如何dump出一个Java进程里的类对应的Class文件

class-dump-x 提取私有库里面的隐藏文件

class-dump
This is a command-line utility for examining the Objective-C runtime information stored in Mach-O files. It generates declarations for the classes, categories and protocols. This is the same information provided by using 'otool -ov', but presented as normal Objective-C declarations, so it is much more compact and readable.
Why use class-dump?
It's a great tool for the curious. You can look at the design of closed source applications, frameworks, and bundles. Watch the interfaces evolve between releases. Experiment with private frameworks, or see what private goodies are hiding in the AppKit. Learn about the plugin API lurking in Mail.app.
If you find class-dump useful, you can donate to help support its development. Thanks!
Download
Current version: 3.3.3 (Universal, 64 and 32 bit)
Requires Mac OS X 10.5 or later.
class-dump-3.3.3.dmg
class-dump-3.3.3.tar.gz
class-dump-3.3.3.tar.bz2
Changes - News
Contact
You can email questions and bug reports to me at class-dump@codethecode.com, or nygard at gmail.com.
Usage
class-dump 3.3.3 (64 bit)
Usage: class-dump [options]

where options are:
-a show instance variable offsets
-A show implementation addresses
--arch choose a specific architecture from a universal binary (ppc, ppc7400, ppc64, i386, x86_64, etc.)
-C only display classes matching regular expression
-f find string in method name
-H generate header files in current directory, or dir