Spring-Data Mysql在数据库中找不到该名称。

huangapple
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英文:

Spring-Data Mysql cannot find the name in the DB

问题

  1. 我对Spring-Data MySQL还不太熟悉，我创建了一个小方法，让它从一个名字列表中返回一个名称，它会返回具有最旧的记录日期的名称。不幸的是，当我执行获取操作时，它返回给我这个：

D:>curl -G localhost:8080/demo/first -d name=Biagio
{"timestamp":"2020-10-02T09:29:33.704+00:00","status":404,"error":"Not Found","message"

  1. 我已经尝试了各种方法，但到目前为止都没有成功。以下是该方法和相关控制器。
  3. UserRepositoryImpl.java
  4. ```java
  5. package com.example.accessingdatamysql;
  7. import javax.persistence.EntityManager;
  8. import javax.persistence.TypedQuery;
  9. import javax.persistence.criteria.CriteriaBuilder;
  10. import javax.persistence.criteria.CriteriaQuery;
  11. import javax.persistence.criteria.Root;
  13. import org.springframework.stereotype.Component;
  15. @Component
  16. public class UserRepositoryImpl implements UserRepository {
  17. 	
  18. 	private final EntityManager em;
  19. 	
  20. 	public UserRepositoryImpl(EntityManager entityManager) {
  21. 		this.em = entityManager;
  22. 	}
  24. 	@Override
  25. 	public User findFirstByName(String name) {
  26. 		CriteriaBuilder builder = em.getCriteriaBuilder();
  27. 		CriteriaQuery<User> criteria = builder.createQuery(User.class);
  28. 		Root<User> root = criteria.from(User.class);
  29. 		criteria.select(root).where(builder.equal(root.get("name"), name));
  30. 		criteria.orderBy(builder.asc(root.get("timestamp")));
  31. 		TypedQuery<User> query = em.createQuery(criteria).setMaxResults(1);
  32. 		return query.getSingleResult();
  33. 	}
  34. 	
  35. 	@Override
  36. 	public void create(User entity) {
  37. 		em.persist(entity);
  38. 	}
  39. }

MainController.java

  1. package com.example.accessingdatamysql;
  3. import javax.persistence.NoResultException;
  4. import org.springframework.beans.factory.annotation.Autowired;
  5. import org.springframework.stereotype.Controller;
  6. import org.springframework.transaction.annotation.Transactional;
  7. import org.springframework.web.bind.annotation.GetMapping;
  8. import org.springframework.web.bind.annotation.PostMapping;
  9. import org.springframework.web.bind.annotation.RequestMapping;
  10. import org.springframework.web.bind.annotation.RequestParam;
  11. import org.springframework.web.bind.annotation.ResponseBody;
  13. @Controller 
  14. @RequestMapping(path="/demo") 
  15. public class MainController {
  16. 	
  17.   @Autowired
  18.   private UserRepository userRepository;
  20.   @Transactional
  21.   @PostMapping(path="/add")
  22.   public @ResponseBody String addNewUser (@RequestParam String name, @RequestParam String email, @RequestParam String surname) {
  23.     User n = new User();
  24.     n.setName(name);
  25.     n.setSurname(surname);
  26.     n.setEmail(email);
  27.     userRepository.create(n);
  28.     return "Saved";
  29.   }
  31.   @GetMapping("/first")
  32.   User one(@RequestParam String name) {
  33.     System.out.print(name);
  34.     try {
  35.       return userRepository.findFirstByName(name); 
  36.     } catch (NoResultException nre) {
  37.       return null;
  38.     }
  39.   }
  40. }

