本文是因为实习结束后学习到了新的技术,想写下来和更多人交流。开发中遇到的问题我也会一一说明,希望有更多人可以互相探讨,加入到一起来。
1. Spring+SpringMvc +Mybatis 的作用有哪些:
Spring作为一个轻量级框架,开发使用已经有很多年了,很好用的底层框架。里面的IOC,AOP详细的我只能说会使用,不能给大家更详细的说明。
Mybatis呢,主要是JDBC使用,连接数据库。它比起hibernate来说我觉得配置文件少了很多,不需要去配置什么数据库方言啊,乱七八糟的东西。
SpringMvc感觉更多的是像一个Spring精简升级版,它里面的应该就是配置文件中的启动注解还有视图的配置吧。
为什么要用这个框架而不是传统的Spring+Struts+Hibernate呢?
传统的SSH之前也学习过,首先hibernate虽然很好用可是配置太过于复杂,不如Mybatis简单明了(Mybatis的动态sql语句我觉得很实用);Struts呢太复杂!各种拦截器,处理缓存。真的配置都得配置好半天才可以。而SSM则简单了很多很多,适合小项目,自己联系时使用;
2.项目的配置:
首先我使用的工具:
编码软件:Eclipse 服务器:Tomcat 数据库:Mysql
2.1在Eclipse中建立web工程
2.2添加相应的架包
由于过多就不截图,自出省略......
2.3 建立数据库表
3.项目的开发
3.1 首先我们需要将src中的po类至Service层写好 顺序为entity—dao—mapper—Service
3.2 这里面需要注意的事项:
3.2.1 CustomerMapper中的方法名需要和CustomerMapper.xml中的id一致;
3.2.2 在写CustomerMapper.xml时 我们需要配置namespace 的路径是CustomerMapper.java的路径,在resultMap中需要说明JdbcType和javaType类型
3.2.3 编写service即实现
service类代码如下:
1 package com.vivebest.service; 2 3 import java.util.List; 4 5 import com.vivebest.entity.Customer; 6 7 public interface CustomerService { 8 public List<Customer> getAllCustomer(); 9 }
serviceImpl类代码如下
1 package com.vivebest.service.impl; 2 3 import java.util.List; 4 import org.springframework.beans.factory.annotation.Autowired; 5 import org.springframework.stereotype.Service; 6 import com.vivebest.dao.CustomerMapper; 7 import com.vivebest.entity.Customer; 8 import com.vivebest.service.CustomerService; 9 10 @Service("customerService") 11 public class CustomerServiceImpl implements CustomerService{ 12 13 @Autowired 14 private CustomerMapper customerMapper; 15 16 @Override 17 public List<Customer> getAllCustomer() { 18 // TODO Auto-generated method stub 19 return customerMapper.getAllCustomer(); 20 } 21 22 }
需要用到@service 和@Autowired .其中@service代表标示为服务层,@Autowired是Spring中自动装配使用,Spring会直接将UserDao类型的唯一一个bean赋值给userDao这个成员变量;
4.配置文件的配置
4.1 jdbc.properties :主要是用来配置数据库信息
1 #DB 2 dataSource.driverClassName=com.mysql.jdbc.Driver 3 dataSource.url=jdbc:mysql://localhost:3306/? 4 dataSource.username = ? 5 dataSource.password = ? 6 7 dataSource.initialSize = 2 8 dataSource.maxActive = 30 9 dataSource.maxIdle = 2 10 dataSource.minIdle = 2 11 dataSource.maxOpenPreparedStatements = 150 12 dataSource.validationQuery = SELECT 1 FROM DUAL 13 dataSource.testWhileIdle = true 14 dataSource.testOnBorrow = false 15 dataSource.testOnReturn = false 16 # u914du7f6eu95f4u9694u591au4e45u624du8fdbu884cu4e00u6b21u68c0u6d4buff0cu68c0u6d4bu9700u8981u5173u95edu7684u7a7au95f2u8fdeu63a5uff0cu5355u4f4du662fu6bebu79d2 17 dataSource.timeBetweenEvictionRunsMillis = 60000 18 # u914du7f6eu4e00u4e2au8fdeu63a5u5728u6c60u4e2du6700u5c0fu751fu5b58u7684u65f6u95f4uff0cu5355u4f4du662fu6bebu79d2 19 dataSource.minEvictableIdleTimeMillis = 300000 20 # u6253u5f00PSCacheuff0cu5e76u4e14u6307u5b9au6bcfu4e2au8fdeu63a5u4e0aPSCacheu7684u5927u5c0f 21 dataSource.poolPreparedStatements = true 22 dataSource.maxPoolPreparedStatementPerConnectionSize = 20 23 # u914du7f6eu76d1u63a7u7edfu8ba1u62e6u622au7684filter 24 dataSource.filters = stat
4.2 applicationContext.xml :主要是用来配置Spring和Mybatis
1 <?xml version="1.0" encoding="UTF-8"?> 2 <beans xmlns="http://www.springframework.org/schema/beans" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" 4 xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jdbc="http://www.springframework.org/schema/jdbc" 5 xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" 6 7 xsi:schemaLocation=" 8 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd 9 http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd 10 http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-4.0.xsd 11 http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd 12 http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd 13 http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd"> 14 <!-- 加载配置文件--> 15 <context:property-placeholder location="classpath:jdbc.properties"/> 16 <!-- 扫描控制包 --> 17 <context:component-scan base-package="com.vivebest.service" /> 18 19 <!