解决使用httpclient传递json数据乱码的问题

今天用httpclient传输json数据，服务端接受数据 中文乱码，下面分别贴上修改前与修改后的代码以及原因分析

（1）修改前：

client端

 public String sendHttpPost(String httpUrl, String data) {
 
 // 创建post请求
 HttpPost httpPost = new HttpPost(httpUrl);
 StringEntity entity;
 try {
 entity = new StringEntity(data);
 entity.setContentEncoding("UTF-8");
 entity.setContentType("application/json");
 httpPost.setEntity(entity);
 } catch (UnsupportedEncodingException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }
 
 return sendHttpPost(httpPost);
 }

private String sendHttpPost(HttpPost httpPost) {
 
 CloseableHttpClient httpClient = null;
 CloseableHttpResponse response = null;
 HttpEntity entity = null;
 String responseContent = null;
 
 // 创建默认的httpclient实例
 httpClient = HttpClients.createDefault();
 httpPost.setConfig(requestConfig);
 httpPost.setHeader("Accept","aplication/json");
 httpPost.addHeader("Content-Type","application/json;charset=UTF-8");
 // 执行请求
 try {
 logger.info("开始同步数据");
 response = httpClient.execute(httpPost);
 entity = response.getEntity();
 responseContent = EntityUtils.toString(entity, "UTF-8");
 logger.info("数据同步结果：" + responseContent);
 } catch (IOException e) {
 logger.error("同步数据出错：" + e.toString());
 e.printStackTrace();
 } finally {
 try {
 if (response != null) {
  response.close();
 }
 if (httpClient != null) {
  httpClient.close();
 }
 
 } catch (Exception e2) {
 logger.error("流关闭出错：" + e2.toString());
 }
 
 }
 return responseContent;
 }

（2）修改后

client端

 public String sendHttpPost(String httpUrl, String data) {
 
 // 创建post请求
 HttpPost httpPost = new HttpPost(httpUrl);
 StringEntity entity;
 entity = new StringEntity(data,"UTF-8");
 entity.setContentType("application/json");
 //entity.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));//用这个跟上面一行那个结果一样，可以查看源码
 httpPost.setEntity(entity);
 
 return sendHttpPost(httpPost);
 }
 
 private String sendHttpPost(HttpPost httpPost) {
 
 CloseableHttpClient httpClient = null;
 CloseableHttpResponse response = null;
 HttpEntity entity = null;
 String responseContent = null;
 
 // 创建默认的httpclient实例
 httpClient = HttpClients.createDefault();
 httpPost.setConfig(requestConfig);
 httpPost.setHeader("Accept","aplication/json");
 
 httpPost.addHeader("Content-Type","application/json;charset=UTF-8");
 }

服务端 代码

 //服务端 代码 通过红色字体的代码接受数据
 public Map<String, Object> getRequestPostParams(HttpServletRequest request) throws BusinessException {
 try {
 //接收数据
 StringBuffer sb = new StringBuffer() ;
 InputStream is = request.getInputStream(); 
 InputStreamReader isr = new InputStreamReader(is, "utf-8"); 
 BufferedReader br = new BufferedReader(isr); 
 String s = "" ; 
 while((s=br.readLine())!=null){ 
 
 sb.append(s) ; 
 } 
 String strData = sb.toString();
 
 if (null == strData || "".equals(strData)) {
 return new HashMap<String, Object>();
 }
 Map<String, Object> params = this.parseJSON2Map(strData);
 return params;
 
 } catch(Exception e) {
 throw new BusinessException(BusinessException.ERROR_INNER, "参数转换错误！");
 }
 }

下面来解释原因：

看到这里 发现了client端的不同的吧，没错 只有一行代码不一样

entity = new StringEntity(data,"UTF-8");

就是这行代码，因为构造方法的不同造成的

本来参考了这篇文章把问题解决了，但是我发现 我自己的代码明明也设置额编码 为什么会出现乱码呢，于是我就去看源代码的实现，差异在哪里？ 下面贴上源代码

public StringEntity(final String string, final ContentType contentType) throws UnsupportedCharsetException {
 
 super();
 Args.notNull(string, "Source string");
 Charset charset = contentType != null ? contentType.getCharset() : null;
 if (charset == null) {
  charset = HTTP.DEF_CONTENT_CHARSET;
 }
 try {
  this.content = string.getBytes(charset.name());
 } catch (final UnsupportedEncodingException ex) {
  // should never happen
  throw new UnsupportedCharsetException(charset.name());
 }
 if (contentType != null) {
  setContentType(contentType.toString());
 }
 
 }

然后就发现，在new StringEntity的时候，就已经将数据根据编码进行了处理，也就是说，如果你调用 new StringEntity(String string)此构造方法，就会使用其默认的编码进行转码（ISO-8859-1），无论你后面设置多少次（

entity.setContentEncoding("UTF-8");

或者

httpPost.addHeader("Content-Type","application/json;charset=UTF-8");

