# 用Hibernate 產生POJO
**建立hibernate.cfg.xml**

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.driver_class">net.sourceforge.jtds.jdbc.Driver</property>
		<property name="hibernate.connection.url">jdbc:jtds:sqlserver://127.0.0.1:1433/CAMIOL</property>
        <property name="hibernate.connection.username">camiol</property>
        <property name="hibernate.connection.password">camiol</property>
        <property name="hibernate.dialect">org.hibernate.dialect.SQLServerDialect</property>
        <property name="hibernate.connection.autocommit">true</property>
    </session-factory>
</hibernate-configuration>

**建立hibernate.reveng.xml**

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-reverse-engineering PUBLIC "-//Hibernate/Hibernate Reverse Engineering DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-reverse-engineering-3.0.dtd" >

<hibernate-reverse-engineering>
	<type-mapping>
		<sql-type jdbc-type="NUMERIC" precision='1' scale="0" hibernate-type="Integer" />
		<sql-type jdbc-type="NUMERIC" precision='2' scale="0" hibernate-type="Integer" />
		<sql-type jdbc-type="NUMERIC" precision='3' scale="0" hibernate-type="Integer" />
		<sql-type jdbc-type="NUMERIC" precision='4' scale="0" hibernate-type="Integer" />
		<sql-type jdbc-type="NUMERIC" precision='5' scale="0" hibernate-type="Integer" />
		<sql-type jdbc-type="NUMERIC" precision='6' scale="0" hibernate-type="Integer" />
		<sql-type jdbc-type="NUMERIC" precision='7' scale="0" hibernate-type="Integer" />
		<sql-type jdbc-type="NUMERIC" precision='8' scale="0" hibernate-type="Integer" />
		<sql-type jdbc-type="NUMERIC" precision='9' scale="0" hibernate-type="Integer" />
		<sql-type jdbc-type="NUMERIC" precision='10' scale="0" hibernate-type="Long" />
		<sql-type jdbc-type="NUMERIC" precision='11' scale="0" hibernate-type="Long" />
		<sql-type jdbc-type="NUMERIC" precision='12' scale="0" hibernate-type="Long" />
		<sql-type jdbc-type="NUMERIC" precision='13' scale="0" hibernate-type="Long" />
		<sql-type jdbc-type="NUMERIC" precision='14' scale="0" hibernate-type="Long" />
		<sql-type jdbc-type="NUMERIC" precision='15' scale="0" hibernate-type="Long" />
		<sql-type jdbc-type="NUMERIC" precision='16' scale="0" hibernate-type="Long" />
		<sql-type jdbc-type="NUMERIC" precision='17' scale="0" hibernate-type="Long" />
		<sql-type jdbc-type="NUMERIC" precision='18' scale="0" hibernate-type="Long" />
		<sql-type jdbc-type="NUMERIC" precision='19' scale="0" hibernate-type="Long" />
		<sql-type jdbc-type="INTEGER" hibernate-type="Long" />
		<sql-type jdbc-type="CHAR" hibernate-type="java.lang.String" />
		<sql-type jdbc-type="VARCHAR" hibernate-type="java.lang.String" />
		<sql-type jdbc-type="BIT" hibernate-type="java.lang.Boolean" />
		<sql-type jdbc-type="TINYINT" hibernate-type="Integer" />
		<sql-type jdbc-type="SMALLINT" hibernate-type="Integer" />
		<sql-type jdbc-type="INTEGER" hibernate-type="Integer" />
		<sql-type jdbc-type="BIGINT" hibernate-type="java.lang.Long" />
		<sql-type jdbc-type="DOUBLE" hibernate-type="java.lang.Double" />
		<sql-type jdbc-type="FLOAT" hibernate-type="java.lang.Double" />
		<sql-type jdbc-type="DECIMAL" hibernate-type="java.lang.Long" />
		<sql-type jdbc-type="NUMERIC" hibernate-type="java.lang.Long" />
		<sql-type jdbc-type="NVARCHAR" hibernate-type="gov.camiol.dialect.NStringUserType" />
		<sql-type jdbc-type="LONGNVARCHAR" hibernate-type="gov.camiol.dialect.NStringUserType" />
	</type-mapping>
	<table-filter match-name="Student" exclude="false" />

</hibernate-reverse-engineering>

**建立NStringUserType**

package gov.nia.cdi.dialect;

/**
 * 
 */

import java.io.Serializable;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;

import org.hibernate.HibernateException;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.type.CustomType;
import org.hibernate.usertype.UserType;


public class NStringUserType implements UserType {
	
    public static final CustomType INSTANCE = new CustomType(new NStringUserType()); 

    @Override
    public Object assemble(Serializable arg0, Object arg1) throws HibernateException {
        return deepCopy(arg0);
    }

    @Override
    public Object deepCopy(Object arg0) throws HibernateException {
        return arg0 == null ? null : arg0.toString();
    }

    @Override
    public Serializable disassemble(Object arg0) throws HibernateException {
        return (Serializable) deepCopy(arg0);
    }

    @Override
    public boolean equals(Object arg0, Object arg1) throws HibernateException {
        if (arg0 == null) {
            return arg1 == null;
        }

        return arg0.equals(arg1);
    }

    @Override
    public int hashCode(Object arg0) throws HibernateException {
        return arg0.hashCode();
    }

    @Override
    public boolean isMutable() {
        return false;
    }

    @Override
    public Object replace(Object arg0, Object arg1, Object arg2) throws HibernateException {
        return deepCopy(arg0);
    }

    @SuppressWarnings("rawtypes")
    @Override
    public Class returnedClass() {
        return String.class;
    }

    @Override
    public int[] sqlTypes() {
        return new int[] {Types.NVARCHAR};
    }

    @Override
    public Object nullSafeGet(ResultSet arg0, String[] arg1,
            SessionImplementor arg2, Object arg3) throws HibernateException,
            SQLException {
        // TODO Auto-generated method stub
        String result = arg0.getString(arg1[0]);
        return result == null ? null : result;
    }

    @Override
    public void nullSafeSet(PreparedStatement arg0, Object arg1, int arg2,
            SessionImplementor arg3) throws HibernateException, SQLException {
        // TODO Auto-generated method stub
        if (arg1 == null) {
            arg0.setNull(arg2, Types.NVARCHAR);
        } else {
            arg0.setNString(arg2, arg1.toString());
        }
    }

}

**在ant的build.xml裡面設定**

<!-- hibernate tool -->
<path id="antlib.class.path">
    <fileset dir="hibernate/lib" includes="*.jar" />
</path>
<taskdef name="hibernatetool" classname="org.hibernate.tool.ant.HibernateToolTask" classpathref="antlib.class.path" />
<target name="pojo">
    <hibernatetool destdir="${src.dir}" templatepath="hibernate">
        <classpath refid="antlib.class.path" />
        <jdbcconfiguration configurationfile="hibernate/hibernate.cfg.xml" revengfile="hibernate/hibernate.reveng.xml" packagename="gov.domain.camiol" />
        <hbm2java jdk5="true" ejb3="true" />
    </hibernatetool>
</target>

**在hibernate/lib 下面放入需要的jar檔**

**設定完後在build.xml上面按右鍵 Run As > Ant Build > 選POJO，即可在我們指定的package下面產生對應DB的POJO出來**

###### tags: `hibernate`