ssm搭建一些笔记 发布于 2 年前 (2017年10月22日) – 3425 次检阅
- 2020 年 4 月 9 日
- 笔记
如果springmvc-config.xml文件和web.xml文件一样，都放在WEB-INF目录下的话。
在web.xml中springmvc最好这样配置一下
<!-- SpringMVC配置 --> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/springmvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <!-- Map all requests to the DispatcherServlet for handling --> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping>
如果<param-value>/WEB-INF/springmvc.xml</param-value>
改为<param-value>classpath:springmvc.xml</param-value>
可能会出现->classpath指向的地址，与需要的文件不一致，报错很明显了。文件不存在
- 警告: No mapping found for HTTP request with URI
- class path resource [springmvc.xml] cannot be opened because it does not exist
那么就顺便记录下web.xml中或者spring配置文件中classpath和classpath*的区别吧
- 【classpath:】此配置表示告诉web容器去classpath（WEB-INF/classes和WEB-INF/lib）中去加载指定名称的配置文件，若是有同名文件，则只会加载一个。
- 【classpath*:】此配置表示告诉web容器去classpath（WEB-INF/classes和WEB-INF/lib）中去加载指定名称的配置文件，若是有同名文件则会全部加载。
即
- classpath：只会到你的class路径中查找找文件;
- classpath*：不仅包含class路径，还包括jar文件中(class路径)进行查找.
可以理解成就在/WEB-INF/classes/
因此classpath或者classpath*，编译之后会在/项目名/build/classes下找你的文件
而当你在WEB-INF目录下放置springmvc-config.xml文件和web.xml文件。
那么需要写成<param-value>/WEB-INF/springmvc.xml</param-value>
注意：
- 用classpath*:需要遍历所有的classpath，所以加载速度是很慢的，因此，在规划的时候，应该尽可能规划好资源文件所在的路径，尽量避免使用classpath*。
- 在多个classpath中存在同名资源时候，都需要加载，但是用classpath:只会加载第一个。
- lib和classes下文件访问优先级的问题:? lib>classes
总结的有点乱…希望日后自己可以理解一半吧
基于(spring+springmvc+mybatis)ssm搭建测试(不是基于maven搭建)
- 创建表
DROP TABLE IF EXISTS `tb_user`; CREATE TABLE `tb_user` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(18) DEFAULT NULL, `sex` char(2) DEFAULT NULL, `age` int(11) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=MyISAM AUTO_INCREMENT=11 DEFAULT CHARSET=utf8; -- ---------------------------- -- Records of tb_user -- ---------------------------- INSERT INTO `tb_user` VALUES ('1', 'admin', '女', '21'); INSERT INTO `tb_user` VALUES ('3', '修改后的', '女', '21'); INSERT INTO `tb_user` VALUES ('4', 'admin', '女', '21'); INSERT INTO `tb_user` VALUES ('2', 'update', '女', '21');
- db.properties
jdbc.driver=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3307/ssm?characterEncoding=utf8 jdbc.username=root jdbc.password=root
- pojo
package com.glj.pojo; import java.io.Serializable; public class User implements Serializable{ private Integer id; private String name; private String sex; private Integer age; //省略set和get... }
- UserMapper
<?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.glj.dao.UserMapper"> <!-- public List<User> getUser(); --> <select id="getUserList" resultType="com.glj.pojo.User"> select * from tb_user </select> </mapper>
- UserMapper接口
package com.glj.dao; import java.util.List; import com.glj.pojo.User; public interface UserMapper { public List<User> getUserList(); }
- UserService
package com.glj.service; import java.util.List; import com.glj.pojo.User; public interface UserService { List<User> getUserList(); }
- UserServiceImpl
package com.glj.service.impl; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import com.glj.dao.UserMapper; import com.glj.pojo.User; import com.glj.service.UserService; @Service public class UserServiceImpl implements UserService{ @Autowired private UserMapper userMapper; @Override public List<User> getUserList() { return userMapper.getUserList(); } }
- UserController
package com.glj.controller; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.servlet.ModelAndView; import com.glj.pojo.User; import com.glj.service.UserService; @Controller public class UserController { @Autowired private UserService userService; @RequestMapping("/listUser") public ModelAndView listToUser(){ ModelAndView mav = new ModelAndView(); List<User> users = userService.getUserList(); mav.addObject("users", users); return mav; } // @RequestMapping(value="/{fromName}") // public String fromName(@PathVariable String fromName){ // return "fromName"; // } }
- 在WEB-INF目录下新增加web.xml，这个web.xml有两个作用：
- 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
