java压缩流的压缩与解压-java基础-Python学习网

本教程操作环境：windows7系统、java10版，DELL G3电脑。

1.概念

压缩流可以将输入的数据变为压缩格式后进行输出，或者读取压缩格式的数据后，解压为正常数据。

2.压缩步骤

（1）生成一个压缩类对象，这个对象来自于一个".zip"的文件，通过它产生一ZipOutputStream对象；

（2）生成压缩对象入口，因为需要被压缩的文件不止一个。需要用ZipEntry方法生成压缩入口文件后才能放进压缩文件；

（3）用putNextEntry将压缩入口放入压缩文件；

（4）将文件内容写入了out.write()，将压缩入口和文件流关闭。

3.目录压缩

import java.io.*;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
  
public class ZipStreamExam2 {
    public static void main(String[] args) {
        try {
            File file = new File("d:\\zipmultidir");
            ZipOutputStream zos = new ZipOutputStream(new BufferedOutputStream(new FileOutputStream("d:\\zipmultidir.zip")));
            zipDir(file, zos, file);
            zos.flush();
            zos.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
  
    //压缩一个目录至zip文件
    private static void zipDir(File dir, ZipOutputStream zos, File rootDir) throws IOException {
        if (!dir.isDirectory())
            return;
  
        File[] files = dir.listFiles();
        for (int i = 0; i < files.length; i++) {
            if (files[i].isFile()) {
                System.out.println(files[i].getAbsolutePath());
                String now = files[i].getAbsolutePath();
                String root = rootDir.getAbsolutePath();
                String name = now.substring(root.length() + 1);
                System.out.println(name);
  
                FileInputStream fis = new FileInputStream(files[i]);
  
                byte buf[] = new byte[1024];
                int len = 0;
                ZipEntry ze = new ZipEntry(name);
                zos.putNextEntry(ze);
                while ((len = fis.read(buf)) != -1) {
                    zos.write(buf, 0, len);
                }
                fis.close();
            } else if (files[i].isDirectory()) {
                zipDir(files[i], zos, rootDir);
            }
        }
    }
}

4.解压到目录

import java.io.*;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
  
/**
 * Created by test2 on 2016/8/19.
 */
public class ZipStreamExam3 {
    public static void main(String[] args) {
        try {
            File srcFile = new File("d:\\zipmultidir.zip");
            System.out.println(srcFile.getCanonicalPath());
            String curDir = srcFile.getParent()+File.separator+"destDir"+File.separator;
  
            ZipInputStream zipInputStream = new ZipInputStream(new BufferedInputStream(new FileInputStream(srcFile)));
            ZipEntry ze = null;
            byte[] buf = new byte[1024];
            int len = 0;
            while ((ze = zipInputStream.getNextEntry()) != null) {
                String filePath = curDir + ze.getName();
                File destFile = new File(filePath);
                File destDir = new File(destFile.getParent());
                if(!destDir.exists()){
                    destDir.mkdirs();
                }
                BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(new FileOutputStream(destFile));
                while ((len = zipInputStream.read(buf)) != -1) {
                    bufferedOutputStream.write(buf, 0, len);
                }
                bufferedOutputStream.flush();
                bufferedOutputStream.close();
            }
            zipInputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

以上就是java压缩流的压缩与解压方法，在学习了压缩流的基础知识后，就压缩、解压的方法分别带来代码展示，学会后就可以运行体验压缩流的用法了。

java压缩流的压缩与解压

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