springMVC框架连接数据库查询数据

1.框架搭建，创建一个maven项目打war包

web.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://java.sun.com/xml/ns/javaee"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
	version="2.5">
	<display-name>SpringMVC</display-name>
	<servlet>
        <servlet-name>appServlet</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>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>appServlet</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>
</web-app>

　　pom.xml文件

<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>com.cn</groupId>
  <artifactId>upload</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>
  <dependencies>
	<dependency>
    	<groupId>org.springframework</groupId>
    	<artifactId>spring-webmvc</artifactId>
    	<version>4.0.6.RELEASE</version>
    </dependency>
    <dependency>
    	<groupId>com.fasterxml.jackson.core</groupId>
    	<artifactId>jackson-annotations</artifactId>
    	<version>2.2.3</version>
    </dependency>
    <dependency>
    	<groupId>com.fasterxml.jackson.core</groupId>
    	<artifactId>jackson-core</artifactId>
    	<version>2.2.3</version>
    </dependency>
    <dependency>
    	<groupId>com.fasterxml.jackson.core</groupId>
    	<artifactId>jackson-databind</artifactId>
    	<version>2.2.3</version>
    </dependency>
    <!--文件上传下载所用的包============  -->
    <dependency>
    	<groupId>commons-fileupload</groupId>
    	<artifactId>commons-fileupload</artifactId>
    	<version>1.3.1</version>
    </dependency>
    <dependency>
    	<groupId>commons-io</groupId>
    	<artifactId>commons-io</artifactId>
    	<version>2.4</version>
    </dependency>
    <dependency> 
	   <groupId>javax.servlet</groupId> 
	   <artifactId>servlet-api</artifactId> 
	   <version>2.5</version> 
	   <scope>provided</scope> 
    </dependency> 
    <!-- jstl-api -->
        <dependency>
            <groupId>javax.servlet.jsp.jstl</groupId>
            <artifactId>jstl-api</artifactId>
            <version>1.2</version>
        </dependency>
        <!-- jstl-impl -->
        <dependency>
            <groupId>org.glassfish.web</groupId>
            <artifactId>jstl-impl</artifactId>
            <version>1.2</version>
        </dependency>
        <!-- 标签standard包 -->
        <dependency>
            <groupId>taglibs</groupId>
            <artifactId>standard</artifactId>
            <version>1.1.2</version>
        </dependency>
        <!-- 数据库配置 -->
        <!--mybatis mysql-->
		<dependency>
		    <groupId>com.alibaba</groupId>
		    <artifactId>druid</artifactId>
		    <version>1.0.2</version>
		</dependency>
		<dependency>
		    <groupId>org.mybatis</groupId>
		    <artifactId>mybatis-spring</artifactId>
		    <version>1.2.2</version>
		</dependency>
		<dependency>
		    <groupId>org.mybatis</groupId>
		    <artifactId>mybatis</artifactId>
		    <version>3.2.6</version>
		</dependency>
		<dependency>
		    <groupId>mysql</groupId>
		    <artifactId>mysql-connector-java</artifactId>
		    <version>5.1.29</version>
		</dependency>
		<!-- jdbc驱动jar包 -->
		<dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>4.1.1.RELEASE</version>
        </dependency>
</dependencies>
</project>

　　//springMVC核心配置文件 psringmvc.xml文件

<?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:mvc="http://www.springframework.org/schema/mvc"    
    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.xsd">  
 
 
     <mvc:annotation-driven />
    <!-- ①：对web包中的所有类进行扫描，以完成Bean创建和自动依赖注入的功能 -->
    <context:component-scan base-package="com.zjn" />

    <!-- 这两个类用来启动基于Spring MVC的注解功能，将控制器与方法映射加入到容器中 -->
    <bean
        class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" />
    <bean
        class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" />

    <!-- 这个类用于Spring MVC视图解析 -->
    <bean id="viewResolver"
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/"></property>
         <property name="suffix" value=".jsp"></property>
    </bean>
    
    <!-- 避免IE执行AJAX时,返回JSON出现下载文件 -->
	<bean id="mappingJacksonHttpMessageConverter"
		class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
		<property name="supportedMediaTypes">
			<list>
				<value>text/html;charset=utf-8</value>
			</list>
		</property>
	</bean>
 
 
	<!-- 启动Spring MVC的注解功能，完成请求和注解POJO的映射 -->
	<bean
		class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
		<property name="messageConverters">
			<list>
				<ref bean="mappingJacksonHttpMessageConverter" /><!-- json转换器 -->
			</list>
		</property>
	</bean>
    
    <!-- 支持上传文件 -->
	<bean id="multipartResolver"
		class="org.springframework.web.multipart.commons.CommonsMultipartResolver" >
		<!-- 100M -->
		<property name="maxUploadSize" value="10485760000"></property>	
		<property name="defaultEncoding" value="utf-8"></property>   
	</bean>
    <!--  数据库配置-->
    <!-- 使用配置文件 -->
    <context:property-placeholder location="classpath:properties/mysql.properties"/>
    
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
        init-method="init" destroy-method="close">
        <property name="driverClassName" value="${jdbc.driverClassName}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
        <!-- 连接池最大使用连接数 -->
        <property name="maxActive" value="20"/>
        <!-- 初始化连接大小 -->
        <property name="initialSize" value="1"/>
        <!-- 获取连接最大等待时间 -->
        <property name="maxWait" value="60000"/>
        <!-- 连接池最小空闲 -->
        <property name="minIdle" value="3"/>
        <!-- 自动清除无用连接 -->
        <property name="removeAbandoned" value="true"/>
        <!-- 清除无用连接的等待时间 -->
        <property name="removeAbandonedTimeout" value="180"/>
        <!-- 连接属性 -->
        <property name="connectionProperties" value="clientEncoding=UTF-8"/>
    </bean>

    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--指定实体类映射文件，可以指定同时指定某一包以及子包下面的所有配置文件 -->
        <property name="mapperLocations"  value="classpath:mapper/**/*.xml"/>
        <!--mybatis全局配置文件 -->
        <property name="configLocation" value="classpath:mybatis/mybatis-config.xml" />
        <property name="dataSource" ref="dataSource" />
    </bean>

    <!-- spring与mybatis整合配置，扫描所有dao -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.zjn.dao"/>
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
    </bean>
    
</beans>  

　　在src/main/resources下新建mapper包放置mapper.xml相关sql文件

<?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.zjn.dao.UserDao">
<select id="getUseInfo" resultType="java.util.Map">
    select * from blade_user
</select>
   
</mapper>

　　在src/main/resources下新建mybatis包放置数据配置文件mybatis-config.xml

<?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>

    <settings>
        <setting name="jdbcTypeForNull" value="NULL" />
    </settings>
    <!-- 命名空间 -->
   <!--  <typeAliases>
        <typeAlias type="com.jing.oa.model.User" alias="User"/>
    </typeAliases> -->
</configuration>

　　//在src/main/resources下新建properties包放置数据配置文件mysql.properties

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/peixian
jdbc.username=root
jdbc.password=123456

　　在src/main/java新建包com.zjn，在com.zjn中新建controller,dao,service包。在service包中新建包impl