hibernate多对多注解配法

下面是权限和角色的多对多配置
角色表实体bean

package com.sxt.beans;import java.io.Serializable;import java.util.HashSet;import java.util.Set;import javax.persistence.CascadeType;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.OneToMany;import javax.persistence.Table;import org.hibernate.annotations.Cascade;@Entity@Table(name="t_role")public class Role implements Serializable {    @Id    @GeneratedValue(strategy=GenerationType.IDENTITY)    private Integer roleId;    @Column    private String roleName;    @OneToMany(cascade=CascadeType.ALL)    @JoinColumn(name="roleId")    private Set<User> users = new HashSet<User>();    @ManyToMany(cascade=CascadeType.ALL)//多对多要配置ManyToMany，Cascade=CascadeType.ALL是是否要级联    @JoinTable(name="t_role_right",joinColumns=@JoinColumn(name="roleId"),inverseJoinColumns=@JoinColumn(name="rightId"))//name="t_role_right"是中间表的表名，joinColumns=@JoinColumn(name="roleId")是这个bean和中间表的关联的字段，也就是roleId，inverseJoinColumns=@JoinColumn(name="rightId"))就是所对应的那个多的表和中间表的关联的字段，也就是rightId    private Set<Right> rights = new HashSet<Right>();    public Role() {    }    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<User> getUsers() {        return users;    }    public void setUsers(Set<User> users) {        this.users = users;    }    public Set<Right> getRights() {        return rights;    }    public void setRights(Set<Right> rights) {        this.rights = rights;    }}

权限表实体bean

package com.sxt.beans;import java.io.Serializable;import java.util.HashSet;import java.util.Set;import javax.persistence.CascadeType;import javax.persistence.Column;import javax.persistence.Entity;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.Table;@Entity@Table(name="t_right")public class Right implements Serializable {    @Id    @GeneratedValue(strategy=GenerationType.IDENTITY)    private Integer rightId;    @Column    private String rightName;    @Column    private String url;    @ManyToMany(mappedBy="rights")//因为是多对多所有要配置ManyToMany,mappedBy="rights"权限反转 也就是把维护两者的关系交给谁，rights就是对面权限(right)的set集合的名称    private Set<Role> roles = new HashSet<Role>();    public Right() {    }    public Integer getRightId() {        return rightId;    }    public void setRightId(Integer rightId) {        this.rightId = rightId;    }    public String getRightName() {        return rightName;    }    public void setRightName(String rightName) {        this.rightName = rightName;    }    public String getUrl() {        return url;    }    public void setUrl(String url) {        this.url = url;    }    public Set<Role> getRoles() {        return roles;    }    public void setRoles(Set<Role> roles) {        this.roles = roles;    }}

在hibernate.cfg.xml文件中引入注解bean

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE hibernate-configuration PUBLIC"-//Hibernate/Hibernate Configuration DTD 3.0//EN""http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"><hibernate-configuration>    <!-- 配置回话工厂 -->    <session-factory>        <!-- 驱动名称 -->        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>        <!-- URL -->        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/sxt</property>        <!-- 用户名 -->        <property name="hibernate.connection.username">root</property>        <!-- 密码 -->        <property name="hibernate.connection.password">root</property>        <!--方言：hibernate根据方言类将对象"翻译"成相对于的sql语句 -->        <property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>        <!-- 打印生成的sql语句 -->        <property name="hibernate.show_sql">true</property>        <!-- 引入注解的bean的java文件 -->        <mapping class="com.sxt.beans.Role" />        <mapping class="com.sxt.beans.Right" />        <!-- 引入映射文件 -->    </session-factory></hibernate-configuration>

注意:多对多只要配置一方很多的配置，另一方只要配置极少就好了
还有装的时候要互相装，如上面这个要权限装角色，角色也要装权限.
还有保存的时候保存级联那一方，被级联那一方会自动的级联保存.如上面这个只要保存角色，会自动级联保存权限