都不会改变字符串已经被按转码变成Byte[]数组的事实，当然在请求中设定传输编码格式还是要做的。

其实说这么多 ，解决问题的关键就一句话，在new StringEntity()的时候指定编码就解决了，因为在new的同时已经做了字符串的转码操作

之所以说这么多，是想告诉自己，问题解决了固然是好，但应该知道为什么这么做，多看源码，多问自己为什么，仅此共勉。

补充：httpclient post发送json数组并解决json乱码问题

业务：

客户端发送json数据，服务端进行解析

client发送json格式：

{"data":[{"name":"1;,a","id_no":"222,a","cellphone":"123141a","abode_detail":"213,a","emp_add":"werew3a","app_no":"111111111111a","create_time":"11a"},{"name":"张三","id_no":"null","cellphone":"null","abode_detail":"null","emp_add":"null","app_no":"null","create_time":"null"},{"name":"1;,","id_no":"222,","cellphone":"123141","abode_detail":"213,","emp_add":"werew3","app_no":"111111111111","create_time":"11"},{"name":"1;,ab","id_no":"222,ab","cellphone":"123141ab","abode_detail":"213,ab","emp_add":"werew3ab","app_no":"111111111111ab","create_time":"11ab"}],"sendtime":"20160503"}

废话少说，直接上主要代码

client端

package msxf.until;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import msxf.until.model.People;
import org.apache.http.HttpStatus;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.client.methods.RequestBuilder;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.DefaultHttpRequestRetryHandler;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicHeader;
import org.apache.http.protocol.HTTP;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
 * Created by 小省.
 */
public class Main {
 private final static org.apache.log4j.Logger logger =org.apache.log4j.Logger.getLogger(Main.class);
 public static void main(String[] args) {
  Map ma=new HashMap();
  ma.put("sendtime","20160503");
  //连接impala查库，返回List<People>，其中peopel为自定义实体类
  List<People> peopleList=ImpalaJdbc.connImpala();
  if(peopleList.size()==0){
   logger.info("peopleList.size()==0");
  }
  ma.put("data",peopleList);
  ObjectMapper om=new ObjectMapper();
  try {
   String jsonStr=om.writeValueAsString(ma);
   System.out.println(jsonStr);
   CloseableHttpResponse httpResponse=null;
   CloseableHttpClient httpClient= HttpClientBuilder.create().setRetryHandler(new DefaultHttpRequestRetryHandler()).build();
   //解决中文乱码，注意与服务端同时存在
   StringEntity stringEntity=new StringEntity(jsonStr,"UTF-8");
  //就目前来说下面这段代码是可有可无 stringEntity.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
  //post 地址
   HttpUriRequest httpUriRequest= RequestBuilder.post("http://localhost:8080/qc").setEntity(stringEntity).build();
  httpResponse=httpClient.execute(httpUriRequest);
   System.out.println("发送");
   int statusCode=httpResponse.getStatusLine().getStatusCode();
   if(statusCode== HttpStatus.SC_OK){
//    HttpEntity entity = httpResponse.getEntity();
//    InputStream in =entity.getContent();
    System.out.println("文件传输服务器正常响应！");
   }
  } catch (JsonProcessingException e) {
   e.printStackTrace();
  } catch (UnsupportedEncodingException e) {
   e.printStackTrace();
  } catch (ClientProtocolException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  }
 }
}

服务端

采用最原始的servlet

import org.apache.http.protocol.HTTP;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URLDecoder;
/**
 * Created by 小省.
 */
public class QcServlet extends javax.servlet.http.HttpServlet {
protected void doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws javax.servlet.ServletException, IOException {
doGet(request,response);
}
protected void doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws javax.servlet.ServletException, IOException {
System.out.println("+++++++++++++++++++");
//解决中文乱码
BufferedReader br =new BufferedReader(new InputStreamReader(request.getInputStream(),"UTF-8"));
String line=null;
StringBuffer sb =new StringBuffer();
while ((line=br.readLine())!=null){
sb.append(line);
}
System.out.println("sb.toString()"+sb.toString());
//就目前而言String reesult = URLDecoder.decode(sb.toString(), HTTP.UTF_8);是可有可无的，httpclient会自动解码
//String reesult =sb.toString();
String reesult = URLDecoder.decode(sb.toString(), HTTP.UTF_8);
try {
//将string 字符串转化为json数组，并且遍历
JSONObject jsonObject =new JSONObject(reesult);
String mesage=(String) jsonObject.getString("data");
JSONArray myJsonArray = new JSONArray(mesage);
for(int i=0 ; i < myJsonArray.length() ;i++){
//获取每一个JsonObject对象
JSONObject myjObject = myJsonArray.getJSONObject(i);
System.out.println(myjObject.getString("name"));
}
System.out.println(reesult);
} catch (JSONException e) {
e.printStackTrace();
}
}
}

以上为个人经验，希望能给大家一个参考，也希望大家多多支持易盾网络。如有错误或未考虑完全的地方，望不吝赐教。