从用户实体获取角色集时，Spring Boot Hibernate 出现异常

Question

我在从数据库中从用户实体中获取角色的结果集时遇到问题 throw hibernate 这是我目前所拥有的： 这是数据库 my sql database

这是我得到的例外

白标错误页面

此应用程序没有 /error 的显式映射，因此您将此视为后备。

2019 年 1 月 19 日星期六 18:37:17 CET 出现意外错误（类型=内部服务器错误，状态=500 ).Could not write JSON: could not extract ResultSet;嵌套异常是 com.fasterxml.jackson.databind.JsonMappingException: could not extract ResultSet (通过引用链: java.util.ArrayList[0]->com.example.springboot.model.User["roles"])

这些是我的 java bean：用户实体

package com.example.springboot.model;



import javax.persistence.*;
import java.util.HashSet;
import java.util.Set;

@Entity
@Table(name="user")
public class User {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name="userid")
private int id;

@Column(name="username")
private String username;

@Column(name="name")
private String name;

@Column(name="email")
private String email;

@Column(name="password")
private String password;

@Column(name="datecreated")
private String dateCreated;

@ManyToMany(cascade = CascadeType.ALL)
@JoinTable(name = "user_role", joinColumns = @JoinColumn(name = "userid"), inverseJoinColumns = @JoinColumn(name = "roleid"))
private Set<Role> roles = new HashSet<>();

public int getId() {
    return id;
}

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

public String getUsername() {
    return username;
}

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

public String getName() {
    return name;
}

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

public String getEmail() {
    return email;
}

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

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}

public String getDateCreated() {
    return dateCreated;
}

public void setDateCreated(String dateCreated) {
    this.dateCreated = dateCreated;
}

public Set<Role> getRoles() {
    return roles;
}

public void setRoles(Set<Role> roles) {
    this.roles = roles;
}

@Override
public String toString() {
    return "Userid: "+id;
}
}

和角色实体

package com.example.springboot.model;

import javax.persistence.*;

@Entity
@Table(name="role")
public class Role {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name="id")
private int id;

@Column(name="role")
private String role;

@Column(name="description")
private String description;
}

请帮助我，我整天都在尝试解决这个问题，但没有希望。

• 2019-01-19 18:28:05.321 INFO 9968 --- [nio-8080-exec-2] o.h.h.i.QueryTranslatorFactoryInitiator：HHH000397：使用 ASTQueryTranslatorFactory
• 2019-01-19 18:28:05.499 WARN 9968 --- [nio-8080-exec-2] o.h.engine.jdbc.spi.SqlExceptionHelper：SQL 错误：1054，SQLState：42S22
• 2019-01-19 18:28:05.499 错误 9968 --- [nio-8080-exec-2] ohengine.jdbc.spi.SqlExceptionHelper：“字段列表”中的未知列“role1_.id”李>
• 2019-01-19 18:28:05.501 WARN 9968 --- [nio-8080-exec-2] .wsmsDefaultHandlerExceptionResolver：已解决 [org.springframework.http.converter.HttpMessageNotWritableException：无法写入 JSON：无法提取结果集；嵌套异常是 com.fasterxml.jackson.databind.JsonMappingException: could not extract ResultSet (through reference chain: java.util.ArrayList[0]->com.example.springboot.model.User["roles"])]李>
• 2019-01-19 18:28:08.440 WARN 9968 --- [nio-8080-exec-3] o.h.engine.jdbc.spi.SqlExceptionHelper：SQL 错误：1054，SQLState：42S22
• 2019-01-19 18:28:08.440 错误 9968 --- [nio-8080-exec-3] ohengine.jdbc.spi.SqlExceptionHelper：“字段列表”中的未知列“role1_.id”李>
• 2019-01-19 18:28:08.440 WARN 9968 --- [nio-8080-exec-3] .wsmsDefaultHandlerExceptionResolver：已解决 [org.springframework.http.converter.HttpMessageNotWritableException：无法写入 JSON：无法提取结果集；嵌套异常是 com.fasterxml.jackson.databind.JsonMappingException: could not extract ResultSet (through reference chain: com.example.springboot.model.User["roles"])]
• 2019-01-19 18:37:17.963 WARN 9968 --- [nio-8080-exec-4] o.h.engine.jdbc.spi.SqlExceptionHelper：SQL 错误：1054，SQLState：42S22
• 2019-01-19 18:37:17.963 错误 9968 --- [nio-8080-exec-4] ohengine.jdbc.spi.SqlExceptionHelper：“字段列表”中的未知列“role1_.id”李>
• 2019-01-19 18:37:17.963 WARN 9968 --- [nio-8080-exec-4] .wsmsDefaultHandlerExceptionResolver：已解决 [org.springframework.http.converter.HttpMessageNotWritableException：无法写入 JSON：无法提取结果集；嵌套异常是 com.fasterxml.jackson.databind.JsonMappingException: could not extract ResultSet (through reference chain: java.util.ArrayList[0]->com.example.springboot.model.User["roles"])]李>

Answer 1

根据your schema，（在角色类中）应该是：

@Column(name="roleid")

..而不是：

@Column(name="id")