MyBatis和Spring的整合

1、什么是MyBatis?
    MyBatis是Apache的一款开源的java的持久层框架，提供了SQL Map和DAO。支持普通的SQL查询，存储过程和高级的映射，myBatis将SQL语句和java代码分离开，解耦了代码，将接口和POJOs映射成数据库表的记录。
    每个数据源对应一个SqlSessionFactory，SqlSessionFactory的创建 可以通过代码调用SqlSessionFactoryBuilder创建，Builder也通过xml资源创建SqlSessionFactory。SqlSessionFactory会创建SqlSession负责执行SQL和结果的映射。
  2、MyBatis和Hibernate的对比
    1）hibernate比MyBatis重量级，难上手。
    2）Mybatis查询能够指定字段和编写复杂的SQL语句，如left join等，而hibernate的HQL若过于复杂则服务器效率会下降，所以Mybatis适合复杂的SQL查询，而hibernate适合并不复杂的简单的SQL。
    3）mybatis因为编写的SQL与具体的数据库类型有关，故移植性差，而hibernate使用HQL，不关心底层数据库的类型，移植性高。
    4）mybatis和hibernate都实现了自己的二级缓存机制，也能够实现自己的二级缓存或者使用第三方机制的缓存如echcache或Redis。hibernate的二级缓存在SessionFactory生成的配置文件里配置，然后再配置具体的表和实体类的映射。如下面例子：
        
  1. <bean id="entityManagerFactory"
  2. 		class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
  3. 		<property name="dataSource" ref="dataSource" />
  4. 		<property name="persistenceProvider" ref="persistenceProvider" />
  5. 		<property name="jpaVendorAdapter" ref="jpaVendorAdapter" />
  7. 		<property name="jpaProperties">
  8. 			<props>
  9. 				<prop key="hibernate.dialect">${hibernate.dialect}</prop>
  10. 				<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
  11. 				<prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
  12. 				<prop key="hibernate.jdbc.fetch_size">50</prop>
  13. 				<prop key="hibernate.jdbc.batch_size">50</prop>
  14.                 <!--二级缓存启用-->
  15. 				<prop key="hibernate.cache.use_second_level_cache">true</prop>
  16.                 <!--查询缓存启用-->
  17. 				<prop key="hibernate.cache.use_query_cache">true</prop>
  18. 				<prop key="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.SingletonEhCacheRegionFactory</prop>
  19. 				<prop key="javax.persistence.sharedCache.mode">ENABLE_SELECTIVE</prop>
  20.                 <!--echcache的配置文件-->
  21. 				<prop key="net.sf.ehcache.configurationResourceName">/ehcache.xml</prop>
  22. 				<prop key="hibernate.generate_statistics">false</prop>
  23. 			</props>
  24. 		</property>
  25. 	</bean>
  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <ehcache>
  3. 	<diskStore path="/opt/bpm/cache/bpm" />
  4. 	<!-- 	 -->	
  5. 	<defaultCache maxElementsInMemory="20000" eternal="false" timeToIdleSeconds="120" timeToLiveSeconds="120" overflowToDisk="true" diskPersistent="false"
  6. 		diskExpiryThreadIntervalSeconds="120" memoryStoreEvictionPolicy="LRU" />
  8. 	<cache name="com.psbc.cfc.bpm.domain.Area"  maxElementsInMemory="500" eternal="false" timeToLiveSeconds="7200" timeToIdleSeconds="3600" overflowToDisk="true" />
  9. </ehcache>
在相关的的实体类中使用xml或者用注解：
    
