使用 REST 模板和 JSON 响应格式在 Spring MVC 上返回 Http Status 500答案

【问题标题】：Http Status 500 returned on Spring MVC Using REST Templates and JSON Response Format使用 REST 模板和 JSON 响应格式在 Spring MVC 上返回 Http Status 500
【发布时间】：2014-12-23 18:46:23
【问题描述】：

我的项目由以下四个表组成：

问题 - Question_id，问题文本
用户 - 用户 ID、姓名
Question_Answer - 用户 ID、Question_ID、答案
QuestionType - QuestionID、标签

我必须根据多个标签生成问题

或者简单地返回所有问题的列表（当没有提供标签时）

或者将用户提供的答案插入到Question_Answer表中。

Controller类SpringServiceController.java（生成JSON格式的结果）如下：

package com.bargadss.SpringService.Controller;

import java.text.ParseException;
import java.util.List;

import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import com.bargadss.SpringService.DAO.QuestionService;
import com.bargadss.SpringService.Domain.*;


@RestController

@RequestMapping("/service/question/")
public class SpringServiceController {
  QuestionService questionService=new QuestionService();

 @RequestMapping(value = "/{tag1},{tag2},{tag3}", method =  RequestMethod.GET,headers="Accept=application/json")
 public List<Questions> getQuestions(@PathVariable("tag1") String tag1, @PathVariable("tag2") String tag2, @PathVariable("tag3") String tag3) {
  List<Questions> Qobj=questionService.getQuestionByTag(tag1, tag2, tag3);
  return Qobj;
 }

 @RequestMapping(method = RequestMethod.GET,headers="Accept=application/json")
 public List<Questions> getAllQuestions() {  
  List<Questions> Qobj=questionService.getAllQuestion();
  return Qobj;   
 }

 @RequestMapping(value="/insert/{user_id}/{question_id}/{answer}",method = RequestMethod.POST,headers="Accept=application/json")
  public List<Questions> addQuestions(@PathVariable int user_id,@PathVariable int question_id,@PathVariable String answer) throws ParseException { 
      Question_Answer qtnAns = new Question_Answer();
      qtnAns.setUser_id(user_id);
      qtnAns.setQuestion_id(question_id);
      qtnAns.setAnswer(answer);
      questionService.insertAnswer(qtnAns.getUser_id(), qtnAns.getQuestion_id(), qtnAns.getAnswer());
      return questionService.getAllQuestion();        
  }        
  }

ListQuestionController.java使用Spring REST模板（生成JSP页面）如下：

package com.bargadss.SpringService.Controller;

import java.util.LinkedHashMap;
import java.util.List;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.servlet.ModelAndView;

import com.bargadss.SpringService.Domain.*;

@Controller
public class ListQuestionController {

 @RequestMapping("/listQuestion/{tag1},{tag2},{tag3}")
    public ModelAndView listQuestions(@PathVariable("tag1") String Tag1, @PathVariable("tag2") String Tag2, @PathVariable("tag3") String Tag3) { 
        RestTemplate restTemplate = new RestTemplate();
        String url="http://localhost:8080/FetchQuestions/service/question/{tag1},{tag2},{tag3}";
        List<LinkedHashMap> Qobj=restTemplate.getForObject(url, List.class,Tag1,Tag2,Tag3);
        return new ModelAndView("listQuestion", "questions", Qobj);
    }

 @RequestMapping("/listAllQuestion/")
    public ModelAndView listAllQuestion() { 
        RestTemplate restTemplate = new RestTemplate();
        String url="http://localhost:8080/FetchQuestions/service/question/";
        List<LinkedHashMap> Qobj=restTemplate.getForObject(url, List.class);
        return new ModelAndView("listQuestion", "questions", Qobj);
    }

