I'm confused on how to correctly specify a applet's code attribute in a webpage. I have an applet with the absolute path of
~/workspace/myProject/bin/A/B/C/app.class
and my HTML is under myProject. app.class has the package declaration of
package A.B.C
How do I specify that the page should first look in bin and then A,B,C? If I stick the page in /bin, I can use
code = "A/B/C/app.class"
and it works fine, but putting it in myProject and trying
code = "bin/A/B/C/app.class"
doesn't work. I think its because of that package declaration but I don't know how to fix it; i can't change the package declaration. Do I need to use . in someway? I've seen that before and used it in another solution but trying with various combinations of . instead of / doesn't work either. As a side question, could someone explain what the difference between . and / is? This just says its used for delineating file type
You would use dots instead of the slashes and specify the CODEBASE accordingly
<applet code="A.B.C.app.class" codebase="bin" width="300" height="200">
</applet>
Related
So I'm running into a problem here getting an applet to run. The .class file is in another directory and I've learned that you can use the codebase attribute to point to where the file is. Here is my calling code.
<applet codebase="/Cartographer/bin" code="CartographerApplet.class" width="300" height="150"></applet>
Now the .class file i'm looking for is in a package I've deemed Cartographer.
My question is, is there something I'm missing? Or is my code completely wrong? I have a hunch that I'm not doing the codebase part correctly because I don't really know how to provide a shortened path without giving the whole C:\ect\ect\ect path.
Edit: The root directory has the folder Cartographer in it which houses the java project for creating the app. So the path I have is what points to the .class file I need. I've tried using the code attribute with and without the Cartographer package attached to the beginning and I keep getting a class not found exception.
I've built an applet (from JApplet) that consumes several other jar files. I've signed my jar that contains the main class and included all of the jars I need (I think). However, no matter what I try, I consistently get "java.lang.ClassNotFoundException: newposting" where 'newposting' is the main class within my signed jar. I'm using the following html for this:
<p><applet code="newposting"
archive="HartfordRowingNewPosting.jar,
javax.mail.jar,
jcalendar-1.4.jar,
junit-4.6.jar,
jgoodies-common-1.2.0.jar,
jgoodies-looks-2.4.1.jar,
mysql-connector-java-5.1.25-bin.jar"
width="500" height="850">
<param name="permissions" value="sandbox" />
<param name="codebase" value="HartfordRowingNewPosting.jar" />
</applet></p>
The jars and html are all located in the same folder on the server. I've tried several combinations of path specifications. I've also tried using jnlp but get the same error. I've been frustrated with this on and off for the last month or so. Can someone shed some light on this?
The fact the ClassNotFoundException is thrown when loading your main class means that either your class cannot be read from jar or your jar cannot be found.
I hope that your verified that your clas is indeed in jar. If not try it. Just to be sure try to use unsigned jar and see that you have exactly the same error.
If so you still have 2 possibilities.
Are you sure that your class is indeed called newposting? Lowercase? In default package? Note: this must be fully qualified class name.
Next, test that your jar is indeed available for browser. To do so just copy and paste the jar name to browser prepending it with your URL. For example if HTML is available under http://myhost/myapp/mypage.html try URL http://myhost/myapp/HartfordRowingNewPosting.jar.
BTW what does parameter codebase mean? Is it your application level parameter? I am not sure but make sure that this does not confuse browser with attribute codebase supported by tag applet. This attribute is typically .: <applet codebase="." that means "download jars from current directory". This is the same as to say java -cp . when running java from command line.
BTW, do you know that applets were almost obsolete about 10 years ago? Moreover as far as I can see you included MySql JDBC driver into your class path. You should understand that this will not work in most cases because typically there is a firewall that does not allow JDBC protocol between clients and server.
This topic has been covered in one form or another but none of the other threads have been able to help. My issue is very similar to this post, I am making a JUNG graph with added functionality, but none of the solutions helped:
JApplet fails to run in HTML page
I had a Java application that I converted to a JApplet. The JApplet works fine in the applet viewer in Eclipse but will not work when I try to open it in a webpage (I have tried IE, FireFox, and Chrome). I have my HTML page and archive folder both in the same directory. When I load the HTML page it just brings up nothing.
