HTML Applet标签，可通过Chrome开发者工具进行访问

Question

i happen to receive a Html with an applet tag, is there a way to access the class received through chrome developer tools, i cant see it in the scripts. If there isnt how can i access it?

<applet name="tradesapp" id="tradesapp" code="loader3.SunLoaderApplet.class" archive="loader_20110113.jar" codebase="http://ih.advfn.com/" width="1100" height="2000" mayscript="" alt="This browser either has java disabled or does not support it" title="Java"><param name="manifestcrc" value="1211857157"><param name="storagepath" value="ih.advfn.com"><param name="masterloader" value="master"><param name="initial_focus" value="false"><param name="cache_archive" value="loader_20110113.jar"><param name="cache_version" value="1.0.7.7"><param name="java_arguments" value="-Dsun.java2d.d3d=false"><param name="advfn_url" value="http://ih.advfn.com/"><param name="streamer" value="stream-9.advfn.com"><param name="user" value="ih_340884"><param name="root" value="advfnclient.framework.BaseControl"><param name="page" value="advfnclient.TradesContainer"><param name="tz" value="US/Eastern"><param name="clearAllDateStamp" value="1272534624504"><param name="clearCacheDateStamp" value="1272534624504"><param name="language" value="us"><param name="view" value="ih"><param name="config_name" value="trades"><param name="config_default" value="Default"><param name="params" value="w=1100&amp;h=2000&amp;symbol=N%5EMSFT&amp;montage=true&amp;sources=afx:ukreg:rssnon&amp;dims=664 79 15 0&amp;col_widths=45 55 344 90 115&amp;sid=1f58fa6b4ea88725c5b8e23d614a6e80&amp;page_key=1338581393&amp;w=1100&amp;h=2000&amp;pid=applet_embed&amp;mypid=trades"><center><iframe width="600" height="300" src="/p.php?pid=javadisabled"></iframe></center></applet>

Answer 1

Chrome doesn't include a Java debugger and an applet isn't a script.

You can access it via document.getElementById('tradesapp'); in the JS console. If you want to do anything with it, then the applet will have to explicitly expose methods to JavaScript .

Answer 2

I suspect this is not your Java project, so I can't imagine Quentin's advice will help you. It sounds to me like you want to run the Java Applet yourself, perhaps making changes and having access to a debugger. I decided to see what I could do as I've never had experience with this kind of stuff before.

First of all, you can download the .jar file in the archive property. In your case it looks to be located at http://ih.advfn.com/loader_20110113.jar

You can then use Java Decomipler to decompile the .jar file. If you do so, you'll see that this jar file acts as a loader, and pulls more java classes from advfn.com. It saves them in the location given by:

String path = System.getProperty("user.home");

On windows this is C:\\<USER>\\advfn

You can decompile these classes as well if you're interested. You'll be left with an approximation of the original source code. In this case, a fairly good one.

If want you go one step further and decide to build the project yourself, you can import the classes into Eclipse. You'll notice there are some strange errors such as the following:

LoadFile(String paramLong, long arg3)
{
    this.name = paramLong;
    Object localObject;
    this.size = localObject;
}

I've never built a decompiler myself and am not at all familiar with Java bytecode, but if I had to guess, I'd imagine that the decompiler was trying to represent a local instance of the argument that was passed in to it.

The fix is fairly obvious once you know this.size is of type Long .

LoadFile(String paramLong, long arg3)
{
    this.name = paramLong;
    this.size = arg3;
}

If you continue to make these changes, your code will compile successfully. But it still won't run as you're missing parameters set in the HTML. A sample line in LoaderApplet.java is as follows:

this.manifestCRC = Long.parseLong(getParameter("manifestcrc"));

If you return to the HTML page you found this at, you'll find a variety of parameters are specified there. You should be able to go through your project and replace requests for parameters with their appropriate values.

This was my first experience decompiling Java, so I might have missed a few details. Let me know if you need more help.