How to read a file from JAR archive?

Question

I need to read the content of /test/a.xml from a test.jar file (they are both variables, of course, not constants). What is the simplest way to do it?

File file = new File("test.jar");
String path = "/test/a.xml";
String content = // ... how?

Answer 1

How about this:

JarFile file = new JarFile(new File("test.jar"));
JarEntry entry = file.getJarEntry("/test/a.xml");
String content = IOUtils.toString(file.getInputStream(entry));

Answer 2

Use a ZipInputStream and search for your requested file.

FileInputStream fis = new FileInputStream(args[0]);
ZipInputStream zis =  new ZipInputStream(fis);
ZipEntry ze;

while ((ze = zis.getNextEntry()) != null)
   if(ze.getName().equals("/test/a.xml")
   {
       //use zis to read the file's content
   }