginFiles[i].length() - 6));
IPlugin plugin = pm.loadPlugin(pluginFiles[i].substring(0, pluginFiles[i].length() - 6));
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protected static IPlugin loadPlugin(String name) {
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Exception in thread "main" java.lang.NoClassDefFoundError: pluginsReloaded/plugins/plugin1 (wrong name: pluginsreloaded/plugins/plugin1)
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        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
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        at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
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        at pluginsreloaded.PluginManager.loadPlugin(PluginManager.java:30)
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Thanks.

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What seesms to be the standard approach is to put a list of plugin classes into the jar as a text file.
Plugins for a given purpose usually implement some specified interface, or extend some abstract class to which their objects can be cast once loaded (without this they aren't really much use).
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Java class uses another class in a Jar file (How do I make Java see it)?

I am trying to figure out how do I make Javac see the thinlet.class in the thinlet.jar.
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//package thinlet.demo;
import thinlet.*;
public class UI extends Thinlet
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when I do the normal compile, I get an error:
UI.java:4: cannot find symbol
symbol: class Thinlet
public class UI extends Thinlet {
^
UI.java:7: cannot find symbol
symbol : method parse(java.lang.String)
location: class thinlet.demo.UI
add(parse("UI.xml"));
^
UI.java:12: cannot find symbol
symbol : class FrameLauncher
location: class thinlet.demo.UI
new FrameLauncher("UI", new UI(), 600, 600);
^
3 errors
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Any help is definitely appreciated.

This thinlet class should be in the thinlet.jar that I have added the directory to the path, the directory and jarfile name to the System CLASSPATH and it couldn't see it. So finally I tried putting the thinlet.jar in the same directory to no avail. I've searched the web for some time an cannot find anything that specifically speaks to compiling a program that has parent classes in a Jar.
Any help is definitely appreciated.You just still haven't provided the jar in the classpath, or you're not using the right class name. Is the class really named thinlet.Thinlet? Or are you thinking "import thinlet.*" means to import all classes in a jar named thinlet.jar? Because the latter is not true. You need to import classes, not jar file names.

Main class in a Jar File

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