这是我学习尚硅谷2022版ssm框架做的笔记
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怎么说呢,要是熟练的话,配置起来问题也不大,同时也有助于理解一些原理。但是用了SpringBoot可能都不愿意使用SSM了,不过如果用的话也不要怕,其实理清楚了就可以了,没什么难的。
SpringMVC和Spring可以整合也可以不整合,不整合就是Spring和SpringMVC用同一个IOC容器,整合就是各自创建IOC容器去管理自己的。
SpringMVC的IOC容器是在DispatcherServlet进行初始化的时候创建的,那么Spring的IOC容器应该在什么时候创建呢?SpringMVC管理的是控制层组件,而其他的需要交给Spring管理,而controller需要自动装配service层,因此在创建SpringMVC的IOC容器时,Spring的IOC容器应该提前创建。
Spring提供了监听器ContextLoaderListener,实现ServletContextListener接口,可监听ServletContext的状态,在web服务器的启动,读取Spring的配置文件,创建Spring的IOC容器。web应用中必须在web.xml中配置。
那么为什么SpringMVC的IOC容器可以访问到Spring的IOC容器呢?是SpringMVC在创建IOC容器时,将Spring的IOC容器设置成了自己的父容器,这样子容器就可以访问到父容器的内容,而父容器无法访问子容器的内容。即SpringMVC可以访问Spring的容器而Spring不可以访问到SpringMVC的容器。
使用监听器,在服务器启动时执行一次创建IOC容器即可。如果用过滤器每次有请求都会拦截执行,没必要。
<artifactId>ssmartifactId>
<packaging>warpackaging>
<properties>
<maven.compiler.source>8maven.compiler.source>
<maven.compiler.target>8maven.compiler.target>
<spring.version>5.3.1spring.version>
properties>
<dependencies>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-contextartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-beansartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-webartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-webmvcartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-jdbcartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-aspectsartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-testartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatisartifactId>
<version>3.5.7version>
dependency>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatis-springartifactId>
<version>2.0.6version>
dependency>
<dependency>
<groupId>com.alibabagroupId>
<artifactId>druidartifactId>
<version>1.0.9version>
dependency>
<dependency>
<groupId>junitgroupId>
<artifactId>junitartifactId>
<version>4.12version>
<scope>testscope>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>8.0.16version>
dependency>
<dependency>
<groupId>log4jgroupId>
<artifactId>log4jartifactId>
<version>1.2.17version>
dependency>
<dependency>
<groupId>com.github.pagehelpergroupId>
<artifactId>pagehelperartifactId>
<version>5.2.0version>
dependency>
<dependency>
<groupId>ch.qos.logbackgroupId>
<artifactId>logback-classicartifactId>
<version>1.2.3version>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>javax.servlet-apiartifactId>
<version>3.1.0version>
<scope>providedscope>
dependency>
<dependency>
<groupId>com.fasterxml.jackson.coregroupId>
<artifactId>jackson-databindartifactId>
<version>2.12.1version>
dependency>
<dependency>
<groupId>commons-fileuploadgroupId>
<artifactId>commons-fileuploadartifactId>
<version>1.3.1version>
dependency>
<dependency>
<groupId>org.thymeleafgroupId>
<artifactId>thymeleaf-spring5artifactId>
<version>3.0.12.RELEASEversion>
dependency>
dependencies>
CREATE TABLE `t_emp` (
`emp_id` int(11) NOT NULL AUTO_INCREMENT,
`emp_name` varchar(20) DEFAULT NULL,
`age` int(11) DEFAULT NULL,
`sex` char(1) DEFAULT NULL,
`email` varchar(50) DEFAULT NULL,
PRIMARY KEY (`emp_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
需要配置的还是那些:
除此之外新加入的:
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<filter>
<filter-name>CharacterEncodingFilterfilter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilterfilter-class>
<init-param>
<param-name>encodingparam-name>
<param-value>UTF-8param-value>
init-param>
<init-param>
<param-name>forceEncodingparam-name>
<param-value>trueparam-value>
init-param>
filter>
<filter-mapping>
<filter-name>CharacterEncodingFilterfilter-name>
<url-pattern>/url-pattern>
filter-mapping>
<filter>
<filter-name>HiddenHttpMethodFilterfilter-name>
<filter-class>org.springframework.web.filter.HiddenHttpMethodFilterfilter-class>
filter>
<filter-mapping>
<filter-name>HiddenHttpMethodFilterfilter-name>
<url-pattern>/url-pattern>
filter-mapping>
<servlet>
<servlet-name>SpringMVCservlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
