import java.util.HashSet;
import java.util.Set;
import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;

@Entity
public class User {
	private Long id;
	private Department department;
	private Set<Role> roles = new HashSet<Role>();
	private String loginName;
	private String password;
	private String name;
	private String gender;
	private String phoneNumber;
	private String email;
	private String description;
	
	
	@Id
	@GeneratedValue
	public Long getId() {
		return id;
	}
	public void setId(Long id) {
		this.id = id;
	}
	
	@ManyToOne()
	public Department getDepartment() {
		return department;
	}
	public void setDepartment(Department department) {
		this.department = department;
	}
	
	@ManyToMany(cascade=CascadeType.PERSIST,fetch=FetchType.LAZY)
	@JoinTable(name="user_role",
	joinColumns={@JoinColumn(name="user_id")},
	inverseJoinColumns={@JoinColumn(name="role_id")})
	public Set<Role> getRoles() {
		return roles;
	}
	public void setRoles(Set<Role> roles) {
		this.roles = roles;
	}
	public String getLoginName() {
		return loginName;
	}
	public void setLoginName(String loginName) {
		this.loginName = loginName;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getGender() {
		return gender;
	}
	public void setGender(String gender) {
		this.gender = gender;
	}
	public String getPhoneNumber() {
		return phoneNumber;
	}
	public void setPhoneNumber(String phoneNumber) {
		this.phoneNumber = phoneNumber;
	}
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	public String getDescription() {
		return description;
	}
	public void setDescription(String description) {
		this.description = description;
	}
	
}
 

第二個類是User  使用者類

每個使用者可以有多個崗位，每個崗位包含多個使用者

這樣的多對多關係。

個人程式設計的時候出現的問題就是，剛開始都只加了一個註解@ManytoMany 後來發現操作對User物件新增Role集合的時候，關聯表裡面的內容沒有改。才發現少了配置。

最簡單的配置首先需要配置，被依賴方 @ManytoMany(mappedBy="roles") ，我在這裡定義的是roles，意思是當對User物件設定roles的時候，關聯表裡面會操作。

@JoinTable(name="user_role",
	joinColumns={@JoinColumn(name="user_id")},
	inverseJoinColumns={@JoinColumn(name="role_id")})
 

@JoinTable是用來設定關聯表的各項屬性的

首先 name 屬性是設定表的名字

joinColumns={}  這是一個列的集合，裡面填入關聯列的列名

當這些配置好過後，當對User物件設定roles集合的時候，關聯表裡面就會新增資料了