ibatis入门实例讲解

之前大家上网的ibatis官方网站：http://www.ibatis.com现在已经不再存在了，已经被MyBatis所替代http://www.mybatis.org/，我现在使用了还是之前的ibatis2.3.4，所以这个例子也是针对2.3.4版本讲解的

首先呢，打开资源包，可以看到里面有一个simple_exzample的文件夹，在MyEclipse8.5中新建一个JAVA项目，将刚才的文件夹中内容复制到项目SRC下，这样的话呢，可以看到这样一个目录

 这个MyTest是我后来加上的测试实实例，当然这些代码还不足以让程序测试出结果来

 看看ibatis的SQL语句配置类MySqlMapConfig.xml

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

<!DOCTYPE sqlMapConfig      
    PUBLIC "-//ibatis.apache.org//DTD SQL Map Config 2.0//EN"      
    "http://ibatis.apache.org/dtd/sql-map-config-2.dtd">

<sqlMapConfig>

  <!-- Configure a built-in transaction manager.  If you're using an 
       app server, you probably want to use its transaction manager 
       and a managed datasource -->
  <transactionManager type="JDBC" commitRequired="false">
    <dataSource type="SIMPLE">
      <property name="JDBC.Driver" value="com.mysql.jdbc.Driver"/>
      <property name="JDBC.ConnectionURL" value="jdbc:mysql://127.0.0.1:3306/ibatis"/>
      <property name="JDBC.Username" value="root"/>
      <property name="JDBC.Password" value="root"/>
    </dataSource>
  </transactionManager>

  <!-- List the SQL Map XML files. They can be loaded from the 
       classpath, as they are here (com.domain.data...) -->
  <sqlMap resource="com/mydomain/data/Account.xml"/>
  <!-- List more here...
  <sqlMap resource="com/mydomain/data/Order.xml"/>
  <sqlMap resource="com/mydomain/data/Documents.xml"/>
  -->

</sqlMapConfig>

这里我修改了下数据源为jdbc形式的，使用的是MySQL数据库，所以要添加数据库驱动包，还有ibatis核心包，在看看数据库表该怎么建立，这得查看下Account.xml了

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

<!DOCTYPE sqlMap      
    PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN"      
    "http://ibatis.apache.org/dtd/sql-map-2.dtd">

<sqlMap namespace="Account">

  <!-- Use type aliases to avoid typing the full classname every time. -->
  <typeAlias alias="Account" type="com.mydomain.domain.Account"/>

  <!-- Result maps describe the mapping between the columns returned
       from a query, and the class properties.  A result map isn't
       necessary if the columns (or aliases) match to the properties 
       exactly. -->
  <resultMap id="AccountResult" class="Account">
    <result property="id" column="ACC_ID"/>
    <result property="firstName" column="ACC_FIRST_NAME"/>
    <result property="lastName" column="ACC_LAST_NAME"/>
    <result property="emailAddress" column="ACC_EMAIL"/>
  </resultMap>

  <!-- Select with no parameters using the result map for Account class. -->
  <select id="selectAllAccounts" resultMap="AccountResult">
    select * from ACCOUNT
  </select>

  <!-- A simpler select example without the result map.  Note the 
       aliases to match the properties of the target result class. -->
  <select id="selectAccountById" parameterClass="int" resultClass="Account">
    select
      ACC_ID as id,
      ACC_FIRST_NAME as firstName,
      ACC_LAST_NAME as lastName,
      ACC_EMAIL as emailAddress
    from ACCOUNT
    where ACC_ID = #id#
  </select>
   
  <!-- Insert example, using the Account parameter class -->
  <insert id="insertAccount" parameterClass="Account">
    insert into ACCOUNT (
      ACC_FIRST_NAME,
      ACC_LAST_NAME,
      ACC_EMAIL
    )values (
      #firstName#, #lastName#, #emailAddress#
    )
  </insert>

  <!-- Update example, using the Account parameter class -->
  <update id="updateAccount" parameterClass="Account">
    update ACCOUNT set
      ACC_FIRST_NAME = #firstName#,
      ACC_LAST_NAME = #lastName#,
      ACC_EMAIL = #emailAddress#
    where
      ACC_ID = #id#
  </update>

  <!-- Delete example, using an integer as the parameter class -->
  <delete id="deleteAccountById" parameterClass="int">
    delete from ACCOUNT where ACC_ID = #id#
  </delete>

