java解压Zip、Rar文件

一、解压zip文件
由于zip是免费的，所以在jdk里提供了相应的类对zip文件的实现：
java.util.zip.*,详细情况可以参考java API

    /** 
     * 解压zip文件 
     * @author Michael sun 
     */  
    public class UnzipFile {  
      
        /** 
         * 解压zip文件 
         *  
         * @param targetPath 
         * @param zipFilePath 
         */  
        public void unzipFile(String targetPath, String zipFilePath) {  
      
            try {  
                File zipFile = new File(zipFilePath);  
                InputStream is = new FileInputStream(zipFile);  
                ZipInputStream zis = new ZipInputStream(is);  
                ZipEntry entry = null;  
                System.out.println("开始解压:" + zipFile.getName() + "...");  
                while ((entry = zis.getNextEntry()) != null) {  
                    String zipPath = entry.getName();  
                    try {  
      
                        if (entry.isDirectory()) {  
                            File zipFolder = new File(targetPath + File.separator  
                                    + zipPath);  
                            if (!zipFolder.exists()) {  
                                zipFolder.mkdirs();  
                            }  
                        } else {  
                            File file = new File(targetPath + File.separator  
                                    + zipPath);  
                            if (!file.exists()) {  
                                File pathDir = file.getParentFile();  
                                pathDir.mkdirs();  
                                file.createNewFile();  
                            }  
      
                            FileOutputStream fos = new FileOutputStream(file);  
                            int bread;  
                            while ((bread = zis.read()) != -1) {  
                                fos.write(bread);  
                            }  
                            fos.close();  
      
                        }  
                        System.out.println("成功解压:" + zipPath);  
      
                    } catch (Exception e) {  
                        System.out.println("解压" + zipPath + "失败");  
                        continue;  
                    }  
                }  
                zis.close();  
                is.close();  
                System.out.println("解压结束");  
            } catch (Exception e) {  
                e.printStackTrace();  
            }  
      
        }  
      
        /** 
         * @param args 
         */  
        public static void main(String[] args) {  
            String targetPath = "D:\\test\\unzip";  
            String zipFile = "D:\\test\\test.zip";  
            UnzipFile unzip = new UnzipFile();  
            unzip.unzipFile(targetPath, zipFile);  
        }  
      
    }  

二、解压rar文件
由于WinRAR 是共享软件，并不是开源的，所以解压rar文件的前提是系统已经安装了winrar，比如本人的安装路径是：
C:\\Program Files\\WinRAR\\winrar.exe
然后运用java.lang.Process 的相关知识来运行系统命令行来实现解压的。
winrar 命令行相关参数自己可以搜索下的网上资料很多

    **  
     * 解压rar文件(需要系统安装Winrar 软件)  
     * @author Michael sun  
     */  
    public class UnRarFile {  
        /** 
         * 解压rar文件 
         *  
         * @param targetPath 
         * @param absolutePath 
         */  
        public void unRarFile(String targetPath, String absolutePath) {  
      
            try {  
      
                // 系统安装winrar的路径  
                String cmd = "C:\\Program Files\\WinRAR\\winrar.exe";  
                String unrarCmd = cmd + " x -r -p- -o+ " + absolutePath + " "  
                        + targetPath;  
      
                Runtime rt = Runtime.getRuntime();  
                Process pre = rt.exec(unrarCmd);  
                InputStreamReader isr = new InputStreamReader(pre.getInputStream());  
                BufferedReader bf = new BufferedReader(isr);  
                String line = null;  
                while ((line = bf.readLine()) != null) {  
                    line = line.trim();  
                    if ("".equals(line)) {  
                        continue;  
                    }  
                    System.out.println(line);  
                }  
      
                bf.close();  
            } catch (Exception e) {  
                System.out.println("解压发生异常");  
            }  
        }  
      
        /** 
         * @param args 
         */  
        public static void main(String[] args) {  
            String targetPath = "D:\\test\\unrar\\";  
            String rarFilePath = "D:\\test\\test.rar";  
            UnRarFile unrar = new UnRarFile();  
            unrar.unRarFile(targetPath, rarFilePath);  
        }  
      
    }  

原文出自：http://sjsky.iteye.com/blog/628920