java解壓zip檔案

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Enumeration;
import java.util.zip.CRC32;
import
 
 java.util.zip.CheckedInputStream;

import org.apache.tools.zip.ZipEntry;
import org.apache.tools.zip.ZipFile;

public class MyZipUtil {
    /**
     * 解壓zip檔案
     * @throws IOException 
     */
    public static String unZIP(String zipPath,String outPath ){
        ZipFile zipFile=null;
        
 
try {
            zipFile = new ZipFile(zipPath,"GBK");             
    //壓縮檔案的實列,並設定編碼
        //獲取壓縮文中的所以項
        for(Enumeration<ZipEntry> enumeration = zipFile.getEntries();enumeration.hasMoreElements();)
        {
            OutputStream os = null;
            BufferedOutputStream bos 
 
=null;
            InputStream is =null;
            BufferedInputStream bis =null;
            CheckedInputStream cos =null;
            ZipEntry zipEntry = null;
            try {
            zipEntry = enumeration.nextElement();//獲取元素
            //排除空資料夾
            if(!zipEntry.getName().endsWith(File.separator))
            {
                System.out.println("正在解壓檔案:"+zipEntry.getName());//列印輸出資訊
                //建立解壓目錄
                File f = new File(outPath);
                //判斷是否存在解壓目錄
                if(!f.exists())
                {
                    f.mkdirs();//建立解壓目錄
                }
                os = new FileOutputStream(outPath+zipEntry.getName().substring(zipEntry.getName().lastIndexOf("/")+1));//建立解壓後的檔案
                bos = new BufferedOutputStream(os);//帶緩的寫出流
                is = zipFile.getInputStream(zipEntry);//讀取元素
                bis = new BufferedInputStream(is);//讀取流的快取流
                cos = new CheckedInputStream(bis, new CRC32());//檢查讀取流，採用CRC32演算法，保證檔案的一致性
                byte [] b = new byte[1024*8];//位元組陣列，每次讀取1024個位元組
                //迴圈讀取壓縮檔案的值
                while(cos.read(b)!=-1)
                {
                    bos.write(b);//寫入到新檔案
                }
                bos.flush();
                os.flush();
        
                
                
                
            }
            else
            {
                //如果為空資料夾，則建立該資料夾
                new File(outPath+zipEntry.getName()).mkdirs();
            }
            
            } catch (Exception e) {
                return "1";
            }finally {
                if(cos!=null){                    
                    cos.close();
                }
                if(bis!=null){                    
                    bis.close();
                }
                if(is!=null){                    
                    is.close();
                }
                if(bos!=null){                    
                    bos.close();
                }
                if(os!=null){                
                    os.close();
                }
                if(zipEntry!=null){                    
                    zipEntry.clone();
                }
            }
        }
        System.out.println("解壓完成");
        } catch (IOException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }finally {
            
            try {
                zipFile.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        
        return "0";
    }
}