Java读取ZIP文件ZipEntry.getsize()总是返回-1？

解决方法（Code）在文章最后面，耐心看完

今天在项目中遇到一个问题，有一个需求是需要验证下载的ZIP文件，解压读取ZIP文件夹内部的文件，文件名称以及大小。
网上搜了下，发现，不用解压可以直接读取，代码如下：

package com.sd.test.readzip;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.util.zip.ZipInputStream;
//注意要将文件保存为utf-8，txt文件的默认保存为ANSI.要改成urf-8不然会像file:ziptestfile/fileInZip.txt
public class ReadZip {

    public static void main(String[] args) throws IOException {
        // TODO Auto-generated method stub
        ReadZip rz=new ReadZip();
        rz.readZipContext();
    }
    public void readZipContext() throws IOException{
        String zipPath="zipFile/ziptestfile.zip";
        ZipFile zf=new ZipFile(zipPath);

        InputStream in=new BufferedInputStream(new FileInputStream(zipPath));
        ZipInputStream zin=new ZipInputStream(in);
        //ZipEntry 类用于表示 ZIP 文件条目。
        ZipEntry ze;
        while((ze=zin.getNextEntry())!=null){
            if(ze.isDirectory()){
                //为空的文件夹什么都不做
            }else{
                System.err.println("file:"+ze.getName()+"\nsize:"+ze.getSize()+"bytes");
                if(ze.getSize()>0){
                    BufferedReader reader;
                    try {
                        reader = new BufferedReader(new InputStreamReader(zf.getInputStream(ze), "utf-8"));
                        String line=null;
                        while((line=reader.readLine())!=null){
                            System.out.println(line);
                        }
                        reader.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }

            }
        }
    }
}

但是后面发现一个问题，读取的时候总是返回-1 ze.getSize()的值总是-1，可是名字都到了。
找不到法子，着实无奈，后面换了种方式，干脆将文件解压出来之后，在对文件里面的内容进行验证文件名和文件大小好了

	public void batchReportZIP(String filePath) throws Exception{
		FileChannel fc= null;
		String unzipPath = filePath.substring(0, filePath.indexOf('.'));
		File file = new File(filePath);
		unZipFiles(file, unzipPath);//解压
		
		File desc = new File(unzipPath);
		String[] filelist = desc.list();
        for (int i = 0; i < filelist.length; i++) {
            File readfile = new File(unzipPath + "\\" + filelist[i]);
            if (!readfile.isDirectory()) {
                FileInputStream fis= new FileInputStream(readfile.getPath().toString());
                fc= fis.getChannel();
                System.out.println("文件大小是："+getNetFileSizeDescription(fc.size()));
                Assert.assertTrue(fc.size() >= 1, "文件名字："+readfile.getName()+"断言描述文件大小是["+fc.size()+"] Please double Check!");
                //这里可以加一些更多的断言验证，针对里面的文件
            }else{
            	System.out.println(readfile+filelist[i]+"is Directory, please check!");
            	break;
            }
        }
	}
	
//这里是转换bytes显示成KB,MB,GB这样更常态化！
	public static String getNetFileSizeDescription(long size) {
        StringBuffer bytes = new StringBuffer();
        DecimalFormat format = new DecimalFormat("###.0");
        if (size >= 1024 * 1024 * 1024) {
            double i = (size / (1024.0 * 1024.0 * 1024.0));
            bytes.append(format.format(i)).append("GB");
        }
        else if (size >= 1024 * 1024) {
            double i = (size / (1024.0 * 1024.0));
            bytes.append(format.format(i)).append("MB");
        }
        else if (size >= 1024) {
            double i = (size / (1024.0));
            bytes.append(format.format(i)).append("KB");
        }
        else if (size < 1024) {
            if (size <= 0) {
                bytes.append("0B");
            }
            else {
                bytes.append((int) size).append("B");
            }
        }
        return bytes.toString();
    }

//解压ZIP文件到文件夹
	public static void unZipFiles(File zipFile,String descDir)throws IOException {
	    File pathFile = new File(descDir);
	    if(!pathFile.exists()) {
	      pathFile.mkdirs();
	    }
	    ZipFile zip = new ZipFile(zipFile);
	    for(Enumeration entries = zip.entries(); entries.hasMoreElements();){
	      ZipEntry entry = (ZipEntry)entries.nextElement();
	      String zipEntryName = entry.getName();
	      if(zipEntryName.endsWith(".pdf")) {
		      InputStream in = zip.getInputStream(entry);
		      //unzip all report to Folder. 
		      String outPath = (descDir+"/"+zipEntryName).replaceAll("\\*", "/");
		      if(new File(outPath).isDirectory()){
		        continue;//
		      }
		      //print the OutPath information
		      System.out.println("PDF OutPath:"+outPath);
		      OutputStream out = new FileOutputStream(outPath);
		      byte[] buf1 = new byte[1024];
		      int len;
		      while((len=in.read(buf1))>0){
		        out.write(buf1,0,len);
		      }
		      in.close();
		      out.close();
	      }else {
	    	  
	      }
	    }
	    System.out.println("******************Extract the complete********************");
	  }

最后发现，着实繁琐，能不能三两行代码解决问题。
后来又继续网上搜索了半天，问了下同事，突然之间找到了一种新的解决方式。成功搞定，代码如下：

		//String path = "D://PDF//PDF Get File//PDF Get File.zip";
		ZipFile zf = new ZipFile(filePath);
		java.util.Enumeration zipEnum = zf.entries();
		InputStream in = new BufferedInputStream(new FileInputStream(filePath));
        while(zipEnum.hasMoreElements ()){
        	ZipEntry ze = (ZipEntry) zipEnum.nextElement();
        	if(ze.isDirectory()){
                //为空的文件夹什么都不做
            }else{
                System.err.println("file:"+ze.getName()+"\nsize:"+ze.getSize()+"bytes\nCompressedSize:"+ze.getCompressedSize());
                if(ze.getSize()>0){
                	
                }
            }     
        }
        in.close();