将指定的zip文件解压缩到指定的目标目录。

//package com.nowjava;
/**
来 自 NowJava.com
**/


import java.io.IOException;

import java.net.URI;


import java.nio.file.FileSystem;

import java.nio.file.FileSystems;

import java.nio.file.FileVisitResult;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.nio.file.SimpleFileVisitor;

import java.nio.file.StandardCopyOption;

import java.nio.file.attribute.BasicFileAttributes;


import java.util.HashMap;

import java.util.Map;/*时代Java公众号 - N o w J a  v a . c o m 提供*/


public class Main {

    /**

     * Unzips the specified zip file to the specified destination directory. Replaces any files in

     * the destination, if they already exist.

     * 

     * @param zipFilename the name of the zip file to extract

     * @param destFilename the directory to unzip to

     * @throws IOException

     */

    public static void unzip(String zipFilename, String destDirname)

            throws IOException {

        final Path destDir = Paths.get(destDirname);

        //if the destination doesn't exist, create it

        if (Files.notExists(destDir)) {

            System.out.println(destDir + " does not exist. Creating...");

            Files.createDirectories(destDir);

        }


        try (FileSystem zipFileSystem = createZipFileSystem(zipFilename,

                false)) {

            final Path root = zipFileSystem.getPath("/");


            //walk the zip file tree and copy files to the destination

            Files.walkFileTree(root, new SimpleFileVisitor<Path>() {

                @Override

                public FileVisitResult visitFile(Path file,

                        BasicFileAttributes attrs) throws IOException {

                    final Path destFile = Paths.get(destDir.toString(),

                            file.toString());

                    System.out.printf("Extracting file %s to %s\n", file,

                            destFile);

                    Files.copy(file, destFile,

                            StandardCopyOption.REPLACE_EXISTING);

                    return FileVisitResult.CONTINUE;

                }


                @Override

                public FileVisitResult preVisitDirectory(Path dir,

                        BasicFileAttributes attrs) throws IOException {

                    final Path dirToCreate = Paths.get(destDir.toString(),

                            dir.toString());

                    if (Files.notExists(dirToCreate)) {

                        System.out.printf("Creating directory %s\n",

                                dirToCreate);

                        Files.createDirectory(dirToCreate);

                    }

                    return FileVisitResult.CONTINUE;

                }

            });

        }

    }


    /**

     * Returns a zip file system

     * 

     * @param zipFilename to construct the file system from

     * @param create <code>true</code> if the zip file should be created

     * @return a zip file system

     * @throws IOException

     */

    public static FileSystem createZipFileSystem(String zipFilename,

            boolean create) throws IOException {

        final Path path = Paths.get(zipFilename);

        final URI uri = URI.create("jar:file:" + path.toUri().getPath());

        final Map<String, String> env = new HashMap<>();

        if (create) {

            env.put("create", "true");

        }

        return FileSystems.newFileSystem(uri, env);

    }


    /**

     * Creates/updates a zip file.

     * 

     * @param zipFilename the name of the zip to create

     * @param filenames list of filename to add to the zip

     * @throws IOException

     */

    public static void create(String zipFilename, String... filenames)

            throws IOException {

        try (FileSystem zipFileSystem = createZipFileSystem(zipFilename,

                true)) {

            final Path root = zipFileSystem.getPath("/");


            //iterate over the files we need to add

            for (String filename : filenames) {

                final Path src = Paths.get(filename);


                //add a file to the zip file system

                if (!Files.isDirectory(src)) {

                    final Path dest = zipFileSystem.getPath(

                            root.toString(), src.toString());

                    final Path parent = dest.getParent();

                    if (Files.notExists(parent)) {

                        System.out

                                .printf("Creating directory %s\n", parent);

                        Files.createDirectories(parent);

                    }

                    Files.copy(src, dest,

                            StandardCopyOption.REPLACE_EXISTING);

                } else {

                    //for directories, walk the file tree

                    Files.walkFileTree(src, new SimpleFileVisitor<Path>() {

                        @Override

                        public FileVisitResult visitFile(Path file,

                                BasicFileAttributes attrs)

                                throws IOException {

                            final Path dest = zipFileSystem.getPath(

                                    roo