Hibernate Annotation 配置ManyToMany

用户权限关系
涉及三个数据库表
SYS_USER,SYS_USER_ROLE,SYS_ROLE
用户类

package pineapple.web.pal.model;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.SequenceGenerator;
import javax.persistence.Table;

import org.hibernate.annotations.Cascade;
import org.hibernate.annotations.CascadeType;

@Entity
@Table(name="SYS_USER")
public class User implements Serializable{
	
	@Id 
	@SequenceGenerator(name = "SEQ_USER", sequenceName = "SEQ_USER")
	@GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "SEQ_USER")
	private Integer id;
	
	@Column(name = "USERNAME", length = 100, nullable = false)
	private String username;
	
	@Column(name = "FULLNAME", length = 255)
	private String fullname;
	
	@Column(name = "PASSWORD", nullable = false)
	private String password;
	
	@Column(name = "ENABLED")
	private Integer enabled;
	
	@Column(name = "IS_ADMIN")
	private Integer isAdmin;
	
	@Column(name = "VERSION")
	private Integer version;
	
	@Cascade(value={CascadeType.SAVE_UPDATE})
	@ManyToMany(fetch = FetchType.LAZY)
	@JoinTable(schema = "TRAIN", name = "SYS_USER_ROLE", joinColumns = { @JoinColumn(name = "USER_ID", referencedColumnName = "ID", nullable = false) }, inverseJoinColumns = { @JoinColumn(name = "ROLE_ID", referencedColumnName = "ID", nullable = false) })
	Set<Role> roles;

权限类

package pineapple.web.pal.model;

import java.io.Serializable;
import java.util.Set;

import javax.persistence.Basic;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.ManyToMany;
import javax.persistence.SequenceGenerator;
import javax.persistence.Table;

import org.hibernate.annotations.Cascade;
import org.hibernate.annotations.CascadeType;

@Entity
@Table(schema = "TRAIN", name = "SYS_ROLE")
public class Role implements Serializable {
	private static final long serialVersionUID = 1L;

	@Id 
	@SequenceGenerator(name = "SEQ_ROLE", sequenceName = "SEQ_ROLE")
	@GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "SEQ_ROLE")
	Integer id;

	@Column(name = "NAME", length = 50, nullable = false)
	@Basic(fetch = FetchType.EAGER)
	String name;
	
	@Column(name = "DESCRIPTION")
	@Basic(fetch = FetchType.EAGER)
	String description;

	@Column(name = "ENABLED")
	@Basic(fetch = FetchType.EAGER)
	Integer enabled;

	@Column(name = "IS_ADMIN")
	@Basic(fetch = FetchType.EAGER)
	Integer isAdmin;

	@Column(name = "VERSION")
	@Basic(fetch = FetchType.EAGER)
	Integer version;

	@Cascade(value={CascadeType.SAVE_UPDATE})
	@ManyToMany(mappedBy = "roles", fetch = FetchType.LAZY)
	java.util.Set<User> users;

这里涉及到JPA的annotation跟Hibernate的annotation，其中基本都是用的JPA的标准标注，但是@Cascade(value={CascadeType.SAVE_UPDATE})这一句的cascade用的是Hibernate的，因为本例子是在spring+Hibernate环境下实现的，并没有用到JPA，所以如果在@ManyToMany标注下声明@Cascade(value={CascadeType.persist})并不能生效。