myBatis应用

最近项目中使用myBatis（iBatis）,所以目前对所遇的一些问题及有些模糊的地方在这里标注一下。

首先mybaits是一个“半自动化”的ORM框架。

需要使用的jar包：mybatis-3.0.2.jar(mybatis核心包)，mybatis-spring-1.0.0.jar(与spring结合jar包)这些jar可以去官网下载。

配置文件：

Xml代码


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

<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"

"http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>

<settings>

<!-- 对在此配置文件下的所有cache进行全局性开/关设置 true|false true -->

<setting name="cacheEnabled" value="true"/>

<!-- 全局性设置懒加载。如果设为‘关',则所有相关联的都会被初始化加载。 -->

<setting name="lazyLoadingEnabled" value="false"/>

<!-- 当设置为‘开’的时候，懒加载的对象可能被任何懒属性全部加载。否则，每个属性都按需加载。 -->

<setting name="aggressiveLazyLoading" value="true"/>

<!-- 允许和不允许单条语句返回多个数据集（取决于驱动需求） -->

<setting name="multipleResultSetsEnabled" value="true"/>

<!-- 使用列标签代替列名称。不用的驱动器有不同的作法。 -->

<setting name="useColumnLabel" value="true"/>

<!-- 允许JDBC生成主键。需要驱动器支持.如果设为了true，这个设置将强制使用被生成的主键，

有一些驱动器不兼容不过仍然可以执行。 -->

<setting name="useGeneratedKeys" value="true"/>

<!-- 指定MyBatis是否并且如何来自动映射数据表字段与对象的属性。PARTIAL将只自动映射简单的，NONE没有嵌套的结果。

FULL将自动映射所有复杂的结果。 -->

<setting name="autoMappingBehavior" value="PARTIAL"/>

<!-- 配置和设定执行器，SIMPLE执行器执行其它语句。REUSE执行器可能重复使用preparedstatements语句，BATCH执行器可以重复执行语句和批量更新。 -->

<setting name="defaultExecutorType" value="SIMPLE"/>

<!-- 设置一个时限，以决定让驱动器等待数据库回应的多长时间为超时. 正整数 -->

<setting name="defaultStatementTimeout" value="25000"/>

</settings>

<!-- 类型别名 -->

<typeAliases>

<typeAlias type="com.igit.storage.client.model.ClientRelation" alias="ClientRelation"/>

</typeAliases>

<!-- 分页查询拦截器

<plugins>

<plugin interceptor="com.igit.storage.util.DiclectStatementHandlerInterceptor"></plugin>

<plugin interceptor="com.igit.storage.util.DiclectResultSetHandlerInterceptor"></plugin>

</plugins>

-->

<!-- 加载映射文件 -->

<mappers>

<mapper resource="com/igit/storage/client/model/ClientRelation.xml"/>

</mappers>

</configuration>

映射文件：

Xml代码


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

<!DOCTYPE mapper PUBLIC

"-//mybatis.org//DTD Mapper 3.0//EN"

"<a href="http://mybatis.org/dtd/mybatis-3-mapper.dtd">http://mybatis.org/dtd/mybatis-3-mapper.dtd</a>">

<!-- 定义命名空间 -->

<mapper namespace="com.igit.storage.client.model.ClientRelation">

<resultMap type="ClientRelation" id="relationResult"><!-- 对象应用关联查询 -->

<association property="client" column="clientId" javaType="Client" select="com.igit.storage.client.model.Client.selectById">

</association>

</resultMap>

<insert id="insert" parameterType="ClientRelation" useGeneratedKeys="true" keyProperty="id">

insert into S_ClientRelation(relation,clientId)

values(#{relation},#{client.clientId})

</insert>

<delete id="delete" parameterType="long" flushCache="true">

delete from S_ClientRelation where relation=#{value}

</delete>

<!-- flushCache="true" 清空缓存 -->

<delete id="remove" parameterType="long" flushCache="true">

delete from S_ClientRelation where id=#{id}

</delete>

<!-- 批量删除多个，参数是数组 key为array map-->

<delete id="removeMore" parameterType="map" flushCache="true">

delete from S_ClientRelation

where id in

<foreach collection="array" index="index" item="ids" open="(" separator="," close=")">

#{ids}

</foreach>

</delete>

Xml代码


<select id="selectById" resultMap="relationResult" parameterType="long">

select * from S_ClientRelation where id=#{value}

</select>

<select id="selectByRelation" resultMap="relationResult" parameterType="long">

select * from S_ClientRelation where relation=#{value}

</select>

<select id="selectByPage" resultMap="relationResult">

select * from S_ClientRelation

</select>

<select id="selectByCount" resultType="long">

select count(*) from S_ClientRelation

</select>

<select id="selectMaxRelation" resultType="long">

select max(relation) from s_clientRelation

</select>

</mapper>

修改application.xml文件

Xml代码


<!-- 因为Hibernate的TransactionManager可以向下兼容JdbcTransactionManager，所以 mybatis事务处理仍和hibernate共用-->

