iBatis3 Note（二） : 初识Hello World

和学习所有框架API一样，有个HelloWorld的例子

本着1+1=2学习的逻辑，以下继续对iBatis3做一些简单实现

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熟悉Hibernate的都知道如下几步

/**   *  1.  create Configuration   *  2.  build SessionFactory   *  3.  open Session   *  4.  begin Transaction   *  5.  do crud operation   *       flush commit rollback   *  6.  close resource   */

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?而iBatis3会有如下几步

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/** *  1.  create SqlSessionFactoryBuilder *  2.  read config file *  3.  build Factory *  4.  open session *  5.  do crud operations *  6.  close session */

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第一个实现Hello World，

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先看下文件结构

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既然是iBatis，首先创建脚本，用的是mysql

DROP TABLE IF EXISTS `ibatis`.`t_helloworld`;CREATE TABLE  `ibatis`.`t_helloworld` (  `hw_id` int(10) unsigned NOT NULL AUTO_INCREMENT,  `name` varchar(45) NOT NULL,  `age` int(2) unsigned NOT NULL,  PRIMARY KEY (`hw_id`)) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;

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?数据如下

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同时关注几个文件

ibatis-config.xmlconfig.propertieshelloworld.map.xml

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ibatis-config.xml

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE configuration PUBLIC "-//ibatis.apache.org//DTD Config 3.0//EN" "http://ibatis.apache.org/dtd/ibatis-3-config.dtd"><configuration><!-- 数据库配置文件 --><properties resource="basic/config.properties"/><!-- default属性一定要指定为其中某一environment的id --><environments default="helloworld"><environment id="helloworld"><!-- type暂时用最简单的JDBC，其他可选项MANAGED --><transactionManager type="JDBC" /><!-- type暂时用最简单的POOLED，其他可选项UNPOOLED,JNDI --><dataSource type="POOLED"><property name="driver"   value="${driver}"/><property name="url"      value="${url}"/><property name="username" value="${username}"/><property name="password" value="${password}"/><!-- property name="driver"   value="com.mysql.jdbc.Driver"/><property name="url"      value="jdbc:mysql://localhost:3306/ibatis"/><property name="username" value="root"/><property name="password" value="abcdef"/ --></dataSource></environment></environments><!-- 映射文件 --><mappers><mapper resource="basic/helloworld.map.xml"/></mappers></configuration>

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???? 2.?? config.properties

driver=com.mysql.jdbc.Driverurl=jdbc\:mysql\://localhost\:3306/ibatisusername=rootpassword=abcdef

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??? 3.?? helloworld.map.xml

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<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE mapper PUBLIC "-//ibatis.apache.org//DTD iBatis Mapper 3.0 //EN" "http://ibatis.apache.org/dtd/ibatis-3-mapper.dtd"><mapper namespace="basic.HelloWorld"><select id="getHelloworlds" resultType="java.util.List">select * from t_helloworld</select><select id="getHelloworldsByHwId" resultType="java.util.List" parameterType="int">select * from t_helloworld where hw_id = #{hw_id}</select></mapper>

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FirstTest.java

package basic;import java.io.IOException;import java.io.Reader;import java.util.List;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;public class FirstTest {public static void main(String[] args) throws IOException {String configXml = "basic/ibatis-config.xml";SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();Reader config = Resources.getResourceAsReader(configXml);SqlSessionFactory factory = builder.build(config);SqlSession session = factory.openSession();List<HelloWorld> list = null;try {list = session.selectList("getHelloworlds");System.out.println(list.size());list = session.selectList("getHelloworldsByHwId", 1);System.out.println(list.size());} finally {session.close();}}}

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