ssm框架理解

SSM框架理解

最近兩星期一直在學JavaEE的MVC框架，因為之前學校開的JavaEE課程就一直學的吊兒郎當的，所以現在真正需要掌握就非常手忙腳亂，在此記錄下這段時間學習的感悟，如有錯誤，希望大牛毫不客氣地指出。
 
 
Spring
Spring就像是整個項目中裝配bean的大工廠，在配置文件中可以指定使用特定的參數去調用實體類的構造方法來實例化對象。
Spring的核心思想是IoC（控制反轉），即不再需要程序員去顯式地`new`一個對象，而是讓Spring框架幫你來完成這一切。

SpringMVC
SpringMVC在項目中攔截用戶請求，它的核心Servlet即DispatcherServlet承擔中介或是前台這樣的職責，將用戶請求通過HandlerMapping去匹配Controller，Controller就是具體對應請求所執行的操作。SpringMVC相當於SSH框架中struts。

mybatis
mybatis是對jdbc的封裝，它讓數據庫底層操作變的透明。mybatis的操作都是圍繞一個sqlSessionFactory實例展開的。mybatis通過配置文件關聯到各實體類的Mapper文件，Mapper文件中配置了每個類對數據庫所需進行的sql語句映射。在每次與數據庫交互時，通過sqlSessionFactory拿到一個sqlSession，再執行sql命令。

SSM框架整合
要讓幾個框架相互配合，配置文件怎么寫，項目的目錄結構怎么設計對我這樣一個新手來說實在很頭疼。
目前我也只剛剛寫過一個用戶登錄的demo，在此記錄一下。

項目目錄結構

    －LoginDemo
        －src
            －項目主包
                －controller
                －mapper
                －entity
                －service
        －web
            －WEB-INF
                －log4j.properties
                －spring-mybatis.xml
                －springMVC-config.xml
                －web.xml
            －index.jsp
        －pom.xml

需要引入的包
pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

    <modelVersion>4.0.0</modelVersion>
    <name>LoginDemo</name>
    <groupId>com.cyan</groupId>
    <artifactId>ssm</artifactId>
    <packaging>war</packaging>
    <version>1.0-SNAPSHOT</version>
    <url>http://maven.apache.org</url>


    <build>
        <finalName>ssm</finalName>
        <plugins>
            <!--mybatis 逆向工程插件-->
            <plugin>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-maven-plugin</artifactId>
                <version>1.3.2</version>
                <configuration>
                    <verbose>true</verbose>
                    <overwrite>true</overwrite>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                </configuration>
            </plugin>
        </plugins>
    </build>


    <properties>
        <spring.version>4.1.1.RELEASE</spring.version>
    </properties>



    <dependencies>
        <!-- springframe start -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</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-oxm</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>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- springframe end -->

        <!--aspectj start-->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.8.6</version>
        </dependency>

        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>1.8.6</version>
        </dependency>
        <!--aspectj end-->

        <!--c3p0-->
        <dependency>
            <groupId>com.mchange</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.5.1</version>
        </dependency>

        <!--servlet/jsp api start-->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
        </dependency>

        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.1</version>
            <scope>provided</scope>
        </dependency>
        <!--servlet/jsp api end-->

        <!--junit4-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>

        <!--mybatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.3.0</version>
        </dependency>
        <!--mybatis spring整合-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.2.3</version>
        </dependency>

        <!--mysql driver-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>

        <!--jstl-->
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

    </dependencies>
</project>

 

配置文件
web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">

    <!-- Spring ApplicationContext 載入 -->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <!-- SpringMVC核心Servlet -->
    <servlet>
        <servlet-name>springMVC-config</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:/WEB-INF/springMVC-config.xml</param-value>
        </init-param>
    </servlet>
    
    <!-- 攔截所有請求 -->
    <servlet-mapping>
        <servlet-name>springMVC-config</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!-- spring配置文件加載 -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:WEB-INF/spring-mybatis.xml</param-value>
    </context-param>

</web-app>

 

spring-mybatis.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:p="http://www.springframework.org/schema/p"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.2.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">

    <!-- 自動搜索bean -->
    <context:annotation-config/>
    <context:component-scan base-package="com.cyan" />

    <bean id="datasource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/Demo"/>
        <property name="username" value="root"/>
        <property name="password" value="2233"/>
    </bean>

    <!-- mybatis核心bean -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="datasource"/>
        <!-- 這句配置mapper配置文件的位置 如果采用注解的方式這句可以省去 -->
        <!--<property name="mapperLocations" value="classpath:/WEB-INF/Mappers/*.xml" />-->
    </bean>

    <!-- 自動搜索mapper接口 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.cyan.Mapper" />
    </bean>


    <!-- 事務處理 -->
    <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="datasource"/>
    </bean>

    <tx:advice id="txAdvice" transaction-manager="txManager">
        <tx:attributes>
            <tx:method name="insert*" propagation="REQUIRED"/>
            <tx:method name="delete*" propagation="REQUIRED"/>
            <tx:method name="update*" propagation="REQUIRED"/>
            <tx:method name="select*" propagation="SUPPORTS"/>
        </tx:attributes>
    </tx:advice>

