Apache的HTTP客户端POST抛出500

Question

我试图通过使用Apache HTTP客户端

http://hc.apache.org/

这里执行POST请求的代码片段

 CloseableHttpClient client = HttpClients.createDefault(); 
     HttpPost httpPost = new HttpPost("http://xav.com/asd"); 

     JSONObject jon = new JSONObject(); 
     jon.put("param", "val"); 
     jon.put("param2", "val2"); 

     String json = jon.toString(); 
     StringEntity entity = new StringEntity(json); 
     httpPost.setEntity(entity); 
     httpPost.setHeader("Accept", "application/json"); 
     httpPost.setHeader("Content-type", "application/json"); 

     CloseableHttpResponse response = client.execute(httpPost); 
     BufferedReader rd = new BufferedReader 
       (new InputStreamReader(
       response.getEntity().getContent())); 

      String line = ""; 
      while ((line = rd.readLine()) != null) { 
       System.out.println(line); 
      } 
     client.close(); 

，但我得到一个500错误。我可以使用存在的swagger UI执行相同的POST请求。我认为在构建我的请求时出现错误，并且参数没有正确传递到后端。

我是否正确创建了POST请求？在添加参数之后，有没有办法获得实际的URL？

Answer 1

这只是工作，并返回404，不500

... 
<title>Error 404 Document Not Found on http://xav.com/asd</title> 
... 

404实际上是在你的榜样http://xav.com/asd正确的反应。

下面是程序：

package com.stackoverflow; 

import java.io.BufferedReader; 
import java.io.IOException; 
import java.io.InputStreamReader; 

import org.apache.http.client.ClientProtocolException; 
import org.apache.http.client.methods.CloseableHttpResponse; 
import org.apache.http.client.methods.HttpPost; 
import org.apache.http.entity.StringEntity; 
import org.apache.http.impl.client.CloseableHttpClient; 
import org.apache.http.impl.client.HttpClients; 
import org.json.JSONObject; 

public class ApacheHttpClientTest { 
    public static void main(String[] args) throws ClientProtocolException, IOException { 
     CloseableHttpClient client = HttpClients.createDefault(); 
     HttpPost httpPost = new HttpPost("http://xav.com/asd"); 

     JSONObject jon = new JSONObject(); 
     jon.put("param", "val"); 
     jon.put("param2", "val2"); 

     String json = jon.toString(); 
     StringEntity entity = new StringEntity(json); 
     httpPost.setEntity(entity); 
     httpPost.setHeader("Accept", "application/json"); 
     httpPost.setHeader("Content-type", "application/json"); 

     CloseableHttpResponse response = client.execute(httpPost); 
     BufferedReader rd = new BufferedReader 
       (new InputStreamReader(
       response.getEntity().getContent())); 

      String line = ""; 
      while ((line = rd.readLine()) != null) { 
       System.out.println(line); 
      } 
     client.close(); 
    } 
} 

而且下面是我使用的库：

<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient --> 
<dependency> 
    <groupId>org.apache.httpcomponents</groupId> 
    <artifactId>httpclient</artifactId> 
    <version>4.5.3</version> 
</dependency> 

<!-- https://mvnrepository.com/artifact/org.json/json --> 
<dependency> 
    <groupId>org.json</groupId> 
    <artifactId>json</artifactId> 
    <version>20170516</version> 
</dependency> 

如果你尝试另一个公共Web服务，http://www.posttestserver.com/，你会得到HTTP状态200：

Successfully dumped 0 post variables. 
View it at http://www.posttestserver.com/data/2017/05/25/22.39.57585465710 
No Post body. 

以下是程序：

package com.stackoverflow; 

import java.io.BufferedReader; 
import java.io.IOException; 
import java.io.InputStreamReader; 

import org.apache.http.client.ClientProtocolException; 
import org.apache.http.client.methods.CloseableHttpResponse; 
import org.apache.http.client.methods.HttpPost; 
import org.apache.http.entity.StringEntity; 
import org.apache.http.impl.client.CloseableHttpClient; 
import org.apache.http.impl.client.HttpClients; 
import org.json.JSONObject; 

public class ApacheHttpClientTest { 
    public static void main(String[] args) throws ClientProtocolException, IOException { 
     CloseableHttpClient client = HttpClients.createDefault(); 
     HttpPost httpPost = new HttpPost("http://posttestserver.com/post.php"); 

     JSONObject jon = new JSONObject(); 
     jon.put("param", "val"); 
     jon.put("param2", "val2"); 

     // Returns the original request URI. Please note URI remains 
     // unchanged in the course of request execution and is not 
     // updated if the request is redirected to another location. 
     System.out.println("URI: " + httpPost.getURI()); 
     // URI: http://posttestserver.com/post.php    

     String json = jon.toString(); 
     StringEntity entity = new StringEntity(json); 
     httpPost.setEntity(entity); 
     httpPost.setHeader("Accept", "application/json"); 
     httpPost.setHeader("Content-type", "application/json"); 

     CloseableHttpResponse response = client.execute(httpPost); 
     BufferedReader rd = new BufferedReader 
       (new InputStreamReader(
       response.getEntity().getContent())); 

      String line = ""; 
      while ((line = rd.readLine()) != null) { 
       System.out.println(line); 
      } 
     client.close(); 
    } 
}