</sqlMap>

 上面的<ResultMap>标签中有指定每个Account属性对应的数据库的列名，所以就新建数据库了

 这样数据建立完成后，我们就可以测试了，这回就用到了SimpleExample.java类了

package com.mydomain.data;

import com.ibatis.sqlmap.client.SqlMapClient;
import com.ibatis.sqlmap.client.SqlMapClientBuilder;
import com.ibatis.common.resources.Resources;
import com.mydomain.domain.Account;

import java.io.Reader;
import java.io.IOException;
import java.util.List;
import java.sql.SQLException;

/**
 * This is not a best practices class.  It's just an example
 * to give you an idea of how iBATIS works.  For a more complete
 * example, see JPetStore 5.0 at http://www.ibatis.com.
 */
public class SimpleExample {

  /**
   * SqlMapClient instances are thread safe, so you only need one.
   * In this case, we'll use a static singleton.  So sue me.  ;-)
   */
  private static SqlMapClient sqlMapper;

  /**
   * It's not a good idea to put code that can fail in a class initializer,
   * but for sake of argument, here's how you configure an SQL Map.
   */
  static {
    try {
      Reader reader = Resources.getResourceAsReader("com/mydomain/data/MySqlMapConfig.xml");
      sqlMapper = SqlMapClientBuilder.buildSqlMapClient(reader);
      reader.close(); 
    } catch (IOException e) {
      // Fail fast.
      throw new RuntimeException("Something bad happened while building the SqlMapClient instance." + e, e);
    }
  }

  public static List selectAllAccounts () throws SQLException {
    return sqlMapper.queryForList("selectAllAccounts");
  }

  public static Account selectAccountById  (int id) throws SQLException {
    return (Account) sqlMapper.queryForObject("selectAccountById", id);
  }

  public static void insertAccount (Account account) throws SQLException {
    sqlMapper.insert("insertAccount", account);
  }

  public static void updateAccount (Account account) throws SQLException {
    sqlMapper.update("updateAccount", account);
  }

  public static void deleteAccount (int id) throws SQLException {
    sqlMapper.delete("deleteAccountById", id);
  }

}

  像上面的增删改查中用到的代替SQL语句的映射KEY，也是可以加上相应的XML文件的配置名称的，如： return sqlMapper.queryForList("Account.selectAllAccounts")那么这个Account就是

Account.xml的名称了

真正想看到测试结果得另写个JUNIT测试类，添加junit的jar包，这里我写了MyTest.java

package com.mydomain.data;

import java.sql.SQLException;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

import org.junit.Test;

import com.mydomain.domain.Account;

public class MyTest {
	@Test
	public void selectAllAccounts(){
		try {
			List list=SimpleExample.selectAllAccounts();
			System.out.println(Arrays.toString(list.toArray()));
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	public void selectAccountById(){
		try {
			Account account=SimpleExample.selectAccountById(1);
			System.out.println(account);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	public void insertAccount(){
		Account account=new Account();
		account.setFirstName("tom");
		account.setLastName("jam");
		account.setEmailAddress("china");
		try {
			SimpleExample.insertAccount(account);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	public void updateAccount(){
	    try {
			Account account=SimpleExample.selectAccountById(2);
			account.setFirstName("gates");
			SimpleExample.updateAccount(account);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	    
	}
	
	public void deleteAccount(){
		try {
			SimpleExample.deleteAccount(1);
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}
	
}

怎么样，ibatis也不是很难吧，将所有的SQL语句统一管理起来，十分方便，对于写复杂的SQL语句也可以直接来写

 顺便介绍下MyBatis

MyBatis来源于iBATIS，iBATIS是一个由Clinton Begin在2001年发起的开放源代码项目，iBATIS一词来源于“internet”和“abatis”的组合。该项目最初侧重于密码软件的开发，现在是一个基于Java的持久层框架。iBATIS提供的持久层框架包括SQL Maps和Data Access Objects（DAO），它是著名的ORM开发框架，分为Java和.NET版本，有着众多的追随者。

iBATIS更名为MyBatis并迁移到Google Code，此次项目迁移后，将启用新的网站http://www.mybatis.org/，由于目前只是改了名字，因此仍然可直接浏览iBatis的文档。

MyBatis开发团队希望脱离Apache而独立发展，并保证不会修改授权协议（Apache License）、代码完全兼容、包名不会更改、也不会删除 Apache站上的任何相关资源。

改名后的第一次版本MyBatis 3.0.1已经发布，基于iBatis 3.0版本，该版本非常稳定，已经有很多用户使用了数周时间，修复了一些小bug。欲下载 MyBatis 3.0.1请到它新的网站http://www.mybatis.org/。 目前版本是3.0.2