7.1 第一个mybatis、spring、springMVC整合

深藏阁楼爱情的钟 2022-05-30 04:35 146阅读 0赞

一.数据库部分（username：root ,password：shapolang）

第一步：使用mysql准备数据库mybatis

CREATE datebase mybatis;

第二步：创建表tbl\_employee

CREATE TABLE tbl_employee (
      id int(11) NOT NULL AUTO_INCREMENT,
      last_name varchar(255) DEFAULT NULL,
      gender char(1) DEFAULT NULL,
      email` varchar(255) DEFAULT NULL,
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDB AUTO_INCREMENT=49 DEFAULT CHARSET=utf8

第三步：准备数据

INSERT INTO tbl_empoyee1(id,last_name,gender,email)
    VALUE(NULL,'yi','1','yi@qq.com');

二.项目结构

![Center][]

注意：此项目是在jdk1.8版本下运行，导入必要的jar包

代码：

Employee.java

package com.mybatis.bean;
    
    public class Employee {
    	private Integer id;
    	private String lastName;
    	private String email;
    	private String gender;
    	public Integer getId() {
    		return id;
    	}
    	public void setId(Integer id) {
    		this.id = id;
    	}
    	public String getLastName() {
    		return lastName;
    	}
    	public void setLastName(String lastName) {
    		this.lastName = lastName;
    	}
    	public String getEmail() {
    		return email;
    	}
    	public void setEmail(String email) {
    		this.email = email;
    	}
    	public String getGender() {
    		return gender;
    	}
    	public void setGender(String gender) {
    		this.gender = gender;
    	}
    	
    	public Employee(Integer id, String lastName, String email, String gender) {
    		super();
    		this.id = id;
    		this.lastName = lastName;
    		this.email = email;
    		this.gender = gender;
    	}
    	public Employee() {};
    	
    	@Override
    	public String toString() {
    		return "Employee [id=" + id + ", lastName=" + lastName + ", email=" + email + ", gender=" + gender + "]";
    	}
    
    	
    
    }

接口EmployeeMapper.java

package com.mybatis.dao;
    
    import java.util.List;
    
    import org.apache.ibatis.annotations.Param;
    
    import com.mybatis.bean.Employee;
    
    public interface EmployeeMapper {
    	
    	public Employee getEmployeeById(Integer id);
    	
    	public List<Employee> getEmps1();
    }

EmployeeMapper.xml

EmployeeMapperxml需要和[EmployeeMapper][]放在同一个包下面，并且namespace必须写[EmployeeMapper][]的完整类名

<?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.mybatis.dao.EmployeeMapper">
    	<select id="getEmployeeById" resultType="com.mybatis.bean.Employee">
    		select * from tbl_employee where id=#{id}
    	</select>
    	
    	<select id="getEmps1" resultType="com.mybatis.bean.Employee">
    		select * from tbl_employee
    	</select>
       		 
    </mapper>

EmployeeService.java

EmployeeService被注解@Service标示为一个Service  
并且装配了employeeMapper

package com.mybatis.service;
    
    import java.util.List;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    
    import com.mybatis.bean.Employee;
    import com.mybatis.dao.EmployeeMapper;
    
    @Service
    public class EmployeeService {
    	
    	@Autowired
    	private EmployeeMapper employeeMapper;
    	
    	public List<Employee> getEmps2(){
    		return employeeMapper.getEmps1();
    		
    	}
    
    }

EmplyeeController.java

EmployeeController被@Controller标示为了控制器  
自动装配了employeeService  
通过@RequestMapping映射访问路径/getemps4路径到方法emps3()。  
在emps3()方法中，通过employeeService获取后，然后将获得的数据存放在allEmps上。

package com.mybatis.controller;
    
    import java.util.List;
    import java.util.Map;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Controller;
    import org.springframework.stereotype.Service;
    import org.springframework.web.bind.annotation.RequestMapping;
    
    import com.mybatis.bean.Employee;
    import com.mybatis.service.EmployeeService;
    
    @Controller
    public class EmplyeeController {
    	@Autowired
    	EmployeeService employeeService;
    	
    	@RequestMapping("/getemps4")
    	public String emps3(Map<String,Object> map) {
    		List<Employee> emp=employeeService.getEmps2();
    		map.put("allEmps", emp);
    		return "list";
    	}
    
    }

web.xml

web.xml有两个作用：  
1. 通过ContextLoaderListener在web app启动的时候，获取contextConfigLocation配置文件的文件名applicationContext.xml，并进行Spring相关初始化工作  
  
2. 有任何访问，都被DispatcherServlet所拦截，这就是Spring MVC那套工作机制了。

<?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" 
             xmlns:web="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">
    	
    	
    	<context-param>
    		<param-name>contextConfigLocation</param-name>
    		<param-value>classpath:applicationContext.xml</param-value>
    	</context-param>
    	<listener>
    		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    	</listener>
    	
    	
    	
    	<servlet>
    		<servlet-name>mvc-dispatcher</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>mvc-dispatcher</servlet-name>
    		<url-pattern>/</url-pattern>
    	</servlet-mapping>
    	
    </web-app>

applicationContext.xml

在src目录下新建applicationContext.xml文件，这是Spring的配置文件，其作用  
1. 通过注解，将Service的生命周期纳入Spring的管理