<init-param>
<param-name>contextConfigLocationparam-name>
<param-value>classpath:springmvc.xmlparam-value>
init-param>
<load-on-startup>1load-on-startup>
servlet>
<servlet-mapping>
<servlet-name>SpringMVCservlet-name>
<url-pattern>/*url-pattern>
servlet-mapping>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListenerlistener-class>
listener>
<context-param>
<param-name>contextConfigLocationparam-name>
<param-value>classpath:spring.xmlparam-value>
context-param>
web-app>
要做的(主要是第一项特殊,其他都一样):
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:contxt="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.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<contxt:component-scan base-package="com.zylai.ssm.controller"/>
<bean id="viewResolver"
class="org.thymeleaf.spring5.view.ThymeleafViewResolver">
<property name="order" value="1"/>
<property name="characterEncoding" value="UTF-8"/>
<property name="templateEngine">
<bean class="org.thymeleaf.spring5.SpringTemplateEngine">
<property name="templateResolver">
<bean class="org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver">
<property name="prefix" value="/WEB-INF/templates/"/>
<property name="suffix" value=".html"/>
<property name="templateMode" value="HTML5"/>
<property name="characterEncoding" value="UTF-8" />
bean>
property>
bean>
property>
bean>
<mvc:view-controller path="/" view-name="index">mvc:view-controller>
<mvc:annotation-driven />
<mvc:default-servlet-handler/>
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"/>
beans>
jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssm?serverTimezone=UTC
jdbc.username=root
jdbc.password=root
initialSize=5
maxActive=9
问题:
我们在学习mybatis时,获取SqlSession然后读取mybatis的配置文件,之后再手动创建mapper接口的代理对象,调用mapper的方法。但是在整合SSM中我们是不可以这样做的,那么如何解决呢?
解决:
SqlSessionFactoryBean
是一个工厂bean,只要在spring中进行配置,那么就会在Spring的IOC容器中直接这个工厂bean造的对象。具体见下一节Spring的配置文件
其实mybatis的配置文件完全可以省略,所有属性配置都可以在之后的spring配置文件中进行配置。不过要是习惯在这里写就在这里写,无所谓的。
这里进行配置的是:1、设置下划线映射为驼峰;2、配置分页插件
DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<settings>
<setting name="mapUnderscoreToCamelCase" value="true"/>
settings>
<plugins>
<plugin interceptor="com.github.pagehelper.PageInterceptor"/>
plugins>
configuration>
public interface EmployeeMapper {
List<Employee> getAllEmployee();
void addEmployee(Employee employee);
}
DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.zylai.ssm.mapper.EmployeeMapper">
<select id="getAllEmployee" resultType="Employee">
select * from t_emp
select>
<insert id="addEmployee">
insert into t_emp values(null,#{empName},#{age},#{gender},#{email})
insert>
mapper>
DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
<appender name="STDOUT" class="org.apache.log4j.ConsoleAppender">
<param name="Encoding" value="UTF-8" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%-5p %d{MM-dd HH:mm:ss,SSS}
%m (%F:%L) \n" />
layout>
appender>
<logger name="java.sql">
<level value="debug" />
logger>
<logger name="org.apache.ibatis">
<level value="info" />
logger>
<root>
<level value="debug" />
<appender-ref ref="STDOUT" />
root>
log4j:configuration>
<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-4.2.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd">
<context:component-scan base-package="com.zylai.ssm">
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
context:component-scan>
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"/>
bean>
<tx:annotation-driven transaction-manager="transactionManager"/>
beans>
<context:property-placeholder location="classpath:jdbc.properties">context:property-placeholder>
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
<property name="driverClassName" value="${jdbc.driver}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
bean>
配置这个工厂bean,可以直接从IOC容器中获取SqlSession实例。
属性:
<bean class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="configLocation" value="classpath:mybatis-config.xml"/>
