实训日记（4）

基于SpringMVC的数据库的增、删、改、查

感想

在昨天配置好Maven和SMM环境的基础下，今天终于可以开始写真正的逻辑代码了。这次的需求主要是写好一个简单的数据库的增删改查。虽然在之前已经用不同语言写过了无数次的数据库操作，但是这次却不一样了，我们需要按照SpringMVC框架来编写相关操作，所以在编写这次的程序之前，我通过询问老师和查询相关网络资源了解了SPringMVC基本的调用和执行过程。虽然如此，在编写程序的时候还是遇到了许多问题，从一开始的404到后来的数据未注入，种种情况都遇到了。但是最终还是依靠和队友讨论以及求助大佬完成了此次的任务。

以下是这次的代码：

applicationContext.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:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
		http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
		http://www.springframework.org/schema/context
		http://www.springframework.org/schema/context/spring-context-4.3.xsd
		http://www.springframework.org/schema/aop
		http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
		http://www.springframework.org/schema/tx
		http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">
    <!-- 1.读取数据库配置文件properties的属性：${url} -->
    <context:property-placeholder location="classpath:properties/db.properties"/>

    <!-- 2.配置数据源 -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
        <property name="maxPoolSize" value="30"/>
        <property name="minPoolSize" value="2"/>
    </bean>

    <!-- 3.配置SqlSessionFactory对象 -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 注入数据库连接池 -->
        <property name="dataSource" ref="dataSource"/>
        <!-- 扫描bean包 使用别名 -->
        <property name="typeAliasesPackage" value="com.zzj.people_manage.entity"/>

        <!--配置加载映射文件 UserMapper.xml，很容易写错-->
        <property name="mapperLocations" value="classpath:mapper/*.xml"/>

        <!--配置mybatis配置文件位置-->
<!--        <property name="configLocation" value="classpath:mybatis/SqlMapConfig.xml"/>-->

    </bean>

    <!-- 自动生成dao,mapper-->
    <!-- 4.配置扫描Dao接口包，动态实现Dao接口，注入到spring容器中 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!-- 给出需要扫描Dao接口包，这里很容易写错 -->
        <property name="basePackage" value="com.zzj.people_manage.dao"/>
        <!-- 注入sqlSessionFactory -->
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
    </bean>



    <!--自动扫描-->
<!--    <context:component-scan base-package="com.zzj.people_manage"/>-->
    <context:component-scan base-package="com.zzj.people_manage.dao"/>
    <context:component-scan base-package="com.zzj.people_manage.service"/>


    <!-- 配置事务-->
    <!-- 5.配置事务管理器 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <!-- 6.开启事务注解-->
    <tx:annotation-driven/>

</beans>

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:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
      http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
      http://www.springframework.org/schema/mvc
      http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
      http://www.springframework.org/schema/context
      http://www.springframework.org/schema/context/spring-context-4.3.xsd
      http://www.springframework.org/schema/aop
      http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
      http://www.springframework.org/schema/tx
      http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">

    <!-- 1.注解扫描位置-->
    <context:component-scan base-package="com.zzj.people_manage.controller" />

    <!-- 2.配置映射处理和适配器-->
    <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"/>
    <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"/>

    <!-- 3.视图的解析器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>
</beans>

UserController

@Controller
@RequestMapping("user")
public class UserController {
    @Autowired
    private IUserDao userDao;

    @RequestMapping("/all")
    public String all(Model model) {
        List<User> users=userDao.getUsers();
        //键值对形式添加进model
        model.addAttribute("users", users);
        return "index";
    }

    @RequestMapping("/toAddUser")
    public String toAddUser(User user){
        return "addUser";
    }

    @RequestMapping("/addUser")
    public String addUser(User user) {
        userDao.addUser(user);
        return "redirect:/user/all";
    }

    @RequestMapping("/toChangeName")
    public String toChangeName(Model model, Integer id){
        model.addAttribute("user",userDao.getUserById(id));
        return "changeName";
    }

    @RequestMapping("/changeName")
    public String changeName(Model model, User user){
        userDao.changeName(user);
        System.out.println(user);
        user = userDao.getUserById(user.id);
        model.addAttribute("user", user);
        return "redirect:/user/all";
    }
}

IUserDao

public interface IUserDao {
    List<User> getUsers();

    int addUser(User user);

    User getUserById(Integer id);

    int changeName(User user);
}

User（实体类）

public class User {
    public Integer id;
    public String name;
    public String sex;

    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 getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", sex='" + sex + '\'' +
                '}';
    }
}

UserMapper.xml（数据库映射）

<?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.zzj.people_manage.dao.IUserDao">
    <resultMap type="User" id="userResultMap" >
        <id property="id" column="id"/>
        <result property="name" column="name"/>
        <result property="sex" column="sex"/>
    </resultMap>
    <select id="getUsers" resultType="User">
        select * from tb_user
    </select>
    <insert id="addUser" parameterType="User">
        INSERT INTO tb_user(id,name,sex) VALUE (#{id},#{name},#{sex})
    </insert>
    <select id="getUserById" resultType="User" parameterType="Integer">
        SELECT id,name,sex
        FROM tb_user
        WHERE id=#{id}
    </select>
    <update id="changeName" parameterType="User">
        UPDATE tb_user
        SET NAME = #{name}
        WHERE  id = #{id}
    </update>
</mapper>

Index.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>武理表</title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <!-- 引入 Bootstrap -->
    <link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">

</head>
<body>
    <h2 align="center">武汉理工大学学生信息表</h2>
    <h2 align="center"><a href="${path }/user/toAddUser">点击进入新增用户界面</a></h2>

    <table class="table table-hover table-striped" >
        <thead>
        <tr>
            <th>姓名</th>
            <th>性别</th>
            <th>操作</th>
        </tr>
        </thead>
        <tbody>
        <c:forEach var="item" items="${users}">
        <tr>
            <td>${item.name}</td>
            <td>${item.sex}</td>
            <td>
                <a href="${path }/user/toChangeName?id=${item.id}">修改${item.name}姓名</a> |
                <a href="${path }/user/toChangeSex?id=${itemm.id}">修改${item.name}性别</a> |
                <a href="${path }/user/deleteUser?id=${item.id}">删除${item.name}</a>
            </td>
        </tr>
        </c:forEach>
        </tbody>
    </table>

</body>
</html>

changeName.jsp

<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://"
            + request.getServerName() + ":" + request.getServerPort()
            + path + "/";
%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>改名</title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <!-- 引入 Bootstrap -->
    <link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
</head>
<body>
<h2 align="center">修改无理人姓名</h2>
<form action="" name="userForm">
    <input type="hidden" name="id" value="${user.id}"/>
    <div align="center">
        <br><br>输入修改后的姓名：<input type="text" name="name" value="${user.name}"/>
        <input type="button" value="提交" onclick="changeName()"/>
    </div>
</form>

<script type="text/javascript">
    function changeName() {
        var form = document.forms[0];
        form.action = "<%=basePath %>user/changeName";
        form.method = "post";
        form.submit();
    }
</script>

</body>
</html>