Main-args in executable Jar file. Possible?

Hello all!
Is it possible to specify arguments for the main class of an executable jar file?
If you call it on the command line this might be possible but what to do if you start the jar with double click?
Any chance?

i don't think so, see http://java.sun.com/docs/books/tutorial/jar/basics/mod.html

Similar Messages

Executable JAR file: Could not find the main class.

Hello,
I have a problem with making an executable JAR file.
I have written a JAVA program that consists of five different classes of which User.java is the main class and I have saved a text document with Main-Class: User and a blank line after that.
If I try:
jar cmf MainClass.txt User.jar User.class Beheerder.class Operator.class Manager.class MaakVisueelSchema.class
it makes a executable jar file which actually works! :)
But when the Operator class trys to open the MaakVisueelSchema class the screen stays blank.
I can run MaakVisueelSchema with java MaakVisueelSchema.
So I tried to make an executable JAR that consists only of MaakVisueelSchema, the same way as I did for User:
Main-Class: MaakVisueelSchema
jar cmf MainClass.txt MaakVisueelSchema.jar MaakVisueelSchema.class
Then I get the error message:
Could not find the main class. Program will exit.
from the Java Virtual Machine Launcher.
The big difference between MaakVisueelSchema and the other classes is that MaakVisueelSchema contains a PaintComponent method and an ComponentListener. Is it possible that one of those creates the error?
Can anyone help me with this problem?
Thanks in advance!
Bye!

Yes,
I tried:
jar xvf MaakVisueelSchema.jar
and it returns:
META-INF/
META-INF/MANIFEST.MF
MaakVisueelSchema.classN/G. You need to manually create a manifest file in a text editor, have it point to your main class, and enter it in your jar command as an argument.

Can we make executable jar file which dont have main method?

I have a problem.
With whatever R&D i have done so far my understanding is that in order to create executable jar files i need a main method.
my problem is i have certain MIS reports which are developed in java and deployed through JSP pages...so my java program has no Main Method and only objects of the classes are being called in the JSP pages.
for e.g: i have a java class file BulkSms.class and i make an object of it in the JSP page through which my purpose is achieved by calling various method in the BulkSms through it s objects and there is no main method.
Can i make an executable jar file without a main method and if so please give me a detailed procedure of how to go about it.
i want to make it executable so tht on the click of it the MIS report is displayed from the JSP page.

I am completely ignorant of JSPs, but you can not execute a jar or any java application unless you have a main method. It sounds like you need a way to launch the JSP - can't you do this with a browser?

Error trying to run an executable Jar file

Hi,
I know a million people have asked this before. In the past 5 hours I have waded thru a dozen questions-answers-FAQs that were no help. So if anyone is willing to help a stupid person her is my problem:
I developed a java program using the eclipse ide and it runs fine from within that ide.
I packaged it into a Jar file, created a manifest file per the instructions.
But when I double click on the jar file I get the following error from the Java Virtual Machine Loader;
"Could not find main class. Program will exit."
My Manifest file has the following text:
Manifest-Version: 1.0
Class-Path: swt.jar
Main-Class: .graphicalUserInterface.AppStandAlone
<blank line>
the class AppStandAlone has the method "public static void main(String[] args) "
it is in a package called "graphicalUserInterface".
Any help anyone can give me would be greatly appreciated.

Another 3 hours spent trying to run this java application in a Jar file.
I identified that I did not have all class paths specified. So I tried to enter them in the "Class-Path:" line of the manifest file. But, according to the java tutorial, the syntax in a manifest file for classpaths is a space SEPARATING each path name. I have a space IN the path name and java is not understanding the paths correctly. For instance, I have a classpath c:\Progran Files\Java\etc... and java interprets this to be a classpath c:\Progran with Files\Java\etc as the program I want to run.
I tried enclosing the paths in double quotes. Didn't work
I tried enclosing the paths in single quotes. Didn't work
I tried using a semicolon as a separator with double quotes. Didn't work
I tried using a semicolon as a separator with single quotes. Didn't work
I tried using a semicolon as a separator with no quotes. Didn't work
I removed the "Class-Path:" line from the manifest and tried adding -cp param to the java command. Example:
java -cp %classpath% -jar myapp.jar
I tried all the variations above in the -cp param. None of them worked.
The only thing that works is if I move executable jar file to the same directory as the required libraries. Then I specify a "Class-Path:" line with no spaces in the path names. Obviously this is not a permanent solution.
If anyone else has the patience to help me I would really appreciate it.