<property name="dataSource" ref="dataSource"/>
<property name="typeAliasesPackage" value="com.zylai.ssm.pojo"/>
bean>
开启mapper扫描,会根据IOC容器中的SqlSession
来创建mapper的代理对象并放到IOC容器中,那么我们直接在service层@Autowired
自动注入
除此之外,直接在mapper接口上加上@Mapper
注解的效果是一样的
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.zylai.ssm.mapper"/>
bean>
由于我们是web项目,所以要打成war包放到Tomcat服务器上面的,因此整个配置文件的入口是web.xml
web.xml文件中
:
SpringMVC的配置文件
Spring的配置文件
,通过context-param设置Spring配置文件的路径Spring的配置文件
:
mybatis的配置文件
写controller、service、mapper、pojo各层即可
=========controller层=================
@Controller
public class EmployeeController {
@Autowired
private EmployeeService employeeService;
@GetMapping("/employee")
public String getAllEmployee(Model model){
//查询所有的员工信息
List<Employee> employeeList = employeeService.getAllEmployee();
//将员工信息在请求域中共享
model.addAttribute("employeeList",employeeList);
//跳转到employee_list.html
return "employee_list";
}
@GetMapping("/employee/page/{pageNum}/{limit}")
public String getEmployeePage(@PathVariable("pageNum") Integer pageNum,
@PathVariable("limit") Integer limit,
Model model){
//获取员工的分页信息
PageInfo<Employee> page = employeeService.getEmployeePage(pageNum,limit);
//将分页的数据共享
model.addAttribute("page",page);
return "employee_list";
}
@PostMapping("/employee")
public String addEmployee(Employee employee){
employeeService.addEmployee(employee);
return "success";
}
}
=========service实现类=================
@Service
@Transactional
public class EmployeeServiceImpl implements EmployeeService {
@Autowired
private EmployeeMapper employeeMapper;
@Override
public List<Employee> getAllEmployee() {
return employeeMapper.getAllEmployee();
}
@Override
public void addEmployee(Employee employee) {
employeeMapper.addEmployee(employee);
}
//分页查询
@Override
public PageInfo<Employee> getEmployeePage(Integer pageNum, Integer limit) {
//开启分页功能
PageHelper.startPage(pageNum,limit);
//查询所有的员工信息
List<Employee> list = employeeMapper.getAllEmployee();
//获取分页相关数据
PageInfo<Employee> pageInfo = new PageInfo<>(list,3);
return pageInfo;
}
}
=========mapper接口================
public interface EmployeeMapper {
List<Employee> getAllEmployee();
void addEmployee(Employee employee);
}
SQL映射文件:
DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.zylai.ssm.mapper.EmployeeMapper">
<select id="getAllEmployee" resultType="Employee">
select * from t_emp
select>
<insert id="addEmployee">
insert into t_emp values(null,#{empName},#{age},#{gender},#{email})
insert>
mapper>
这是整个文件组成:
前端页面:
DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>员工列表title>
<link rel="stylesheet" th:href="@{/static/css/index_work.css}">
<link rel="stylesheet" th:href="@{/static/layui/css/layui.css}">
head>
<body>
<div class="width:80%">
<table class="layui-table">
<colgroup>
<col width="150">
<col width="200">
<col>
colgroup>
<thead>
<tr>
<th colspan="6">员工列表th>
tr>
<tr>
<th>流水号th>
<th>员工姓名th>
<th>年龄th>
<th>性别th>
<th>邮箱th>
<th>操作th>
tr>
thead>
<tbody>
<tr th:each="employee,status : ${page.list}">
<td th:text="${status.count}">td>
<td th:text="${employee.empName}">td>
<td th:text="${employee.age}">td>
<td th:text="${employee.gender}">td>
<td th:text="${employee.email}">td>
<td>
<a href="">删除a>
<a href="">修改a>
td>
tr>
tbody>
table>
div>
<div style="text-align: center">
<a th:disabled="${page.hasPreviousPage==false}" th:href="@{/employee/page/1/4}">首页a>
<a th:disabled="${page.hasPreviousPage==false}" th:href="@{|/employee/page/${page.prePage}/4|}">上一页a>
<span th:each="num : ${page.navigatepageNums}">
<a th:if="${page.pageNum == num}" style="color:red" th:href="@{|/employee/page/${num}/4|}" th:text="|[${num}]|">a>
<a th:unless="${page.pageNum == num}" th:href="@{|/employee/page/${num}/4|}" th:text="${num}">a>
span>
<a th:disabled="${!page.hasNextPage}" th:href="@{|/employee/page/${page.nextPage}/4|}">下一页a>
<a th:disabled="${!page.hasNextPage}" th:href="@{|/employee/page/${page.pages}/4|}">末页a>
div>
body>
html>
测试效果:
感谢你的阅读
本篇文章是我学习尚硅谷2022版ssm框架做的笔记
欢迎访问我的个人博客