-- ***************以下是dataSource 和 Mybatis配置****************** --> 20 <!-- dataSource --> 21 <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close"> 22 <property name="driverClassName" value="${dataSource.driverClassName}"/> 23 <property name="url" value="${dataSource.url}"/> 24 <property name="username" value="${dataSource.username}" /> 25 <property name="password" value="${dataSource.password}" /> 26 <property name="initialSize" value="${dataSource.initialSize}"/> 27 <property name="maxActive" value="${dataSource.maxActive}"/> 28 <property name="maxWait" value="30000"/> 29 <property name="maxIdle" value="${dataSource.maxIdle}"/> 30 <property name="minIdle" value="${dataSource.minIdle}"/> 31 <property name="validationQuery" value="${dataSource.validationQuery}"/> 32 <property name="testWhileIdle" value="${dataSource.testWhileIdle}"/> 33 <property name="testOnBorrow" value="${dataSource.testOnBorrow}"/> 34 <property name="testOnReturn" value="${dataSource.testOnReturn}"/> 35 <property name="timeBetweenEvictionRunsMillis" value="${dataSource.timeBetweenEvictionRunsMillis}" /> 36 <property name="minEvictableIdleTimeMillis" value="${dataSource.minEvictableIdleTimeMillis}" /> 37 <property name="poolPreparedStatements" value="${dataSource.poolPreparedStatements}" /> 38 <property name="maxPoolPreparedStatementPerConnectionSize" value="${dataSource.maxPoolPreparedStatementPerConnectionSize}" /> 39 <property name="filters" value="${dataSource.filters}" /> 40 </bean> 41 42 <!-- define the SqlSessionFactory --> 43 <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> 44 <property name="dataSource" ref="dataSource" /> 45 <property name="configLocation" value="classpath:mybatis-config.xml" /> 46 <!-- 要映射类的包路径 --> 47 <!-- <property name="typeAliasesPackage" value="com.vivebest.erp.entity" /> --> 48 <!-- 若无上条就需要有该配置 --> 49 <property name="mapperLocations" value="classpath:com/vivebest/mapper/CustomerMapper.xml"></property> <!-- 当配置文件在其他目录时 --> 50 </bean> 51 52 <!-- scan for mappers and let them be autowired --> 53 <!-- DAO接口所在包名,Spring会自动查找其下的类 --> 54 <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> 55 <property name="basePackage" value="com.vivebest.dao"/> 56 </bean> 57 58 </beans>
需要注意的是:value=“” 填写的是你*Mapper.xml文件的位置(我的是dao和mapper不在一个包下)
这样application就配置成功了。
4.3 web.xml配置(主要为配置Spring)
1 <?xml version="1.0" encoding="UTF-8"?> 2 <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_3_0.xsd" id="WebApp_ID" version="3.0"> 3 <display-name>bankERP</display-name> 4 <!-- Spring 服务层的配置文件 --> 5 <context-param> 6 <param-name>contextConfigLocation</param-name> 7 <param-value>classpath:applicationContext.xml</param-value> 8 </context-param> 9 10 <!-- Spring 容器启动监听器 --> 11 <listener> 12 <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> 13 </listener> 14 17 <!-- 配置spring核心servlet --> 18 <servlet> 19 <servlet-name>spring</servlet-name> 20 <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> 21 <init-param> 22 <param-name>contextConfigLocation</param-name> 23 <param-value>classpath:spring-mvc.xml</param-value> 24 </init-param> 25 <load-on-startup>1</load-on-startup> 26 </servlet> 27 28 <!-- url-pattern配置为/,不带文件后缀,会造成其它静态文件(js,css等)不能访问。如配为*.do,则不影响静态文件的访问 --> 29 <servlet-mapping> 30 <servlet-name>spring</servlet-name> 31 <url-pattern>*.do</url-pattern> 32 </servlet-mapping> 33 34 35 <!-- encode filter 支持中文转码 --> 36 <filter> 37 <filter-name>characterEncodingFilter</filter-name> 38 <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> 39 <init-param> 40 <param-name>encoding</param-name> 41 <param-value>UTF-8</param-value> 42 </init-param> 43 <init-param> 44 <param-name>forceEncoding</param-name> 45 <param-value>true</param-value> 46 </init-param> 47 </filter> 48 <filter-mapping> 49 <filter-name>characterEncodingFilter</filter-name> 50 <url-pattern>/*</url-pattern> 51 </filter-mapping> 52 57 </web-app>