<bean id="transactionManager"

class="org.springframework.orm.hibernate3.HibernateTransactionManager">

<property name="sessionFactory">

<ref local="sessionFactory" />

</property>

</bean>

Xml代码


<!-- 用注解来实现事务管理 -->

<tx:annotation-driven transaction-manager="transactionManager"/>

<tx:advice id="txAdvice" transaction-manager="transactionManager">

<tx:attributes>

<tx:method name="*" />

</tx:attributes>

</tx:advice>

Xml代码


<!-- mybatis sqlSessionFactory 注入datasource和配置文件-->

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">

<property name="configLocation" value="classpath:mybatisconfig.xml" />

<property name="dataSource" ref="dataSource" />

</bean>

<!-- 定义mybatis操作模板类似hibernateTemplate -->

<bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">

<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>

</bean>

代码实现

Java代码


package com.igit.storage.client.service.imp;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import org.apache.ibatis.session.RowBounds;

import org.mybatis.spring.SqlSessionTemplate;

import org.springframework.util.Assert;

import org.springside.core.dao.Page;

import com.igit.exception.BusinessException;

import com.igit.storage.client.model.Client;

import com.igit.storage.client.model.ClientRelation;

import com.igit.storage.client.service.ClientRelationService;

public class ClientRelationServiceImp implements ClientRelationService {

private SqlSessionTemplate sqlSessionTemplate;

/**

* 新增关联客户

*/

public void addRelationByClients(Long relation, List<Client> clients) {

//判断该关联id是否存在

if(!isValidRelation(relation)){

throw new BusinessException("该关联关系不存在！");

}

//新增关联客户

for(Client client : clients){

ClientRelation cr = new ClientRelation();

cr.setRelation(relation);

cr.setClient(client);

Assert.notNull(client, "客户不能为Null");

sqlSessionTemplate.insert(ClientRelation.class.getName()+".insert", cr);

}

}

/**

* 取消关联客户

*/

public void cancelRelation(Long relation) {

sqlSessionTemplate.delete(ClientRelation.class.getName()+".delete", relation);

}

/**

* 创建关联客户

*/

public void createRelation(List<Client> clients) {

// 客户是否可以创建关联

if(clients.size()<=1){

throw new BusinessException("无法创建关联,关联客户不能低于2个！");

}

ClientRelation cr = new ClientRelation();

cr.setRelation(getMaxRelation());

//创建关联客户

for(Client client : clients){

cr.setClient(client);

Assert.notNull(client, "客户不能为Null");

sqlSessionTemplate.insert(ClientRelation.class.getName()+".insert", cr);

}

}

/**

* 获取最大关联ID

* @return

*/

private Long getMaxRelation(){

Long relation = 1L;

Long maxRelation = (Long) sqlSessionTemplate.selectOne(ClientRelation.class.getName()+".selectMaxRelation");

if(maxRelation==null){

return relation;

}

return maxRelation+1;

}

/**

* 分页获取关联客户

*/

public Page getClientRelationByPage(int startIndex, int pageSize) {

List<ClientRelation> list = sqlSessionTemplate.selectList(ClientRelation.class.getName()+".selectByPage", new RowBounds(startIndex,pageSize));

Long totalCount = (Long) sqlSessionTemplate.selectOne(ClientRelation.class.getName()+".selectByCount");

return new Page(list,totalCount,pageSize,startIndex);

}

/**

* 获取没有关联的客户列表

*/

public Page getNoRelationClients(int startIndex,int pageSize) {

List<Client> list = sqlSessionTemplate.selectList(Client.class.getName()+".selectSingleClient", new RowBounds(startIndex,pageSize));

Long totalCount = (Long) sqlSessionTemplate.selectOne(Client.class.getName()+".selectSingleCount");

return new Page(list,totalCount,pageSize,startIndex);

}

/**

* 删除关联客户

*/

public void removeRelationByClients(Long relation, List<Client> clients) {

//1.该客户是否可以从关联中移除

List<ClientRelation> list = getRelationClients(relation);

if((list.size()-clients.size())<=1){

throw new BusinessException("不允许删除，关联客户至少存在2个！");

}

//2.移除客户

for(Client c : clients){

Map<String,Long> params = new HashMap<String,Long>();

params.put("relation", relation);

params.put("clientId", c.getClientId());

sqlSessionTemplate.delete(ClientRelation.class.getName()+".remove", params);

}

}

private boolean isValidRelation(Long relation) {

List<ClientRelation> list = getRelationClients(relation);

if(list.size()<=1){

return false;

}

return true;

}

private List<ClientRelation> getRelationClients(Long relation) {

List<ClientRelation> list = sqlSessionTemplate.selectList(ClientRelation.class.getName()+".selectByRelation", relation);

return list;

}

public SqlSessionTemplate getSqlSessionTemplate() {

return sqlSessionTemplate;

}

public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate) {

this.sqlSessionTemplate = sqlSessionTemplate;

}

}