Trace jar file of applet.

Hi,
I have an application in which some jar file is downloded from server to run applet. How can I trace that jar file...like..which java file calling which function & all..
I have the source code for that jar file.But the problem is it has lots of java files in it.
Please help me.
Thank You.

say if u are running on windows machine and your home directory is "pritam" and primary drive is "C:\ "then search if there is a directory like C:\Documents and Settings\pritam\Application Data\Sun\Java\Deployment\cache\javapi\v1.0\jar
this directory would contain jar files that are downloaded in zip format

Similar Messages

Can i load a class in subdirectoy inside a jar file using applet tag?

hi every one.. thank you for reading ... i am really in dire need for the solution..
my problem is that i have a jar file contianing a package which inturn contains my applet class...
i am trying to access this applet class using a applet tag in html file. this html file is in same directory as the jar file. i am having no problems in windows but when i am doing this in linux apache server i was getting class not found exception. (already checked the file permissions). and when i am successful when using simple package directory instead of jar file . so gist of my quesition is "can i load a class in subdirectoy inside a jar file using applet tag in a html file"?

When you tested in Windows were you using Internet Explorer? On Linux you will be using a different browser, usually Mozilla of some version, or Firefox. Note that the HTML tags for applets will be different between the browsers if you are using the object tag. Principally the classid value for the object tag will differ between Firefox and Internet Explorer.

Jar files and applet

My applet class is using other classes in my package,
So do i need to create a jar file and specify that jar file in <applet archieve = :myjar.jar"
I did created the jar file , but its not loading up, the browser just says Loading java applet, what might be the reason, does it depends on size of jar file?
or my tags are wrong.
my applet tag is
<html>
<applet archive = "myjar.jar"
code = "front.class"
width.. >
the front.class file is also in myjar.jar.
Any help....
Also one more question,
Can i call other applets within one applet class.
I have a gui, when a particular button is clicked on applet
i want to go to other applet, so how should i call it in that buttons action listner?
And in my applet class i am using one other class from my package which actually coonects to databse through JDBC. now say i have a button on my applet whihc says "Connect", and when that button is clicked then I created object of my other class which makes connection
through databse. So will this work from applet?
Thanks

You didn't show all of your applet tag, but it should look like this:
<HTML>
<APPLET CODE = front.class, ARCHIVE = myjar.jar, width = ???, height = ???>
</APPLET>
</HTML>
Assuming your applet is not crashing, this should load it. I recommend using the appletviewer tool in the JDK, it provides more detailed error messages. I hope this works for you.
Now inter-applet communication. This is forbidden, sorry. However, if you really want to get fancy; remember that all applets can communicate back to the host from which they came. So if you want to build a small server on your host machine which all your applets log into, they can then communicate with each other through the server.

Tracing jar files of Applet

Hi,
I have an application in which some jar file is downloded from server to run applet. How can I trace that jar file...like..which java file calling which function & all..
I have the source code for that jar file.But the problem is it has lots of java files in it.
Please help me.
Thank You.

Why would you want to trace which function is called in which jar file?

How to list files from .jar file in applet?

I have created applet and export all files to .jar file.
I use File.list() method in applet to list files from one directory and that works ok but if I try to do that from web browser it sends exception AccessDenied meaning that File.list() isn't allowed in browser.
I know what's the problem but I don't know how to solve it.
What I want is to read from directory list of files.
Help anyone?

I will post here my code so that can be seen what I want to do:
import java.awt.BorderLayout;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URLClassLoader;
import java.nio.charset.Charset;
import javax.swing.JApplet;
import javax.swing.JPanel;
import javax.swing.JTextPane;
public class test extends JApplet {
     private static final long serialVersionUID = 1L;
     private JPanel jContentPane = null;
     private JTextPane jTextPane = null;
      * This is the xxx default constructor
     public test() {
          super();
      * This method initializes this
      * @return void
     public void init() {
          this.setSize(449, 317);
          this.setContentPane(getJContentPane());
      * This method initializes jContentPane
      * @return javax.swing.JPanel
     private JPanel getJContentPane() {
          if (jContentPane == null) {
               jContentPane = new JPanel();
               jContentPane.setLayout(new BorderLayout());
               jContentPane.add(getJTextPane(), BorderLayout.CENTER);
          return jContentPane;
      * This method initializes jTextPane
      * @return javax.swing.JTextPane
     private JTextPane getJTextPane() {
          if (jTextPane == null) {
               jTextPane = new JTextPane();
          return jTextPane;
     public void start(){
          File fileDir= new File("somedirectory");
          String strFiles[]= fileDir.list();
          String a="";
          for(int i =0;i<strFiles.length;i++){
               a=a+strFiles;
          this.jTextPane.setText(a);
Method init() is irelevant, it just adds JTextPane in applet.
Method start() is relevant, it runs normaly when started from Eclipse but from browser it sends exception AccessDenied.

