controller包：界面层
dao包：数据库访问层
service包：业务逻辑层
domain包：每一个Java类对应于数据库中的一个表
resources目录：mybatis主配置文件、spring配置文件、jdbc外部属性配置文件
webapp：web项目相关内容，注册servlet、监听器、jsp页面

2.2 数据库

2.3 在pom.xml文件中加入依赖

<?xml version="1.0" encoding="UTF-8"?>

<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/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>org.example</groupId>
  <artifactId>ch15-Web</artifactId>
  <version>1.0.0</version>
  <packaging>war</packaging>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>

<!--    监听器依赖-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>5.2.5.RELEASE</version>
    </dependency>

<!--    servlet-->
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>javax.servlet.jsp</groupId>
      <artifactId>jsp-api</artifactId>
      <version>2.2.1-b03</version>
    </dependency>
    <!--  Spring依赖-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>5.2.5.RELEASE</version>
    </dependency>
    <!--    spring事务的依赖-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>5.2.5.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>5.2.5.RELEASE</version>
    </dependency>
    <!--    mybatis依赖-->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.5.1</version>
    </dependency>
    <!--    spring和mybatis集成-->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>1.3.1</version>
    </dependency>
    <!--    mysql驱动-->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.9</version>
    </dependency>
    <!--    阿里的连接池-->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.1.12</version>
    </dependency>
  </dependencies>

  <build>
    <resources>
      <resource>
        <directory>src/main/java</directory><!--所在的目录-->
        <includes><!--包括目录下的.properties,.xml 文件都会扫描到-->
          <include>**/*.properties</include>
          <include>**/*.xml</include>
        </includes>
        <filtering>false</filtering>
      </resource>
    </resources>
  </build>

</project>

2.4 创建Student实体类

package com.liuhaiyang.domain;

public class Student {
    private Integer id;
    private  String name;
    private  Integer age;

    //set()和get()方法、toString()、有参构造和无参构造

}

2.5 创建dao接口和对应的mapper文件

package com.liuhaiyang.dao;

import com.liuhaiyang.domain.Student;

public interface StudentDao {
    public int insertStudent(Student student);
    public Student selectId(Integer id);
}

<?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.liuhaiyang.dao.StudentDao">
    <!--使用insert，uodate，delete，select标签写sql-->
    <insert id="insertStudent">
        insert  into student2(name,age) values(#{name},#{age})
    </insert>

    <select id="selectId" resultType="com.liuhaiyang.domain.Student">
        select * from student2 where id=#{id}
    </select>
    <!--    定义列和属性的对应关系

    <resultMap id="studentMap" type="com.liuhaiyang.domain.Student">
        <id column="列" property="属性"/>
    </resultMap>
   -->
</mapper>

2.6 创建mybatis主配置文件

<?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>
<!--    设置日志-->
<!--        <settings>-->
<!--            <setting name="logImpl" value="STDOUT_LOGGING"/>-->
<!--        </settings>-->
    <!--指定其他mapper文件的位置  才能找到其他文件sql语句-->
    <mappers>
<!--        <mapper resource="com/lhy/dao/studentDao.xml"/>-->
        <package name="com.liuhaiyang.dao"/>
    </mappers>
</configuration>

2.7 创建service接口和实现类

2.7.1 StudentService接口

package com.liuhaiyang.service;

import com.liuhaiyang.domain.Student;

public interface StudentService {
    int addStudent(Student student);
    Student findStudentId(Integer id);
}

2.7.2 StudentServiceImpl实现类

package com.liuhaiyang.service.impl;

import com.liuhaiyang.dao.StudentDao;
import com.liuhaiyang.domain.Student;
import com.liuhaiyang.service.StudentService;

public class StudentServiceImpl implements StudentService {

    private  StudentDao stuDao;

    public void setStuDao(StudentDao studentDao) {
        this.stuDao = studentDao;
    }

    @Override
    public int addStudent(Student student) {
        System.out.println(student.getName());
        int a=stuDao.insertStudent(student);
        return a;
    }

    @Override
    public Student findStudentId(Integer id) {
        Student student=stuDao.selectId(id);
        return student;
    }
}

2.8 创建jdbc外部属性配置文件、spring配置文件

jdbc.url=jdbc:mysql://localhost:3306/test?useUnicode=true&amp;characterEncoding=utf-8
jdbc.username=root
jdbc.password=123456

<?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:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd">
<!--       加载引入外部属性配置文件-->
        <context:property-placeholder location="classpath:jdbc.properties"/>
        <!--声明数据源DataSource-->
        <bean id="myDataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
                <property name="url" value="${jdbc.url}"/>
                <property name="username" value="${jdbc.username}"/>
                <property name="password" value="${jdbc.password}"/>
        </bean>

        <!--声明SqlSessionFactoryBean，在这个类内部，创建SqlSessionFactory-->
        <bean id="factory" class="org.mybatis.spring.SqlSessionFactoryBean">
                <!--指定数据源-->
                <property name="dataSource" ref="myDataSource"/>
                <!--指定myBatis主配置文件
                Resource可以直接使用value属性赋值-->
                <property name="configLocation" value="classpath:mybatis.xml"/>
        </bean>


        <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!--                指定sqlsessionFactory对象的名称-->
                <property name="sqlSessionFactoryBeanName" value="factory"/>
<!--                指定基本包，dao接口所在的包名-->
                <property name="basePackage" value="com.liuhaiyang.dao"/>
        </bean>

<!--        声明式事务：不用写代码（只需要在文件中更改即可）
            优点：代码和事务配置是分开的。控制事务源代码不能更改 能快速的了解和掌控项目的全部事务。适合大型项目
-->
<!--        1.声明事务管理器-->
        <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
            <property name="dataSource" ref="myDataSource"/>
        </bean>
    <bean id="studentService" class="com.liuhaiyang.service.impl.StudentServiceImpl">
        <property name="stuDao" ref="studentDao"/>
    </bean>
</beans>