  1. /**
  2.  * Created By: Comwave Project Team
  3.  * Created Date: 2014-4-28
  4.  */
  5. package com.psbc.cfc.bpm.domain;
  7. import java.io.Serializable;
  9. import javax.persistence.Cacheable;
  10. import javax.persistence.Column;
  11. import javax.persistence.Entity;
  12. import javax.persistence.Id;
  13. import javax.persistence.Table;
  15. import org.hibernate.annotations.Cache;
  16. import org.hibernate.annotations.CacheConcurrencyStrategy;
  18. /**
  19.  * 区域
  20.  * 
  21.  * @author James
  22.  * @version 1.0
  23.  */
  24. @Entity
  25. @Cacheable
  26. @Cache(usage=CacheConcurrencyStrategy.READ_ONLY)
  27. @Table(name = "VIEW_AREA")
  28. public class Area implements Serializable {
  30. 	private static final long serialVersionUID = 6474865115108614073L;
  32. 	/** 区域编号 */
  33. 	@Id
  34. 	@Column(name = "AREA_CODE", length = 100)
  35. 	private String areaCode;
  37. 	/** 区域名称 */
  38. 	@Column(name = "AREA_NAME", length = 100)
  39. 	private String areaName;
  41. 	public String getAreaCode() {
  42. 		return areaCode;
  43. 	}
  45. 	public void setAreaCode(String areaCode) {
  46. 		this.areaCode = areaCode;
  47. 	}
  49. 	public String getAreaName() {
  50. 		return areaName;
  51. 	}
  53. 	public void setAreaName(String areaName) {
  54. 		this.areaName = areaName;
  55. 	}
  57. }
CacheConcurrencyStrategy有四种类型：
    NONE
    READ_ONLY：只读和缓存，不能修改缓存，但数据库修改能够立即见效。
    READ_WRITE：严格的读写，更新缓存时加锁，其他线程查询缓存时查数据库。
    NONSTRICT_READ_WRITE：不严格的读写，更新缓存不加锁，适合偶尔的更新，即两个事务更新同一缓存比较少。
而myBatis的缓存具体到在表和实体的Mapper里，如：
    
  1. <mapper namespace="com.cnblogs.yjmyzz.mybatis.mapper.OrderMapper">
  3.     <cache 
  4.         eviction="LRU"
  5.         flushInterval="60000"
  6.         size="1024"
  7.         readOnly="true"
  8.     />    
  9. ...
  10. </mapper>
在<Select"></Select>这样使用则表示不使用缓存机制。
Mapper里的所有操作默认是会作用到缓存，若使用 useCache="false"，则可以禁止掉缓存。
    但通常在效率上hibernate的效能比Mybatis好。

总结：
    hibernate：
       1）hibernate对对象的维护和缓存比Mybatis好。
       2）hibernate增删查改已经为用户实现了，要写的SQL比较少。
       3）hibernate的移植性比mybatis好。
        4）hibernate的二级缓存能够支持第三方缓存，而且比Mybatis好。
    Mybatis：
        1）支持复杂的SQL查询，效率比hibernate快。
        2）门槛低，容易上手。
3、Spring和Mybatis的整合
    1)创建Maven WebApp项目
          这里贴上我自己的Maven的setting.xml，下载快：
            
  1. <?xml version="1.0"?>  
  2. <settings>  
  3. <localRepository>C:\job\maven_repository\maven_repository</localRepository>  
  4.     <mirrors>  
  5.         <mirror>  
  6.             <id>alimaven</id>  
  7.             <name>aliyun maven</name>  
  8.             <url>http://maven.aliyun.com/nexus/content/groups/public/</url>  
  9.             <mirrorOf>central</mirrorOf>  
  10.         </mirror>  
  11.     </mirrors>  
  12.   <profiles>  
  13.     <profile>  
  14.        <id>nexus</id>   
  15.         <repositories>  
  16.             <repository>  
  17.                 <id>nexus</id>  
  18.                 <name>local private nexus</name>  
  19.                 <url>http://maven.oschina.net/content/groups/public/</url>  
  20.                 <releases>  
  21.                     <enabled>true</enabled>  
  22.                 </releases>  
  23.                 <snapshots>  
  24.                     <enabled>false</enabled>  
  25.                 </snapshots>  
  26.             </repository>  
  27.         </repositories>  
  28.            
  29.         <pluginRepositories>  
  30.             <pluginRepository>  
  31.             <id>nexus</id>  
  32.             <name>local private nexus</name>  
  33.             <url>http://maven.oschina.net/content/groups/public/</url>  
  34.             <releases>  
  35.                 <enabled>true</enabled>  
  36.             </releases>  
  37.             <snapshots>  
  38.                 <enabled>false</enabled>  
  39.             </snapshots>  
  40.             </pluginRepository>  
  41.         </pluginRepositories>  
  42.     </profile>  
  43.     </profiles>  
  44. </settings>
   项目结构如下：  
 
