SSM整合 —— 在Spring中配置MyBtis
一、前言
本文需要所有Spring、MyBatis、SpringMVC框架的依赖,外加mybatis和spring的整合依赖,坐标如下:
<dependencies><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.13.1</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-web</artifactId><version>5.1.9.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>5.1.9.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>5.1.9.RELEASE</version></dependency><dependency><groupId>org.aspectj</groupId><artifactId>aspectjweaver</artifactId><version>1.9.24</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-test</artifactId><version>5.1.9.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>5.1.9.RELEASE</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.32</version></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.6</version></dependency><dependency><groupId>log4j</groupId><artifactId>log4j</artifactId><version>1.2.12</version></dependency><dependency><groupId>com.github.pagehelper</groupId><artifactId>pagehelper</artifactId><version>3.7.5</version></dependency><dependency><groupId>com.github.jsqlparser</groupId><artifactId>jsqlparser</artifactId><version>0.9.1</version></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>2.0.7</version></dependency><dependency><groupId>com.mchange</groupId><artifactId>c3p0</artifactId><version>0.9.5.2</version></dependency><dependency><groupId>javax.servlet</groupId><artifactId>javax.servlet-api</artifactId><version>3.1.0</version><scope>provided</scope></dependency><dependency><groupId>javax.servlet.jsp</groupId><artifactId>javax.servlet.jsp-api</artifactId><version>2.3.3</version><scope>provided</scope></dependency><dependency><groupId>jstl</groupId><artifactId>jstl</artifactId><version>1.2</version></dependency><dependency><groupId>taglibs</groupId><artifactId>standard</artifactId><version>1.1.2</version></dependency>
同时,由于是web项目,所以还需要tomcat插件:
<plugins><plugin><groupId>org.opoo.maven</groupId><artifactId>tomcat9-maven-plugin</artifactId><version>3.0.0</version></plugin></plugins>
二、SSM的传统整合方法
1.创建骨架
我们这里设定一个情景:创建一个Account类 ,设计每个账户的属性(id、name、money),设计两个功能,分别是添加账户和查询所有账户。
public class Account {private Integer id;private String name;private Double money;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Double getMoney() {return money;}public void setMoney(Double money) {this.money = money;}}
同时设计一个account表:
设计mybatis的映射接口(实现两个功能):
public interface AccountMapper {public void save(Account account);public List<Account> findAll();}
同时配置mybatis的核心配置文件和映射文件:
核心配置文件:
<configuration><!--通过properties标签加载外部properties文件--><properties resource="jdbc.properties"/><!--取别名--><typeAliases>
<!-- <typeAlias type="com.yds.domain.Account" alias="account"/>--><package name="com.yds.domain"/></typeAliases><!--配置数据源环境--><environments default="development"><environment id="development"><transactionManager type="JDBC"/><dataSource type="POOLED"><property name="driver" value="${jdbc.driver}"/><property name="url" value="${jdbc.url}"/><property name="username" value="${jdbc.username}"/><property name="password" value="${jdbc.password}"/></dataSource></environment></environments><!--加载映射文件(使用注解不需要了)--><mappers><mapper resource="com.yds.mapper/AccountMapper.xml"/></mappers></configuration>
映射文件:
<mapper namespace="com.yds.mapper.AccountMapper"><insert id="save" parameterType="account">insert into account values(#{id},#{name},#{money})</insert><select id="findAll" resultType="account">select * from account</select></mapper>
由于是web项目,我们需要继续添加service层和web层(controller):
service接口:
public interface AccountService {public void save(Account account) throws IOException;public List<Account> findAll();
}
@Service("accountService")
public class AccountServiceImpl implements AccountService {@Autowiredprivate AccountMapper accountMapper;@Overridepublic void save(Account account) {}@Overridepublic List<Account> findAll() {}
}
这里我们先创建骨架,不写具体内容。
别忘了在web.xml中配置前端控制器、监听器、过滤器:
<!-- 配置配置文件--><context-param><param-name>contextConfigLocation</param-name><param-value>classpath:applicationContext.xml</param-value></context-param><!-- 配置全局过滤的filter(解决乱码问题)--><filter><filter-name>CharacterEncodingFilter</filter-name><filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class><init-param><param-name>encoding</param-name><param-value>utf-8</param-value></init-param></filter><filter-mapping><filter-name>CharacterEncodingFilter</filter-name><url-pattern>/*</url-pattern></filter-mapping><!-- 配置监听器--><listener><listener-class>org.springframework.web.context.ContextLoaderListener</listener-class></listener><!-- 配置SpringMVC的前端控制器--><servlet><servlet-name>DispatcherServlet</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class><init-param><param-name>contextConfigLocation</param-name><param-value>classpath:spring-mvc.xml</param-value></init-param><load-on-startup>1</load-on-startup></servlet><servlet-mapping><servlet-name>DispatcherServlet</servlet-name><url-pattern>/</url-pattern></servlet-mapping>
由于涉及到注解开发,在Spring的配置文件中还需要扫描注解,但是这里需要排除controller包的扫描(controller需要由SpringMVC来扫描)
<context:component-scan base-package="com.yds"><!--排除controller的扫描--><context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/></context:component-scan>
SpringMVC配置文件如下:(注册驱动、扫描web层注解...)