2.9 创建servlet

2.9.1 AddStudentServlet——对应添加学生操作

package com.liuhaiyang.controller;

import com.liuhaiyang.domain.Student;
import com.liuhaiyang.service.StudentService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.web.context.WebApplicationContext;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class AddStudentServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("UTF-8");
        String name=req.getParameter("name");
       String age=req.getParameter("age");
       //这里写text的的东西
//        String config="application.xml";
//        ApplicationContext ctx=new ClassPathXmlApplicationContext(config);
        //使用监听器创建application.xml文件的容器
        WebApplicationContext ctx=null;
        String key=WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE;  //获取key的值
        ServletContext sc=req.getServletContext(); //获得全局作用域对象
        Object attr=sc.getAttribute(key); //取出全局作用域对象的value
        if (attr!=null){
            ctx=(WebApplicationContext) attr;  //强转，将object转换成为ApplicationContext类型
        }

        System.out.println("在servlet在创建的对象容器======"+ctx);
        StudentService service=(StudentService) ctx.getBean("studentService");
        Student student=new Student();
        student.setName(name);
        student.setAge(Integer.valueOf(age));
        service.addStudent(student);
        req.getRequestDispatcher("/show.jsp").forward(req,resp);
    }
}

2.9.2 QueryStudentServlet——对应查询学生操作

package com.liuhaiyang.controller;

import com.liuhaiyang.domain.Student;
import com.liuhaiyang.service.StudentService;
import com.liuhaiyang.service.impl.StudentServiceImpl;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class QueryStudentServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       resp.setContentType("");
        String id=req.getParameter("id");
//        String config="application.xml";
//        ApplicationContext ctx=new ClassPathXmlApplicationContext(config);
        //使用spring提供的工具方法，获取容器对象
        // getRequiredWebApplicationContext底层还是调用全局变量的key值取获取value，在进行判断和强转 只是帮我们做好封装起来了而已
        WebApplicationContext ctx= WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext());

        StudentService service=(StudentService)ctx.getBean("studentService");
        Student student=service.findStudentId(Integer.valueOf(id));
        req.setAttribute("stu",student);
        req.getRequestDispatcher("/find.jsp").forward(req,resp);


    }

}

2.9.3 在web.xml中注册servlet和监听器

<?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_4_0.xsd"
         version="4.0">

    <servlet>
        <servlet-name>one</servlet-name>
        <servlet-class>com.liuhaiyang.controller.AddStudentServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>one</servlet-name>
        <url-pattern>/one</url-pattern>
    </servlet-mapping>
    <servlet>
        <servlet-name>two</servlet-name>
        <servlet-class>com.liuhaiyang.controller.QueryStudentServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>two</servlet-name>
        <url-pattern>/two</url-pattern>
    </servlet-mapping>
    
<!--    声明监听器   默认规则：创建容器对象，读取配置文件： /WEB-INF/applicationContext.xml-->
<!--   自定义使用容器的配置 context-param:叫做上下文参数，给监听器提供参数的
-->
    <context-param>
<!--        contextConfigLocation：名称是固定的，表示自定义spring配置文件的路径-->
        <param-name>contextConfigLocation</param-name>
<!--        自定义配置文件的路径  可以是多个用逗号的方式连接-->
        <param-value>classpath:application.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
</web-app>

2.10 创建jsp页面

2.10.1 提交请求参数（主界面）


<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>添加学生</title>
</head>
<body>
    <div align="center">
        <p>添加学生</p>
        <form action="one" method="post">
            姓名:<input type="text" name="name"> <br>
            年龄:<input type="text" name="age"> <br>
            <input type="submit" value="注册学生"> <br>
        </form>
        <br>
        <p>查询学生</p>
        <form action="two" method="get">
            学生id:<input type="text" name="id"> <br>
            <input type="submit" value="查询学生">
        </form>
    </div>
</body>
</html>

2.10.2 显示添加学生处理结果——对应AddStudentServlet

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
        <h1>注册成功</h1>
</body>
</html>

2.10.3 显示查询学生处理结果——对应QueryStudentServlet

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    <p>查询结果：${stu}</p>
</body>
</html>

2.11测试结果截图

2.11.1 添加学生（AddStudentServlet）的测试结果

数据库数据截图

2.11.2 查询学生（QueryStudentServlet）的测试结果

和数据库的数据是一致的，证明程序没有错误，这就是前后端数据交互，界面很简陋主要是学习中间的操作，要在心里有相关步骤，会自己添加相关功能就可以了。spring基本学完了，接下来就是开始springMVC的学习了。

1.前言

2. 项目步骤

2.1 目录结构

2.2 数据库

2.3 在pom.xml文件中加入依赖

2.4 创建Student实体类

2.5 创建dao接口和对应的mapper文件

2.6 创建mybatis主配置文件

2.7 创建service接口和实现类

2.7.1 StudentService接口

2.7.2 StudentServiceImpl实现类

2.8 创建jdbc外部属性配置文件、spring配置文件

2.9 创建servlet

2.9.1 AddStudentServlet——对应添加学生操作

2.9.2 QueryStudentServlet——对应查询学生操作

2.9.3 在web.xml中注册servlet和监听器

2.10 创建jsp页面

2.10.1 提交请求参数 （主界面）

2.10.2 显示添加学生处理结果——对应AddStudentServlet

2.10.3 显示查询学生处理结果——对应QueryStudentServlet

2.11测试结果截图

2.11.1 添加学生（AddStudentServlet）的测试结果

2.11.2 查询学生（QueryStudentServlet）的测试结果

2.10.1 提交请求参数（主界面）