Question about Executable JAR Files

Is it possible to make an executable JAR file that has all of the *.class files, all of the *.jar archives used, etc. packaged into one file that doesn't need these external files within the same directory? I've been having a ton of trouble finding the answer to this. (If it's blatantly obvious, please forgive me.)

Hello,
I went through the same thing recently. Here is a piece of the build file I use:
<project name="MyProj" basedir="." default="main">
    <property name="src.dir"     value="src"/>
    <property name="build.dir"   value="build"/>
    <property name="classes.dir" value="${build.dir}/classes"/>
    <property name="jar.dir"     value="${build.dir}/jar"/>
    <property name="main-class" value="MyProj.Main"/>
    <property name="lib.dir"     value="lib"/>
    <path id="classpath">
        <fileset dir="${lib.dir}" includes="**/*.jar"/>
    </path>
    <target name="compile">
        <mkdir dir="${classes.dir}"/>
        <javac srcdir="${src.dir}" destdir="${classes.dir}" classpathref="classpath"/>
    </target>
    <target name="jar" depends="compile">
        <mkdir dir="${jar.dir}"/>
        <jar destfile="${jar.dir}/${ant.project.name}.jar" basedir="${classes.dir}">
          <zipfileset src="lib/commons-codec-1.3.jar"/>
          <zipfileset src="lib/commons-fileupload-1.1.1.jar"/>
          <zipfileset src="lib/commons-httpclient-3.0.1.jar"/>
            <manifest>
                <attribute name="Main-Class" value="${main-class}"/>
            </manifest>
        </jar>
    </target>
    <target name="main" depends="clean,run"/>
</project>Note the <zipfileset> tags that contain the .jars.
There are, however, many good reasons to not do this. Some were already mentioned, another is in the case of update external libraries, you might not want to rebuild your whole project, replacing a jar may be easier.
Good luck,
-Sam

Finding a file in the current executable jar file.

Hi all,
I am writing a little command line type application and I thought it would be neat to embed it's 'help file' into it's executable JAR file.
Please can someone show me how to code my application to extract a file from the JAR file from which the Main.class also came?
(Is that possible?)
I've been looking around, I can find out how to work with a different JAR file but NOT how to examine the currently 'executing' one.
Many thanks,
- jon.

Excellent! Thank you very much. It's easy when you know how. This works a treat!:
     private static void printHelp() {
          InputStream helpFile = Misql.class.getClassLoader().getResourceAsStream("doc/MISQLhelp.txt");
          if (helpFile == null) {
               _out.println("Help file: doc/MISQLhelp.txt not found.");
               return;
          try {
               int c;
               while ((c = helpFile.read()) != -1)
                    _out.write(c);
               helpFile.close();
          } catch (IOException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
          return;
     }

Unable to create Executable JAR file

Hi,
I tried to create Executable JAR file for
//JarTest.java
class JarTest
     public static void main( String args[] )
          System.out.println("i am EXECUTABLE JAR ");
mf is like
Manifest-Version: 1.0
Main-Class: JarTest
used jar cmf JarTest.mf exe.jar *.classIt created a jar file but i can't Execute the file
Help me
Thanks
AE

java is choosy about the actual manifest file format (line ending, trailing empty line, whatever).
This works for me with your example:
posman@proli:~/ivan/aa> cat mf
Manifest-Version: 1.0
Main-Class: JarTest
posman@proli:~/ivan/aa> od -cx mf
0000000   M   a   n   i   f   e   s   t   -   V   e   r   s   i   o   n
        614d 696e 6566 7473 562d 7265 6973 6e6f
0000020   :       1   .   0 \n   M   a   i   n   -   C   l   a   s   s
        203a 2e31 0a30 614d 6e69 432d 616c 7373
0000040   :       J   a   r   T   e   s   t \n \n \0
        203a 614a 5472 7365 0a74 000a

