“出现意外错误（类型=内部服务器错误，状态=500）”的 Spring-boot 问题。

Question

我使用 spring-boot 启动了一个项目，实际上我正在尝试在我的 localhost 端口上获取 JSON（如果我理解的话）信息。但是我遇到了这个错误：“Internal Server Error, status=500”

我在某个地方犯了一个愚蠢的错误，但我找不到我做错的地方...... 我正在将 springboot 与 JPA 和 h2 数据库一起使用

提前感谢您的帮助！

这是我的代码：

型号：

@Entity
public class User {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private int id;
    @Column (name = "name", nullable = false, unique = false)
    private String name;
    @Column (name = "firstname", nullable = false, unique = false)
    private String firstname;
    @Column (name = "username", nullable = false, unique = true)
    private String username;
    @Column (name = "email", nullable = false, unique = true)
    private String email;

    // Constructors
    public User(int id, String name, String firstname, String username, String email) {
        super();
        this.id = id;
        this.name = name;
        this.firstname = firstname;
        this.username = username;
        this.email = email;
    }

    public User(String name, String firstname, String username, String email) {
        super();
        this.name = name;
        this.firstname = firstname;
        this.username = username;
        this.email = email;
    }

    //Getters Setters
    public User() {
        super();
    }

    public long getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getFirstname() {
        return firstname;
    }

    public void setFirstname(String firstname) {
        this.firstname = firstname;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((username == null) ? 0 : username.hashCode());
        result = prime * result + ((email == null) ? 0 : email.hashCode());
        result = prime * result + ((firstname == null) ? 0 : firstname.hashCode());
        result = prime * result + (int) (id ^ (id >>> 32));
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        User other = (User) obj;
        if (username == null) {
            if (other.username != null)
                return false;
        } else if (!username.equals(other.username))
            return false;
        if (email == null) {
            if (other.email != null)
                return false;
        } else if (!email.equals(other.email))
            return false;
        if (firstname == null) {
            if (other.firstname != null)
                return false;
        } else if (!firstname.equals(other.firstname))
            return false;
        if (id != other.id)
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }

    @Override
    public String toString() {
        return "User [id=" + id + ", name=" + name + ", firstname=" + firstname + ", Username=" + username + ", email="
                + email + ", getId()=" + getId() + ", getName()=" + getName() + ", getFirstname()=" + getFirstname()
                + ", getUsername()=" + getUsername() + ", getEmail()=" + getEmail() + ", hashCode()=" + hashCode()
                + ", getClass()=" + getClass() + ", toString()=" + super.toString() + "]";
    }


    }

控制器：

@Controller
@RestController
@CrossOrigin(origins = "*", maxAge = 3600)
public class UserController {

    @Autowired
    UserService UserService;

    @GetMapping(value = "/user/{id}")
    public Optional<User> findById(@PathVariable int id) {
        return UserService.findById(id);
    }

    @GetMapping(value = "/user/{name}")
    public Optional<User> findByName(@PathVariable String name) {
        return UserService.findByName(name);
    }
}

存储库：

@Repository
public interface UserRepository extends JpaRepository<User, Integer> {

    Optional <User> findById(int id);

    Optional <User> findByName(String name);

}

服务：

@Service
public class UserService {

    @Autowired
    static UserRepository UserRepository;

    public Optional<User> findById(int id) {
        return UserRepository.findById(id);

    }
    public Optional<User> findByName(String name) {
        return UserRepository.findByName(name);
}
}

我存储用户对象的Data.sql：

INSERT INTO User (ID, name , firstname, userName, email) VALUES
(1 , 'bon', 'jean', 'bjean', 'bjean@gmail.com');

INSERT INTO User (ID, name , firstname, userName, email) VALUES
(2 , 'motte', 'bob', 'bmotte', 'bmotte@gmail.com');

INSERT INTO User (ID, name , firstname, userName, email) VALUES
(3 , 'wose', 'guy', 'gwose', 'gwose@gmail.com');

application_properties：

# To See H2 Console in Browser:
# http://localhost:8080/h2-console
# Enabling H2 Console
spring.h2.console.enabled=true

# ===============================
# DATABASE CONNECTION
# ===============================
spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=h2
spring.datasource.password=h2

# ===============================
# JPA / HIBERNATE
# ===============================
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=update
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.H2Dialect

Answer 1

我认为你必须更改 GetMapping 值，例如：

@GetMapping(value = "/user/{id}")
public Optional<User> findById(@PathVariable int id) {
    return UserService.findById(id);
}

@GetMapping(value = "/user/by-name/{name}")
public Optional<User> findByName(@PathVariable String name) {
    return UserService.findByName(name);
}

或

@GetMapping(value = "/user/")
public Optional<User> findByName(@RequestParam(name="name") String name) {
    return UserService.findByName(name);
}

并且它可以与相对url一起使用：/user/?name=bon

Answer 2

我终于找到了我的问题。

感谢您花时间帮助我！

我刚刚删除了我的服务类并像这样更新了我的控制器，它现在直接通过存储库传递：

@RestController
@CrossOrigin(origins = "*", maxAge = 3600)
public class UserController {

    @Autowired
    UserRepository userRepository;

    @GetMapping(value = "/user/{id}")
    public Optional<User> findById(@PathVariable(required = true) int id) {
        return userRepository.findById(id);
    }

    @GetMapping(value = "/user/name/{name}")
    public Optional<User> findByName(@PathVariable(required = true) String name) {
        return userRepository.findByName(name);
    }
}