IDEA搭建传统的SSM项目

1、新建一个maven项目，选择maven-archetpe-webapp模板。

2、配置项目名称和本地保存路径

3、配置Maven

等待项目初始化完成，大概是这个样子的

4、在src/main文件夹下面新建java文件夹和resources文件夹。

5、pom.xml文件引入依赖

spring基础包

<!--spring相关-->
<!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-context</artifactId>
  <version>4.3.18.RELEASE</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.springframework/spring-core -->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-core</artifactId>
  <version>4.3.18.RELEASE</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.springframework/spring-beans -->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-beans</artifactId>
  <version>4.3.18.RELEASE</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.springframework/spring-web -->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-web</artifactId>
  <version>4.3.18.RELEASE</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-webmvc</artifactId>
  <version>4.3.18.RELEASE</version>
</dependency>

持久层mybatis和mysql

<!--mybatis-->
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
<dependency>
  <groupId>org.mybatis</groupId>
  <artifactId>mybatis</artifactId>
  <version>3.4.6</version>
</dependency>

<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>8.0.23</version>
</dependency>

数据库事务管理

<!--数据库事务管理-->
<!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-jdbc</artifactId>
  <version>4.3.18.RELEASE</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.springframework/spring-tx -->
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-tx</artifactId>
  <version>4.3.18.RELEASE</version>
</dependency>

spring和mybatis整合

<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
<dependency>
  <groupId>org.mybatis</groupId>
  <artifactId>mybatis-spring</artifactId>
  <version>1.3.2</version>
</dependency>

jsp页面

<!--jsp-->
<!-- https://mvnrepository.com/artifact/javax.servlet/jstl -->
<dependency>
  <groupId>javax.servlet</groupId>
  <artifactId>jstl</artifactId>
  <version>1.2</version>
</dependency>

<!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
<dependency>
  <groupId>javax.servlet</groupId>
  <artifactId>javax.servlet-api</artifactId>
  <version>3.1.0</version>
  <scope>provided</scope>
</dependency>

数据库连接池

<dependency>
  <groupId>commons-dbcp</groupId>
  <artifactId>commons-dbcp</artifactId>
  <version>1.4</version>
</dependency>

json解析

<dependency>
  <groupId>com.alibaba</groupId>
  <artifactId>fastjson</artifactId>
  <version>1.2.47</version>
</dependency>

6、在resources目录下新建spring文件夹，并新建spring-mvc.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/beans http://www.springframework.org/schema/beans/spring-beans.xsd
      http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
      http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd">

    <!--使用注解驱动-->
    <mvc:annotation-driven/>

    <mvc:default-servlet-handler/>

    <!--配置视图解析器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!--重定向时,是否加上上下文路径-->
        <property name="redirectContextRelative" value="true"/>
        <!--配置解析前后缀-->
        <property name="prefix" value="/WEB-INF/View/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

    <!--扫描所有handler(控制器)-->
    <context:component-scan base-package="com.demo.controller"/>
</beans>

7、在resources目录下，新建jdbc.properties文件

#mysql驱动
driver=com.mysql.cj.jdbc.Driver
#News为我本地的数据库名
url=jdbc:mysql://localhost:3306/News?useUnicode=true&serverTimezone=GMT%2B8&useSSL=false
#数据库登录用户名
username=root
#下面输入自己数据库的密码
password=123456
#定义初始连接数
initialSize=1
#定义最大连接数
maxActive=20
#定义最大空闲
maxIdle=20
#定义最小空闲
minIdle=1
#定义最长等待时间
maxWait=60000

8、在resources目录下新建mapper文件夹，用来保存mapper.xml映射文件，并在该文件夹下面的spring文件夹中新建spring和mybatis的整合配置文件：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:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
                        http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
                        http://www.springframework.org/schema/context
                        http://www.springframework.org/schema/context/spring-context-4.0.xsd">

    <!--自动扫描-->
    <context:component-scan base-package="com.demo"/>

    <!--引入properties文件-->
    <bean id="placeholderConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location" value="classpath:jdbc.properties"></property>
    </bean>

    <!--配置数据源-->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <!--数据库连接池-->
        <property name="driverClassName" value="${driver}"/>
        <property name="url" value="${url}"/>
        <property name="username" value="${username}"/>
        <property name="password" value="${password}"/>
        <!-- 初始化连接大小 -->
        <property name="initialSize" value="${initialSize}"></property>
        <!-- 连接池最大数量 -->
        <property name="maxActive" value="${maxActive}"></property>
        <!-- 连接池最大空闲 -->
        <property name="maxIdle" value="${maxIdle}"></property>
        <!-- 连接池最小空闲 -->
        <property name="minIdle" value="${minIdle}"></property>
        <!-- 获取连接最大等待时间 -->
        <property name="maxWait" value="${maxWait}"></property>
    </bean>

