用Java创建zip存档 [英] Creating zip archive in Java

问题描述

我有一个由7zip程序创建的文件。我使用 deflate 方法来压缩它。现在我想在 java 中创建相同的存档（具有相同的MD5sum）。当我创建zip文件时，我使用了我在互联网上找到的算法，例如 http：// www.kodejava.org/examples/119.html 但是当我使用这种方法创建zip文件时，压缩的大小高于未压缩文件的大小，那么发生了什么？这不是一个非常有用的压缩。那么如何创建与我用7zip程序创建的zip文件完全相同的zip文件呢？如果它有助于我获得有关我在7zip程序中创建的zip文件的所有信息。

I have one file created by 7zip program. I used deflate method to compress it. Now I want to create the same archive (with the same MD5sum) in java. When I create zip file, I used the algorithm that I found on the Internet for example http://www.kodejava.org/examples/119.html but when I created zip file with this method the compressed size is higher than size of the uncompressed file so what is going on? This isn't a very useful compression. So how I can create zip file that is exactly same as zip file that I created with 7zip program ? If it helps I have all information about zip file that I created in 7zip program.

推荐答案

// simplified code for zip creation in java

import java.io.*;
import java.util.zip.*;

public class ZipCreateExample {

    public static void main(String[] args) throws Exception {

        // input file 
        FileInputStream in = new FileInputStream("F:/sometxt.txt");

        // out put file 
        ZipOutputStream out = new ZipOutputStream(new FileOutputStream("F:/tmp.zip"));

        // name the file inside the zip  file 
        out.putNextEntry(new ZipEntry("zippedjava.txt")); 

        // buffer size
        byte[] b = new byte[1024];
        int count;

        while ((count = in.read(b)) > 0) {
            out.write(b, 0, count);
        }
        out.close();
        in.close();
    }
}

这篇关于用Java创建zip存档的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！