Creating an executable jar-file including a custom package

I am trying to learn how to create executable jar-files. I have managed this with a single class. However having a class which is an extention of another class which in turn belongs to custom package, I can't make it work.Running the program normally is not a problem. I don't think the problem is the actual code, but I will include it here anyway. I create the jar-file using:
jar -cmf Direkt2b.txt Direkt2b.jar *.class
where Direkt2b.txt is just:
Main-Class: Diriekt2b
Only the main class-file is included this way. Copying the other file to the same directory before creation doesn't help either. There is no error messages, the jar-file just refuses to run no matter what.
The main-class:
import java.awt.*;
import extra.*;
class Direkt2b extends ExtendedFrame {
     Font f;
     Direkt2b() {
          f = new Font("SansSerif", Font.BOLD, 24);
          setBackground(Color.yellow);
          setSize(400,150);
     public void paint(Graphics g) {
          g.setFont(f);
          g.setColor(Color.blue);
          g.drawString("V?lkommen till Java Direkt", 45, 100);
     public static void main (String[] arg) {
          Direkt2b d2 = new Direkt2b();
          d2.setVisible(true);
The help-class:
package extra;
import java.awt.*;
import java.awt.event.*;
public class ExtendedFrame extends Frame {
     private static boolean first = true;
     private boolean isFirst = first;
     public ExtendedFrame() {
          addWindowListener(theListener);
          first=false;
     WindowAdapter theListener = new WindowAdapter () {
          public void windowClosing(WindowEvent e) {
          dispose();
          if (isFirst)
               System.exit(0);
}

My problem wasn't really getting more than one class in a jar-file,
but rather that my jar-file with multiple classes wouldn't execute.
Reading the original post I realized that maybe I was unclear about that.
However I have solved the problem now so for anybody reading this
thread in the future I will tell you how.
The general setting is this: You have a bunch of self-made help-classes
organized in some classdirectory somewhere in the filesystem. You use these
in your programming from time to time. You have set a classpath-varible
in your OS such that Java could find your help-classes.
Now you want to create executable jar-files so that you could publish your work.
My problem was that while I added all needed classes in a jar-file, the main-class
couldn't find the others because they were referenced incorrectly. The solution I
came up with may not be elegant, but it works. I copied the main-class and all directories
(only one in my case) just as they appear in the classpath-directory, to the same temporary
directory. Then I created the jar-file from there, using: jar -cmfv Direkt2b.txt Direkt2b.jar Direkt2b.class extra/*.class
I suspected that incorrect referencing was the problem and I tried several variations on the theme above
before giving up and writing the first post. Part the problem was that I didn't get any error messages,
just an annoying error-sound double-clicking the jar-file. I learned later that you could run jar-files from
the command -prompt using: java -jar myjarfile.jar. This way you get a more useful response.
I guess there is a way to include the classpath instead somehow, but I will use my method for now.
I hope this was helpful to somebody.

How to pass paramets to executable jar file

hello,
i have made a executable jar file. i want to pass a text file to the MAIN class of that executable jar at runtime, what can i do ?
kindly please help.
regards,
mohamed asif

I was not thinking of changing the manifest, but of how you invoke the main class.
Consider the following three files:
File: test.txtThis is
a text fileFile: manifestmain-class: JarTestFile: JarTest.javaimport java.io.*;
public class JarTest {
    public static void main(String args[]) throws IOException {
        BufferedReader in;
        if(args.length == 0) {
            in = new BufferedReader(new InputStreamReader(System.in));
        } else {
            in = new BufferedReader(new FileReader(args[0]));
        System.out.printf("The first line is: %s%n", in.readLine());
}Compile and run like the following:pbrockway@linuxdeskd6off:~/Desktop$ javac -cp . JarTest.java
pbrockway@linuxdeskd6off:~/Desktop$ jar cmf manifest test.jar JarTest.class
pbrockway@linuxdeskd6off:~/Desktop$ java -jar test.jar test.txt
The first line is: This is
pbrockway@linuxdeskd6off:~/Desktop$ java -jar test.jar <test.txt
The first line is: This is
pbrockway@linuxdeskd6off:~/Desktop$ cat test.txt | java -jar test.jar
The first line is: This is
pbrockway@linuxdeskd6off:~/Desktop$In each case the contents of the text file are available to
the main() method.

Why -jar option used to install a software which is in executable jar file?

Hi all,
i have a query, i have a generic installer which is used to install the oracle weblogic 10.3 software in unix platform(i.e., which is in .jar extension) which is executable jar file.
To install this software which have to use -jar option to install
java -jar net_server<version>_generic.jar
my question that why we use -jar option to install or to extract the software
can any one clarify my doubt...
thanks in advance
abhi
Edited by: sumanth_abhi on Jan 27, 2009 11:50 PM

According to the Jar Guide (http://java.sun.com/j2se/1.4.2/docs/guide/jar/jarGuide.html)
Executable Jar Files
On Microsoft Windows systems, the Java 2 Runtime Environment's installation program will register a default association for Jar files so that double-clicking a Jar file on the desktop will automatically run it with javaw -jar. Dependent extensions bundled with the application will also be loaded automatically. This feature makes the end-user runtime environment easier to use on Microsoft Windows systems.
The Solaris 2.6 kernel has already been extended to recognize the special "magic" number that identifies a Jar file, and to invoke java -jar on such a Jar file as if it were a native Solaris executable. A application packaged in a Jar file can thus be executed directly from the command line or by clicking an icon on the CDE desktop.
Despite that every JAR file can be executed as a program if and only if the META-INF/Manifest.mf contains the Main-Class tag. This done through java -jar jarfile.jar
--olaf

How can I add image files to a executable jar file ?

