java对文件的操作(一) --------文件解压缩

package com.tw.file.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipException;
import java.util.zip.ZipFile;
import java.util.zip.ZipInputStream;

/**
 * 文件解压缩类
 * @author tw5566
 *
 */
public class ZipUtils {
	private static final String tt="";

	/**
	 * 主方法
	 * @param arg
	 * @throws Exception
	 */
	public static void main(String arg[])throws Exception{
		ZipUtils.unZip_java("F:/POIDemo/uedit32c.zip");//测试OK

	}

	/**
	 * <p>文件解缩方法2 java本身自带的解压包。
	 * 只会解压到当前目录下。</p>
	 * @param zipFileName  要解压文件的全路径 
	 */    
    public static void unZip_java(String zipFileName){
		File infile = new File(zipFileName);

		try {
			// 检查是否是ZIP文件
			ZipFile zip = new ZipFile(infile);
			zip.close();

			// 建立与目标文件的输入连接
			ZipInputStream in = new ZipInputStream(new FileInputStream(infile));
			ZipEntry file = in.getNextEntry();

			int i = infile.getAbsolutePath().lastIndexOf('.');
			String dirname = new String();
			if (i != -1)
				dirname = infile.getAbsolutePath().substring(0, i);
			else
				dirname = infile.getAbsolutePath();

			File newdir = new File(dirname);
			newdir.mkdir();

			byte[] c = new byte[1024];
			int len;
			int slen;

			while (file != null) {
				i = make8859toGB(file.getName()).replace('/', '\\').lastIndexOf('\\');
				if (i != -1) {
					File dirs = new File(dirname
							+ File.separator
							+ make8859toGB(file.getName()).replace('/', '\\')
									.substring(0, i));
					dirs.mkdirs();
					dirs = null;
				}

				System.out.print("Extract "
						+ make8859toGB(file.getName()).replace('/', '\\')
						+ " ........ ");

				if (file.isDirectory()) {
					File dirs = new File(make8859toGB(file.getName()).replace(
							'/', '\\'));
					dirs.mkdir();
					dirs = null;
				} else {
					FileOutputStream out = new FileOutputStream(dirname
							+ File.separator
							+ make8859toGB(file.getName()).replace('/', '\\'));
					while ((slen = in.read(c, 0, c.length)) != -1)
						out.write(c, 0, slen);
					out.close();
				}
				System.out.print("O.K.\n");
				file = in.getNextEntry();
			}
			in.close();
		} catch (ZipException zipe) {
			System.out.println(infile.getName() + "不是一个ZIP文件！");
		} catch (IOException ioe) {
			System.out.println("读取文件时错误！");
		} catch (Exception i) {
			System.out.println("over");
		}

    }

	public static String make8859toGB(String str) {
		try {
			String str8859 = new String(str.getBytes("8859_1"), "GB2312");
			return str8859;
		} catch (UnsupportedEncodingException ioe) {
			return str;
		}
	}

}