Java實現對文件的壓縮和解壓縮

JDK提供了GZIP、zip的算法實現，可以在java.util.zip包下找到相關的類庫，RAR壓縮算法JDK並不提供，可以用一些第三方的類庫實現

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

public class Zip {
public Zip(){}

/**
* 壓縮目錄下的文件
* @param zipFileName
* @param inputFile 目錄
* @throws java.lang.Exception
*/
public void zip(String zipFileName, String inputFile) throws Exception {
	zip(zipFileName, new File(inputFile));
}

/**
* 壓縮文件
* @param zipFileName
* @param inputFile 文件
* @throws java.lang.Exception
*/
public void zip(String zipFileName, File inputFile) throws Exception {
	ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipFileName));
	zip(out, inputFile, "");
	System.out.println("壓縮成功!");
	out.close();
}

public void zip(ZipOutputStream out, File f, String base) throws Exception {
	System.out.println("正在壓縮  " + f.getName());
	if (f.isDirectory()) {
		File[] fl = f.listFiles();
		out.putNextEntry(new ZipEntry(base + "/"));
		base = base.length() == 0 ? "" : base + "/";
		for (int i = 0; i < fl.length; i++) {
			zip(out, fl[i], base + fl[i].getName());
		}
	}else {
		out.putNextEntry(new ZipEntry(base));
		FileInputStream in = new FileInputStream(f);
		int b;
		while ( (b = in.read()) != -1)
			out.write(b);
	in.close();
	}

}

/**
* 解壓縮
* @param zipFileName
* @param outputDirectory 輸出目錄
* @throws java.lang.Exception
*/
public void unzip(String zipFileName, String outputDirectory) throws Exception {
	ZipInputStream in = new ZipInputStream(new FileInputStream(zipFileName));
	ZipEntry z;
	while ( (z = in.getNextEntry()) != null) {
		System.out.println("正在解壓 " + z.getName());
		if (z.isDirectory()) {
			String name = z.getName();
			name = name.substring(0, name.length() - 1);
			File f = new File(outputDirectory + File.separator + name);
			f.mkdir();
			System.out.println("創建目錄 " + outputDirectory + File.separator + name);
		}else {
			File f = new File(outputDirectory + File.separator + z.getName());
			f.createNewFile();
			FileOutputStream out = new FileOutputStream(f);
			int b;
			while ( (b = in.read()) != -1)
				out.write(b);
		out.close();
		}
	}

	in.close();
}

public static void main(String[] args) {
	try {
		Zip t = new Zip();
		//t.zip("D://IdeaProjects.zip", "D://IdeaProjects");
		//t.unzip("d://ddd//api.jar", "d://ddd//");
	}catch (Exception e) {
		e.printStackTrace(System.out);
	}
}
}