java gzip压缩数据

太过爱你忘了你带给我的痛 2022-03-18 09:56 247阅读 0赞

1.gzip 工具类

import javax.servlet.ServletException;
    import javax.servlet.http.HttpServletResponse;
    import java.io.ByteArrayOutputStream;
    import java.io.IOException;
    import java.io.OutputStream;
    import java.util.zip.GZIPOutputStream;
    
    
    public class GZIPUtils {
        private static final String ENCODING = "UTF-8";
        /**
         * 压缩
         *
         * @param data
         * @return
         * @throws Exception
         */
        public static byte[] compress(byte[] data) throws Exception {
    
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
    
            // 压缩
            GZIPOutputStream gos = new GZIPOutputStream(baos);
    
            gos.write(data, 0, data.length);
    
            gos.finish();
    
            byte[] output = baos.toByteArray();
    
            baos.flush();
            baos.close();
    
            return output;
        }
    
        /**
         * @param response
         * @throws ServletException
         * @throws IOException
         */
        public static void excute(HttpServletResponse response, String str)
                throws ServletException, IOException {
    
            byte[] data = str.toString().getBytes(ENCODING);
    
            try {
                byte[] output = compress(data);
                // 设置Content-Encoding，这是关键点！
                response.setHeader("Content-Encoding", "gzip");
                response.setContentType("text/plain;charset=utf-8");
                // 设置字符集
                response.setCharacterEncoding(ENCODING);
                // 设定输出流中内容长度
                response.setContentLength(output.length);
    
                OutputStream out = response.getOutputStream();
                out.write(output);
                out.flush();
                out.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

2.测试

@ResponseBody
    @RequestMapping("/a")
    public void a(HttpServletResponse response){
        String str =
                "流浪地球，相信你也看过，哈哈，你觉得怎么样呢，这不重要，重要的是可以压缩哦!一个现象就是，当数据不多时，压缩反而变大，你可以试试看哦";
        System.out.println("原字符串：" + str);
        System.out.println("原长度：" + str.length());
            try {
                GZIPUtils.excute(response,str);
            }catch (Exception e){
                e.printStackTrace();
            }
    }

3.测试结果

因为浏览器自带解析，只需要告诉浏览器格式为gizp。重点就是下面这句

response.setHeader("Content-Encoding", "gzip");

![20190220152807749.png][]

4.看结果

可以下载一个叫fiddler 的软件

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpd2VuMTk4NzA2MTg_size_16_color_FFFFFF_t_70][]

如果不用压缩

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpd2VuMTk4NzA2MTg_size_16_color_FFFFFF_t_70 1][]

[20190220152807749.png]: /images/20220318/cad4d44512594f0e91f4186f9487f39e.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpd2VuMTk4NzA2MTg_size_16_color_FFFFFF_t_70]: /images/20220318/32a80c135d1349b1ad727889ba0a5922.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpd2VuMTk4NzA2MTg_size_16_color_FFFFFF_t_70 1]: /images/20220318/36201e0067b243d1ad97ab56741fffb2.png