Jar file in applet not saved in internet files when using jdk plugin

Hello,
I recently upgarded to jdk1.3.1 and converted our applet and classes to jdk1.3.1 using swing classes. From there, we converted the html file with htmlconverter and diployed this on the web. When a user goes to the web, the system automatically downloads the java plugins and installs them on the clients maching. From there our jar file loads and executes. Our applet runs fine. However, every time our website is accessed, our jar file cookie must be downloaded which is just over 1meg and I know this is not going to fly with our clients.
What needs to be done so the jar file is not downloaded every time, to work like java version 1.x ?
Thanks for your help in advance with this one.
Jay Ford

Hi Jay Ford,
Enable the "Recycle Classloader" in Control Panel-->Java Plug-in1.3.1-->Basic.
The main purpose of this Recycle classloader is it will enable the "javaplugin.classloader.cache.enabled" property to true and it caches the jar files for performance enchancement.
Hope this will help you.
Anil.
Developer Technical Support,
Sun Microsystems Inc,
http://www.sun.com/developers/support

How to use packages and jar files for applet?

Hi!
My applet takes a class say a.class.
Now this class depends on other classes that are packaged
in a directory and put separately.
I want to put this applet on the web.
So how do I manage the .class files in he package.
I have tried using jar file format.But I was not able to get it working.
Can someone please help me?
Thanks

Use Archive instead of codebase:
<APPLET CODE="MyApplet.class" ARCHIVE="MyApplet.jar" WIDTH=400 HEIGHT=300></APPLET>

Accessing web application JAR files from applet

I've got an applet which is part of a web application.
All the web application JARs are in the webapps/myappl/WEB-INF/lib directory, and I
can't seem to place anything in that directory on the archive attribute of <OBJECT> tag.
I'm running into trouble because I'm sending objects from the servlet to the applet and keep getting classnot found during deserialization because I've missed some jar file on the archive attribute. I've had to copy lots of jar files up to where the codebase in the HTML file is to make this run. My question is this.
Is it better to just change the tomcat security policy file (catalina.policy in tomcat conf directory) so that the JARs are directly accessible and I don't have to copy them from WEB-INF/lib???? Has anyone done this before? What would the line look like?
I'm assuming that I have to follow the instructions (THAT I DON'T UNDERSTAND)
at the bottom of the policy file. Can someone help me out here????
should I have something like
grant codeBase "file:${catalina.home}/webapps/myappl/WEB-INF/classes/-"
{ permission java.security.AllPermission; };
grant codeBase "file:${catalina.home}/webapps/myappl/WEB-INF/lib/-"
{ permission java.security.AllPermission; };
Will this allow me to place references to jar files (and the classes directory) in the archive attribute, such as
<OBJECT ..... >
    <param name="archive" value="../WEB-INF/lib/applet.jar,../WEB-INF/lib/someapp.jar,../WEB-INF/classes" />trailer for catalina.policy is
// You can assign additional permissions to particular web applications by
// adding additional "grant" entries here, based on the code base for that
// application, /WEB-INF/classes/, or /WEB-INF/lib/ jar files.
// Different permissions can be granted to JSP pages, classes loaded from
// the /WEB-INF/classes/ directory, all jar files in the /WEB-INF/lib/
// directory, or even to individual jar files in the /WEB-INF/lib/ directory.
// For instance, assume that the standard "examples" application
// included a JDBC driver that needed to establish a network connection to the
// corresponding database and used the scrape taglib to get the weather from
// the NOAA web server. You might create a "grant" entries like this:
// The permissions granted to the context root directory apply to JSP pages.
// grant codeBase "file:${catalina.home}/webapps/examples/-" {
//   permission java.net.SocketPermission "dbhost.mycompany.com:5432", "connect";
//   permission java.net.SocketPermission "*.noaa.gov:80", "connect";
// The permissions granted to the context WEB-INF/classes directory
// grant codeBase "file:${catalina.home}/webapps/examples/WEB-INF/classes/-" {
// The permission granted to your JDBC driver
// grant codeBase "file:${catalina.home}/webapps/examples/WEB-INF/lib/driver.jar" {
//   permission java.net.SocketPermission "dbhost.mycompany.com:5432", "connect";
// The permission granted to the scrape taglib
// grant codeBase "file:${catalina.home}/webapps/examples/WEB-INF/lib/scrape.jar" {
//   permission java.net.SocketPermission "*.noaa.gov:80", "connect";
// };

