I'm trying to run a code on lifecycle of applet as shown. This file is saved as Lifecycle.java
I compiled it by
javac Lifecycle.java
then tried to run it by
appletviewer Lifecycle.java
package APPLETS;
import java.applet.Applet;
public class Lifecycle extends Applet
{
/*
< APPLET
code = "Lifecycle.class"
height = "300"
width = "300">
< \APPLET>
*/
public void init()
{System.out.print("INIT");}
public void stop()
{System.out.print("STOP");}
public void start()
{System.out.print("Start");}
public void destroy()
{System.out.print("Destroy");}
}
APPLET is not loading then, though my code compiles successfully, no instructions are seen on command prompt. I'm just seeing a blank page with error -> Start:applet not initialized
HERE is the Lifecycle.html code-->
and here is the ERROR-
load: class APPLETS.Lifecycle.class not found.
java.lang.ClassNotFoundException: APPLETS.Lifecycle.class
The appletviewer is expecting to find HTML content so cannot parse the input file. Use appletviewer against a URL rather than a Java source file.
appletviewer is used to view applets using a URL. This URL can be in the format of a local or remote HTML document. Create a HTML document including the tag specifying your class and run the appletviewer against it.
life.html:
<APPLET CODE="APPLETS.Lifecycle" width="300" height="300"></APPLET>
then use
appletviewer life.html
The simplest folder structure for this to run is
./
|life.html
|-APPLETS
Lifecycle.class
Related: The Java Applet Viewer
Aside: Consider using the more up-to-date Swing JApplet.
Put Lifecycle.java in a folder called APPLETS, and try running:
appletviewer APPLETS.Lifecycle
Related
I am trying to run Java applet using Google Chrome browser. Everytime I am getting no class found exception. Here is my code.
HelloWorld.java
package my.first.pack;
import java.applet.Applet;
import java.awt.*;
public class HelloWorld extends Applet {
/**
*
*/
private static final long serialVersionUID = 2741715258812838900L;
public void paint(Graphics g) {
g.drawString("welcome", 150, 150);
}
}
Hello.html
<applet code="my.first.pack.HelloWorld" width="300" height="300">
Sign your applet and all the .jar dependencies with a certificate.
Populate your manifest with all the tags mentioned below (it's in xml because I use maven, you can write in the way you prefer)
<codebase>http://location.of.your.jar/</codebase>
<permissions>all-permissions</permissions>
<Application-Library-Allowable-Codebase>http://location.of.your.jar/</Application-Library-Allowable-Codebase>
<Manifest-Version>1.0</Manifest-Version>
<Implementation-Title>App Name</Implementation-Title>
<Implementation-Version>0.1.0</Implementation-Version>
<Application-Name></Application-Name>
<Created-By>1.8.0_45</Created-By>
<Main-Class>package.YourClass</Main-Class>
<mode>development (or production)</mode>
<url>url of the application</url>
Surround your java method with the doPrivileged
Be sure that your browser has the java plugin enabled
Put your http path of your web app in the java exception list
If your url has _ (underscore/underline) probably it won't be recognized.
Try to move your .jar to the same folder of your html, not using the /applet folder.
Take a look on this post, I was having a similar issue.
Remember, this error saying that 'is not a function' is because your .jar is not loading - or you made something wrong with the js syntax, what I don't think so.
I am beginner to Applets. Here is code for a basic applet to display string.
package firstjavaapplet;
import java.awt.Graphics; // program uses class Graphics
import javax.swing.JApplet; // program uses class JApplet
public class FirstJavaApplet extends JApplet
{
// draw text on applet’s background
#Override
public void paint( Graphics g )
{
// call superclass version of method paint
super.paint( g );
// draw a String at x-coordinate 25 and y-coordinate 25
g.drawString( "Welcome to Java Programming!", 25, 25 );
} // end method paint
public static void main(String[] args)
{
FirstJavaApplet obj = new FirstJavaApplet();
}
}
Following is HTML file I am using to include applet in webpage.
