Detailed explanation of Hibernate mapping files

<?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" ><hibernate-mapping>
    <class name="com.troyforever.example.data.bean.Test" table="test" schema="example">
        <id name="id" type="java.lang.Integer" column="id">
            <generator class="identity">
            </generator>
        </id>
        <property name="age" type="java.lang.Integer">
            <column name="age" not-null="true" />
        </property>
        <property name="content" type="java.lang.String">
            <column name="content" length="2000" not-null="true" />
        </property>
        <property name="addtime" type="java.util.Date">
            <column name="addtime" />
        </property>
    </class></hibernate-mapping>