一个iBatis的demo

相对Hibernate和Apache OJB 等“一站式”ORM解决方案而言，ibatis 是一种“半
自动化”的ORM实现。
所谓“半自动”，可能理解上有点生涩。纵观目前主流的ORM，无论Hibernate 还是
Apache OJB，都对数据库结构提供了较为完整的封装，提供了从POJO 到数据库表的全
套映射机制。程序员往往只需定义好了POJO 到数据库表的映射关系，即可通过Hibernate
或者OJB 提供的方法完成持久层操作。程序员甚至不需要对SQL 的熟练掌握，
Hibernate/OJB 会根据制定的存储逻辑，自动生成对应的SQL 并调用JDBC 接口加以执
行。 ----摘自官方资料的一段话

iBatis是一种很好的解决方案，使用起来很灵活，参考一些网络中的资料我也想把自己的使用过程写下来，如有错误希望指正。

环境：JDK1.5+Eclipse3.2 使用时仅需要在Eclipse中导入项目。

首先是表结构, 提供了两种数据库的支持分别为MySQL与hsqldb，可以根据实际情况选择使用。以MySQL为例：
[code]create database if not exists `ibatis_schema`;

USE `ibatis_schema`;

drop table if exists `t_user`;

CREATE TABLE `t_user` (
`id` int(12) NOT NULL auto_increment,
`name` varchar(50) default NULL,
`date` date default NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=GBK;

Insertinto `t_user`(name,date) values('liulu','2007-03-15'),('liulu2','2007-03-15'),('liulu3','2007-03-15');
[/code]
然后是iBatis的配置文件 SqlMapConfig.xml
这里进行数据源的配置以及一些参数的设置和优化
[code]<?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>

<settings cacheModelsEnabled="true" useStatementNamespaces="true" />
<transactionManager type="JDBC">
<dataSource type="SIMPLE">
<property name="JDBC.Driver" value="com.mysql.jdbc.Driver" />
<property name="JDBC.ConnectionURL" value="jdbc:mysql://localhost/ibatis_schema" />
<property name="JDBC.Username" value="root" />
<property name="JDBC.Password" value="1234" />
</dataSource>
</transactionManager>

<sqlMap resource="com/javaeye/liulu/maps/User.xml" />
</sqlMapConfig>
[/code]
User.java就是domain了，是映射的对象。
[code]package com.javaeye.liulu.domain;

import java.io.Serializable;
import java.util.Date;

public class User implements Serializable{
private int id;
private String name;
private Date date;
public Date getDate() {
return date;
}
public void setDate(Date date) {
this.date = date;
}
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;
}
}
[/code]
下面是比较重要的SQL Map XML映射文件，所有方法都在这里。
User.xml
[code]<?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="User">
<typeAlias alias="UserObject" type="com.javaeye.liulu.domain.User" />
<resultMap id="userResult" class="UserObject">
<result property="id" column="id" jdbcType="NUMBER" />
<result property="name" column="name" jdbcType="VARCHAR2" />
<result property="date" column="date" jdbcType="DATE" />
</resultMap>

<select id="getByPK" resultMap="userResult" parameterClass="UserObject">
<![CDATA[
select
id,
name,
date
from t_user
where id = #id#
]]>
</select>

<select id="getById" resultMap="userResult" parameterClass="java.lang.String">
<![CDATA[
select
id,
name,
date
from t_user
where id = $String$
]]>
</select>

<sql id="Dy_SC">
<dynamic prepend="WHERE">
<isNotNull prepend="AND" property="id">id like #id#</isNotNull>
<isNotNull prepend="AND" property="name">name like #name#</isNotNull>
</dynamic>
</sql>

<select id="getUser" resultMap="userResult">
<![CDATA[
select
id,
name,
date
from t_user
]]>
<include refid="Dy_SC" />
</select>

<insert id="insertUser" parameterClass="UserObject">
INSERT INTO t_user (name,date) VALUES (#name#,#date#)
</insert>