Here is my html code:
<html>
<title>Applet</title>
<head>
</head>
<body>
<applet code="prerna.blueprint.main.BPTester.class"
archive="applet1.jar"
width="800" height="800">
</applet>
</body>
</html>
When I try to have code="BPTester.class" it gives java.lang.ClassNotFoundException: BPTester.class but when I use code="prerna.blueprint.main.BPTester.class" it gives me no errors just nothing happens. (prerna/blueprint/main/BPTester.class is the file path in my src folder). I exported my Java project as a runnable jar file, is this correct? I created a simple JApplet that worked fine when I did all the same steps but it won't work for BPTester.class.
If I need to post my BPTester.class code I can.
I don't understand why I can't view the JApplet in a webpage, any help is greatly appreciated.
What ended up working for me was adding every single jar I used in the japplet to the HTML archive tag then had to sign every jar. I then had an issue with accessing my database within the applet1.jar so I just put an absolute path for its location.
java.security.AccessControlException: access denied (java.util.PropertyPermission user.dir read)
The applet needs to be digitally signed (by you) and trusted (by the end user, when prompted) before it can obtain such information. Given this applet is being deployed using a traditional applet element (i.e. not using web start), all jars need to be signed.
You need to sign every jar. You can sign all the jars with the jarsigner utility. Example:
jarsigner.exe "nameofthejar.jar" "alias"
Remove .class from the end. You either use a file path with slashes and .class at the end or you only use periods and no .class at the end.
Try turning on tracing in the java control panel. It will then produce a log file in the following path that may help: %USERPROFILE%\AppData\LocalLow\sun\java\Deployment\log
Directory is like so:
test.html
blah
hmmm
Inside "blah" we have all the applet files, including blahBlah.class. Inside "hmmm" are a few more more class files that were taken from a library or something, they are used by the project also.
I write in test.html...
<applet name="blah" code="/blahBlah.class" codebase="blah"></applet>
(along with every other variation I could think of)
Farthest I've gotten is:
java.lang.NoClassDefFoundError: blahBlah (wrong name: blah/blahBlah)
Now inside blahBlah.java, we have:
package blah;
I'm not sure if it's related.
Also wondering if it may be necessary to place the project in a jar file and set the archive attribute of the applet?
The real files are not blah and blahBlah, but I've replaced the names faithfully.
java.lang.NoClassDefFoundError: blahBlah (wrong name: blah/blahBlah)
This basically means that it's been executed as
java blahBlah
instead of
java blah.blahBlah
In other words, your code attribtue is wrong. It has to be
<applet name="blah" code="blah/blahBlah.class" />
or just by FQN (see also Andrew's comment)
<applet name="blah" code="blah.blahBlah" />
The codebase defaults to the current folder, which is fine in this case, so it's removed. An alternative is to put it in another folder, such as /applet or something. You should at least not use a package folder as code base, but instead the package root.
Can anyone help me out. I've written a program that controls the heating system in an imaginery house, an applet actually. it runs fine in netbeans but i cant get it to run as an applet in a browser, can anyone help me out please, I linked to a zip folder of all my code...
http://dl.dropbox.com/u/47863/Heating%20System.zip
http://alcaeos.com/applet/classes/MyHomeHeating.class -> 404.
Or to put that another way.
The applet element is telling the JRE to look for the class at the URL mentioned above.
The class is not at that location. (Neither is it in the same directory as the HTML.)
Where is the class file?
BTW: Typical bloody Netbeans generated code (/HTML). When what it generates is not invalid, it is redundant.
code="MyHomeHeating.class" The code attribute should not include .class.
<HR WIDTH="100%"> An HR element normally spans the entire width of the page.
You need to compile your applet into .class files (not .java files like you have in the ZIP; those are source code) and embed it into an HTML page. You can use the tag in HTML to do these; read more here: http://www.echoecho.com/applets01.htm