使用uuid作为主键生成策略

之前的Hibernate使用int作为主键,其主键生成策略(在映射文件中定义)为native,这是一种根据当前使用的数据库自动选择主键策略的方法.现在使用uuid作为主键生成策略.

若使用uuid作为主键的生成策略,前提是主键要定义为String型,且映射文件中写:

<generator class = "uuid"></generator>

下面是持久类和映射文件:

持久类:

package hiber1;

public class User {
	private String uid;
	private String username;
	private String password;
	private String address;
	public String getUid() {
		return uid;
	}
	public void setUid(String uid) {
		this.uid = uid;
	}
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public String getAddress() {
		return address;
	}
	public void setAddress(String address) {
		this.address = address;
	}
	
	

	

}

映射文件:

<?xml version="1.0" encoding="UTF-8"?>

<!--引入dtd约束-->
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    
<hibernate-mapping>
    <class name = "hiber1.User" table = "newtableTest2"><!--class中写类的全路径-->
        <id name = "uid" column = "uid">
            <generator class = "uuid"></generator>
        </id>
        
        <property name="username" column = "username"></property>
        <property name="password" column = "password"></property>
        <property name="address" column = "address"></property>
    </class>
</hibernate-mapping>

主要就是这两处改动.
之后查看生成的表格,