 
  Pom.xml如下：
    
  1. <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  2.   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  3.   <modelVersion>4.0.0</modelVersion>
  4.   <groupId>yi.zhen.mo</groupId>
  5.   <artifactId>spring_myBatis</artifactId>
  6.   <packaging>war</packaging>
  7.   <version>0.0.1-SNAPSHOT</version>
  8.   <name>spring_myBatis Maven Webapp</name>
  9.   <url>http://maven.apache.org</url>
  10.   <properties>
  11.     <!-- spring版本号 -->
  12.     <spring.version>4.2.4.RELEASE</spring.version>
  13.     <!-- mybatis版本号 -->
  14.     <mybatis.version>3.2.6</mybatis.version>
  15.     <!-- log4j日志文件管理包版本 -->
  16.     <slf4j.version>1.7.7</slf4j.version>
  17.     <log4j.version>1.2.17</log4j.version>
  18. </properties>
  19.   <dependencies>
  20.     <dependency>
  21.       <groupId>junit</groupId>
  22.       <artifactId>junit</artifactId>
  23.       <version>3.8.1</version>
  24.       <scope>test</scope>
  25.     </dependency>
  26. <dependency>
  27.         <groupId>org.springframework</groupId>
  28.         <artifactId>spring-core</artifactId>
  29.         <version>${spring.version}</version>
  30.     </dependency>
  31.     <dependency>
  32.         <groupId>org.springframework</groupId>
  33.         <artifactId>spring-web</artifactId>
  34.         <version>${spring.version}</version>
  35.     </dependency>
  36.     <dependency>
  37.         <groupId>org.springframework</groupId>
  38.         <artifactId>spring-oxm</artifactId>
  39.         <version>${spring.version}</version>
  40.     </dependency>
  41.     <dependency>
  42.         <groupId>org.springframework</groupId>
  43.         <artifactId>spring-tx</artifactId>
  44.         <version>${spring.version}</version>
  45.     </dependency>
  46.     <dependency>
  47.         <groupId>org.springframework</groupId>
  48.         <artifactId>spring-jdbc</artifactId>
  49.         <version>${spring.version}</version>
  50.     </dependency>
  51.     <dependency>
  52.         <groupId>org.springframework</groupId>
  53.         <artifactId>spring-webmvc</artifactId>
  54.         <version>${spring.version}</version>
  55.     </dependency>
  56.     <dependency>
  57.         <groupId>org.springframework</groupId>
  58.         <artifactId>spring-aop</artifactId>
  59.         <version>${spring.version}</version>
  60.     </dependency>
  61.     <dependency>
  62.         <groupId>org.springframework</groupId>
  63.         <artifactId>spring-context-support</artifactId>
  64.         <version>${spring.version}</version>
  65.     </dependency>
  66.     <dependency>
  67.         <groupId>org.springframework</groupId>
  68.         <artifactId>spring-test</artifactId>
  69.         <version>${spring.version}</version>
  70.     </dependency>
  71.     <!-- mybatis核心包 -->
  72.     <dependency>
  73.         <groupId>org.mybatis</groupId>
  74.         <artifactId>mybatis</artifactId>
  75.         <version>${mybatis.version}</version>
  76.     </dependency>
  77.      <!-- mybatis/spring包 -->
  78.     <dependency>
  79.         <groupId>org.mybatis</groupId>
  80.         <artifactId>mybatis-spring</artifactId>
  81.         <version>1.2.2</version>
  82.     </dependency>
  83.       <dependency>
  84.         <groupId>javax</groupId>
  85.         <artifactId>javaee-api</artifactId>
  86.         <version>7.0</version>