 @RequestMapping("/insertQuestionAnswer/{user_id}/{qtn_id}/{answer}")
    public ModelAndView insertQuestionAnswer(@PathVariable("user_id") String user_ID,
           @PathVariable("qtn_id") String qtn_ID, @PathVariable("answer") String answer) { 
        RestTemplate restTemplate = new RestTemplate();
        String url="http://localhost:8080/FetchQuestions/service/question/insert/{user_id}/{qtn_id}/{answer}";
        List<LinkedHashMap> Qobj=restTemplate.getForObject(url, List.class,user_ID,qtn_ID,answer);
        return new ModelAndView("listQuestion", "questions", Qobj);
    }

  }

QuestionService.java 类执行 DAO 活动如下：

package com.bargadss.SpringService.DAO;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.List;
import com.bargadss.SpringService.Domain.*;
import com.bargadss.SpringService.Utility.DBUtility;


public class QuestionService {

private Connection connection;

 public QuestionService() {
  connection = DBUtility.getConnection();
 }

 public void insertAnswer(int userId,int qtnId,String answer){
    //Question_Answer objQA = new Question_Answer();
    PreparedStatement preparedStatement = null;
    try{
         preparedStatement = connection.prepareStatement("insert into question_answer values (?,?,?)");
         preparedStatement.setInt(1, userId);
         preparedStatement.setInt(2, qtnId);
         preparedStatement.setString(3, answer);
         int result = preparedStatement.executeUpdate();
         if(result == 0)
            System.out.println("INSERTION OF DATA FAILED");
    } catch (SQLException e){
         e.printStackTrace();
    }
    finally{
        try { if (preparedStatement != null) preparedStatement.close(); } catch (Exception e) {System.out.println("Exception Closing The Prepared Statement");e.printStackTrace();};
    }
 }

 public List<Questions> getAllQuestion(){
     Questions objQ = new Questions();
     ResultSet rs = null;
     PreparedStatement preparedStatement = null;
     List<Questions> qtns = new ArrayList<Questions>();
     try {
           preparedStatement = connection.prepareStatement("select * from questions");             
           rs = preparedStatement.executeQuery();

           while(rs.next()) {
            objQ.setQuestion_id(Integer.parseInt( rs.getString("Question_id") ) );
            objQ.setQuestion_text(rs.getString("Question_Text"));
            qtns.add(objQ);   
           }
     } catch (SQLException e) {
           e.printStackTrace();
       }    
       finally{
           try { if (rs != null) rs.close(); } catch (Exception e) {System.out.println("Exception Closing The result Set");e.printStackTrace();};
           try { if (preparedStatement != null) preparedStatement.close(); } catch (Exception e) {System.out.println("Exception Closing The Prepared Statement");e.printStackTrace();};
           /*try { if (connection != null) connection.close(); } catch (Exception e) {System.out.println("Exception Closing The Connection");e.printStackTrace();};*/
       }
    return qtns;
 }

 public List<Questions> getQuestionByTag(String Tag1,String Tag2,String Tag3){       
     Questions objQ = new Questions();
     ResultSet rs = null;
     PreparedStatement preparedStatement = null;
     List<Questions> qtns = new ArrayList<Questions>();
     try {
           preparedStatement = connection.
           prepareStatement("select questions.Question_id,questions.Question_Text from questions,questiontype " +
                            "where questions.Question_id=questiontype.Question_id " +
                            "and questiontype.Tag in (?,?,?)");
           preparedStatement.setString(1, Tag1);
           preparedStatement.setString(2, Tag2);
           preparedStatement.setString(3, Tag3);
           rs = preparedStatement.executeQuery();

           while(rs.next()) {
            objQ.setQuestion_id(Integer.parseInt( rs.getString("Question_id") ) );
            objQ.setQuestion_text(rs.getString("Question_Text"));
            qtns.add(objQ);   
           }
     } catch (SQLException e) {
           e.printStackTrace();
       }    
       finally{
           try { if (rs != null) rs.close(); } catch (Exception e) {System.out.println("Exception Closing The result Set");e.printStackTrace();};
           try { if (preparedStatement != null) preparedStatement.close(); } catch (Exception e) {System.out.println("Exception Closing The Prepared Statement");e.printStackTrace();};
           /*try { if (connection != null) connection.close(); } catch (Exception e) {System.out.println("Exception Closing The Connection");e.printStackTrace();};*/
       }
    return qtns;
}