<insert id="insertUserTest" parameterClass="UserObject">
INSERT INTO t_user (id,name,date) VALUES (#id#,#name#,#date#)
</insert>

<update id="updateUser" parameterClass="UserObject">
<![CDATA[
UPDATE t_user
SET
name=#name#,
date=#date#
WHERE id = #id#
]]>
</update>

<delete id="deleteUser" parameterClass="java.lang.String">
delete from t_user where id=#value#
</delete>

<statement id="getMaxId" resultClass="java.lang.Integer">
select Max(id) from t_user
</statement>

<statement id="getMax" resultClass="java.util.HashMap">
select Max(id) as id,Max(name) as name,Max(date) as date from t_user
</statement>

</sqlMap>
[/code]
这样就可以来测试了，测试也使用了两种方法，先使用一个普通应用程序来测试一下程序的运行好了。
[code]package com.javaeye.liulu;

import java.io.Reader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;

import com.ibatis.common.jdbc.ScriptRunner;
import com.ibatis.common.resources.Resources;
import com.ibatis.sqlmap.client.SqlMapClient;
import com.ibatis.sqlmap.client.SqlMapClientBuilder;
import com.javaeye.liulu.domain.User;

public class Main {

//hsql初始化,对MySQL没有影响
static {
try {
Properties props = Resources.getResourceAsProperties("properties/database.properties");
String url = props.getProperty("url");
String driver = props.getProperty("driver");
String username = props.getProperty("username");
String password = props.getProperty("password");
if (url.equals("jdbc:hsqldb:mem:ibatisDemo")) {
Class.forName(driver).newInstance();
Connection conn = DriverManager.getConnection(url, username, password);
try {
ScriptRunner runner = new ScriptRunner(conn, false, false);
runner.setErrorLogWriter(null);
runner.setLogWriter(null);
runner.runScript(Resources.getResourceAsReader("ddl/hsql/ibatisdemo-hsqldb-schema.sql"));
runner.runScript(Resources.getResourceAsReader("ddl/hsql/ibatisdemo-hsqldb-dataload.sql"));
} finally {
conn.close();
}
}
} catch (Exception e) {
throw new RuntimeException("Description. Cause: " + e, e);
}
}

/**
* 初始化iBatis获得一个SqlMapClient对象
*
* @param
* @return SqlMapClient
*/
public static SqlMapClient getSqlMapClient() {
String resource = "com/javaeye/liulu/maps/SqlMapConfig.xml";
SqlMapClient sqlMap = null;
try {
Reader reader = Resources.getResourceAsReader(resource);
sqlMap = SqlMapClientBuilder.buildSqlMapClient(reader);
} catch (Exception e) {
e.printStackTrace();
}
return sqlMap;
}

/**
* 插入一条记录
*
* @param
* @return
*/
public static void insert() {
SqlMapClient sqlMap = getSqlMapClient();
try {
sqlMap.startTransaction();
User user = new User();
user.setName("insert1");
user.setDate(new Date());
sqlMap.insert("User.insertUser", user);
sqlMap.commitTransaction();
} catch (SQLException e) {
e.printStackTrace();
}
}

/**
* 将第一条记录的信息更新
*
* @param
* @return
*/
public static void update() {
SqlMapClient sqlMap = getSqlMapClient();
try {
sqlMap.startTransaction();
User user = (User)sqlMap.queryForObject("User.getById", "1");
user.setName("update1");
sqlMap.update("User.updateUser", user);
sqlMap.commitTransaction();
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
sqlMap.endTransaction();
} catch (SQLException e) {
e.printStackTrace();
}
}
}

/**
* 删除id最大的记录
*
* @param
* @return
*/
public static void delete() {
SqlMapClient sqlMap = getSqlMapClient();
try {
sqlMap.startTransaction();
String maxId = sqlMap.queryForObject("User.getMaxId", null).toString();
sqlMap.delete("User.deleteUser", maxId);
sqlMap.commitTransaction();
} catch (SQLException e) {
e.printStackTrace();
}
}

