ssm之spring+springmvc+mybatis整合初探
1、基本目录如下
2、首先是向lib中加入相应的jar包
3、然后在web.xml中加入配置，使spring和springmvc配置文件起作用。
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"> <!-- needed for ContextLoaderListener --> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring.xml</param-value> </context-param> <!-- Bootstraps the root web application context before servlet initialization --> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <!-- The front controller of this Spring Web application, responsible for handling all application requests --> <servlet> <servlet-name>springDispatcherServlet</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:springmvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <!-- Map all requests to the DispatcherServlet for handling --> <servlet-mapping> <servlet-name>springDispatcherServlet</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>
4、新建一个conf源文件，相关配置在里面编写，即spring配置文件spring.xml，springmvc配置文件springmvc.xml，mybatis全局配置文件mybatis-conf.xml。连接数据库所需的外部引用文件dbconfig.properties。
首先我们来看mybatis-conf.xml
<?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> <setting name="mapUnderscoreToCamelCase" value="true"/> <setting name="jdbcTypeForNull" value="NULL"/> <!--显式的指定每个我们需要更改的配置的值，即使他是默认的。防止版本更新带来的问题 --> <setting name="cacheEnabled" value="true"/> <setting name="lazyLoadingEnabled" value="true"/> <setting name="aggressiveLazyLoading" value="false"/> </settings> <databaseIdProvider type="DB_VENDOR"> <property name="MySQL" value="mysql"/> <property name="Oracle" value="oracle"/> <property name="SQL Server" value="sqlserver"/> </databaseIdProvider> </configuration>
在这里主要的就是一些设置<setting>，像驼峰命名、开启二级缓存、延迟加载等等。以及标识各种数据库，像mysql、oracle等等。
然后再来看看springmvc.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd"> <!--SpringMVC只是控制网站跳转逻辑 --> <!-- 只扫描控制器 --> <context:component-scan base-package="com.gong.mybatis" use-default-filters="false"> <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/> </context:component-scan> <!-- 视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/pages/"></property> <property name="suffix" value=".jsp"></property> </bean> <mvc:annotation-driven></mvc:annotation-driven> <mvc:default-servlet-handler/> </beans>
主要是四个方面：
- 让springmvc只处理标识了@Controller的IOC容器
- 视图解析器
- 配置默认的servletHandler
- 配置<mvc:annotation-driven></mvc:annotation-driven>
具体用法参考以前的学习笔记。
接着看看spring.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mybatis-spring="http://mybatis.org/schema/mybatis-spring" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://mybatis.org/schema/mybatis-spring http://mybatis.org/schema/mybatis-spring-1.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd"> <!-- Spring希望管理所有的业务逻辑组件，等。。。 --> <context:component-scan base-package="com.gong.mybatis"> <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" /> </context:component-scan> <!-- 引入数据库的配置文件 --> <context:property-placeholder location="classpath:dbconfig.properties" /> <!-- Spring用来控制业务逻辑。数据源、事务控制、aop --> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="jdbcUrl" value="${jdbc.url}"></property> <property name="driverClass" value="${jdbc.driver}"></property> <property name="user" value="${jdbc.username}"></property> <property name="password" value="${jdbc.password}"></property> </bean> <!-- spring事务管理 --> <bean id="dataSourceTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"></property> </bean> <!-- 开启基于注解的事务 --> <tx:annotation-driven transaction-manager="dataSourceTransactionManager"/> <!-- 整合mybatis 目的：1、spring管理所有组件。mapper的实现类。 service==>Dao @Autowired:自动注入mapper； 2、spring用来管理事务，spring声明式事务 --> <!--创建出SqlSessionFactory对象 --> <bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"></property> <!-- configLocation指定全局配置文件的位置 --> <property name="configLocation" value="classpath:mybatis-config.xml"></property> <!--mapperLocations: 指定mapper文件的位置--> <property name="mapperLocations" value="classpath:mybatis/mapper/*.xml"></property> </bean> <!--配置一个可以进行批量执行的sqlSession --> <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate"> <constructor-arg name="sqlSessionFactory" ref="sqlSessionFactoryBean"></constructor-arg> <constructor-arg name="executorType" value="BATCH"></constructor-arg> </bean> <!-- 扫描所有的mapper接口的实现，让这些mapper能够自动注入； base-package：指定mapper接口的包名 --> <mybatis-spring:scan base-package="com.gong.mybatis.dao"/> <!-- <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.gong.mybatis.dao"></property> </bean> --> </beans>