Thank you for your reply.
As I mentioned in my first post I had seen a couple of posts mentioning ServletContext before, but dismissed them as I am not using any servlets of my own. However, since you showed me exactly how it was used I realised I could probably just use a dummy servlet to get this information.
The following page suggests a couple of techniques for doing just this.
http://www.jguru.com/forums/view.jsp?EID=1087411
So I think that's me sorted, cheers.

Download and extract jar file from applet

Can any one provide me a solution for my below problem. Thanks in advance for all the suggestions.
I want my applet to download a jar file, extract into users home directory by creating a folder and then set the created folder to java library path.
My applet html file is in "root" directory. The applet is included into applet.jar and placed under "lib" directory which is under "root" directory.
Now i also had another jar file(contains dlls what I packed) under the same lib folder.
The below is the following directory structure in my server.
root ---
     |
     |
     default.html
     lib--
     |
     |
     applet.jar - contains applet related classes
     native.jar - contains dlls which are to be loaded
When a client downloads my applet, it should copy the native.jar and then extract into a new folder under user home directory. Then set this folder to java library path.
Regards
raman kumar

I managed to do it this way, Just remember that you need to sign the jar files for your applet, else it won't work.
package jar.extract;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.jar.JarFile;
import java.util.zip.ZipEntry;
public class JarExtractor {
     // Dll file in the jar
     private static String JAR_FILE = "dll.jar";
     public void extract() {
          try {
               JarFile jf = new JarFile(JAR_FILE);
               // Entry in the jar file rember package and dll file
               ZipEntry ze = new ZipEntry("package/dll_file");
               int length = (int) ze.getSize();
               byte fileContent[] = new byte[length];
               InputStream fin = jf.getInputStream(ze);
               fin.read(fileContent, 0, length);
               // CODE missing.
               // You need to write the input stream (fin) to a new files output stream
               // it is like copying a file !!!
          } catch (IOException e) {
               e.printStackTrace();
}Tom

How to add jar files to applet's classpath

hi everyone,
i got an issue to add jar file's to applt's classpath,
i looked around accross many resources but getting no solution on this.
i have a commons-httpclient3.1.jar and i have to make it available it to a an applet class bundled in a jar file say myjar.jar
how can i achieve it?
any help would be much appreciated
thanks

That's a long time I haven't written applets, but if I remind well, we are able to set multilple jar in the classapth parameter, separated by semicolon.
Look the page http://java.sun.com/docs/books/tutorial/deployment/applet/html.html
Edited by: jswim on Dec 6, 2007 3:51 PM

Three questions about signed jar file and applet

I use three signed jar file. Each of them signed by different certificate. First of JARs contain applet class. When I start applet from html page I see message “This applet was signed by…… but Java cannot verify it… Do you trust…?”. All times I press “Yes I trust” and after this questions applet stop to work end exit. If I use only one certificate for signing of three JARs then applet continue to work after question. 1) What should I do to fix this bug? 2) Is it any method to check from applet that user press Trust button? Is it any method to emulate work of SecurityManager to check that Certificate object is trusted (I want do call some method check(Certificate) and if certificate is not trusted I want to see message with question: “Do you want to trust this certificate” and so on)?

Hello Jarman,
1. If I have a signed jar file, then as long as the
certificate is recognised as trusted that applet can
run as a fully trusted application on the client
machine. So I should not have to add lines such as
permission java.lang.RuntimePermission
"readFileDescriptor", "read" ;
permission java.lang.RuntimePermission
"writeFileDescriptor", "write" ;
to my java.policy file. true/false ?true
2. If I am running a signed jar file in the Java
plugin then I do not need to have a verisign or thawte
certificate (however to allow my certificate to be
accepted I do have to import it into the cacerts file
on the client machine). True/false?true
3. Following on from question 2, if I want to be able
to run an applet on a client machine, without messing
around with ANY files on those machines, I need a
verisign or thawte certificate. True/false?true
4. (And finally) Apart from a security exception
saying that I need to add one of the lines like those
of question 1, is there any way I can get other debug
information as to why the signed jar file is not being
recognised as signed?No. This could be a problem of importing your certifcate into the wrong place.
The information on the following link is a little bit dated but it helped me to successfully install a testcertificate and sign an applet with it.
http://www.suitable.com/Doc_CodeSigning.shtml