/**
* 根据name查询User为Map的List
*
* @param
* @return List
*/
public static List getUser() {
SqlMapClient sqlMap = getSqlMapClient();
List<User> user = null;
try {
sqlMap.startTransaction();
HashMap params = new HashMap();
params.put("name", "%liulu%");
user = sqlMap.queryForList("User.getUser", params);
sqlMap.commitTransaction();
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
sqlMap.endTransaction();
} catch (SQLException e) {
e.printStackTrace();
}
}
return user;
}

/**
* 查询各个字段的最大值(一般用于统计，此处演示使用方法)
*
* @param
* @return
*/
public static void getMax() {
SqlMapClient sqlMap = getSqlMapClient();
try {
sqlMap.startTransaction();
Map search = (HashMap) sqlMap.queryForObject("User.getMax", null);
System.out.println(search.get("id").toString() + "\n"
+ search.get("name").toString() + "\n"
+ search.get("date").toString());
sqlMap.commitTransaction();
} catch (SQLException e) {
e.printStackTrace();
}
}

/**
* 通过主键查找,返回user
*
* @param
* @return
*/
public static void getByPK() {
SqlMapClient sqlMap = getSqlMapClient();
User user = new User();
try {
sqlMap.startTransaction();
user.setId(1);
user = (User) sqlMap.queryForObject("User.getByPK", user);
System.out.println(user.getId() + "\n" + user.getName() + "\n"
+ user.getDate());
sqlMap.commitTransaction();
} catch (SQLException e) {
e.printStackTrace();
}
}

public static void main(String[] args) {
//insert();
//update();
//delete();

List<User> user = getUser();
for (User o : user) {
System.out.println("id:" + o.getId() + "\nname:" + o.getName()
+ "\nDate:" + o.getDate() + "\n------------");
}
//getMax();
//getByPK();
}
}
[/code]
所有的方法都是静态的，可以分别对映射方法进行测试。

下面使用的是单元测试对iBatis来测试，使用了dbunit这个开源项目。
首先，要为单元测试准备数据。使用DbUnit，我们可以用XML文件来准备测试数据集。
t_user对应表名
id，name，date分别对应列名

user_seed.xml
[code]<?xml version="1.0" encoding="GBK"?>
<dataset>
<t_user id="1"
name="liulu"
date="2007-01-01"/>

<t_user id="2"
name="liulu2"
date="2007-03-15"/>

<t_user id="3"
name="liulu3"
date="2007-03-18"/>
</dataset>
[/code]
方便测试，首先为SqlMap的单元测试编写一个抽象的测试基类
[code]package com.javaeye.liulu.test;

import java.io.Reader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.util.Properties;

import javax.sql.DataSource;

import org.dbunit.DatabaseTestCase;
import org.dbunit.database.DatabaseConnection;
import org.dbunit.database.IDatabaseConnection;

import com.ibatis.common.resources.Resources;
import com.ibatis.db.util.ScriptRunner;
import com.ibatis.sqlmap.client.SqlMapClient;
import com.ibatis.sqlmap.client.SqlMapClientBuilder;

public abstract class BaseSqlMapTest extends DatabaseTestCase {
protected static SqlMapClient sqlMap;

protected IDatabaseConnection getConnection() throws Exception {
return new DatabaseConnection(getJdbcConnection());
}
protected void setUp() throws Exception {
super.setUp();
init();
}
protected void tearDown() throws Exception {
super.tearDown();
getConnection().close();
if (sqlMap != null) {
DataSource ds = sqlMap.getDataSource();
Connection conn = ds.getConnection();
conn.close();
}
}
protected void init() throws Exception {
initSqlMap("com/javaeye/liulu/maps/SqlMapConfig.xml", null);
}
protected SqlMapClient getSqlMapClient() {
return sqlMap;
}
protected void initSqlMap(String configFile, Properties props)
throws Exception {
Reader reader = Resources.getResourceAsReader(configFile);
sqlMap = SqlMapClientBuilder.buildSqlMapClient(reader, props);
reader.close();
}
protected void initScript(String script) throws Exception {
DataSource ds = sqlMap.getDataSource();
Connection conn = ds.getConnection();

