分析并获取jar文件的代码/字符串-Java

Question

I want to analyze the code (or strings) of a jar file (example: if a jar file contains "cheese"), I searched a lot but I don't know how to do this :/ I don't want to use JD-GUI because my program have to be automatic (user press a button and then he have to know if a jar file contains a specific method (for example "public void onEnable()" or a string (for example "cheese"))

I searched and I found:

analyze jar file programmatically

Extract source code from .jar file

https://tomassetti.me/getting-started-with-javaparser-analyzing-java-code-programmatically/

http://docs.oracle.com/javase/7/docs/technotes/tools/windows/javap.html

How to search for a string in JAR files

Answer 1

Something along these lines:

• open the jar with a JarInputStream
• for each JarEntry do a Class.forName to load the class (compose the package correctly)
• use reflection to get the method names ( Class.getMethods )
• add the names, and required attributes, to a List to do the searches. Unless you are using huge jars or very old hardware you can do a simple full scan of the list of names using a contains() or matches() , probably you do not need fancy indexing tools (Sphinx, Lucene, etc.). If the RegExp part should be slow, create a regexp Pattern instance and reuse it.

A quick (Linux) alternative, for classes names only, is this:

jar tvf file.jar | grep ClassName