Gzip压缩文件和压缩字符串，web接口应用

package com.example.core.mydemo.gzip;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

/**
 * 压缩文件
 */
public class GzipUtil {

    public static void compressFile(String sourceFile, String compressedFile) {
        try {
            FileInputStream fis = new FileInputStream(sourceFile);
            FileOutputStream fos = new FileOutputStream(compressedFile);
            GZIPOutputStream gzos = new GZIPOutputStream(fos);

            byte[] buffer = new byte[1024];
            int len;
            while ((len = fis.read(buffer)) != -1) {
                gzos.write(buffer, 0, len);
            }

            gzos.finish();
            gzos.close();
            fos.close();
            fis.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void decompressFile(String compressedFile, String decompressedFile) {
        try {
            FileInputStream fis = new FileInputStream(compressedFile);
            FileOutputStream fos = new FileOutputStream(decompressedFile);
            GZIPInputStream gzis = new GZIPInputStream(fis);

            byte[] buffer = new byte[1024];
            int len;
            while ((len = gzis.read(buffer)) != -1) {
                fos.write(buffer, 0, len);
            }

            gzis.close();
            fos.close();
            fis.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}


package com.example.core.mydemo.gzip;

public class GzipUtilExample {
    public static void main(String[] args) {
        // 压缩文件
        String sourceFile = "F:\\scooterOrderCommon241021.log";
        String compressedFile = "F:\\compressed2.gz";
        GzipUtil.compressFile(sourceFile, compressedFile);

        // 解压缩文件
        String decompressedFile = "F:\\decompressed2.txt";
        GzipUtil.decompressFile(compressedFile, decompressedFile);
    }

}

package com.example.core.mydemo.gzip;

import java.io.*;
import java.nio.charset.StandardCharsets;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

/**
 * gzip字符串压缩的使用
 * 使用gzip对字符串进行压缩可以帮助我们在网络传输、文件压缩等场景中减小数据体积，提高传输效率。在实际应用中，我们可以将压缩后的字节数组进行传输或保存到文件中，然后在需要时解压缩并恢复原始字符串。
 *
 * output:
 Compressed string size before: 200
 Compressed string size after: 72
 byte转字符串(字节大小): 146
 byte转字符串=       �H����Q(��,V �D�����⒢̼t���"�������܂������<=�A� �����
 解压缩字符串=java.io.ByteArrayInputStream@65b3120a
 compressed addr=[B@6f539caf
 compressed2 addr=[B@79fc0f2f
 解压缩字符串2=Hello, this is a test string for gzip compression.Hello, this is a test string for gzip compression.Hello, this is a test string for gzip compression.Hello, this is a test string for gzip compression.
 res=abcd
 */
public class GzipHelper {

    /**
     * 压缩方法
     * @param input
     * @return
     * @throws IOException
     */
    public static byte[] compressString(String input) throws IOException {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        GZIPOutputStream gzip = new GZIPOutputStream(bos);
        gzip.write(input.getBytes());
        gzip.flush();
        gzip.close();
        return bos.toByteArray();
    }

    private static StringBuffer unCompressed(byte[] compressed2) throws IOException {
        /**
         * 解压缩 - 正解
         */
        InputStream in = new ByteArrayInputStream(compressed2);
        GZIPInputStream gzin = new GZIPInputStream(in);
        BufferedReader reader = new BufferedReader(new InputStreamReader(gzin,"UTF-8"));
        String line;
        StringBuffer sb = new StringBuffer();
        while ((line = reader.readLine()) != null) {
            sb.append(line);
        }
        reader.close();
        return sb;
    }

    public static void main(String[] args) throws IOException {
        String input = "Hello, this is a test string for gzip compression.Hello, this is a test string for gzip compression.Hello, this is a test string for gzip compression.Hello, this is a test string for gzip compression.";
        System.out.println("Compressed string size before: " + input.getBytes().length);
        byte[] compressed = compressString(input);
        System.out.println("Compressed string size after: " + compressed.length);

        //byte转字符串   >> 输出错误 不能通过这种方式转字符串，需要解压缩的方式来处理。
        String ss = new String(compressed, StandardCharsets.UTF_8);
        System.out.println("byte转字符串(字节大小): " + ss.getBytes().length);
        System.out.println("byte转字符串=" + ss);  //输出错误

//        byte[] compressed2 = compressed;  //会报错：Exception in thread "main" java.util.zip.ZipException: Not in GZIP format
        //需要克隆对象,使用同一个对象会报错。 解决以上报错
        byte[] compressed2 = compressed.clone();

        //压缩接口传输
        //gzip压缩的逆运算
        ByteArrayInputStream ios = new ByteArrayInputStream(compressed);
        GZIPInputStream gzip = new GZIPInputStream(ios);
        gzip.read(compressed);
        gzip.close();
        String ss2 = ios.toString();
        ios.close();
        System.out.println("解压缩字符串=" + ss2);

        //Exception in thread "main" java.util.zip.ZipException: Not in GZIP format
        /**
         * 报错："Not in GZIP format" 通常出现在处理压缩文件时，尤其是在解压GZIP格式的文件时。这个错误表明你尝试解压的文件并不是有效的GZIP格式，可能是因为文件已损坏、不完整或者根本不是GZIP压缩过的。
         * 打印出来是2个地址
         */
        System.out.println("compressed addr=" + compressed.toString());
        System.out.println("compressed2 addr=" + compressed2.toString());