<!--mvc组件扫描(只扫描controller),dao层和service层由spring扫描--><context:component-scan base-package="com.yds.controller"/><!-- 配置内部资源视图解析器(自动指定前后缀)--><bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"><property name="prefix" value="/WEB-INF/pages/"/><property name="suffix" value=".jsp"/></bean><!-- mvc的注解驱动--><mvc:annotation-driven/><!-- 让tomcat去找静态资源--><mvc:default-servlet-handler/>
web层:
@Controller
@RequestMapping("/account")
public class AccountController {@Autowiredprivate AccountService accountService;//保存@RequestMapping(value = "/save",produces = "text/html;charset=UTF-8")@ResponseBodypublic String save(Account account) throws IOException {accountService.save(account);return "保存成功";}//查询@RequestMapping("/findAll")public ModelAndView findAll(ModelAndView modelAndView){List<Account> accountList = accountService.findAll();modelAndView.addObject("accountList",accountList);modelAndView.setViewName("accountList");return modelAndView;}
}
为了方便查看和存储,我们创建两个JSP文件作为前端页面:
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page isELIgnored="false" %><html>
<head><title>Title</title>
</head>
<body><h1>展示账户数据列表</h1><table border="1"><tr><th>账户id</th><th>账户名</th><th>账户金额</th></tr><c:forEach items="${accountList}" var="account"><tr><td>${account.id}</td><td>${account.name}</td><td>${account.money}</td></tr></c:forEach></table>
</body>
</html>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page isELIgnored="false" %><html>
<head><title>Title</title>
</head>
<body>
<h1>添加账户信息表单</h1>
<form name="accountForm" action="${pageContext.request.contextPath}/account/save" method="post">账户名称:<input type="text" name="name"><br>账户金额:<input type="text" name="money"><br><input type="submit" value="保存"><br>
</form>
</body>
</html>
2.存储和查询的逻辑
骨架搭建好后,我们就可以在serviceImp中填充逻辑了:
@Service("accountService")
public class AccountServiceImpl implements AccountService {@Autowiredprivate AccountMapper accountMapper;@Overridepublic void save(Account account) {try {InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapConfig.xml");SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);SqlSession sqlSession = sqlSessionFactory.openSession();AccountMapper mapper = sqlSession.getMapper(AccountMapper.class);mapper.save(account);sqlSession.commit();sqlSession.close();} catch (IOException e) {throw new RuntimeException(e);}}@Overridepublic List<Account> findAll() {try {InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapConfig.xml");SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);SqlSession sqlSession = sqlSessionFactory.openSession();AccountMapper mapper = sqlSession.getMapper(AccountMapper.class);List<Account> all = mapper.findAll();sqlSession.close();return all;} catch (IOException e) {throw new RuntimeException(e);}}
}
3.测试
我们访问资源:
查看表格:
三、SSM整合(Spring整合MyBatis)
在Spring配置文件中,我们还需要追加如下配置(将MyBatis整合到Spring中去)。
主要目的是要获取sessionFactory的bean,这是连接spring和mybatis的桥梁(这里相当于将数据源、核心配置文件、映射文件放在spring中了)。
同时将数据源(从mybatis核心配置文件中)转移到Spring配置文件中,最后进行事务控制,aop织入。
<!--加载properties文件--><context:property-placeholder location="classpath:jdbc.properties"/><!--配置数据源信息--><bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"><property name="driverClass" value="${jdbc.driver}"/><property name="jdbcUrl" value="${jdbc.url}"/><property name="user" value="${jdbc.username}"/><property name="password" value="${jdbc.password}"/></bean><!--配置sessionFactory--><bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"><property name="dataSource" ref="dataSource"/><!--加载mybatis的核心文件--><property name="configLocation" value="classpath:sqlMapConfig-spring.xml"/><!--注意!!!下面的也要写,而且c3p0版本要到0.9.5.2--><property name="mapperLocations" value="classpath:com.yds.mapper/AccountMapper.xml"/></bean><!--扫描mapper所在的包 为mapper创建实现类--><bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"><property name="basePackage" value="com.yds.mapper"/></bean><!--声明式事务控制--><!--平台事务管理器--><bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"><property name="dataSource" ref="dataSource"/></bean><!--配置事务增强--><tx:advice id="txAdvice"><tx:attributes><tx:method name="*"/></tx:attributes></tx:advice><!--事务的aop织入--><aop:config><aop:advisor advice-ref="txAdvice" pointcut="execution(* com.yds.service.impl.*.*(..))"/></aop:config>
这里我们的新mybatis核心配置文件如下:(只需要取别名了,其他操作交由Spring配置文件进行)
<configuration><!--取别名--><typeAliases><package name="com.yds.domain"/></typeAliases></configuration>
由于这一配置:
<!--扫描mapper所在的包 为mapper创建实现类--><bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"><property name="basePackage" value="com.yds.mapper"/></bean>
我们在service层中可以将AccountMapper自动装配然后直接调用(配置自动生成mapper的实现类,所以我们在service层中直接调用实现类即可)
@Service("accountService")
public class AccountServiceImpl implements AccountService {@Autowiredprivate AccountMapper accountMapper;@Overridepublic void save(Account account) {accountMapper.save(account);}@Overridepublic List<Account> findAll() {return accountMapper.findAll();}
}
测试一下:
四、SSM尾声
就此,SSM的三个框架的内容全部结束,我们从spring的依赖注入,到web层使用SpringMVC,再到学会mybatis,最后将三个框架全部整合在Spring中。从使用servlet,到现在使用controller,从使用jdbc,到现在使用mybatis框架,从service层继承dao层的紧耦合,到使用ioc容器松耦合,开发时的分层更加明显了,更加松耦合了,开发效率也更高了,在这里感谢上一个月努力的自己。