还有User和UserRepository.java

User.java

  1. package com.example.accessingdatamysql;
  3. import java.sql.Timestamp;
  4. import java.time.Instant;
  5. import javax.persistence.Column;
  6. import javax.persistence.Entity;
  7. import javax.persistence.GeneratedValue;
  8. import javax.persistence.GenerationType;
  9. import javax.persistence.Id;
  11. @Entity 
  12. public class User {
  13.   @Id
  14.   @GeneratedValue(strategy=GenerationType.AUTO)
  15.   private Integer id;
  16.  
  17.   public String name;
  18.   private String email;
  19.   private String surname;
  20.   
  21.   @Column(name="stmp", columnDefinition = "TIMESTAMP (6)")
  22.   Timestamp timestamp = Timestamp.from(Instant.now());
  24.   public void setTimestamp(Timestamp timestamp) {
  25.     this.timestamp = timestamp;
  26.   }
  28.   public Timestamp getTimestamp() {
  29.     return timestamp;
  30.   }
  32.   public String getSurname() {
  33.     return surname;
  34.   }
  35.  
  36.   public void setSurname(String surname) {
  37.     this.surname = surname;
  38.   }
  39.  
  40.   public Integer getId() {
  41.     return id;
  42.   }
  44.   public void setId(Integer id) {
  45.     this.id = id;
  46.   }
  48.   public String getName() {
  49.     return name;
  50.   }
  52.   public void setName(String name) {
  53.     this.name = name;
  54.   }
  56.   public String getEmail() {
  57.     return email;
  58.   }
  60.   public void setEmail(String email) {
  61.     this.email = email;
  62.   }
  63. }

UserRepository.java

  1. package com.example.accessingdatamysql;
  3. import org.springframework.stereotype.Repository;
  5. @Repository
  6. public interface UserRepository {
  7.   User findFirstByName(String name);
  8.   void create(User entity);
  9. }
英文:

I'm new to Spring-Data Mysql, I created a little method to make it give me a name from a list of names, it returns me the name with the oldest entry date. Unfortunately when I do the get it returns me this :

  1. D:\&gt;curl -G localhost:8080/demo/first  -d name=Biagio
  2. {&quot;timestamp&quot;:&quot;2020-10-02T09:29:33.704+00:00&quot;,&quot;status&quot;:404,&quot;error&quot;:&quot;Not Found&quot;,&quot;message

I've tried them all a little but so far I can't be successful. Below is the method and the relative controller

UserRepositoryImpl.java

  2. package com.example.accessingdatamysql;
  3. import javax.persistence.EntityManager;
  4. import javax.persistence.TypedQuery;
  5. import javax.persistence.criteria.CriteriaBuilder;
  6. import javax.persistence.criteria.CriteriaQuery;
  7. import javax.persistence.criteria.Root;
  8. import org.springframework.stereotype.Component;
  9. @Component
  10. public class UserRepositoryImpl implements UserRepository {
  11. private final EntityManager em;
  12. public UserRepositoryImpl(EntityManager entityManager) {
  13. this.em = entityManager;
  14. }
  15. @Override
  16. public User findFirstByName(String name) {
  17. CriteriaBuilder builder = em.getCriteriaBuilder();
  18. CriteriaQuery&lt;User&gt; criteria = builder.createQuery(User.class);
  19. Root&lt;User&gt; root = criteria.from(User.class);
  20. criteria.select(root).where(builder.equal(root.get(&quot;name&quot;), name));
  21. criteria.orderBy(builder.asc(root.get(&quot;timestamp&quot;)));
  22. TypedQuery&lt;User&gt; query = em.createQuery(criteria).setMaxResults(1);
  23. return query.getSingleResult();
  24. }
  25. @Override
  26. //	per la creazione//
  27. public void create(User entity) {
  28. em.persist(entity);	
  29. }
  30. }

