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。

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配置文件：

<?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> 

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映射文件：

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE mapper PUBLIC ?"-//mybatis.org//DTD Mapper 3.0//EN" ?"http://mybatis.org/dtd/mybatis-3-mapper.dtd"><!-- 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>

?<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>

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修改application.xml文件

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<!-- 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"??/>??</property>?</bean>

?<!-- 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>

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<!-- mybatis  sqlSessionFactory 注入datasource和配置文件--><bean id="sqlSessionFactory" value="classpath:mybatisconfig.xml" />      <property name="dataSource" ref="dataSource" />  </bean><!-- 定义mybatis操作模板类似hibernateTemplate --><bean id="sqlSessionTemplate" ref="sqlSessionFactory"></property></bean>

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代码实现

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;}}

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单元测试请看上一篇文章

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<insert id="insertBatch" > insert into student ( <include refid="Base_Column_List" /> ) values <foreach collection="list" item="item" index="index" separator=","> (null,#{item.name},#{item.sex},#{item.address},#{item.telephone},#{item.tId}) </foreach></insert>