    <!--配置sqlsession工厂-->
    <!-- spring和MyBatis完美整合，不需要mybatis的配置映射文件 -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <!-- 自动扫描mapping.xml文件 -->
        <property name="mapperLocations" value="classpath:mapper/*.xml"/>
    </bean>

    <!--配置DAO所在spring会自动查找下面的类-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.demo.dao"/>
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
    </bean>

    <!-- (事务管理)transaction manager, use JtaTransactionManager for global tx -->
    <bean id="transactionManager"
          class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
</beans>

9、在web.xml配置前端控制器

字符集监听器：org.springframework.web.filter.CharacterEncodingFilter

主要用来限制整个工程的字符集的。

前端控制器：org.springframework.web.servlet.DispatcherServlet

是spring用来接收用户请求的同时分配用户请求给控制器(controller)来控制请求处理

<!DOCTYPE web-app PUBLIC
        "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
        "http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app
        xmlns="http://java.sun.com/xml/ns/javaee"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
        version="3.0"
        metadata-complete="true">
  <display-name>Archetype Created Web Application</display-name>

  <!--请求和应答字符编码过滤器-->
  <filter>
    <filter-name>encoding-filter</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>encoding-filter</filter-name>
    <!--<url-pattern>/*</url-pattern>-->
    <servlet-name>springDispatcherServlet</servlet-name>
  </filter-mapping>

  <!--启动spring容器-->
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:spring/spring-mybatis.xml</param-value>
  </context-param>


  <!-- 用前端控制器初始化springmvc容器 -->
  <!-- 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:spring/spring-mvc.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>

10、准备数据库news表

CREATE TABLE `news` (
  `id` int NOT NULL AUTO_INCREMENT,
  `name` varchar(50) DEFAULT NULL,
  `info` longtext,
  `date` datetime DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;

11、接下来编辑业务代码部分

准备实体News

package com.demo.pojo;

import java.util.Date;

public class News {

    private Integer id;

    private String name;

    private String info;

    private Date date;

    public News() {
    }

    public News(Integer id, String name, String info, Date date) {
        this.id = id;
        this.name = name;
        this.info = info;
        this.date = date;
    }

    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 String getInfo() {
        return info;
    }

    public void setInfo(String info) {
        this.info = info;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }

    @Override
    public String toString() {
        return "News{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", info='" + info + '\'' +
                ", date=" + date +
                '}';
    }
}

控制器NewsController

package com.demo.controller;

import com.demo.pojo.News;
import com.demo.service.NewsService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

import java.util.List;

@Controller
@RequestMapping("/news")
public class NewsController {

    @Autowired
    private NewsService newsService;

    @GetMapping("/getNews")
    public ModelAndView getNews(){
        List<News> newsList = newsService.getNewsList();
        newsList.forEach(item -> {
            System.out.println(item);
        });
        ModelAndView modelAndView = new ModelAndView("newlist");
        modelAndView.addObject("newsList", newsList);
        return modelAndView;
    }
}

业务层接口NewsService

package com.demo.service;

import com.demo.pojo.News;

import java.util.List;

public interface NewsService {

    List<News> getNewsList();
}

业务层实现NewsServiceImpl

package com.demo.service.impl;

import com.demo.dao.NewsDao;
import com.demo.pojo.News;
import com.demo.service.NewsService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class NewsServiceImpl implements NewsService {

    @Autowired
    private NewsDao newsDao;

    @Override
    public List<News> getNewsList() {

        return newsDao.getNewsList();
    }
}

持久层NewsDao

package com.demo.dao;

import com.demo.pojo.News;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface NewsDao {

    List<News> getNewsList();

}

Mapper映射文件NewsMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org/DTD Mapper 3.0" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.demo.dao.NewsDao">

    <select id="getNewsList" resultType="com.demo.pojo.News">
        select `id`, `name`, `info`, `date` from `news`;
    </select>

</mapper>

在WEB-INF下面新建View文件夹，里面新建newlist.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib uri = "http://java.sun.com/jsp/jstl/core" prefix = "c" %>
<html>
<head>
    <title>新闻列表</title>
</head>
<body>
    <div>
        <table border="1" cellspacing="0" cellpadding="0">
            <tr>
                <th>编号</th>
                <th>标题</th>
                <th>内容</th>
                <th>日期</th>
            </tr>
            <c:forEach items="${requestScope.newsList }" var="item">
                <tr>
                    <td>${item.id}</td>
                    <td>${item.name}</td>
                    <td>${item.info}</td>
                    <td>${item.date}</td>
                </tr>
            </c:forEach>
        </table>
    </div>
</body>
</html>

12、配置tomcat

把war包添加进来

13、启动测试