<body>
<applet code = "FirstJaveApplet.class" width = "300" height = "300">
</applet>
</body>
</html>
When I run Applet in appletviewer FirstJaveApplet.html , I get following:
String is not being displayed rather "Start: applet is not initialized."
<applet code = "FirstJaveApplet.class" width = "300" height = "300">
</applet>
The code attribute value should be the Fully Qualified Class name as opposed to the applet file name. So that should read:
<applet code = "firstjavaapplet.FirstJavaApplet" width = "300" height = "300">
</applet>
Note that the JRE will search for the class in a sub-directory of the HTML directory named firstjavaapplet. Unless the class is present in the right place, the problem will continue.
code = "FirstJaveApplet.class" : Java not Jave
I was also facing the same issue and none of the forum's solution rescued me :(
Then I realized, we need the set the size and visibility of the applet.
You can include the following constructor as your code:
FirstJavaApplet()
{
setSize(500, 500);
setVisible(true);
}
Applet don't need a main method to start
Just run without main method
I think you having the problem with your package name
compile without the package name package firstjavaapplet;
public class FirstJavaApplet extends JApplet
{
#Override
public void paint( Graphics g )
{
// call superclass version of method paint
super.paint( g );
// draw a String at x-coordinate 25 and y-coordinate 25
g.drawString( "Welcome to Java Programming!", 25, 25 );
} // end method paint
}
In the case of PApplet. On MacOS 10.10
You need to change the the JRE System Library min to 1.7.
In my case java.lang.UnsupportedClassVersionError: processing/core/PApplet : Unsupported major.minor version 51.0
Its throwing above. Its resolved when I'd set .JRE System Library-1.7
Hope its help you.
For PApplet
On Mac
Usually happens with JRE 1.6
Change the Build path as:
On your Project
JRE system Library > Build Path> Configure Build path
Choose JRE 1.7 or 1.8 (if installed it will be displayed)
Remove the old one from build path by right-clicking and choosing the right option
Try after placing the above java file,in a folder with name firstjavaapplet(pakage name) in the source pakagefolder.
Don't name your HTML file same as the Class File I think that will work.
Write the HTML code as below:
<html>
<body>
<applet code="firstjavaapplet.FirstJavaApplet" width ="300" height ="300">
</applet>
</body>
</html>
Save it as: FirstJavaApplet.html
Compile your Java Source File as:
javac -d . FirstJavaApplet.java
(You might have skipped compiling your Java Source File)
Then run your HTML file as:
appletviewer FirstJavaApplet.html
no need to create html file.whatever line you write in html also write in java after import statement
import java.awt.Graphics; // program uses class Graphics
import javax.swing.JApplet; // program uses class JApplet
/*<applet code = "FirstJaveApplet.class" width = "300" height = "300">
</applet>*/
public class FirstJavaApplet extends JApplet
{
// draw text on applet’s background
#Override
public void paint( Graphics g )
{
// call superclass version of method paint
super.paint( g );
// draw a String at x-coordinate 25 and y-coordinate 25
g.drawString( "Welcome to Java Programming!", 25, 25 );
} // end method paint
public static void main(String[] args)
{
FirstJavaApplet obj = new FirstJavaApplet();
}
}
No Need to write the main method in applet and you have to extend Applet than your applet will run
public class FirstJavaApplet extends Applet
I was also facing same problem because, i have changed path during installation of Older JDK (jdk 10.0.2)
to D Drive.
By doing this what happen is your main jdk-10.0.2 folder will install in C Drive's ProgramFiles folder and only copy of bin and some other folder is created in you newly mentioned path during installation.
So What You Can do is
Go to C Drive > Programfiles > java.
Cut Whole jdk-10.0.2(or older whichever yo have downloaded) and paste it wherever you want.
