用java原生api写解压缩
	  package com.unis.io;
	  import java.io.BufferedInputStream;
	  import java.io.BufferedOutputStream;
	  import java.io.File;
	  import java.io.FileInputStream;
	  import java.io.FileOutputStream;
	  import java.io.IOException;
	  import java.util.zip.ZipEntry;
	  import java.util.zip.ZipInputStream;
	  public class UnZipUtil {
	  private static int BUFFER_SIZE = 2048;
	  private static byte[] BUFFER_DATA = new byte[BUFFER_SIZE];
	  /**
	  *
	  * @param src
	  * 源文件
	  * @param dest
	  * 目标目录
	  * @throws IOException
	  */
	  public static void unZip(String src, String dest) throws IOException {
	  ZipInputStream zis = null;
	  BufferedOutputStream bos = null;
	  ZipEntry zn = null;
	  // 这里可以判断是否是压缩文件,如果不是抛出自定义异常
	  try {
	  zis = new ZipInputStream(new BufferedInputStream(
	  new FileInputStream(new File(src))));
	  while ((zn = zis.getNextEntry()) != null) {
	  if (zn.isDirectory()) {
	  // 如果条目是目录,并且该目录不存在,创建该目录