Spring+Spring MVC+MyBatis整合

一、准备工作

　   1.1导入所需jar包                                                    

　　　　

　　

　　1.2数据库

　　

　　

CREATE TABLE `t_customer` (
  `id` int(32) NOT NULL AUTO_INCREMENT,
  `username` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `jobs` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `phone` varchar(16) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=19 DEFAULT CHARSET=utf8;

 二、编写配置文件

　　2.1编写db.propertise文件　

#dataSource
#Thu Mar 07 16:27:40 CST 2019
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/sm
jdbc.username=root
jdbc.password=123456
jdbc.maxTotal=30
jdbc.maxIdle=10
jdbc.initialSize=5

　　2.2在src目录下创建beans.xml(applicationContext.xml)　

<?xml  version="1.0"  encoding="UTF-8"?> 
<beans  xmlns="http://www.springframework.org/schema/beans" 
        xmlns:aop="http://www.springframework.org/schema/aop"
        xmlns:tx="http://www.springframework.org/schema/tx"
        xmlns:context="http://www.springframework.org/schema/context"         
        xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" 
        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/tx
             http://www.springframework.org/schema/tx/spring-tx-4.3.xsd
             http://www.springframework.org/schema/aop
             http://www.springframework.org/schema/aop/spring-aop-4.3.xsd" > 
    <!-- 读取 db.properties-->
    <context:property-placeholder location = "classpath:db.properties"/>
    <!-- 配置数据源 -->
    <bean id = "dataSource" class = "org.apache.commons.dbcp2.BasicDataSource">
        <!-- 数据库驱动 -->
        <property name = "driverClassName" value = "${jdbc.driver}" />
        <!-- 数据库url -->
        <property name = "url" value = "${jdbc.url}" />
        <!-- 数据库用户名 -->
        <property name = "username" value = "${jdbc.username}" />
        <!-- 数据库密码 -->
        <property name = "password" value = "${jdbc.password}" />
        <!-- 数据库最大连接数 -->
        <property name="maxTotal" value = "${jdbc.maxTotal}"/>
        <!-- 数据库最大空闲数 -->
        <property name="maxIdle" value = "${jdbc.maxIdle}"/>
        <!-- 初始化连接数 -->
        <property name="initialSize" value = "${jdbc.initialSize}"/>
    </bean>    
    <!-- 配置事务管理，并指定数据源 -->
    <bean id = "transactionManager" 
            class = "org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name = "dataSource" ref = "dataSource" />
    </bean>
    <!-- 开启事务注解 -->
    <tx:annotation-driven transaction-manager = "transactionManager" />
    <!-- 扫描 此处会扫描com.ssm.service及com.ssm.service.Impl-->
    <context:component-scan base-package="com.ssm.service"/>
    <!-- 配置MyBatis工厂 -->
    <bean id = "sqlSessionFactory" class = "org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 注入数据源 -->
        <property name="dataSource" ref = "dataSource"/>
        <!-- 指定核心配置文件 -->
        <property name="configLocation" value = "classpath:mybatis-config.xml"/>
    </bean>
    <!-- 基于MapperScannerConfigurer，会自动扫描指定包下的接口文件和映射文件 -->
    <bean class = "org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name = "basePackage" value = "com.ssm.dao"/>
    </bean>
</beans>

　　　　2.3在src目录下创建mybatis-congfig.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>
    <!-- 采用扫描包定义别名 -->
    <typeAliases>
        <package name="com.ssm.po"/>
    </typeAliases>
    
    <!-- 配置映射文件 -->
    <mappers>
        
    </mappers>
</configuration>

　　　　2.4在src目录下创建springmvc-config.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"
        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"> 
       <!-- 开启扫描 -->
       <context:component-scan base-package = "com.ssm.controller"/>
　　　　<!--加载注解驱动-->
       <mvc:annotation-driven/>
   　　 <!--配置视图解析器 设置前缀后缀-->
       <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>
</beans>

　　　　

　　2.5web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns="http://xmlns.jcp.org/xml/ns/javaee" 
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" 
id="WebApp_ID" version="3.1">
  <display-name>SSM</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <!-- 配置Spring文件的监听器 -->
  <context-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:beans.xml</param-value>
  </context-param>
  <listener>
      <listener-class>
          org.springframework.web.context.ContextLoaderListener
      </listener-class>
  </listener>
  <!-- 配置编码过滤器 -->
  <filter>
      <filter-name>encoding</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-name>
      <url-pattern>*.action</url-pattern>
  </filter-mapping>
  <!-- 配置Spring MVC前端控制器 -->
  <servlet>
      <servlet-name>springmvc</servlet-name>
      <servlet-class>
          org.springframework.web.servlet.DispatcherServlet
      </servlet-class>
      <init-param>
          <param-name>contextConfigLocation</param-name>
          <param-value>classpath:springmvc-config.xml</param-value>
      </init-param>
      <!-- 服务器启动立即加载SpringMVC配置文件 -->
      <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
      <servlet-name>springmvc</servlet-name>
      <!-- 拦截所有请求 -->
      <url-pattern>/</url-pattern>
  </servlet-mapping>
   