  87.     </dependency>
  88.      <dependency>
  89.         <groupId>mysql</groupId>
  90.         <artifactId>mysql-connector-java</artifactId>
  91.         <version>5.1.30</version>
  92.     </dependency>
  93.      <dependency>
  94.         <groupId>commons-dbcp</groupId>
  95.         <artifactId>commons-dbcp</artifactId>
  96.         <version>1.2.2</version>
  97.     </dependency>
  98.      <dependency>
  99.         <groupId>jstl</groupId>
  100.         <artifactId>jstl</artifactId>
  101.         <version>1.2</version>
  102.     </dependency>
  103.     <!-- 日志文件管理包 -->
  104.     <!-- log start -->
  105.     <dependency>
  106.         <groupId>log4j</groupId>
  107.         <artifactId>log4j</artifactId>
  108.         <version>${log4j.version}</version>
  109.     </dependency>
  110.     <!-- 格式化对象，方便输出日志 -->
  111.     <dependency>
  112.         <groupId>com.alibaba</groupId>
  113.         <artifactId>fastjson</artifactId>
  114.         <version>1.1.41</version>
  115.     </dependency>
  116.     <dependency>
  117.         <groupId>org.slf4j</groupId>
  118.         <artifactId>slf4j-api</artifactId>
  119.         <version>${slf4j.version}</version>
  120.     </dependency>
  121.     <dependency>
  122.         <groupId>org.slf4j</groupId>
  123.         <artifactId>slf4j-log4j12</artifactId>
  124.         <version>${slf4j.version}</version>
  125.     </dependency>
  126.     <!-- log end -->
  127.     <!-- 映入JSON -->
  128.     <dependency>
  129.         <groupId>org.codehaus.jackson</groupId>
  130.         <artifactId>jackson-mapper-asl</artifactId>
  131.         <version>1.9.13</version>
  132.     </dependency>
  133.     <!-- 上传组件包 -->
  134.     <dependency>
  135.         <groupId>commons-fileupload</groupId>
  136.         <artifactId>commons-fileupload</artifactId>
  137.         <version>1.3.1</version>
  138.     </dependency>
  139.     <dependency>
  140.         <groupId>commons-io</groupId>
  141.         <artifactId>commons-io</artifactId>
  142.         <version>2.4</version>
  143.     </dependency>
  144.     <dependency>
  145.         <groupId>commons-codec</groupId>
  146.         <artifactId>commons-codec</artifactId>
  147.         <version>1.9</version>
  148.     </dependency>
  149.   </dependencies>
  150.   <build>
  151.     <finalName>spring_myBatis</finalName>
  152.     <plugins>
  153. 			<plugin>
  154. 				<groupId>org.apache.maven.plugins</groupId>
  155. 				<artifactId>maven-compiler-plugin</artifactId>
  156. 				<version>3.1</version>
  157. 				<configuration>
  158. 					<source>1.7</source>
  159. 					<target>1.7</target>
  160. 					<encoding>utf8</encoding>
  161. 				</configuration>
  162. 			</plugin>
  163. 			<plugin>
  164. 				<groupId>org.apache.maven.plugins</groupId>
  165. 				<artifactId>maven-surefire-plugin</artifactId>
  166. 				<version>2.19.1</version>
  167. 				<configuration>
  168. 					<groups>org.apache.surefire.BuildTest</groups>
  169. 					<parallel>classes</parallel>
  170. 					<threadCount>10</threadCount>
  171. 					<forkCount>3</forkCount>
  172. 					<reuseForks>true</reuseForks>
  173. 					<skipTests>true</skipTests>
  174. 					<argLine>-Xmx1024m -XX:MaxPermSize=256m</argLine>
  175. 				</configuration>
  176. 			</plugin>	
  177. 			</plugins>		
  178.   </build>
  179. </project>
    看applicationContext.xml如下：
            
