小试Ibatis

iBatis 是一个 O/R Mapping 解决方案， iBatis 最大的特点就是小巧，上手很快。如果你不需要太多复杂的功能， iBatis 是能满足你的要求又足够灵活的最简单的解决方案。iBatis中所有的DAO方法都只传一个值对象，复杂查询当然也不例外。另外对常见的1:1，1:N关系的支持不如Hibernate。Ibatis是应该属于面向SQL的O/RMapping 而Hibernate 则属于面向对象的O/R Mappding相对比较复杂。

一直听说Ibatis很简单，而且很不错。所以，今天就学习一下。

先建数据库和表:
/*
MySQL Data Transfer
Source Host: localhost
Source Database: ibatis
Target Host: localhost
Target Database: ibatis
Date: 2007-4-24 1:02:15
*/

SET FOREIGN_KEY_CHECKS=0;
-- ----------------------------
-- Table structure for t_user
-- ----------------------------
Create TABLE `t_user` (
`id` int(11) NOT NULL auto_increment,
`name` varchar(50) default NULL,
`password` varchar(10) default NULL,
`email` varchar(50) default NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=gbk;

-- ----------------------------
-- Records
-- ----------------------------
Insert INTO `t_user` VALUES ('1', '小林', 'admin', 'test#baidu.com.cn');
Insert INTO `t_user` VALUES ('2', 'Eays, 'admin', 'test2#163.com');
Insert INTO `t_user` VALUES ('3', '8', '8888', 'test3#google.net');

我的Eclipse工程目录:

现在编写Ibatis的SqlMapConfig.xml文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE sqlMapConfig
PUBLIC "-//iBATIS.com//DTD SQL Map Config 2.0//EN"
"http://www.ibatis.com/dtd/sql-map-config-2.dtd">
<!-- Ibatis配置文件-->

<sqlMapConfig >
<!-- 加载连接数据库属性文件 -->
<properties resource="net/eays/maps/SqlMapConfig.properties" />

<!--
cacheModelsEnabled:是否启动SqlMapClient的缓存机制。
enhancementEnabled：是否针对POJO启用字节码增加机制以提升geter/seter的调用效用，为延迟加载带来了及大的性能提升。
lazyLoadingEnabled：是否启用延迟加载机制。
maxRequests：最大并大请求数。
maxSessions：最大Session数，即当前最大允许的开发SqlMapClient数
maxTransactions：最大并发事务数。
-->
<settings
cacheModelsEnabled = "true"
enhancementEnabled = "true"
lazyLoadingEnabled = "true"
maxRequests = "32"
maxSessions = "10"
maxTransactions = "5"
useStatementNamespaces = "false"
/>
<!-- DataSource -->
<transactionManager type="JDBC">
<dataSource type="SIMPLE">
<!--JDBC驱动-->
<property name="JDBC.Driver" value="${driver}" />
<!--数据库URL-->
<property name="JDBC.ConnectionURL" value="${url}" />
<!--数据库用户名-->
<property name="JDBC.Username" value="${username}" />
<!--数据库密码-->
<property name="JDBC.Password" value="${password}" />
<!--不知道,在网站上查不出来，有时间再研究-->
<property name="JDBC.DefaultAutoCommit" value="true" />
<!--数据库连接池可维持的最大容量-->
<property name="Pool.MaximumActiveConnections" value="10"/>
<!--数据库连接池中允许的可挂起连接数-->
<property name="Pool.MaximumIdleConnections" value="5"/>
<!--数据库连接池中，连接被某个任务所占用的最大时间-->
<property name="Pool.MaximumCheckoutTime" value="120000"/>
<!--当线程想从连接池中获取连接时，连接池中无可用连接，该参数设置线程所允许等待的最长时间-->
<property name="Pool.TimeToWait" value="500"/>
<!--数据库连接状态检查语句-->
<property name="Pool.PingQuery" value="select 1 from t_user"/>
<!--是否允许检查连接状态-->
<property name="Pool.PingEnabled" value="false"/>
<!--对持续连接超过设定值的连接进行检查-->
<property name="Pool.PingConnectionsOlderThan" value="1"/>
<!--对空闲超过设定值的连接进行检查-->
<property name="Pool.PingConnectionsNotUsedFor" value="1"/>
</dataSource>
</transactionManager>
<!--加载SqlMap文件-->
<sqlMap resource="net/eays/maps/User.xml" />
</sqlMapConfig>

