java实现压缩和压缩zip格式文件的功能

import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.util.zip.CRC32; import java.util.zip.CheckedInputStream; import java.util.zip.CheckedOutputStream; import java.util.zip.ZipEntry; import java.util.zip.ZipInputStream; import java.util.zip.ZipOutputStream; public class Zip{ public static final String EXT = ".zip"; private static final String BASE_DIR = ""; // 符号"/"用来作为目录标识判断符 private static final String PATH = "/"; private static final int BUFFER = 2048; public static void compress(String fileName) throws Exception{ //fileName为指定路径下的待压缩文件 File srcFile=new File(fileName); String currentPath=srcFile.getPath(); String destPath= currentPath +EXT; File destFile=new File(destPath); //采用最常见的CRC32进行解压 CheckedOutputStream cos = new CheckedOutputStream(new FileOutputStream( destFile), new CRC32()); ZipOutputStream zos = new ZipOutputStream(cos); compress(srcFile, zos, BASE_DIR); zos.flush(); zos.close(); } private static void compress(File srcFile, ZipOutputStream zos, String basePath) throws Exception { if (srcFile.isDirectory()) { compressDir(srcFile, zos, basePath); } else { compressFile(srcFile, zos, basePath); } } private static void compressDir(File dir, ZipOutputStream zos, String basePath) throws Exception { //列出目录下的所有子目录，这些子目录可能是文件也可能仍旧是目录，采用递归方式压缩 File[] files = dir.listFiles(); // 构建空目录 if (files.length < 1) { ZipEntry entry = new ZipEntry(basePath + dir.getName() + PATH); zos.putNextEntry(entry); zos.closeEntry(); } for (File file : files) { // 递归压缩 compress(file, zos, basePath + dir.getName() + PATH); } } //file为待压缩文件，dir为压缩文件中的当前路径 private static void compressFile(File file, ZipOutputStream zos, String dir) throws Exception { //entry为待压缩条目 ZipEntry entry = new ZipEntry(dir + file.getName()); zos.putNextEntry(entry); BufferedInputStream bis = new BufferedInputStream(new FileInputStream( file)); int count; byte data[] = new byte[BUFFER]; while ((count = bis.read(data, 0, BUFFER)) != -1) { zos.write(data, 0, count); } bis.close(); zos.closeEntry(); } //以下实现代码解压缩 public static void Decompress(String srcPath) throws Exception{ File srcFile=new File(srcPath); String basePath = srcFile.getParent(); File destFile=new File(basePath); CheckedInputStream cis = new CheckedInputStream(new FileInputStream( srcFile), new CRC32()); ZipInputStream zis = new ZipInputStream(cis); Decompress(destFile, zis); zis.close(); } private static void Decompress(File destFile, ZipInputStream zis) throws Exception { ZipEntry entry = null; while ((entry = zis.getNextEntry()) != null) { // 文件 String dir = destFile.getPath() + File.separator + entry.getName(); File dirFile = new File(dir); fileProber(dirFile); if (entry.isDirectory()){ dirFile.mkdirs(); }else{ DecompressFile(dirFile, zis); } } } //当父目录不存在时候，创建目录 private static void fileProber(File dirFile) { File parentFile = dirFile.getParentFile(); if(!parentFile.exists()){ fileProber(parentFile); parentFile.mkdir(); } } private static void DecompressFile(File destFile, ZipInputStream zis) throws Exception { BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(destFile)); int count; byte data[] = new byte[BUFFER]; while ((count = zis.read(data, 0, BUFFER)) != -1) { bos.write(data, 0, count); } bos.close(); } }