<context:annotation-config />

<context:component-scan base-package="com.mybatis.service" />

2. 配置数据源

3. 扫描存放SQL语句的Category.xml

4. 扫描Mapper，并将其生命周期纳入Spring的管理

<?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:aop="http://www.springframework.org/schema/aop"
    	xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jdbc="http://www.springframework.org/schema/jdbc"
    	xmlns:context="http://www.springframework.org/schema/context"
    	xmlns:mvc="http://www.springframework.org/schema/mvc"
    	xsi:schemaLocation="
         http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
         http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
         http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd
         http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
         http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
         http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">
    	
    	
    	
    
       <context:annotation-config />
    	<context:component-scan base-package="com.mybatis.service" />
    
    	<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">  
    	  <property name="driverClassName">  
    	      <value>com.mysql.jdbc.Driver</value>  
    	  </property>  
    	  <property name="url">  
    	      <value>jdbc:mysql://localhost:3306/mybatis?characterEncoding=UTF-8</value>  
    	
    	  </property>  
    	  <property name="username">  
    	      <value>root</value>  
    	  </property>  
    	  <property name="password">  
    	      <value>shapolang</value>  
    	  </property>  	
    	</bean>
    	
    	
    	<bean id="sqlSession" class="org.mybatis.spring.SqlSessionFactoryBean">
    		
    		<property name="dataSource" ref="dataSource"/>
    		<property name="mapperLocations" value="classpath:com/mybatis/dao/*.xml"/>
    	</bean>
    
    	<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    		<property name="basePackage" value="com.mybatis/dao"/>
    	</bean>
    	
    
    
    </beans>

spingMVC.xml

1. 扫描Controller,并将其生命周期纳入Spring管理

<context:annotation-config/>
    
        <context:component-scan base-package="com.mybatis.controller">
              <context:include-filter type="annotation" 
              expression="org.springframework.stereotype.Controller"/>
        </context:component-scan>

2. 注解驱动，以使得访问路径与方法的匹配可以通过注解配置

<mvc:annotation-driven />

3. 静态页面，如html,css,js,images可以访问

<mvc:default-servlet-handler />

4. 视图定位到/WEB-INF/pages这个目录下

代码如下：

<?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:aop="http://www.springframework.org/schema/aop"
        xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jdbc="http://www.springframework.org/schema/jdbc"
        xmlns:context="http://www.springframework.org/schema/context"
        xmlns:mvc="http://www.springframework.org/schema/mvc"
        xsi:schemaLocation="http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd
            http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
            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/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd 
            http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">
    
    
    
        <context:annotation-config/>
    
        <context:component-scan base-package="com.mybatis.controller">
              <context:include-filter type="annotation" 
              expression="org.springframework.stereotype.Controller"/>
        </context:component-scan>
    
        <mvc:annotation-driven />
        
        <mvc:default-servlet-handler />
    
    
        <bean
            class="org.springframework.web.servlet.view.InternalResourceViewResolver">
            <property name="viewClass"
                value="org.springframework.web.servlet.view.JstlView" />
            <property name="prefix" value="/WEB-INF/pages/" />
            <property name="suffix" value=".jsp" />
        </bean>
    </beans>

log4j.properties

# Global logging configuration
    log4j.rootLogger=ERROR, stdout
    # MyBatis logging configuration...
    log4j.logger.com.how2java=TRACE
    # 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

list.jsp

在这个jsp文件中，通过forEach标签,遍历employeeController传递过来的集合数据。

<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>员工列表</title>
    </head>
    <body>
    	<table>
    		<tr>
    			<td>id</td>
    			<td>lastName</td>
    			<td>email</td>
    			<td>gender</td>
    		</tr>
    		<c:forEach items="${allEmps}" var="empOne">
    			<tr>
    				<td>${empOne.id }</td>
    				<td>${empOne.lastName }</td>
    				<td>${empOne.email }</td>
    				<td>${empOne.gender }</td>
    			</tr>
    		</c:forEach>
    	</table>
    </body>
    </html>

运行index.jsp，测试

<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Insert title here</title>
    </head>
    <body>
    	<a href="getemps4">查询所有员工</a>
    </body>
    </html>

结果：

![Center 1][]

思路：

1. 首先浏览器上访问路径 index.jsp  
2. tomcat根据web.xml上的配置信息，拦截到了请求getemps4，并将其交由DispatcherServlet处理。  
3. DispatcherServlet 根据springMVC的配置，将这次请求交由employeeController类进行处理，所以需要进行这个类的实例化  
4. 在实例化employeeController的时候，注入employeeService。 (自动装配实现了employeeService接口的的实例，只有employeeService实现了employeeService接口，所以就会注入employeeService)  
5. 在实例化employeeService的时候，又注入employeeMapper  
6. 根据ApplicationContext.xml中的配置信息，将employeeMapper和employee.xml关联起来了。  
7. 这样拿到了实例化好了的CategoryController,并调用emps3()方法  
8. 在emps3方法中，访问employeeService,并获取数据，并把数据放在"allEmps"上，接着服务端跳转到list.jsp去  
9. 最后在list.jsp 中显示数据

源码下载地址：http://download.csdn.net/download/yiguang\_820/10269691，有需要的可以留言，看到了就会回复

遇到bug不要慌，相信自己是可以弄出来的,一步一步检查，实在出不来就先放着，把知识点掌握，以上项目如有问题，可以一起交流

[Center]: /images/20220530/33ed67d51cb3487ca9ae017243e9c26d.png
[EmployeeMapper]: http://how2j.cn/k/ssm/ssm-tutorial/1137.html#step4508
[Center 1]: /images/20220530/6dd8a9a3e1fb486b8253a363a450fcd4.png