}

在执行项目时(Apache Tomcat 7.0.12) 使用以下 URL 会生成 HTTP STATUS 500

http://localhost:8080/FetchQuestions/insertQuestionAnswer/3/9/True

此外，当我执行以下 URL 时，它会生成 HTTP 状态 405 - 不支持请求方法“GET”

http://localhost:8080/FetchQuestions/service/question/insert/3/9/True

我做错了什么？我错过了什么吗？

HTTP 状态 500 的堆栈跟踪如下：

严重：servlet [rest] 的 Servlet.service() 在路径 [/FetchQuestions] 的上下文中抛出异常 [请求处理失败；嵌套异常是 org.springframework.web.client.HttpClientErrorException: 405 Method Not Allowed] 根本原因 org.springframework.web.client.HttpClientErrorException：405 方法不允许在 org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:91) 在 org.springframework.web.client.RestTemplate.handleResponseError(RestTemplate.java:576) 在 org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:532) 在 org.springframework.web.client.RestTemplate.execute(RestTemplate.java:489) 在 org.springframework.web.client.RestTemplate.getForObject(RestTemplate.java:226) 在 com.bargadss.SpringService.Controller.ListQuestionController.insertQuestionAnswer(ListQuestionController.java:47) 在 sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 在 sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) 在 sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 在 java.lang.reflect.Method.invoke(Method.java:606) 在 org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:214) 在 org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) 在 org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) 在 org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:748) 在 org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689) 在 org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83) 在 org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945) 在 org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876) 在 org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:931) 在 org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:822) 在 javax.servlet.http.HttpServlet.service(HttpServlet.java:621) 在 org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:807) 在 javax.servlet.http.HttpServlet.service(HttpServlet.java:722) 在 org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304) 在 org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 在 org.apache.catalina.core.StandardWrapperValve.invoke（StandardWrapperValve.java:240）在 org.apache.catalina.core.StandardContextValve.invoke（StandardContextValve.java:164）在 org.apache.catalina.authenticator.AuthenticatorBase.invoke（AuthenticatorBase.java:462）在 org.apache.catalina.core.StandardHostValve.invoke（StandardHostValve.java:164）在 org.apache.catalina.valves.ErrorReportValve.invoke（ErrorReportValve.java:100）在 org.apache.catalina.valves.AccessLogValve.invoke（AccessLogValve.java:562）在 org.apache.catalina.core.StandardEngineValve.invoke（StandardEngineValve.java:118）在 org.apache.catalina.connector.CoyoteAdapter.service（CoyoteAdapter.java:395）在 org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250) 在 org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188) 在 org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:166) 在 org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302) 在 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) 在 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) 在 java.lang.Thread.run(Thread.java:745)

【问题讨论】：

你是用断点调试的吗？
是的，我调试了代码并对其进行了测试。
能否请您添加堆栈跟踪
请分享异常堆栈跟踪
Http 状态 405 返回以下堆栈跟踪 - >2014 年 10 月 28 日下午 5:23:47 org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver handleHttpRequestMethodNotSupported 警告：不支持请求方法“GET”

标签： java json spring rest

【解决方案1】：

当我执行以下 URL 时，它还会生成 HTTP 状态 405 - 不支持请求方法“GET”

将SpringServiceController.SpringServiceController方法的请求方法从POST改为GET。它应该可以解决您的问题。

@RequestMapping(value="/insert/{user_id}/{question_id}/{answer}",method = RequestMethod.GET,headers="Accept=application/json")

【讨论】：