        StringBuffer sb = unCompressed(compressed2);
        System.out.println("解压缩字符串2=" + sb);


        //普通字符串与byte转换，以上是gzip压缩的字符串与byte转换。
        String str = "abcd";
        byte[] bs = str.getBytes();
        String res = new String(bs,"UTF-8");
        System.out.println("res=" + res);

    }
}

import com.test.commons.utils.GsonUtils;
import com.test.commons.web.ErrorCode;
import com.test.insurancedock.service.EhCacheService;
import com.test.insurancedock.vo.req.UserVo;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.*;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

@RestController
@RequestMapping("/gzip")
@lombok.extern.slf4j.Slf4j
public class GzipController {
    @Autowired
    private EhCacheService ehCacheService;

    private static final String ENCODING_UTF8 = "UTF-8";
    protected static ObjectMapper mapper = new ObjectMapper();

    /**
     * 方法返回类型：void
     * @param request
     * @param response
     */
    @PostMapping("/saveUser")
    public void saveUser(HttpServletRequest request, HttpServletResponse response) {
        BufferedReader reader = null;
        try {
            long start = System.currentTimeMillis();
            log.info("添加开始:" + start);
            GZIPInputStream gzipIn = new GZIPInputStream(request.getInputStream());
            reader = new BufferedReader(new InputStreamReader(gzipIn,"UTF-8"));
            String reqContent = reader.readLine();
            UserVo userVo = null;
            if(StringUtils.hasText(reqContent)){
                userVo = mapper.readValue(reqContent,UserVo.class);
            }
            log.info("接收到的参数值:" + GsonUtils.toJson(userVo));
            String res = ehCacheService.updateUser(userVo.getId(),userVo.getName());
            System.out.println("添加成功的记录=" + res);
            long end = System.currentTimeMillis();
            log.info("添加结束:" + end);
            log.info("添加耗时：" + (end - start));

            writeResponse(response, "json串返回成功");
        }catch (Exception e) {
            e.printStackTrace();
        }finally{
            if(reader != null){
                try {
                    reader.close();
                } catch (Exception e) {
                    log.error("",e);
                }
            }
        }
        writeResponse(response, "json串返回失败");
    }

    protected void writeResponse(HttpServletResponse response, Object outJB){
//        response.setContentType("text/html; charset=utf-8");
        response.setContentType("application/json; charset=utf-8");
        //response.setContentType("text/json; charset=utf-8");
        response.setCharacterEncoding(ENCODING_UTF8);
        response.setHeader("Content-Encoding", "gzip");
        GZIPOutputStream out = null;
        //byte[] jsonOut = null;
        log.info("response start.");
        String jsonOut = null;
        try {
            jsonOut = mapper.writeValueAsString(outJB);
            out = new GZIPOutputStream(response.getOutputStream());
            out.write(jsonOut.getBytes(ENCODING_UTF8));
            out.flush();
        } catch (Exception e) {
            log.error("output error",e);
        } finally{
            if(out != null){
                try {
                    out.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

}


//单元测试类：
package com.test.insurancedock;

import org.junit.Test;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;


public class GzipTest {
    
    private static final String reqUrl = "http://localhost:1340/";

    @Test
    public void testGzip() {
        String url = "gzip/saveUser";

        // 获取TN码
        String strReq = "{\"id\":\"10\",\"name\":\"zhangliao\"}";
        try {
            String result = appPost(strReq, reqUrl + url);
            System.err.println("接口调用返回结果：" + result);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
     /* 
     * @param str   json数据格式
     * @param reqUrl
     */
    public static String appPost(String str, String reqUrl) throws Exception{
        //发送数据
        HttpURLConnection conn = null;
        StringBuffer sb = new StringBuffer();
        try {
            URL url = new URL(reqUrl);
            conn = (HttpURLConnection) url.openConnection();
            conn.setDoOutput(true);
            conn.setDoInput(true);
            conn.setUseCaches(false);
            conn.setInstanceFollowRedirects(false);//是否自动处理重定向
            conn.setRequestMethod("POST");
            conn.setRequestProperty("User-Agent", "no");
            conn.setRequestProperty("Content-Type", "application/json; charset=utf-8");
            conn.connect();
            GZIPOutputStream out = new GZIPOutputStream(conn.getOutputStream());
            byte[] reqContent = str.getBytes();
            System.out.println("testPost发送内容："+new String(reqContent,"UTF-8"));
            out.write(reqContent);
            out.flush();
            out.close();
            
            //接收返回数据
            InputStream in = conn.getInputStream();
            GZIPInputStream gzin = new GZIPInputStream(in);
            BufferedReader reader = new BufferedReader(new InputStreamReader(gzin,"UTF-8"));
            String line;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
            reader.close();
            return sb.toString();
        } catch (Exception e) {
            e.printStackTrace();
        } finally{
            if(conn != null){
                conn.disconnect();
            }
        }
        return sb.toString();
    }
    
}