mainController.java

  1. package com.example.accessingdatamysql;
  2. import javax.persistence.NoResultException;
  3. import org.springframework.beans.factory.annotation.Autowired;
  4. import org.springframework.stereotype.Controller;
  5. import org.springframework.transaction.annotation.Transactional;
  6. import org.springframework.web.bind.annotation.GetMapping;
  7. import org.springframework.web.bind.annotation.PostMapping;
  8. import org.springframework.web.bind.annotation.RequestMapping;
  9. import org.springframework.web.bind.annotation.RequestParam;
  10. import org.springframework.web.bind.annotation.ResponseBody;
  11. @Controller 
  12. @RequestMapping(path=&quot;/demo&quot;) 
  13. public class MainController {
  14. @Autowired 
  15. private UserRepository userRepository;
  16. @Transactional
  17. @PostMapping(path=&quot;/add&quot;)
  18. public @ResponseBody String addNewUser (@RequestParam String name
  19. , @RequestParam String email,@RequestParam String surname) 
  20. {
  21. User n = new User();
  22. n.setName(name);
  23. n.setSurname(surname);
  24. n.setEmail(email);
  25. userRepository.create(n);
  26. return &quot;Saved&quot;;
  27. }
  28. @GetMapping(&quot;/first&quot;)
  29. User one(@RequestParam String name) {
  30. System.out.print(name);
  31. try { return userRepository.findFirstByName(name); 
  32. } catch (NoResultException nre) { 
  33. return null; } 
  34. }
  35. }

I add User and UserRepository.java for everything

User.java

  1. package com.example.accessingdatamysql;
  2. import java.sql.Timestamp;
  3. import java.time.Instant;
  4. import javax.persistence.Column;
  5. import javax.persistence.Entity;
  6. import javax.persistence.GeneratedValue;
  7. import javax.persistence.GenerationType;
  8. import javax.persistence.Id;
  9. @Entity 
  10. public class User {
  11. @Id
  12. @GeneratedValue(strategy=GenerationType.AUTO)
  13. private Integer id;
  14. public String name;
  15. private String email;
  16. private String surname;
  17. @Column(name=&quot;stmp&quot;, columnDefinition = &quot;TIMESTAMP (6)&quot;)
  18. Timestamp timestamp = Timestamp.from(Instant.now());
  19. public void setTimestamp(Timestamp timestamp) {
  20. this.timestamp = timestamp;
  21. }
  22. public Timestamp getTimestamp() {
  23. return timestamp;
  24. }
  25. public String getSurname() {
  26. return surname;
  27. }
  28. public  void setSurname(String surname) {
  29. this.surname = surname;
  30. }
  31. public Integer getId() {
  32. return id;
  33. }
  34. public void setId(Integer id) {
  35. this.id = id;
  36. }
  37. public String getName() {
  38. return name;
  39. }
  40. public void setName(String name) {
  41. this.name = name;
  42. }
  43. public String getEmail() {
  44. return email;
  45. }
  46. public void setEmail(String email) {
  47. this.email = email;
  48. }
  49. }

UserRepository.java

  1. package com.example.accessingdatamysql;
  2. import org.springframework.stereotype.Repository;
  3. @Repository
  4. public interface UserRepository {
  5. User findFirstByName(String name);
  6. void create(User entity);
  7. }

EDIT: I insert the database referenced by this small project:

  1. +----+---------------------+--------+----------------------------+---------+
  2. | id | email               | name   | stmp                       | surname |
  3. +----+---------------------+--------+----------------------------+---------+
  4. | 32 | mirketto90@yahoo.it | Mirko  | 2020-10-01 12:31:47.827000 | NULL    |
  5. | 36 | biagio@gmail.com    | Biagio | 2020-10-01 16:31:31.687000 | Vaso    |
  6. | 37 | biagio@gmail.com    | Biagio | 2020-10-01 16:31:50.077000 | Vaso    |
  7. | 38 | biagio@gmail.com    | Biagio | 2020-10-01 18:35:45.992000 | Vaso    |
  8. +----+---------------------+--------+----------------------------+---------+

答案1

得分: 1

我看到的第一件事如下：

  • 你的 /demo/first 方法不是公开的。
  • 调用此端点的正确方法应为 curl localhost:8080/demo/first?name=Biagio -H "Accept: application/json"。
英文:

the first things I see are the following:

  • Your method for /demo/first is not public.
  • The proper way to call this endpoint should be curl localhost:8080/demo/first?name=Biagio -H &quot;Accept: application/json&quot;