    <aop:config>
        <aop:pointcut id="serviceCut" expression="execution(public * Service.*.*(..))" />
        <aop:advisor pointcut-ref="serviceCut" advice-ref="txAdvice" />
    </aop:config>


</beans>

springMVC-config.xml

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc" 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-3.0.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.0.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

    <!--spring可以自動去掃描base-pack下面或者子包下面的java文件，
    如果掃描到有@Component @Controller@Service等這些注解的類，則把這些類注冊為bean-->
    <context:component-scan base-package="com.cyan.Controller">
        <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
        <context:include-filter type="annotation" expression="org.springframework.web.bind.annotation.ControllerAdvice"/>
    </context:component-scan>

    <mvc:annotation-driven />
    <mvc:default-servlet-handler/>

    <!-- 配置jsp文件的前后綴 “／”代表的是項目設定的Resource目錄 -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/"/>
        <property name="suffix" value=".jsp" />
    </bean>

</beans>

 

數據庫表結構

詳細類設計
－mapper
UserMapper

package com.cyan.Mapper;

import com.cyan.Model.User;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;

import javax.annotation.Resource;
import java.util.List;

/**
 * Created by cyan on 16/3/29.
 */

public interface UserMapper {
    @Select("select * from LoginDemo")
    public List<User> selectUser();
    @Select("select * from LoginDemo where username=#{username}")
    public List<User> selectUserByUsername(@Param("username")String username);

}

 

－entity
User

package com.cyan.Entity;

/**
 * Created by cyan on 16/3/29.
 */
public class User {
    private int id;
    private String username,password,slogan;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getSlogan() {
        return slogan;
    }

    public void setSlogan(String slogan) {
        this.slogan = slogan;
    }

}

－service
IUserService

package com.cyan.Service;

import com.cyan.Entity.User;

/**
 * Created by cyan on 16/3/31.
 */
public interface IUserService {
    public User getUserByName(String name);
    public boolean verify(String username,String pwd);
}

UserService

Spring中的幾個標簽@Component（聲明一個類是Spring容器管理的類，可以細分為后面提到的三個標簽）、@Controller（控制層）、@Service（服務層）、@Repository（持久層）。標簽的作用是讓Spring根據名字關聯到這個類。

@Autowired標簽默認以byType的形式注入，使用這個標簽是不需要getter和setter方法的。（這次代碼中因為用戶名密碼校驗部分要用到get方法所以寫上了）
可以配合@Qualifier標簽根據bean的id來裝配。

package com.cyan.Service;

import com.cyan.Mapper.UserMapper;
import com.cyan.Entity.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

/**
 * Created by cyan on 16/3/31.
 */

@Service("userService")
public class UserService implements IUserService{

    @Autowired
    private UserMapper userMapper;

    public void setUserMapper(UserMapper userMapper) {
        this.userMapper = userMapper;
    }

    @Override
    public User getUserByName(String name) {
        return userMapper.selectUserByUsername(name).get(0);
    }

    @Override
    public boolean verify(String username, String pwd) {
        if(userMapper.selectUserByUsername(username).get(0).getPassword().equals(pwd))
            return true;
        else return false;
    }

}

－controller
Login

package com.cyan.Controller;

import com.cyan.Service.IUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Created by cyan on 16/3/29.
 */

@Controller
public class Login {

    @Autowired
    private IUserService userService;

    @RequestMapping("/index")
    public String index(){
        return "index";
    }

    @RequestMapping(value ="/login",method = RequestMethod.POST)
    public String login(HttpServletRequest req, HttpServletResponse resp){
        String username=req.getParameter("username");
        String pwd=req.getParameter("password");
        if(userService.verify(username,pwd)){
            req.getSession().setAttribute("user",userService.getUserByName(username));
            return "success";
        }
        else return "index";

    }
}

jsp頁面
index.jsp

<%--
  Created by IntelliJ IDEA.
  User: cyan
  Date: 16/3/29
  Time: 15:55
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
  <head>
    <title>Login</title>
  </head>
  <body>
    <form action="/login" method="post">
      用戶名:<input type="text" name="username" id="username"/>
      <br>
      密碼:<input type="password" name="password" id="password"/>
      <br>
      <input type="submit" value="登錄"/>
    </form>
  </body>
</html>

success.jsp

<%@ page import="com.cyan.Entity.User" %><%--
  Created by IntelliJ IDEA.
  User: cyan
  Date: 16/3/31
  Time: 23:45
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>LoginSuccess</title>
</head>
<body>
登錄成功!
<%
    User user=(User)session.getAttribute("user");
%>
用戶名:<%=user.getUsername()%><br>
個性簽名:<%=user.getSlogan()%><br>
</body>
</html>

運行結果

>作者：cyan
>歡迎訪問我的博客www.cyancyr.me

>項目源碼下載 https://github.com/verlen/SSMDemo