SpringBoot---dady09--Spring Data JPA配置一对多和多对多

一：关联映射操作

1.一对多的关联映射

需求：角色与用户的一对多的关联关系。

角色：一方

用户：多方

1.1User和Roles类的配置

@Entity 
@Table(name="t_users")
public class Users {
	@Id
	@GeneratedValue(strategy=GenerationType.IDENTITY)
	@Column(name="id")
	private Integer id;
	@Column(name="name")
	private String name;
	@Column(name="age")
	private Integer age;
	@Column(name="address")
	private String address;
	@ManyToOne
	@JoinColumn(name="roles_id")  //维护外键 
	private Roles roles;
	
	
	public Roles getRoles() {
		return roles;
	}
	public void setRoles(Roles roles) {
		this.roles = roles;
	}
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public Integer getAge() {
		return age;
	}
	public void setAge(Integer age) {
		this.age = age;
	}
	public String getAddress() {
		return address;
	}
	public void setAddress(String address) {
		this.address = address;
	}
	@Override
	public String toString() {
		return "Users [id=" + id + ", name=" + name + ", age=" + age + ", address=" + address + "]";
	}
	
}
@Entity
@Table(name="t_roles")
public class Roles {
	@Id
	@GeneratedValue(strategy=GenerationType.IDENTITY)
	@Column(name="roleid")
	private Integer roleid;
	@Column(name="rolename")
	private String rolename;
	@OneToMany(mappedBy="roles")
	private Set<Users> users = new HashSet<Users>();
	
	
	public Set<Users> getUsers() {
		return users;
	}
	public void setUsers(Set<Users> users) {
		this.users = users;
	}
	public Integer getRoleid() {
		return roleid;
	}
	public void setRoleid(Integer roleid) {
		this.roleid = roleid;
	}
	public String getRolename() {
		return rolename;
	}
	public void setRolename(String rolename) {
		this.rolename = rolename;
	}
	
}

1.2测试一对多的关联关系

/**
 * 一对多关联测试
 * @author Administrator
 *
 */
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes=App.class)
public class OneToManyTest {

	@Autowired
	private UsersRepository usersRepository;
	/**
	 * 一对多关联关系的添加
	 */
	@Test
	public void testSave() {
		//创建一个用户
		Users users = new Users();
		users.setAddress("珠海");
		users.setAge(21);
		users.setName("小牧");
		//创建一个角色
		Roles roles = new Roles();
		roles.setRolename("管理员");
		//关联
		roles.getUsers().add(users);
		users.setRoles(roles);
		//保存
		usersRepository.save(users);
		
	}
	
	/**
	 * 一对多关联查询
	 */
	@Test
	public void testFind() {
		Users users = usersRepository.findOne(5);
		System.out.println(users);
		Roles roles = users.getRoles();
		System.out.println(roles);
	}
	
}

2.多对多关联映射

需求：角色与菜单多对多关联关系

角色：多方

菜单：多方

2.1 Roles 和 Menus 类配置

@Entity
@Table(name = "t_roles")
public class Roles {
	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	@Column(name = "roleid")
	private Integer roleid;
	@Column(name = "rolename")
	private String rolename;
	@OneToMany(mappedBy = "roles")
	private Set<Users> users = new HashSet<Users>();
	
	/**
	 * @JoinTable:映射中间表
	 * joinColumns:当前表中的主键所关联的中间表的外键字段
	 */
	@ManyToMany(cascade=CascadeType.PERSIST,fetch=FetchType.EAGER)
	@JoinTable(name="t_roles_menus",joinColumns=@JoinColumn(name="role_id"),inverseJoinColumns=@JoinColumn(name="menu_id"))
	private Set<Menus> menus = new HashSet<Menus>();

	public Set<Users> getUsers() {
		return users;
	}

	public void setUsers(Set<Users> users) {
		this.users = users;
	}

	public Integer getRoleid() {
		return roleid;
	}

	public void setRoleid(Integer roleid) {
		this.roleid = roleid;
	}

	public String getRolename() {
		return rolename;
	}

	public void setRolename(String rolename) {
		this.rolename = rolename;
	}
	
	public Set<Menus> getMenus() {
		return menus;
	}

	public void setMenus(Set<Menus> menus) {
		this.menus = menus;
	}

	@Override
	public String toString() {
		return "Roles [roleid=" + roleid + ", rolename=" + rolename + "]";
	}

}




@Entity
@Table(name="t_menus")
public class Menus {
	@Id
	@GeneratedValue(strategy=GenerationType.IDENTITY)
	
	@Column(name="menusid")
	private Integer menusid;
	
	@Column(name="menusname")
	private String menusname;
	
	@Column(name="menusurl")
	private String menusurl;
	
	@Column(name="fatherid")
	private Integer fatherid;
	
	@ManyToMany(mappedBy="menus")
	private Set<Roles> roles = new HashSet<Roles>();
	
	public Integer getMenusid() {
		return menusid;
	}
	public void setMenusid(Integer menusid) {
		this.menusid = menusid;
	}
	public String getMenusname() {
		return menusname;
	}
	public void setMenusname(String menusname) {
		this.menusname = menusname;
	}
	public String getMenusurl() {
		return menusurl;
	}
	public void setMenusurl(String menusurl) {
		this.menusurl = menusurl;
	}
	public Integer getFatherid() {
		return fatherid;
	}
	public void setFatherid(Integer fatherid) {
		this.fatherid = fatherid;
	}
	public Set<Roles> getRoles() {
		return roles;
	}
	public void setRoles(Set<Roles> roles) {
		this.roles = roles;
	}
	@Override
	public String toString() {
		return "Menus [menusid=" + menusid + ", menusname=" + menusname + ", menusurl=" + menusurl + ", fatherid="
				+ fatherid +  "]";
	}

2.2 测试多对多的关联关系

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes=App.class)
public class ManyToManyTest {

	@Autowired
	private RolesRepository rolesRepository;
	
	/**
	 * 添加测试
	 */
	@Test
	public void testSave() {
		//创建角色对象 
		Roles r = new Roles();
		r.setRolename("项目经理");
		//创建菜单对象
		Menus menus = new Menus();
		menus.setMenusname("xxx管理系统");
		menus.setFatherid(0);
		
		Menus menus2 = new Menus();
		menus2.setMenusname("项目管理");
		menus2.setFatherid(1);
		//关联
		r.getMenus().add(menus);
		r.getMenus().add(menus2);
		menus.getRoles().add(r);
		menus2.getRoles().add(r);
		//保存
		rolesRepository.save(r);
	}
	
	/**
	 * 查询操作
	 */
	@Test
	public void testFind() {
		Roles roles = rolesRepository.findOne(2);
		System.out.println(roles);
		Set<Menus> menus = roles.getMenus();
		for (Menus menus2 : menus) {
			System.out.println(menus2);
		}
	}
	
}