So I'm having a tough time trying to understand the criteria that I need to follow in order for my Java program to be able to be embedded in HTML. Do I just have to extend my main class to the Applet class, or is there more that I have to do? Also, in every Applet example I've seen, it shows the code embedding a .class file, like so:
<Applet Code="MyApplet.class" width=200 Height=100>
</Applet>
Do I need to have all the .class files stored in a folder seperately, or does it just read the .class file specified from the compiled .jar?? I'm fairly lost here, if someone could clarify it would be much appreciated. Thanks
Definitely you can specify the jar class of jar file. be sure that you have put the jar in your class path and specify the full qualified path of the class file
refer for how to create applet
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I have i problem, I made a program in java using eclipse compilator, the thing is that It has two packages and in each package there are 3 classes i have tried to insert this code in a html file useing the applet tag but the problem is that it doesnt works, i dont know how to do it, and its quite important
I have tried using applet tags and tried the .jar I found something like this
<applet codebase ="." code="zuve.ZuveApplet.class"
archive=".jar,1.jar"
height="1000" width="1000"/>
I recomend you do a short tutorial on Applets:
http://java.about.com/od/webapplications/ss/firstapplet_3.htm
It is quite easy and you may made a misstake at one of those important points:
Compile your source: This includes a.) having your .java files beeing transformed to .class files and b.) packaging everything into a .jar file (you can make a .zip and rename it to .jar by hand).
Link your applet: This is done like described here: http://docs.oracle.com/javase/tutorial/uiswing/components/applet.html. You want to have both of your different packages packed in ONE .jar and have that single jar defined as argument 'archive' while your argument Code has to point to your applet class (e.g. the one extending from either Applet or JApplet or something like that).
Make sure that paths are set properly, easiest way would be to have everything (the .html with the applet tag and the .jar with your applet code inside) inside the same folder.
I build project in eclipse - swing applet and now I'm trying to run it in a browser.
I have 3 packages, let's say they are called: "pkgApplet", "pkgFirst", "pkgSecond" with .class files. In pkgApplet I have class "main" with method main(). No matter what I do, I can't run this applet in browser. Currently my html code looks like this
<applet code="bin/pkgApplet/main" height="1000" width="1000"/>
Browser gives this error every time no matter how I modify applet tag:
NoClassDefFoundError with message bin/pkgApplet/main(wrong name: applet/main)
I tried using codebase attribute, packing applet into .jar file and using archive attribute, but nothing seems to work. Do you have any idea what am I doing wrong?
Your applet format should be:
<applet codebase="bin" code="pkgApplet.main" height="1000" width="1000"></applet>
bin is the default target directory (for Eclipse) so will require the codebase attribute as shown above. For this to work, your HTML file needs to be located in your project directory.
Note classes in Java start with uppercase, while package names are lowercase. Also its helpful to name classes describing what they do. You could have instead:
<applet codebase="bin" code="pkgapplet.MyMainApplet" height="1000" width="1000"></applet>
Do you realize that nothing in main will be called by your applet client? Any startup functionality should be placed in the init method.
I have made a Java applet game in Eclipse which has many classes and media associated with it. I have now been trying to finally test the game in a browser but I am having a hell of a hard time getting it to work.
I have exported a .jar file (a non-runnable, could that be a problem?) and tried many different ways of loading the applet. I have read over the materials on the oracle website as well.
My first two basic questions are:
My applet does not have a static void main(String args[]){ line because I was under the impression that for applets you use a init() and start() method. Could this be the problem?
if not, my class which contains the init and start and the other basic methods is called Start.class and is located in a bin/ directory. Am I able to edit the manifest which is included in the .jar exported from eclipse and but this Start.class as the main class using Main-Class: Game.Start?
Another very basic question also when it comes to directories in java or specifically in .jar archives, are folders in a path names always separated by a .? or do /'s work too?
My project name is simply Game, I have a src folder with .java files and a bin folder with .class how do I direct the manifest to the bin/start.class file?
Sorry this has been rather frustrating especially because I really want to be able to share this applet. Any help would be greatly appreciated.