After pasting it go into jdk-10.0.2 folder -> Go to bin folder of it and write all your programs here.
i face the same,
but in my case i was using jdk17 to compile and using that .class file to run on appletviewer but appletviewer is closed after jdk9 so, any .class file that was created using jdk9 or higher it can't support so, i just used jdk8 to compile my program and it run fine on that appleviewer
Hi everyone I made a calculator applet and am trying to export it as a JAR file, since you can't export applets as runnable JARs. When I try to do java -jar Calculator.jar in command line though I get an error "saying no main manifest attribute, in Calculator.jar". I'm wondering if I need to do anything else in my main method other than below to fix this?
public static void main(String[] args) {
Calculator calculator = new Calculator();
}
To use an applet, you have to embed it in a webpage.
Here's some HTML for your use case.
<applet code = 'PACKAGE.Calculator'
archive = 'Calculator.jar'
width = 300
height = 300>
<param name="permissions" value="sandbox" />
</applet>
Fill in PACKAGE with your package for the applet and modify the height/width to fit.
i've created a java applet last year for a socket connection from a web application to a local running java server. it worked fine.
since the last java updates (7 r21 i guess), i cannot access the methods within javascript anymore. Right now, i reduced the applet to a test applet (without the doPriviligedAction methods) but even this does not work anymore.
The current code is like
import java.applet.*;
public class socketApplet extends Applet {
public void init() {
System.out.println("Applet initialisiert.");
}
public void start() {
System.out.println("Applet gestartet.");
}
public void paint() {
System.out.println("Applet aktualisiert.");
}
public void stop() {
System.out.println("Applet angehalten.");
}
public void destroy() {
System.out.println("Applet beendet.");
}
public String testApplet() {
System.out.println("Applet getestet.");
return "Yep, I'm the Applet.";
}
}
Before the update i could access methods like testApplet() in javascript like this:
document.socketApplet.testApplet();
The applet is self-signed and embedded with an applet html-tag. It is starting (the java console is opening and prints the debug messages defined in the init, start and paint methods) but i cannot access the testApplet() method. The response in Javascript is "undefined" while the applet exists.
after reading a while (a few days now...) about the new security changes, i've added a manifest.txt with the following content:
Main-Class: socketApplet
Permissions: all-permissions
Codebase: *
Trusted-Library: true
No luck with or without the Trusted-Library attribute.
What do i have to do to enable the access with javascript again?
Edit:
The implementation:
<applet id="socketApplet" width="100" height="100" archive="../../socketApplet.jar" name="socketApplet" code="socketApplet" scriptable="true">
I am testing with the newest versions of Firefox and Safari on an up to date Mac OS X machine.
Edit2:
i am creating and signing the jar like this
Edit3:
Okay, now my jar worked a few times (not in a row), i got
and in the console
But most of the time it does not work. restarting the browser, clearing caches, nothing works. going to test this on another pc now (again).
Edit4:
Okay it is running on a virtual machine with windows xp and java 32bit 7u25 - on my 64bit mac just only 1 out of 30 tries.
Okay i found the source of all evil...
it had nothing to do with the applet. the confusing situation was that it worked in firefox on windows and not in firefox on the mac (same FF versions, same java versions). Safari on my mac didn't work because the plugin was disabled...
So it was a Firefox on mac problem only. I've tested different situations and the applet worked when writing the applet code above into a html page. Before, i've created the applet dynamically (what is necessary in the software):
var applet = document.createElement('applet');
applet.archive = 'socketApplet.jar';
applet.id = 'socketApplet';
applet.name = 'socketApplet';
applet.code = 'socketApplet';
applet.scriptable = 'true';
applet.width = '0';
applet.height = '0';
document.body.appendChild(applet);
It works everywhere but not in Firefox on Mac. So as a workaround i have to embed the applet in an iframe and i have to embed the iframe dynamically. that works...
var mFrame = document.createElement('iframe');
mFrame.id = 'testFrame';
mFrame.height = '200';
mFrame.width = '400';
document.body.appendChild(mFrame);
mFrame.src = 'frame.html'; // contains the applet code
Next i am going to change the html tag to the object and embed tag for IE support. Thanks for your help Andrew Thompson!
