因为项目需要，要把一个zip/jar文件读入到后台服务器上，前台用户选择好zip/jar文件

以后，upload文件之后，从JarFile对象中循环读取JarEntry对象，然后根据JarFile的

API使用jarFile.getInputStream(JarEntry jarEntry)来读取每个JarEntry的内容。

可是最近他们想把文件读入变成基于inputstream的直接读取，从http请求中获取

inputstream之后可以直接读入。这样问题就来，怎么从流中知道每个JarEntry对象

一番研究之后，有了下面的代码：

package com.gloomyfish.image.study;  import java.io.BufferedInputStream; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.util.HashMap; import java.util.Iterator; import java.util.jar.JarEntry; import java.util.jar.JarInputStream; import java.util.jar.Manifest;  public class JarFileReader { 	private JarInputStream jarInput; 	private HashMap
     
       entriesStreamMap; 	public JarFileReader(InputStream in) throws IOException { 		jarInput = new JarInputStream(in); 		entriesStreamMap = new HashMap
      
       (); 	} 	 	public void readEntries() throws IOException { 		JarEntry entry = jarInput.getNextJarEntry(); 		String manifestEntry = null; 		while(entry != null) { 			System.out.println("Entry Name = " + entry.getName()); 			if("jp/co/sony/csl/nielsen/phoenix/objectremoval/Mark.class".equals(entry.getName())) { 				manifestEntry = entry.getName(); 				copyInputStream(jarInput, entry.getName());		 			} 			entry = jarInput.getNextJarEntry(); 		} 		System.out.println("Now!! + get jar entry inputstream again..."); 		InputStream inputStream = getCopy(manifestEntry); 		System.out.println(inputStream.read()); 	} 	 	public void copyInputStream(InputStream in, String entryName) throws IOException { 		if(!entriesStreamMap.containsKey(entryName)) { 			ByteArrayOutputStream _copy = new ByteArrayOutputStream(); 			int read = 0; 			int chunk = 0; 			byte[] data = new byte[256]; 			while(-1 != (chunk = in.read(data))) 			{ 				read += data.length; 				_copy.write(data, 0, chunk); 			} 			entriesStreamMap.put(entryName, _copy); 		} 	} 	 	public InputStream getCopy(String entryName) { 		ByteArrayOutputStream _copy = entriesStreamMap.get(entryName); 		return (InputStream)new ByteArrayInputStream(_copy.toByteArray()); 	} 	 	public static void main(String[] args) { 		File jarFile = new File("D:\\agriculture\\clickremoval.jar"); 		try { 			InputStream in = new BufferedInputStream(new FileInputStream(jarFile)); 			JarFileReader reader = new JarFileReader(in); 			reader.readEntries(); 		} catch (IOException e) { 			e.printStackTrace(); 		} 	} 	 }