package com.gq.gqrhm.pojo;

import javax.persistence.*;
import java.util.List;

@Entity
public class SysUser {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    private String username;
    private String password;
    @ManyToMany(cascade = {CascadeType.REFRESH},fetch = FetchType.LAZY)
    @JoinTable(name = "sys_user_role",joinColumns = @JoinColumn(name = "sys_user_id"),
            inverseJoinColumns = @JoinColumn(name = "role_id"))
    private List<SysRole> roleList;

}

开启懒加载
spring.jpa.open-in-view=true

    @Test
    @Transactional
    public void  testFind(){
        SysUser sysUser= repository.findById(4).get();
        System.out.println(sysUser.getRoleList());
        System.out.println(sysUser);
    }
}

总结:

1.配置文件： spring.jpa.open-in-view=true

2. 实体类： fetch = FetchType.LAZY
3. 查询方法：@Transactional