Getting JAR file for Applet doesn't work

Hi,
We have the following problem: we have some clients who want to use our applet. There are some clients that have problems with receiving the .jar file:
When the applet tries to start we get a ClassNotFoundException: 'prestaties.class' not found. (the client wants to acces the class file directly from the server)
If we check the .jar file, it exists on the client, but the file is empty.
What could be the problem?
- PRoxy or firewall blocks the jar file
- applet doesn't have enough rights to write.
Does anyone a solution, some workarounds or suggestions for this problem.
Thanks!
Luk

Hi,
Thanks for answering my question!
Here is the extra information you asked.
At server side everything is OK (the jar file is present and has all the class files).
Where working with Weblogic server 4.51
The clients run JRE 1.3.0-C
I can't give you the applet code (confidential) but here is the html code:
<OBJECT classid="clsid:8AD9C840-044E-11D1-B3E9-00805F499D93" width="600" height="80" align="middle">
<PARAM NAME="cache_archive" VALUE="prestaties.jar">
<PARAM NAME="cache_option" VALUE="Plugin">
<PARAM NAME="cache_version" VALUE="1.4.2.1">
<PARAM NAME="code" VALUE="be.vdab.cvsesf.applet.prestaties.PrestatiesApplet">
     <PARAM NAME="codebase" VALUE="/lib">
     <PARAM NAME="type" VALUE="application/x-java-applet;version=1.3">
     <PARAM NAME="scriptable" VALUE="true">
     <PARAM NAME="windowId" VALUE="185498422412000">
     <PARAM NAME="cursusId" VALUE="23178">
     <PARAM NAME="opleiding" VALUE="boetseren">
     <PARAM NAME="organisator" VALUE="TESTOE Omschrijving">
     <PARAM NAME="locatie" VALUE="TESTDOSSIER HELKPDESK / 0">
     <PARAM NAME="instructeur" VALUE="TESTDOSSIER HELKPDESK / 0">
     <PARAM NAME="WebLogicSession" VALUE="1">
<COMMENT>
<EMBED type="application/x-java-applet;version=1.3" width="600" height="80" align="middle"code="be.vdab.cvsesf.applet.prestaties.PrestatiesApplet"codebase="/lib"pluginspage="cvsesf/plugin.jsp"cache_option="Plugin" cache_version="1.4.2.1" cache_archive="prestaties.jar" windowId = "185498422412000"cursusId = "23178"opleiding="boetseren" organisator="TESTOE Omschrijving" locatie="TESTDOSSIER HELKPDESK / 0" instructeur="TESTDOSSIER HELKPDESK / 0"WebLogicSession="1">
<NOEMBED>
</COMMENT>
          <html>
               <head>
                    <title>Java plugin download</title>
                    <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
                    <link rel="stylesheet" href="../includes/vdabstyle.css">
               </head>
               <body bgcolor="#FFFFFF">
               <TABLE width="600" border="0" cellpadding="1" cellspacing="0">
                    <tr>
                         <td>
                              <h1 align="right"><b><font face="Verdana, Arial, Helvetica, sans-serif">Java plugin</font></b></h1>
                              <P><B>Voor het invullen van prestaties en vergoedingen heeft u de JRE 1.3 Java Plugin nodig: deze staat op de CD-ROM die u normaal gezien van de VDAB gekregen heeft.<br><br>
                              Ofwel kan u de plugin hier zelf downloaden (<U>opgelet:</U> bestand is 8 MB groot).<br><br>
                         U kan het VDAB callcenter contacteren om een CD-ROM aan te vragen of om problemen te melden. Het nummer vindt u onderaan het scherm.</B></p>
                         </td>
                    </TR>
               </table>
               </body>
          </html>
     </NOEMBED>
</EMBED>
</OBJECT>
Hope this helps.
Luk

Including multiple jar files to applet

In one of my application I am using severla third party apis (JavaHelp, JFreeReport, NanoXml ...) which comes as a seperate jar file each.
Is there is a way that I can include these multiple jar files to be downloaded automaticaly when the applet is starting.
currently I am extracting all the jar files and then re compressing them in to one file and place it in the archive property in the applet tab.
Is there a way I can avoid extraction and recompression and directly use the jar files

<param nama="archive" value="myjar.jar, myOtherjar.jar" />
You could try to create an installer that wil put the 3rd party jars in the users lib/ext directory.