答案2

得分: 0

你应该能够通过浏览器验证端点 localhost:8080/demo/first?name=Biagio，因为它默认提交 GET 请求。

我成功复现了这个问题，你应该移除类级别的映射，并在 MainController 的方法中提供完整路径：

  1. @RestController
  2. public class MainController {
  3.     @Autowired
  4.     private UserRepository userRepository;
  6.     @Transactional
  7.     @PostMapping("/demo/add")
  8.     public @ResponseBody String addNewUser (
  9.             @RequestParam String name,
  10.             @RequestParam String email,
  11.             @RequestParam String surname) 
  12.     {
  13.         User n = new User();
  14.         n.setName(name);
  15.         n.setSurname(surname);
  16.         n.setEmail(email);
  17.         userRepository.create(n);
  18.         return "Saved";
  19.     }
  21.     @GetMapping("/demo/first")
  22.     public User one(@RequestParam String name) {
  23.         System.out.print(name);
  24.         return userRepository.findFirstByName(name); 
  25.     }
  26. }

以下 curl 请求应该成功：

  1. curl -X GET localhost:8080/demo/first?name=Biagio
  2. curl -G localhost:8080/demo/first?name=Biagio
  3. curl -G localhost:8080/demo/first -d name=Biagio

更新：
以下修复方法在方法级别的映射中也可以正常工作，无需在映射前添加斜杠：

  1. @Controller
  2. @RequestMapping("/demo") // 尾部斜杠可选，也可以是 "/demo/"
  3. public class MainController {
  4.     @Autowired
  5.     private UserRepository userRepository;
  7.     @Transactional
  8.     @PostMapping("add") // 无前导斜杠
  9.     public @ResponseBody String addNewUser (/* ... */) {
  10.     // ...
  11.     }
  13.     @GetMapping("first") // 无前导斜杠
  14.     public User one(@RequestParam String name) {
  15.         return userRepository.findFirstByName(name); 
  16.     }
  17. }
英文:

You should be able to verify the endpoint localhost:8080/demo/first?name=Biagio using your browser, as it submits GET requests by default.

I managed to reproduce this issue, you should remove the class-level mapping and provide full path on the method in MainController:

  1. @RestController
  2. public class MainController {
  3.     @Autowired
  4.     private UserRepository userRepository;
  6.     @Transactional
  7.     @PostMapping(&quot;/demo/add&quot;)
  8.     public @ResponseBody String addNewUser (
  9.             @RequestParam String name,
  10.             @RequestParam String email,
  11.             @RequestParam String surname) 
  12.     {
  13.         User n = new User();
  14.         n.setName(name);
  15.         n.setSurname(surname);
  16.         n.setEmail(email);
  17.         userRepository.create(n);
  18.         return &quot;Saved&quot;;
  19.     }
  21.     @GetMapping(&quot;/demo/first&quot;)
  22.     public User one(@RequestParam String name) {
  23.         System.out.print(name);
  24.         return userRepository.findFirstByName(name); 
  25.     }
  26. }

The following curl requests should succeed:

  1. curl -X GET localhost:8080/demo/first?name=Biagio
  2. curl -G localhost:8080/demo/first?name=Biagio
  3. curl -G localhost:8080/demo/first -d name=Biagio

Update<br/>
The following fix is also working without leading slashes in the method-level mappings:

  1. @Controller
  2. @RequestMapping(&quot;/demo&quot;) // trailing slash optional, could be &quot;/demo/&quot;
  3. public class MainController {
  4.     @Autowired
  5.     private UserRepository userRepository;
  7.     @Transactional
  8.     @PostMapping(&quot;add&quot;) // no leading slash
  9.     public @ResponseBody String addNewUser (/* ... */) {
  10.     // ...
  11.     }
  13.     @GetMapping(&quot;first&quot;) // no leading slash
  14.     public User one(@RequestParam String name) {
  15.         return userRepository.findFirstByName(name); 
  16.     }
  17. }

huangapple
  • 本文由 发表于 2020年10月2日 18:13:58
  • 转载请务必保留本文链接：https://go.coder-hub.com/64169880.html
  • java
  • spring
  • spring-boot
  • spring-mvc
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