我们一个个来看：
- 首先是配置除了@Controller其余的注解皆由spring来管理
- 引入外部的数据库的信息，并进行数据库连接配置
- 配置事务管理器
- 配置基于注解的事务，即可以使用@Transactional注解
- 配置SqlSessionFactoryBean，不用我们每次都要获取SqlSessionFactory和SqlSession实例，同时引用mybatis配置文件以及mapper.xml文件存在的位置。
- 配置一个可以进行批量执行的sqlSession。
- 配置mapper.xml对应的接口文件的位置
dbconfig.properties
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis?allowMultiQueries=true
jdbc.username=root
jdbc.password=123456
5、最后就是编写相应的文件进行测试了
具体流程：bean包里存放普通的实体类，controller包里面主要是后台和视图view之间进行交互，dao包主要是相关操作数据库的方法与mybatis.mapper中的xml相对应，service主要是存放着接口，serviceImpl主要是实现service中的方法，这些方法是可以是不同数据库方法的结合使用。首先是controller调用serviceImpl中的方法，serviceImpl中的方法调用dao里面的方法，dao里面的方法对应着mapper.xml文件中操作数据库的方法，最后controller将数据传给视图view或者view通过请求到controller。
Employee.java
package com.gong.mybatis.bean; import java.io.Serializable; public class Employee implements Serializable{ /** * */ private static final long serialVersionUID = 1L; public Employee() {} public Employee(Integer id, String lastName, String gender, String email) { super(); this.id = id; this.lastName = lastName; this.gender = gender; this.email = email; } private Integer id; private String lastName; private String gender; private String email; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public String getGender() { return gender; } public void setGender(String gender) { this.gender = gender; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } @Override public String toString() { return "Employee [id=" + id + ", lastName=" + lastName + ", gender=" + gender + ", email=" + email + "]"; } }
EmployeeController.java
package com.gong.mybatis.controller; import java.util.List; import java.util.Map; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import com.gong.mybatis.bean.Employee; import com.gong.mybatis.service.EmployeeService; @Controller public class EmployeeController { @Autowired private EmployeeService employeeService; @RequestMapping("/getemps") public String emps(Map<String,Object> map) { List<Employee> emps = employeeService.getEmps(); map.put("emps", emps); return "list"; } }
EmployeeService.java
package com.gong.mybatis.service; import java.util.List; import com.gong.mybatis.bean.Employee; public interface EmployeeService { public List<Employee> getEmps(); }
EmployeeServiceImpl.java
package com.gong.mybatis.serviceImpl; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import com.gong.mybatis.bean.Employee; import com.gong.mybatis.dao.EmployeeMapper; import com.gong.mybatis.service.EmployeeService; @Service public class EmployeeServiceImpl implements EmployeeService{ @Autowired private EmployeeMapper employeeMapper; public List<Employee> getEmps(){ return employeeMapper.getEmps(); } }
EmployeeMapper.java
package com.gong.mybatis.dao; import java.util.List; import com.gong.mybatis.bean.Employee; public interface EmployeeMapper { public List<Employee> getEmps(); }
EmployeeMapper.xml
<?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"> <mapper namespace="com.gong.mybatis.dao.EmployeeMapper"> <select id="getEmps" resultType="com.gong.mybatis.bean.Employee"> select id,last_name lastName,email,gender from tbl_employee </select> </mapper>
6、相关视图页面
index.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <a href="getemps">查询所有员工</a> </body> </html>
list.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>员工列表</title> </head> <body> <table> <tr> <td>id</td> <td>lastName</td> <td>email</td> <td>gender</td> </tr> <c:forEach items="${emps}" var="emp"> <tr> <td>${emp.id }</td> <td>${emp.lastName }</td> <td>${emp.email }</td> <td>${emp.gender }</td> </tr> </c:forEach> </table> </body> </html>
7、启动tomcat服务器
点击查询所有员工：
得到如图所示界面，说明spring+springmvc+mybatis整合基本完成。
