Hibernate之复合主键

先有数据库如下(MS-SQL2005)：
-- 创建 person 表

-- 删除 Person 表
DROP TABLE person ;

-- 创建 Person 表
CREATE TABLE person (
name VARCHAR(100) not null ,
phone VARCHAR(50) not null ,
age INT ,
PRIMARY KEY (name,phone)
)

1.向项目的lib目录中添加commons-lang-x.x.x.jar

2.创建Person类,实现 Serializable 接口
  复写 equals 和 hashCode 方法
  • equals：对象比较方法
  • hashCode：取得 Hash 编码

 public boolean equals(Object obj)
    {
    	if (this == obj) {
			return true;
		}
		if (!(obj instanceof Person)) {
			return false;
		}
		PersonKey p = (PersonKey) obj;
		return new EqualsBuilder().append(this.name, p.getName()).append(this.phone,
				p.getPhone()).isEquals();
    }

    /**
     * Implementation of the hashCode method conforming to the Bloch pattern with
     * the exception of array properties (these are very unlikely primary key types).
     * @return int
     */
    public int hashCode()
    {
    	return new HashCodeBuilder().append(this.name).append(
				this.phone).toHashCode();
    }

-----Person.hbm.xml----

<?xml version="1.0" encoding='UTF-8'?>
<!DOCTYPE hibernate-mapping PUBLIC
                            "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
                            "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<!-- DO NOT EDIT: This is a generated file that is synchronized -->
<!-- by MyEclipse Hibernate tool integration.                   -->
<!-- Created Sat Nov 11 21:36:21 CST 2006                         -->
<hibernate-mapping package="org.lxh.hibernate03">

    <class name="Person" table="PERSON">
        <composite-id name="id" class="PersonKey">
            <key-property name="name" column="NAME" type="string"/>
            <key-property name="phone" column="PHONE" type="string"/>
        </composite-id>
 
        <property name="age" column="AGE" type="int" />
    </class>
    
</hibernate-mapping>

注意class="PersonKey
新建类PersonKey.java

package org.lxh.hibernate03;
import java.io.Serializable;
import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
public class PersonKey
    implements Serializable
{
    private volatile int hashValue = 0;
    private java.lang.String name;
    private java.lang.String phone;
    public PersonKey() {}
    public java.lang.String getName()
    {
        return name;
    }
	public void setName(java.lang.String name)
    {
        hashValue = 0;
        this.name = name;
    }
    public java.lang.String getPhone()
    {
        return phone;
    }
    public void setPhone(java.lang.String phone)
    {
        hashValue = 0;
        this.phone = phone;
    }
    public boolean equals(Object obj)
    {
    	if (this == obj) {
			return true;
		}
		if (!(obj instanceof Person)) {
			return false;
		}
		PersonKey p = (PersonKey) obj;
		return new EqualsBuilder().append(this.name, p.getName()).append(this.phone,
				p.getPhone()).isEquals();
    }
    public int hashCode()
    {
    	return new HashCodeBuilder().append(this.name).append(
				this.phone).toHashCode();
    }
}

Person.java

private PersonKey id ;
	private int age;
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public PersonKey getId() {
		return id;
	}
	public void setId(PersonKey id) {
		this.id = id;
	}