这堂课来自哪里？

Question

How would you go about establishing where a class ( or maybe resource ) has been loaded from?

I am trying to work out exactly where a class has been loaded from. Does anyone know if you can find out the following:

1. Which Jar file did the class come from ?
2. What classloader loaded the file?

Answer 1

The class Class has an instance method getClassLoader() that returns a reference to the class loader that loaded the class it represents. Note that this can return null . See here .

So, if you wanted to know which classloader loaded String (just as an example) you could do:

ClassLoader loader = String.class.getClassLoader();

or:

ClassLoader loader = "I'm a String".getClass().getClassLoader();

Answer 2

例如，您可以通过调用MyClass.class.getResource（“MyClass.class”）来获取URL。

Answer 3

For a class one solution is MyClass.class.getProtectionDomain().getCodeSource().getLocation() . (Actually, may have a null ProtectionDomain or that may not hava a CodeSource . My also throw a SecurityException .

Answer 4

i think you will get the answer here :

http://www.jugpadova.it/articles/2005/11/13/from-which-jar-a-class-was-loaded

http://www.techtalkz.com/java/102114-how-find-jar-file-ava-class-all-successorshad-been-loaded.html

Answer 5

我会使用-verbose:class命令行选项，将输出保存到文本文件，然后使用grep（或DOS查找，如果你是Windows）来查看有关如何加载该类的详细信息。

Answer 6

if you have an instance of the class insta.getClass().getClassLoader().getName() -->this is the classloader that loaded the class

insta.getClass().getProtectionDomain().getCodeSource().getLocation()- where the class was loader from