Java使用GZIP进行压缩和解压

╰半夏微凉° 2022-07-12 23:43 245阅读 0赞

1、项目目录截图

![20161215215630129][]

2、关于Java使用GZIP进行压缩和解压的工具类

import java.io.ByteArrayInputStream;
    import java.io.ByteArrayOutputStream;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.util.zip.GZIPInputStream;
    import java.util.zip.GZIPOutputStream;
    
    public class GzipUtils {
    
    	public static byte[] gzip(byte[] data) throws Exception {
    		ByteArrayOutputStream bos = new ByteArrayOutputStream();
    		GZIPOutputStream gzip = new GZIPOutputStream(bos);
    		gzip.write(data);
    		gzip.finish();
    		gzip.close();
    		byte[] ret = bos.toByteArray();
    		bos.close();
    		return ret;
    	}
    
    	public static byte[] ungzip(byte[] data) throws Exception {
    		ByteArrayInputStream bis = new ByteArrayInputStream(data);
    		GZIPInputStream gzip = new GZIPInputStream(bis);
    		byte[] buf = new byte[1024];
    		int num = -1;
    		ByteArrayOutputStream bos = new ByteArrayOutputStream();
    		while ((num = gzip.read(buf, 0, buf.length)) != -1) {
    			bos.write(buf, 0, num);
    		}
    		gzip.close();
    		bis.close();
    		byte[] ret = bos.toByteArray();
    		bos.flush();
    		bos.close();
    		return ret;
    	}
    }

3、测试代码

public static void main(String[] args) throws Exception {
    
    		// 读取文件
    		String readPath = System.getProperty("user.dir") + File.separatorChar
    				+ "sources" + File.separatorChar + "005.jpg";
    		File file = new File(readPath);
    		FileInputStream in = new FileInputStream(file);
    		byte[] data = new byte[in.available()];
    		in.read(data);
    		in.close();
    
    		System.out.println("文件原始大小:" + data.length);
    
    		// 测试压缩
    		byte[] ret1 = GzipUtils.gzip(data);
    		System.out.println("压缩之后大小:" + ret1.length);
    
    		// 还原文件
    		byte[] ret2 = GzipUtils.ungzip(ret1);
    		System.out.println("还原之后大小:" + ret2.length);
    
    		// 写出文件
    		String writePath = System.getProperty("user.dir") + File.separatorChar
    				+ "receive" + File.separatorChar + "005.jpg";
    		FileOutputStream fos = new FileOutputStream(writePath);
    		fos.write(ret2);
    		fos.close();
    
    	}

[20161215215630129]: /images/20220713/e92d9578cdaf4592a79a471899834260.png