编写配置文件类:SqlMapConfig.properties

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/ibatis
username=root
password=password

编写User.java类

package net.eays.maps;

/**
* @author 小林信仁
* @version 2007.4.23
*/
public class User {

private int id;
private String name;
private String password;
private String email;

public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}

}
然后编写User.java类关联映射的User.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE sqlMap
PUBLIC "-//iBATIS.com//DTD SQL Map 2.0//EN"
"http://www.ibatis.com/dtd/sql-map-2.dtd">
<sqlMap namespace="Author">
<!--模块配置-->
<!--设置本映射文件中的别名-->
<typeAlias alias="user" type="net.eays.maps.User" />
<!--Statement配置-->

<select id="getUser" parameterClass="java.lang.String" resultClass="user">
<![CDATA[ select name,password,email from t_user where name = #name#]]>
</select>
<!--查询所有的记录-->
<select id="getAllUser" resultClass="user">
<![CDATA[ select * from t_user]]>
</select>
<!--修改-->
<update id="updateUser" parameterClass="user">
<![CDATA[ update t_user set name = #name#,password = #password# where id = #id#]]>
</update>
<!--删除-->
<delete id="deleteUser" parameterClass="user">
<![CDATA[ delete from t_user where id = #id# ]]>
</delete>
<insert id="insertUser" parameterClass="user">
<![CDATA[ insert into t_user(name,password,email) values(#name#,#password#,#email#)]]>
</insert>
</sqlMap>

编写测试类:
package com.eays;

import java.sql.*;
import java.io.Reader;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import net.eays.maps.User;
import com.ibatis.sqlmap.client.SqlMapClient;
import com.ibatis.sqlmap.client.SqlMapClientBuilder;
import com.ibatis.common.resources.Resources;

/**
* @author 小林信仁
* @version 2007/4/23
*/
public class TestIbatis {
//首先初始化一个Ibatis获取一个SqlMapConfig.xml对象
public static SqlMapClient sqlMap = null;
TestIbatis(){

String resource = "net/eays/maps/SqlMapConfig.xml";
try {
Reader reader = Resources.getResourceAsReader(resource);
sqlMap = SqlMapClientBuilder.buildSqlMapClient(reader);
} catch (IOException e) {
// TODO Auto-generated catch block
System.err.print("无价实例化SqlMapConfig对象");
}
}
public void updateUser(String name,String password,int id){
User user = new User();
user.setId(id);
user.setName(name);
user.setPassword(password);
try {
sqlMap.startTransaction();
sqlMap.update("updateUser", user);
sqlMap.commitTransaction();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
System.err.println("修改错误");
}finally{
try {
sqlMap.endTransaction();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public static List getAllUser(){
List list = null;
try {
sqlMap.startTransaction();
list = sqlMap.queryForList("getAllUser");
sqlMap.commitTransaction();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
sqlMap.endTransaction();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return list;
}

public boolean insertUser(String name,String password,String email){
boolean bool = false;
User user = new User();
user.setName(name);
user.setEmail(email);
user.setPassword(password);
try {
sqlMap.startTransaction();
sqlMap.insert("insertUser",user);
bool = true;
sqlMap.commitTransaction();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
sqlMap.endTransaction();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return bool;

}
public static void main(String[] args) {

TestIbatis testIbatis = new TestIbatis();
testIbatis.updateUser("易思网", "sydica", 2);
List list = TestIbatis.getAllUser();
Iterator iterator = list.iterator();
while(iterator.hasNext()){
User user = (User)iterator.next();
System.out.print("Email=" + user.getEmail() + " ");
System.out.print("Id=" + user.getId() + " ");
System.out.print("Password=" + user.getPassword() + " ");
System.out.println("Name=" + user.getName() + " ");

}
}

}