JAR files and Applets

I'm completely new to the whole .jar thing so i was wondering, after i package an applet and its respected classes within a .jar archive. what information should be in the manifest file?
lets say the applet is called, AppletText.class , and it makes use of the classTest.class class.
im using netbeans and i made it generate manfest file automaticaly. this is what it gives.
Manifest-Version: 1.0
Created-By: NetBeans IDE
Specified-By: TestJar.jarContent
when i click to execute the jar, i get an error message
Failed to load Main-Class manifest attribute from
C:\Documents and Settings\xxxxxxxxxx\xxxxxxxxxxxxx\xxxxxxxxxxx\AppletJartest.jar
x's are used to censor filenames
so how do i make it execute the way i want? (execute the applet and allow use of the class)

Just for reference may be. Sorry if it does not met your need..:
How to jar a packaged java class? (I write this so I don't forget to create jar file again :-( ..)
Consider the package is under the folder c:\classes and you have folder ml where you write several packages such as
- package ml.gui (c:\classes\ml\gui)
- package ml.algorithm (c:\classes\ml\algorithm)
- package ml.utils (c:\classes\ml\util)
- etc..
- and a main class, lets say "tool" as package under ml\gui (package ml.gui.tool)
so the folder c:\classes actually contains folder ml and ml has another folders.
Step to create packaged class jar:
Step1: Create a "Manifest.mf" file at least contains the following text:
Manifest-Version: 1.0
Main-Class: ml.gui.tool
Created-By: XXXXXX
Note:
* tool is the main class that will be executed
* the purpose of manifest can be found anywhere
in internet
Step2: Open MSDOS to c:\classes
Step3:
Execute the following command:
jar -cvfm <jarfiletobecreated.jar> Manifest.mf <packaged class>
In my case, the command is:
jar -cvfm ml.jar Manifest.mf ml/*
The above steps should create a jar file ml.jar and can be executed with command java -jar ml.jar or write batch file that contains the command.
Correct if i'm wrong.

JAR Files and Applets with Java Plug-In

This seems to be a basic question, but I can't figure it out! I have a jar file that contains all my class files for my applet. The jar file is in the same directory as the following html file:
<html>
<body>
<OBJECT classid="clsid:8AD9C840-044E-11D1-B3E9-00805F499D93"
WIDTH = 700 HEIGHT = 510 codebase="http://java.sun.com/products/plugin/1.3.1/jinstall-131-win32.cab#Version=1,3,1,0">
<PARAM NAME = ARCHIVE VALUE = "myFiles.jar" >
<PARAM NAME = CODE VALUE = "MainView.class" >
<PARAM NAME="type" VALUE="application/x-java-applet;jpi-version=1.3.1">
<PARAM NAME="scriptable" VALUE="false">
</OBJECT>
</body>
</html>
I've checked the jar file, it's the same name. MainView.class is most certainly in the jar file - yet everytime I open the page up, I get the class not found error:
java.lang.ClassNotFoundException: java.io.FileNotFoundException
MainView.class (The system cannot find the file specified)
If I don't jar the files, the applet works fine - but I want to jar them as it's some 20 class files. What am I doing wrong?

I've had a similar problem where it pops up the Java Extension Installation window, and starts downloading. Everything appears normal, but when it tries to run the applet it gets "load: class <className> not found" where <className> is the name of the class in my CODE parameter.
It appears that on occasion the download of the jar gets cut off. When I searched the browser's cache, I find a jar file that has fewer bytes than it should. In order to initiate a retry, you have to delete the jar file from your browser's cache, close all your browser windows so that the Plug-in with its truncated jar file stops running, and load the HTML page again. It appears that it checks the timestamp of the jar file in your cache and the one on the server and decides that it doesn't need to download it again. But if you delete it from your cache, it forces a retry.
I never have this problem when I open from my hard drive. I've never had the problem with a cable modem connection. I've had it once from a corporate LAN hitting an internet server (ie., outside corporate WAN). I've had people report the problem with dial-up connections. My theory is that whatever Sun is using to download the applet is more sensitive than either HTTP download or FTP.
Has anybody else experienced this problem? Is there anything you can do about it? I couldn't find a bug report on it. Is there one?

Trace jar file of applet.

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