I dislike the iframe version because the access to the applet via javascript is more complex, but it seems like there is no other way around.
I am going to submit a Mozilla bug ticket for this.
https://bugzilla.mozilla.org/show_bug.cgi?id=912880
Maybe similar to this one but another situation:
https://bugzilla.mozilla.org/show_bug.cgi?id=872969
I am trying to run simple "Hello world" java applet program. But on execution applet does not appear in browser instead ClassNotFoundException occurs.
This is how I am accessing it from browser:-
<applet width="500" height="50" codebase="http://localhost:13383/tuexample/"
code="dk.certificate.demo.DemoApplet.class" >...applet..</applet>
JavaCode:-
import java.applet.Applet;
import java.awt.Graphics;
public class DemoApplet extends Applet
{
private static final long serialVersionUID = 1L;
#Override
public void paint(Graphics g)
{
g.drawString("Welcome in Java Applet.",40,20);
}
}
Exception Log:-
Java Plug-in 10.21.2.11
Using JRE version 1.7.0_21-b11 Java HotSpot(TM) Client VM
User home directory = C:\Users\rahil_khan
----------------------------------------------------
c: clear console window
f: finalize objects on finalization queue
g: garbage collect
h: display this help message
l: dump classloader list
m: print memory usage
o: trigger logging
q: hide console
r: reload policy configuration
s: dump system and deployment properties
t: dump thread list
v: dump thread stack
x: clear classloader cache
0-5: set trace level to <n>
----------------------------------------------------
28-May-2013 14:20:51 <INFO> thread applet-dk.pbs.applet.bootstrap.BootApplet-1 - stop
28-May-2013 14:20:51 <INFO> thread applet-dk.pbs.applet.bootstrap.BootApplet-1 -
destroy
Let me finally answer this Question:
You are getting ClassNotFoundException because Applet class, it seems, can not be found in the configuration you have provided.
Your code does this: It is trying to find DemoApplet.class inside the package dk.certificate.demo inside the localhost:13383/tuexample/
So, if we consider localhost:13383/tuexample/ to be your root webapp directory called xyz then your possible file structure should be like this:
XYZ/dk/certificate/demo/DemoApplet.class which clearly does not seem to be the case.
Also make sure you have package dk.certificate.demo inside your class file which I don't see at the moment.
Now, it should be easy to fix your code from what I have explained.
In tag:
code="dk/certificate/demo/DemoApplet.class"
package dk.certificate.demo;?
dk/certificate/demo/DemoApplet.class?
By the way JApplet, swing i.o. AWT, is the better solution.
Maybe in your case the code base resides in (should be) WEB-INF/classes, which normally is notokay, as WEB-INF files should not be accessible by URL.
In fact normally a .jar is created in a separate project and deposited in the Web Contents directory.
#RaviTrivedi and #JoopEggen thanks for your support I was able to fix the problem.
Two solutions:-
DemoApplet.jar:-
I created jar(DemoApplet.jar) of my applet code(DemoApplet.java) and
placed it in AppletDemo\WebContent\lib folder.
I moved classes folder
from AppletDemo\WebContent\WEB-INF\classes
to AppletDemo\WebContent\classes
And from login.jsp I made call to applet in following way:-
<!-- DemoApplet.jar -->
<applet
width="500"
height="50"
codebase="http://localhost:8080/AppletDemo"
archive="lib/demoApplet.jar"
code=dk.certificate.demo.DemoApplet.class >...applet..</applet>
<!-- classes -->
<applet
width="500"
height="50"
codebase="http://localhost:8080/AppletDemo/classes"
code=dk.certificate.demo.DemoApplet.class >...class...applet..</applet>
It worked both ways.
Thanks a lot. :D