Could you tell me how can I add image files to executable jar file ?
package structure:
../com/Main.class
../images/..

Please don't cross post, and read this
http://forum.java.sun.com/thread.jsp?forum=31&thread=271751
I've answered the question in the New To Java thread.

Add classpath in an executable jar file

an executable jar file contains a manifest file with entry main-class: MyApplicationClass.
if we double click the jar file on Windows OS, main class is loaded.
my question is:
if classes in he jar file use classpaths which are not default, how to add those classpaths into manifest file to tell classes to use those classpaths?
it is similar to command line:
java -classpath c;\mypackage; .......; MyApplicationClass

Thanks, i will try soon.
here is another Q.
if i need to add tools.jar (JDK lib) as classpath in manifest file, it is as following in my PC
d:\install\java\jdk14101\lib\tools.jar.
but my customers install JDK in different path (should be considered as unknown), how to add it as entry Class-path for all customers?

Classpath is not working for executable jar file

I have created executable jar file using following command where manifest file contains Main-Class and Class-Path entries.
jar cvfm app.jar META-INF/* lib/* *.class
So here app.jar contains my external jar's in lib directory
but when I move app.jar to another directory, it's doesn't get my external files.
I'm not getting this problem as these jar's are in app.jar
class-path entry in manifest file:
Class-Path: lib/abc.jar lib/xyz.jar
Pls help me where it is getting fail?
Thanks in advance,
Vikas

Java doesn't handle jars within jars. Your library jars need to be outside of the executable jar as in
dist - main.jar
- lib - lib1.jar
- lib2.jar

Including a jar file inside an executable jar file

Is it possible to include a jar file inside another (executable) jar file such that the included file is part of the class path for the outer file? If so, how do you specify this in the classpath in the manifest?

Russ_Bjork wrote:
Is it possible to include a jar file inside another (executable) jar file such that the included file is part of the class path for the outer file?No. Actually, I suppose it would be possible if you do all the 'heavy lifting', but Java is not designed to handle Jars within Jars.
What do you see as the advantage of doing that?
Is your app. a rich client (e.g. Swing, AWT, SWT..)?
Can you distribute the app. from a server or the internet?

Unable to execute JAR files

I am unable to execute jar files and applets. Also, the Java Web Start and the Java Plugin Control Panel will not load. I have unloaded the JRE and installed other versions. To date I have loaded and unloaded the following:
1.4.1
1.4.2_01, _02, _04
1.4.2_04 SDK
But no change in the outcome.
The javaw application starts but does not load the jar file.
The applets and jar files run fine on other computers with any of those JRE/SDK's installed.
Any suggestions would be helpful.

Command line
To create a JAR file >jar cvf filename.jar filename.class(s)
To view the contents of a JAR file >jar tvf filename.jar
To extract the contents of a JAR file >jar xf filename.jar
To extract specific files from a JAR file >jar xf filename.jar archived-file(s)
To run an application packaged as a JAR file
>jar xvf filename.jar META-INF/MANIFEST.MF
The above will place META-INF/MANIFEST.MF file in your working directory. Open this file in text editor. Under Version, type in
Main-Class: filename
example;
Manifest-Version: 1.0
Main-Class: SelectPurchase
Created-By: 1.3.0 (Sun Microsystems Inc.)
save file
update META-INF/MANIFEST.MF file in jar file with;
jar umf META-INF/MANIFEST.MF filename.jarto run jar file from command line;
java -jar filename.jarTo run an application packaged as a JAR file
(version 1.1) jre -cp app.jar MainClass
(version 1.2 -- requires Main-Class
manifest header)
To invoke an applet packaged as a JAR file <applet code=AppletClassName.class
archive="JarFileName.jar"
width=width height=height>
</applet>
Does anyone know how to get the application to run by clicking on a Desktop Icon?

Main-args in executable Jar file. Possible?

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