如何将数据从MongoDb传递到Jsp Spring Boot

Question

I am beginner to spring mvc. And I'm trying to pass data from mongodb to JSP. I've seen tutorials and answers in other sites but I donno whay am I missing.

The error I get :

java.lang.NumberFormatException: For input string: "url" at java.lang.NumberFormatException.forInputString(Unknown Source) ~[na:1.8.0_144] at java.lang.Integer.parseInt(Unknown Source) ~[na:1.8.0_144].....

Here's my code :

Service:

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;


import io.javabrains.springbootstarter.dao.TopicRepository;
import io.javabrains.springbootstarter.model.Topic;

@Service

public class TopicServic {

@Autowired
private TopicRepository topicRepository;


public List<Topic> getAllTopics(){      
    return (List<Topic>) topicRepository.findAll();
}


public Topic getTopic(String id) {
    //return topics.stream().filter(t -> t.getId().equals(id)).findFirst().get();
    return topicRepository.findOne(id);
}


public void addTopic(Topic topic) { 
    topicRepository.save(topic);
}


public void updateTopic(String id, Topic topic) {
    topicRepository.save(topic);
}


public void deleteTopic(String id) {
    topicRepository.delete(id);
}



}

Controller:

import java.util.List;

import javax.servlet.http.HttpServletRequest;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

import io.javabrains.springbootstarter.model.Topic;
import io.javabrains.springbootstarter.service.TopicServic;

@Controller

public class TopicController {

@Autowired
private TopicServic topicServic;

public TopicController(TopicServic topicServic) {
    this.topicServic = topicServic;
}

@GetMapping("/topics")
public String ListDocuments(Model model) {
    model.addAttribute("topics", topicServic.getAllTopics());
    return "/bonjour";
}
}

JSP "/bonjour": ....

.....
<table class="table table-striped table-bordered text-left">
  <thead>
      <tr>
          <th>Url</th>
          <th>Name</th>
          <th>Description</th>
          <th>Tags</th>
          <th>Type</th>

      </tr>
  </thead>                    


  <tbody>
      <c:forEach var="topics" items="${topics}">                     
          <tr>
              <td>${topic.url}</td>
              <td>${topic.name}</td>
              <td>${topic.description}</td>
              <td>${topic.tags}</td>
              <td>${topic.type}</td>

          </tr>
      </c:forEach>                                
  </tbody>
</table>

Answer 1

your var is spelt wrong, should have been topic not topics

<c:forEach var="topic" items="${topics}">                      
    <tr>
        <td>${topic.url}</td>
        <td>${topic.name}</td>
        <td>${topic.description}</td>
        <td>${topic.tags}</td>
        <td>${topic.type}</td>
    </tr>
</c:forEach>