从jar获取资源：classloader vs class resourceasstream [英] Getting Resources from a jar: classloader vs class resourceasstream

问题描述

我正在尝试实现一种方法，当该方法被调用时，从加载类的jar中的特定资源获取字符串。

I am trying to implement a method that when called, get a string from a particular resource in the jar that the class is loaded from.

例如：

import mypath.myclass; //from a jar
String result = gitid.getGitId(myclass.class);

我目前正在使用：

InputStream is = null;
BufferedReader br = null;
String line;
is = c.getResourceAsStream("/com/file.text");

问题是无论我给什么班级，我都不断获得相同的资源。

The problem is I keep getting the same resource for no matter what class I give it.

我也尝试过：

is = c.getClassLoader().getResourceAsStream("/com/file.text");

这完全失败。

任何建议

此外，从类加载器与类调用getResourceAsStream和类之间有什么区别？

Also,what is the difference between calling getResourceAsStream from the class loader vs the class?

推荐答案

Class.getResourceAsStream（）获得一个 ClassLoader 实例，从 Class.getClassLoader（）调用中获得的效果几乎相同。

The Class.getResourceAsStream() gets a ClassLoader instance, pretty much the same you get from Class.getClassLoader() call.

您可以做的就是获取URL对于给定的类，并替换类资源路径，即文件的路径。例如，以下代码将从同一个jar中返回资源：

What you could do, is get the URL for a given class and replace class resource path your path of your file. for example, the following code will return resource from the same jar:

  Class c = String.class;
  URL u = c.getResource('/' + c.getName().replace('.', '/') + ".class");
  String s = u.toString();
  URL url = new URL(s.substring(0, s.indexOf('!')) + "!/META-INF/MANIFEST.MF");
  InputStream is = url.openStream();

您将不得不分别处理未受干扰的类文件夹。

You'll have to handle not jarred class folders separately.

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