SSM整合

Spring整合SpringMVC，MyBatis
一 Spring整合SpringMVC

思路：首先让Spring和SpringMVC各自能够运行，然后再整合到一起

第一步：搭建Spring环境
1.引入坐标（pom.xml）

<!--版本锁定-->
<properties>    
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
    <spring.version>5.0.2.RELEASE</spring.version>
    <slf4j.version>1.6.6</slf4j.version>
    <log4j.version>1.2.12</log4j.version>
    <mysql.version>5.1.6</mysql.version>
    <mybatis.version>3.4.5</mybatis.version>
  </properties>

<!--导入坐标-->
  <dependencies>
    <!-- spring -->
    <dependency>
      <groupId>org.aspectj</groupId>
      <artifactId>aspectjweaver</artifactId>
      <version>1.6.8</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aop</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>${mysql.version}</version>
    </dependency>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>servlet-api</artifactId>
      <version>2.5</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>javax.servlet.jsp</groupId>
      <artifactId>jsp-api</artifactId>
      <version>2.0</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>jstl</groupId>
      <artifactId>jstl</artifactId>
      <version>1.2</version>
    </dependency>
    <!-- log start -->
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>${log4j.version}</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>${slf4j.version}</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-log4j12</artifactId>
      <version>${slf4j.version}</version>
    </dependency>
    <!-- log end -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>${mybatis.version}</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>1.3.0</version>
    </dependency>
    <dependency>
      <groupId>c3p0</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.1.2</version>
      <type>jar</type>
      <scope>compile</scope>
    </dependency>
  </dependencies>

2.编写Spring的配置文件：applicationContext.xml
将配置文件都放在rescourse目录下，便于管理

<?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:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/tx
    http://www.springframework.org/schema/tx/spring-tx.xsd
    http://www.springframework.org/schema/aop
    http://www.springframework.org/schema/aop/spring-aop.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context.xsd">

    <!--开启注解扫描，只扫描service和dao，不扫描Controller-->
    <context:component-scan base-package="com.ssm">
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>
</beans>

在添加依赖时，会报红，解决方法：
File | Settings | Languages & Frameworks | Schemas and DTDs

添加报红语句：http://www.springframework.org/schema/tx即可

第二步：搭建SpringMVC的环境
配置前端控制器

<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:springmvc.xml</param-value>
    </init-param>
  </servlet>
  <servlet-mapping>
    <servlet-name>dispatcherServlet</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>

配置springmvc.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
 http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    <!-- 配置spring创建容器时要扫描的包,这里只扫描controller包 -->
    <context:component-scan base-package="com.ssm">
        <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>
    <!-- 配置视图解析器 -->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/pages/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>
    <!--开启注解支持-->
    <mvc:annotation-driven></mvc:annotation-driven>
</beans>

第三步：整合Spring和SpingMVC

本质是在SpringMVC在Controller的方法中调用service的方法
要解决的问题：启动web项目时，只扫描了SpringMVC的配置文件，没有扫描Spring的配置文件applicationContext.xml，因此就不会将service,dao类加载到容器中
解决方法：利用监听器，在监听到服务器启动时，加载Spring的配置文件

Spring的配置文件加载原理：

1.ServletContext：web项目最大的域对象，在服务器启动时创建，且只会创建一个实例对象，服务器关闭时该实例被销毁。
2. 一类监听器：可以监听ServletContext实例的创建和销毁。ServletContext只会实例化一次因此监听器只会执行一次
3.让监听器去加载Spring的配置文件，加载后创建web版本工厂，存储在ServletContext对象中，需要使用时去ServletContext对象中拿

在web.xml中配置监听器

<!--配置监听器,默认只加载WEB-INF目录下的applicationContext.xml配置文件，但现在的配置文件在src的resource目录下-->
  <!--解决方法：设置配置文件的路径(context-param)，不用默认的加载路径-->
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:applicationContext.xml</param-value>
  </context-param>

加载spring的配置文件后，就能在Controller类中注入service和dao的类

@Controller
@RequestMapping("test")
public class AccountController{

    //依赖注入
    @Autowired  //自动注入
    private AccountService accountService;

    @RequestMapping("/hello")
    public String Hello(){
        System.out.println("AccountController的Hello方法执行了");
        accountService.findAll();
        return  "success";
    }
}

Spring整合SpringMVC完成

第四步 整合Mybatis
目标：service能够调用dao的方法
dao是接口，框架能够生成dao接口的代理对象，将代理对象存到ioc容器中，在注入到service中
在spring配置文件中进行配置
1.配置连接池
2.配置工厂对象（工厂创建sqlsession，sqlsession创建代理对象）
3.配置dao接口所在的包（说明生成哪些接口的代理）
总体上和mybatis的核心配置文件的内容相同