</web-app>

三、测试整合

　　3.1在src目录下创建com.ssm.po包，并创建Customer类

Customer.java

package com.ssm.po;

public class Customer {
    private Integer id;
    private String username;
    private String jobs;
    private String phone;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getJobs() {
        return jobs;
    }
    public void setJobs(String jobs) {
        this.jobs = jobs;
    }
    public String getPhone() {
        return phone;
    }
    public void setPhone(String phone) {
        this.phone = phone;
    }
    @Override
    public String toString() {
        return "Customer [id=" + id + ", username=" + username + ", jobs=" + jobs + ", phone=" + phone + "]";
    }
}

　　3.2在src目录下创建com.ssm.dao包，并创建接口文件CustomerDao.java和映射文件CustomerDao.xml

　　CustomerDao.java

package com.ssm.dao;

import com.ssm.po.Customer;

public interface CustomerDao {
    public Customer findCustomerById(Integer id);
}

　　CustomerDao.xml

<?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.ssm.dao.CustomerDao" >
    <!-- 根据ID查询客户信息 -->
    <select id = "findCustomerById" parameterType = "Integer" resultType = "com.ssm.po.Customer">
        select * from t_customer where id = #{id}
    </select>
    
</mapper>

　　注：接口文件和映射文件的名称要保持一致，映射文件namespace名称要符合规范。

　　　　接口方法名和映射文件语句id，返回值类型、参数类型要保持一致。

　　　　两个文件要在同一包中。

　

　　3.3在src目录下创建com.ssm.service包，并创建接口文件CustomerService.java　

package com.ssm.service;

import org.springframework.stereotype.Service;

import com.ssm.po.Customer;
@Service
public interface CustomerService {
    public Customer findCustomerById(Integer id);
}

　　3.4在src目录下创建com.ssm.service.Impl包，并在其中创建CustoemrService接口的实现类CustomerServiceImpl.java

　　CustomerService.java

package com.ssm.service.Impl;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import com.ssm.dao.CustomerDao;
import com.ssm.po.Customer;
import com.ssm.service.CustomerService;

@Service   //标记当前类，通过扫描注册
@Transactional
public class CustomerServiceImpl implements CustomerService{
    @Autowired //按类型自动装配
    private CustomerDao customerDao;
    
    @Override
    public Customer findCustomerById(Integer id) {
        return this.customerDao.findCustomerById(id);
    }

}

　　　　3.5在src目录下创建com.ssm.controller包，并创建CustomerController类

　　CustomerController.java

package com.ssm.controller;


import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

import com.ssm.po.Customer;
import com.ssm.service.CustomerService;

@Controller //标注为控制类，自动扫描
public class CustomerController {
    @Autowired //按类型自动装配
    private CustomerService customerService;
    
    @RequestMapping("/findCustomerById")
    public String findCustomerById(Integer id, Model model) {
        Customer customer = customerService.findCustomerById(id);
        model.addAttribute("customer", customer);
        return "customer";//返回WEB-INF/jsp/customer.jsp
    }
}

　　　3.6在WEB-INF目录下创建文件夹jsp，并在其中创建customer.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    <table border="1">
        <tr>
            <td>id</td>
            <td>姓名</td>
            <td>职业</td>
            <td>电话</td>
        </tr>
        <tr>
            <td>${customer.id}</td>
            <td>${customer.username}</td>
            <td>${customer.jobs}</td>
            <td>${customer.phone}</td>
        </tr>
    </table>
</body>
</html>

启动服务器，添加项目。

地址栏输入：http://localhost:8080/SSM/findCustomerById?id=1

项目结构：

常见错误：

1、配置文件中书写错误，例如classpath拼写错误、文件名拼写错误（beans.xml写错了benas.xml）。

2、com.ssm.service.Impl写成了com.ssm.serviceImpl,

　  在beans.xml中配置的:

    <context:component-scan base-package="com.ssm.service"/>(会扫描com.ssm.service及com.ssm.service.*)

　不会扫描com.ssm.serviceImpl.

3、com.ssm.dao中映射文件和接口文件不匹配。

4、注解导入错误：注意导入的注解多是org.springframework中的注解。

5、视图解析器前后缀配置错误，找不到路径。

7、RequestMapping("xxx")中设置路径与地址栏输入路径不一致。

8. 文件中未设置自动扫描，找不到指定类。