springmvc整合mybatis

springmvc，表现层框架，和spring是一家人。

springmvc处理流程图：

废话不多说，直接先上springmvc整合mybatis，整个简单Hello World!再说···

第一步肯定是先引包（maven工程）：

<dependencies>
    <!-- spring-webmvc包 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>5.0.6.RELEASE</version>
    </dependency>
    <!-- mybatis包 -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.4.5</version>
    </dependency>
    <!-- mybatis-spring整合包 -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>1.3.1</version>
    </dependency>
    <!-- spring-jdbc包 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>5.0.6.RELEASE</version>
    </dependency>
    <!-- spring-tx事务包 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>5.0.6.RELEASE</version>
    </dependency>
    <!-- mysql数据库驱动包 -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.11</version>
    </dependency>
    <!-- c3p0数据库连接池包 -->
    <dependency>
      <groupId>com.mchange</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.5.2</version>
    </dependency>
    <!-- log4j日志包 -->
    <dependency>
      <groupId>org.apache.logging.log4j</groupId>
      <artifactId>log4j-core</artifactId>
      <version>2.11.0</version>
    </dependency>
    <!-- junit测试包 -->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <!-- spring-test整合测试包 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>5.0.6.RELEASE</version>
      <scope>test</scope>
    </dependency>
    <!-- fastjson阿里巴巴的json包 -->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>fastjson</artifactId>
      <version>1.2.44</version>
    </dependency>
  </dependencies>

在Web.xml配置文件里添加如下：

<!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>
    <display-name>Archetype Created Web Application</display-name>

    <servlet>
        <servlet-name>dispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:applicationContext.xml</param-value>
        </init-param>
    </servlet>

    <servlet-mapping>
        <servlet-name>dispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <welcome-file-list>
        <welcome-file>/WEB-INF/index.jsp</welcome-file>
    </welcome-file-list>
    
</web-app>

在resources目录中创建log4j.properties配置文件和 applicationContext.xml配置文件。

log4j.properties配置文件：

# Global logging configuration
log4j.rootLogger=DEBUG, stdout
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

applicationContext.xml配置文件：

<?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:Context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
       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.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
    <!--注解包扫描-->
    <Context:component-scan base-package="com.springmvc"/>
    <!--事务-->
    <tx:annotation-driven transaction-manager="transactionManager"/>
    <bean name="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <!--数据库连接池-->
    <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver"/>
        <property name="jdbcUrl" value="jdbc:mysql://119.23.12.242:3306/abc"/>
        <property name="user" value="root"/>
        <property name="password" value="Aliyun1234."/>
        <property name="minPoolSize" value="1"/>
    </bean>
    <!--sql。xml配置文件扫描-->
    <bean class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="mapperLocations" value="classpath:daoxml/*.xml"/>
    </bean>
    <!--sql。接口文件扫描-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.springmvc.dao"/>
    </bean>
</beans>

然后用mybatis逆向工程生成sql的接口和sq的xml配置文件还有，pojo文件。

请参考mybatis逆向工程→https://blog.csdn.net/qq_40550973/article/details/80788662

现在环境就算搭建好了，下面测试一下：

service层来个全查数据库表。

controller层把数据转成json字符串。

然后配置tomcat服务器，运行效果如下：

Hello World出现。

访问：http://localhost:8080/user也获得到了json数据。

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