Reader reader = Resources.getResourceAsReader(script);
ScriptRunner runner = new ScriptRunner();
runner.setStopOnError(false);
runner.setLogWriter(null);
runner.setErrorLogWriter(null);

runner.runScript(conn, reader);
conn.commit();
conn.close();
reader.close();
}
private Connection getJdbcConnection() throws Exception {
/*
Properties props = new Properties();
props.load(Resources.getResourceAsStream("properties/database.properties"));
Class driver = Class.forName(props.getProperty("driver"));
Connection conn = DriverManager.getConnection(props.getProperty("url"),
props.getProperty("username"), props.getProperty("password"));
*/
Class driver = Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/ibatis_schema","root","1234");
return conn;
}
}
[/code]
然后为每个SqlMap映射文件编写一个测试用例，extends上面的抽象类
[code]package com.javaeye.liulu.test;

import java.io.Reader;
import java.util.Date;
import java.util.HashMap;
import java.util.List;

import org.dbunit.dataset.IDataSet;
import org.dbunit.dataset.xml.FlatXmlDataSet;
import org.dbunit.operation.DatabaseOperation;

import com.ibatis.common.resources.Resources;
import com.javaeye.liulu.domain.User;

public class UserTest extends BaseSqlMapTest {

protected IDataSet getDataSet() throws Exception {
Reader reader = Resources.getResourceAsReader("com/javaeye/liulu/test/user_seed.xml");
return new FlatXmlDataSet(reader);
}

public void testGetByPK() throws Exception {
User user = new User();
user.setId(1);
user = (User) sqlMap.queryForObject("User.getByPK", user);
assertNotNull(user);
assertEquals(user.getId(), 1);
assertEquals(user.getName(), "liulu");
assertEquals(user.getDate().getDay(), 1);
}

public void testGetUser() throws Exception {
List users = null;
HashMap params = new HashMap();
params.put("name", "%liulu%");
users = (List) sqlMap.queryForList("User.getUser", params);
assertEquals(users.size(),3);
}

public void testInsertUser() throws Exception {
User user = new User();
user.setId(4);
user.setName("insert1");
user.setDate(new Date());
sqlMap.insert("User.insertUserTest", user);

User user2 = new User();
user2.setId(4);
user2 = (User) sqlMap.queryForObject("User.getById", "4");
assertEquals(user.getId(),user2.getId());
assertEquals(user.getName(),user2.getName());

}

public void testUpdateUser() throws Exception {
User user = (User)sqlMap.queryForObject("User.getById", "1");
user.setName("liulu7");
sqlMap.update("User.updateUser", user);
User user2 = (User)sqlMap.queryForObject("User.getById", "1");
assertEquals(user2.getName(),"liulu7");
}

public void testDeleteUser() throws Exception {
int num = sqlMap.delete("User.deleteUser", "1");
assertEquals(num,1);
}

public void testGetMaxId() throws Exception {
int i = (Integer)sqlMap.queryForObject("User.getMaxId", null);
assertEquals(3,i);
}

}
[/code]
注意，其中测试insert时由于id为auto_increment，可能需要对测试数据中<dataset/>进行设置，网络中并未查询到相关的方法，所以在映射文件中加入了一个
[code]<insert id="insertUserTest" parameterClass="UserObject">
INSERT INTO t_user (id,name,date) VALUES (#id#,#name#,#date#)
</insert>
[/code]
用例测试中测试的是insertUserTest，并非insertUser，请注意。

到这里就结束了，demo比较简单，希望能给大家带来帮助。

参考：
http://ibatis.apache.org/
http://hsqldb.org/
http://www.dbunit.org/