  1. <beans xmlns="http://www.springframework.org/schema/beans"
  2.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
  3.     xmlns:context="http://www.springframework.org/schema/context"
  4.     xmlns:mvc="http://www.springframework.org/schema/mvc"
  5.     xsi:schemaLocation="http://www.springframework.org/schema/beans  
  6.                         http://www.springframework.org/schema/beans/spring-beans-4.0.xsd  
  7.                         http://www.springframework.org/schema/context  
  8.                         http://www.springframework.org/schema/context/spring-context-4.0.xsd  
  9.                         http://www.springframework.org/schema/mvc  
  10.                         http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">
  13. <!-- 自动扫描 -->
  14. <context:component-scan base-package="yi.zhen.mo" />
  15. <!-- <context:annotation-config />   -->
  16.  <bean id="propertyConfigurer"
  17.         class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
  18.         <property name="location" value="classpath:jdbc.properties" />
  19.  </bean>
  20. <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
  21. 	<property name="driverClassName" value="${driver}" />
  22.         <property name="url" value="${url}" />
  23.         <property name="username" value="${username}" />
  24.         <property name="password" value="${password}" />
  25.         <!-- 初始化连接大小 -->
  26.         <property name="initialSize" value="${initialSize}"></property>
  27.         <!-- 连接池最大数量 -->
  28.         <property name="maxActive" value="${maxActive}"></property>
  29.         <!-- 连接池最大空闲 -->
  30.         <property name="maxIdle" value="${maxIdle}"></property>
  31.         <!-- 连接池最小空闲 -->
  32.         <property name="minIdle" value="${minIdle}"></property>
  33.         <!-- 获取连接最大等待时间 -->
  34.         <property name="maxWait" value="${maxWait}"></property>
  35. </bean>
  36. <!-- SqlSessionFactoryBean是的getObject方法会返回一个sqlSessionFactory实例 -->
  37. <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
  38.         <property name="dataSource" ref="dataSource" />
  39.         <!-- 自动扫描mapping.xml文件 若使用注解则不需 -->
  40.         <property name="mapperLocations" value="classpath:yi/zhen/mo/mapping/*.xml"></property>
  41. </bean>
  42.      
  43.     <!-- 单个dao的配置-->
  44.  	<!-- <bean id="useDao" class="org.mybatis.spring.mapper.MapperFactoryBean">
  45.  		<property name="mapperInterface" value="com.xxx.dao.UserDao" />  
  46.     	<property name="sqlSessionFactory" ref="sqlSessionFactory" />  
  47.  	</bean> -->
  48.     <!-- 多个dao的配置 MapperScannerConfigurer会将生成的Mapper代理注册到Spring IOC容器中-->
  49.     <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
  50.         <property name="basePackage" value="yi.zhen.mo.dao" />
  51.         <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>
  52.     </bean>
  53.     <!-- dataSource的事务配置-->
  54.      <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
  55.         <property name="dataSource" ref="dataSource" />
  56.     </bean>
  57. </beans>
   Mapper的配置有两种：
       （1）xml：
  1. <?xml version="1.0" encoding="UTF-8" ?>
  2. <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
  3. <mapper namespace="yi.zhen.mo.dao.UserMapper">
  4. 	<select id="getUser" resultType="yi.zhen.mo.entity.User">
  5. 		select * from User where username=#{username} and password=#{password}
  6. 	</select>
  7. </mapper>
       （2）注解：
    
 
2）
    简单的写了个测试类：
        
    
  1.  public static void main(String[] args) {
  2.         ClassPathXmlApplicationContext cx=new ClassPathXmlApplicationContext("spring-mybatis.xml");
  3.         UserMapper um=(UserMapper)cx.getBean("userMapper");
  4.         List<User> list=um.getUser("xiaoming","111111");
  5.         if(list==null||list.size()==0)
  6.             System.out.println("can not find !");
  7.         else System.out.println("find the record !");
  8.     }




 







posted @ 2017-08-07 17:11  pgrDog  阅读(255)  评论(0)    收藏  举报