httpClient4发送gzip的post数据，servlet接收并解压

原创

赶路人儿 2022-06-16 08:56:16 博主文章分类：java ©著作权

文章标签 servlet httpClient gzip json 客户端 文章分类 运维

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1、gzipUtils工具类：

package nc.edu.nuc.utils;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

public class GzipUtils {
  public static String compress(String str) throws IOException {
    if (str == null || str.length() == 0) {
      return str;
    }
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    GZIPOutputStream gzip = new GZIPOutputStream(out);
    gzip.write(str.getBytes());
    gzip.close();
    return out.toString("ISO-8859-1"); // UTF-8 ISO-8859-1
  }
  // 解压缩
  public static String uncompress(String str) throws IOException {
    if (str == null || str.length() == 0) {
      return str;
    }
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    ByteArrayInputStream in = new ByteArrayInputStream(
        str.getBytes("ISO-8859-1"));
    GZIPInputStream gunzip = new GZIPInputStream(in);
    byte[] buffer = new byte[256];
    int n;
    while ((n = gunzip.read(buffer)) >= 0) {
      out.write(buffer, 0, n);
    }
    // toString()使用平台默认编码，也可以显式的指定如toString("GBK")
    return out.toString();
  }
}

2、客户端：

pom.xml文件：

<dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpcore</artifactId>
        <version>4.4</version>
      </dependency>
      <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.5.1</version>
      </dependency>
      <dependency>
          <groupId>org.apache.httpcomponents</groupId>
          <artifactId>httpasyncclient</artifactId>
          <version>4.1.1</version>
      </dependency>

代码：

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

    String str = "msg=[{p1:\"12_22_235\",pu:\"1\",v:\"1.0.1\",net_work:\" \",ua_model:\" \",os_v:\"\",t:\"1\",rpage:\"1\",tm_1:2,tm_2:2,tm_3:2,tm_4:2,tm_5:2,rload:2},"
        + "{p1:\"2_22_235\",pu:\"1\",v:\"1.0.1\",net_work:\" \",ua_model:\" \",os_v:\"\",t:\"1\",rpage:\"1\",tm_1:2,tm_2:2,tm_3:2,tm_4:2,tm_5:2,rload:2},"
        + "{p1:\"2_22_235\",pu:\"1\",v:\"1.0.1\",net_work:\" \",ua_model:\" \",os_v:\"\",t:\"1\",rpage:\"1\",tm_1:2,tm_2:2,tm_3:2,tm_4:2,tm_5:2,rload:2}]";
    
    HttpClient httpClient = new DefaultHttpClient();
    HttpPost method = new HttpPost("http://localhost:8080/WebTest/ReciveAndUnzipServlet?a=test1");
    method.addHeader("Content-type","application/json; charset=ISO-8859-1");
    method.setHeader("Accept", "application/json");
    method.setHeader("Content-Encoding", "gzip");
    method.setEntity(new StringEntity(GzipUtils.compress(str), Charset.forName("ISO-8859-1")));

    HttpResponse response = httpClient.execute(method);
    
    int statusCode = response.getStatusLine().getStatusCode();
    
    if (statusCode != HttpStatus.SC_OK) {
      System.out.println("error...");
    }

    // Read the response body
    String body = EntityUtils.toString(response.getEntity());
    
    
    System.out.println(body);
  }

对key=value使用gzip进行压缩，同时设置header的Content-Encoding，发送post请求。

3、服务端：

/**
   * 接受httpClient发过来的gzip压缩数据，解压，然后使用。
   */
  protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    String parameter = request.getParameter("a");
    System.out.println(parameter);
    
    String acceptjson = "";
    String contentEncoding = request.getHeader("Content-Encoding");
    if (null != contentEncoding && contentEncoding.indexOf("gzip") != -1) {
      ServletInputStream inputStream = request.getInputStream();
      if (inputStream !=null) {
        GZIPInputStream gzis = new GZIPInputStream(inputStream);
        InputStreamReader reader = new InputStreamReader(gzis);
        BufferedReader br = new BufferedReader(reader);

        StringBuffer sb = new StringBuffer("");
        String temp;
        while ((temp = br.readLine()) != null) {
          sb.append(temp);
        }
        
        br.close();
        acceptjson = sb.toString();
      } 
    } else {
      acceptjson = "no compress...";
    }
    
    PrintWriter out = response.getWriter();
    out.println(acceptjson);
    out.close();
  }

1）打印url传来的参数；

2）通过http的header中Content-Encoding判断是否压缩数据；

3）把压缩的数据解压，然后原封不动key=value的格式返回给客户端。

运行服务端，然后运行客户端，最后客户端返回：

msg=[{p1:"12_22_235",pu:"1",v:"1.0.1",net_work:" ",ua_model:" ",os_v:"",t:"1",rpage:"1",tm_1:2,tm_2:2,tm_3:2,tm_4:2,tm_5:2,rload:2},{p1:"2_22_235",pu:"1",v:"1.0.1",net_work:" ",ua_model:" ",os_v:"",t:"1",rpage:"1",tm_1:2,tm_2:2,tm_3:2,tm_4:2,tm_5:2,rload:2},{p1:"2_22_235",pu:"1",v:"1.0.1",net_work:" ",ua_model:" ",os_v:"",t:"1",rpage:"1",tm_1:2,tm_2:2,tm_3:2,tm_4:2,tm_5:2,rload:2}]

4）直接通过浏览器请求：http://localhost:8080/WebTest/ReciveAndUnzipServlet?a=test

在浏览器上显示：

no compress...

补充：

1）nginx中配置的gzip on，是指户请求的内容再发送到用户客户端之前，Nginx服务器会根据一些具体的策略实施压缩。

2）通常在server端需要解压gzip数据的时候，一般都是通过过滤器来完成，可以参考下面的链接