1) My applet does not have a static void main (args[]){ line because I was under the impression that for applets you use a init() and start() method. Could this be the problem?
No, this is not a problem, as Applets and JApplets do not use main methods to run. Note that some may have main methods that may be used to allow the coder to test the code in a non-applet environment, but when run as an applet, the main methods are ignored.
2) Another very basic question also when it comes to directories in Java or specifically in .jar archives, are folders in a path names always separated by a "."? or do "/"'s work too?
the directeries in jar files use "/". Please check that you are not trying to use resources as Files since jar files do not hold files (but rather resources).
My project name is simply Game, I have a src folder with .java files and a bin folder with .class how do I direct the manifest to the bin/start.class file?
Consider showing the structure of your jar file and also a small test html file where you try to run the applet.
Start.class and is located in a bin/ directory
I agree with Hovercratft about a missing main (not missing), about runnable jar (not necessary).
One problem which might exists is the exact location of files and naming of classes.
If your class name is bin.Start, because you defined a package bin (very uncommon), you need to put the bin directory into the jar.
If you didn't declare a package, you don't have a directory to put into the jar. Maybe eclipse handles this for you automatically.
To test your applet, you need a html file, and start the html file in the appletviewer. If this works, you test it in the browser. Else verify that you can start foreign applets in your browser, to make sure it is installed in the correct way.
Since you show a sloppy habit in the question of cases: Start.class or start.class: This is significant for Java. Use initial uppercase names everywhere.
Currently I am trying to embed a Java applet onto a webpage, and the only result I get is the java logo spinning and an empty loading bar.
example
I can't tell if its an error in my Java code or if I did something wrong with the HTML file.
Here is what I have for HTML.
<applet>
archive="game.jar"
code="BRANDON.GameApplet.class"
width=800
height=600
</applet>
BRANDON is the package I created with the rest of my files and GameApplet is the class which has the applet necessary methods. The game.jar is located in the same location as my HTML file, and the GameApplet class file is located in the jar within the BRANDON folder. The applet runs just fine in eclipse when told to run as an applet so I can't imagine it being a problem with the Java code.
My suspension is that it is a problem with file placement but every variation I try comes up with similar results. Anyone know what the mysterious loader means, and what I am doing to cause it?
Thanks to anyone who might answer.
EDIT: Just enabled the developer console and the only output it gives me is:
APPLET tag missing CODE parameter.
I don't know how much this helps.
Enable the Java Console so you can see the error messages and take appropriate action.
edit: You need it inside the applet tag
<apple code="..." ...>
now it is just some text inside the tag.
My suspicion is that your class files are simply not being found, though I don't have enough info to know for sure. Some thoughts:
double-check the file structure inside of game.jar. e.g. GameApplet.class should appear in the BRANDON/GameApplet.class folder relative to the root of your jar file.
check that your folder names and class names are correct
check that when you jar'd your applet, you didn't forget to include class files. I have jar'd all of my source files before, forgetting to compile them before creating the jar
I have an applet that works alright on this page. It just references the .class file. (unfortunately, I have lost the source, and the jar files.)
I want to reference it here, however it does not start. Probably because it cannot find the class file. the applet tag looks like this
<applet code="/applets/language/LanguageEngineApplet.class" width="1174" Height="402">
<embed code="/applets/language/LanguageEngineApplet.class" width="1174" height="402" type="application/x-java-applet" pluginspage="http://www.java.com/en/download/manual.jsp"/>
</applet>
I know the .class file is there, because I can link to it. So I'm stumped as to why this won't work.
I just put the applet in a page on it's own. The problem was not my Java version, it was the class name and the path and the package interacting somehow. I had to put it in a directory on its own, with the html file that referenced it in that directory.
You may want to look at the Java Deployment Toolkit
If you do decide to embed a Java applet inside WordPress and not outside, I just released a new plugin that easily allows you to do that. It uses shortcodes.
http://huyz.us/2011/the-easiest-way-to-embed-java-in-wordpress/
Hmmm, maybe I have to support uploading *.class files in your case. Let me know, if you need that.