- 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" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5"> <!--Spring配置： needed for ContextLoaderListener --> <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> <!-- SpringMVC配置 --> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/springmvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <!-- Map all requests to the DispatcherServlet for handling --> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>
- 在src目录下新建applicationContext.xml文件，这是Spring的配置文件，其作用
- 通过注解，将com.glj.*的生命周期纳入Spring的管理
- ?配置数据源
- 扫描存放SQL语句的UserMapper.xml
- 扫描Mapper接口，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:context="http://www.springframework.org/schema/context" xmlns:mybatis-spring="http://mybatis.org/schema/mybatis-spring" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://mybatis.org/schema/mybatis-spring http://mybatis.org/schema/mybatis-spring-1.2.xsd 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-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd"> <!-- Spring希望管理所有的业务逻辑组件，等。。。 --> <context:annotation-config /> <context:component-scan base-package="com.glj"> <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" /> </context:component-scan> <!-- 引入数据库的配置文件 --> <context:property-placeholder location="classpath:db.properties"/> <!-- Spring用来控制业务逻辑。数据源、事务控制、aop --> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="jdbcUrl" value="${jdbc.url}"></property> <property name="driverClass" value="${jdbc.driver}"></property> <property name="user" value="${jdbc.username}"></property> <property name="password" value="${jdbc.password}"></property> </bean> <!-- spring事务管理 --> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"></property> </bean> <!-- 开启基于注解的事务 --> <tx:annotation-driven transaction-manager="dataSourceTransactionManager"/> <!--创建出SqlSessionFactory对象 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="typeAliasesPackage" value="com.glj.pojo" /> <property name="dataSource" ref="dataSource" /> <property name="configLocation" value="classpath:mybatis-config.xml" /> <property name="mapperLocations" value="classpath:com/glj/mapper/*.xml" /> </bean> <!-- 扫描所有的mapper接口的实现自动注入； <mybatis-spring:scan base-package="com.glj.dao"/> --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <!-- 可以不用指定，因为MapperScannerConfigurer会自动装配 <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" /> --> <property name="basePackage" value="com.glj.dao"></property> </bean> </beans>
- 在src目录下新建mybatis-config.xml文件
<?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> <!-- 配置全局属性 --> <settings> <!-- 使用jdbc的getGeneratedKeys获取数据库自增主键值 --> <setting name="useGeneratedKeys" value="true" /> <!-- 使用列别名替换列名 默认:true --> <setting name="useColumnLabel" value="true" /> <!-- 开启驼峰命名转换:Table{create_time} -> Entity{createTime} --> <setting name="mapUnderscoreToCamelCase" value="true" /> </settings> </configuration>
- 在WEB-INF目录下新建springMVC.xml(也可以在src目录下创建,然后就可以用classpath:springMVC.xml即可)
- ?扫描Controller,并将其生命周期纳入Spring管理
- 注解驱动
- 静态页面，如html,css,js,images可以访问
- 视图定位到/WEB/INF/jsp 这个目录下
<?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:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd 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-4.0.xsd"> <!-- 只扫描Controller,并将其生命周期纳入Spring管理 --> <context:component-scan base-package="com.glj" use-default-filters="false"> <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/> </context:component-scan> <context:annotation-config/> <!-- 注解驱动 --> <mvc:annotation-driven /> <!--静态页面，如html,css,js,images可以访问 --> <mvc:default-servlet-handler /> <!-- 视图定位 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" /> <property name="prefix" value="/WEB-INF/jsp/"></property> <property name="suffix" value=".jsp"></property> </bean> </beans>
- 在WEB-INF下创建jsp目录，并创建文件listUser.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <!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> <table align='center' border='1' cellspacing='0'> <tr> <td>id</td> <td>name</td> </tr> <c:forEach items="${users}" var="c" varStatus="st"> <tr> <td>${c.id}</td> <td>${c.name}</td> </tr> </c:forEach> </table> </body> </html>
