1、業務模塊與數據模塊分離
在實際開發中,我們項目的架構業務模塊和數據模塊是分離的,舉個例子,假設我們的項目有"人員管理模塊"和"酒店管理模塊"兩個模塊,按照上一章的介紹,我們會建立下圖所示的項目結構:

其中,人員管理模塊的controller、service、dao、mapper都在一個項目中,而在實際使用中,我們會將數據模塊分離出來,即將以上兩個子模塊的service、dao、mapper拿出來,放在一個子項目中,形成如下的項目結構:

注意以下幾點:
- 包的命名最好是com.xxx.mapper.user和不是com.xxx.user.mapper,前者在spring.xml中配置mybatis時更方便,具體見spring.xml的中的注釋
- 在controller那一層的項目是需要部署的,即是war,而下邊的數據模塊是作為war的一個jar,所以在war層的pom.xml需要將下邊的數據模塊作為一個jar來引入到項目中
- service層到底是放在業務模塊處還是放在數據模塊處,這個根據需求而定,一般而言,都放在數據模塊處,方便彼此service的調用,如userService調用hotelService,如果這個時候把兩個service分別放在各自的業務模塊層中,相互的調用就要通過RPC了,當然,有的時候可能有些與其他模塊都不調用的service放在war層可能會好一些。
- 將來編寫的緩存模塊類、通用模塊類、RPC工具類等都會作為jar被war層調用。
2、實現
我將上一章的項目做了修改,將ssmm項目改成了userManagement項目,並將userManagement項目實現了業務模塊和數據模塊的分離,具體的操作參照第一章和第二章的相關內容,這里直接給出項目結構和各個文件。
2.1、項目結構

2.2、代碼實現
2.2.1、ssmm0
pom.xml
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.xxx</groupId> <artifactId>ssmm0</artifactId> <version>1.0-SNAPSHOT</version> <name>ssmm0</name> <packaging>pom</packaging><!-- 父模塊 --> <!-- 管理子模塊 --> <modules> <module>userManagement</module><!-- 具體業務1-人員管理系統 --> <module>data</module><!-- 封裝數據操作 --> </modules> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> </properties> <!-- dependencyManagement不會引入實際的依賴,只是作為一個依賴池,供其和其子類使用 --> <dependencyManagement> <dependencies> <!-- json --> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.1.39</version> </dependency> <!-- servlet --> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>3.0.1</version> <scope>provided</scope> </dependency> <!-- spring --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>3.2.6.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>3.2.6.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>3.2.6.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>3.2.6.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>3.2.6.RELEASE</version> </dependency> <!-- 這個是使用velocity的必備包 --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>3.2.6.RELEASE</version> </dependency> <!-- mysql --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.27</version> <scope>runtime</scope> </dependency> <!-- 數據源 --> <dependency> <groupId>org.apache.tomcat</groupId> <artifactId>tomcat-jdbc</artifactId> <version>7.0.47</version> </dependency> <!-- mybatis --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.1.1</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>1.1.1</version> </dependency> <!-- velocity --> <dependency> <groupId>org.apache.velocity</groupId> <artifactId>velocity</artifactId> <version>1.5</version> </dependency> <dependency> <groupId>velocity-tools</groupId> <artifactId>velocity-tools-generic</artifactId> <version>1.2</version> </dependency> <!-- 用於加解密 --> <dependency> <groupId>commons-codec</groupId> <artifactId>commons-codec</artifactId> <version>1.7</version> </dependency> <dependency> <groupId>org.bouncycastle</groupId> <artifactId>bcprov-jdk15on</artifactId> <version>1.47</version> </dependency> <!-- 集合工具類 --> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-collections4</artifactId> <version>4.0</version> </dependency> <!-- http --> <dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpclient</artifactId> <version>4.2.6</version> </dependency> </dependencies> </dependencyManagement> <!-- 引入實際依賴 --> <dependencies> <!-- json --> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> </dependency> <!-- spring --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> </dependency> <!-- 集合工具類 --> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-collections4</artifactId> </dependency> </dependencies> <build> <resources> <!-- 這里配置了這一塊兒true,才可以讓指定文件(這里是src/main/resources/*.xml)讀到pom.xml中的配置信息 , 值得注意的是,如果src/main/resources下還有其他文件,而你不想讓其讀pom.xml, 你還必須得把src/main/resources下的其余文件再配置一遍,配置為false(不可讀pom.xml), 如下邊的注釋那樣,否則,會報這些文件(在這里,就是*.properties)找不到的錯誤 --> <resource> <directory>src/main/resources</directory> <filtering>true</filtering> <includes> <include>*.xml</include> </includes> </resource> <!-- <resource> <directory>src/main/resources</directory> <filtering>false</filtering>可以讀 ,若改為false就是不可讀 <includes> <include>*.properties</include> </includes> </resource> --> </resources> </build> <!-- profiles可以定義多個profile,然后每個profile對應不同的激活條件和配置信息,從而達到不同環境使用不同配置信息的效果 注意兩點: 1)<activeByDefault>true</activeByDefault>這種情況表示服務器啟動的時候就采用這一套env(在這里,就是prod) 2)當我們啟動服務器后,想采用開發模式,需切換maven的env為dev,如果env的配置本身就是dev,需要將env換成rc或prod,點擊apply,然后再將env切換成dev,點擊apply才行 --> <profiles> <!-- 開發env --> <profile> <id>dev</id> <activation> <activeByDefault>false</activeByDefault> <property> <name>env</name> <value>dev</value> </property> </activation> <properties> <env>dev</env> <jdbc.driverClassName>com.mysql.jdbc.Driver</jdbc.driverClassName> <!-- 對於jdbc.url中內容的配置,如果需要配置 &時,有兩種方法: 1)如下邊這樣,使用<![CDATA[XXX]]>包起來 2)使用jdbc.properties文件來讀取此pom.xml,然后spring.xml再讀取jdbc.properties文件 顯然,前者更方便,而且還省了一個jdbc.properties的文件,但是,有的時候,還是會用后者的; 在使用后者的時候,注意三點: 1)需要修改上邊的build中的內容 2)需要在spring.xml中配置<context:property-placeholder location="classpath:jdbc.properties"/> 3)將jdbc.properties放在ssmm0-data項目中,之后需要將ssmm0-data項目的env配置為dev --> <jdbc.url><![CDATA[jdbc:mysql://127.0.0.1:3306/blog?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf-8]]></jdbc.url> <jdbc.username>root</jdbc.username> <jdbc.password>123456</jdbc.password> </properties> </profile> <!-- 預上線env --> <profile> <id>rc</id> <activation> <activeByDefault>false</activeByDefault> <property> <name>env</name> <value>rc</value> </property> </activation> <properties> <env>rc</env> <jdbc.driverClassName>com.mysql.jdbc.Driver</jdbc.driverClassName> <!-- 假設的一個地址 --> <jdbc.url><![CDATA[jdbc:mysql://10.10.10.100:3306/blog?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf-8]]></jdbc.url> <jdbc.username>root2</jdbc.username> <jdbc.password>1234562</jdbc.password> </properties> </profile> <!-- 線上env --> <profile> <id>prod</id> <activation> <activeByDefault>true</activeByDefault> <property> <name>env</name> <value>prod</value> </property> </activation> <properties> <env>prod</env> <jdbc.driverClassName>com.mysql.jdbc.Driver</jdbc.driverClassName> <!-- 假設的一個地址 --> <jdbc.url><![CDATA[jdbc:mysql://99.99.99.999:3307/blog?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf-8]]></jdbc.url> <jdbc.username>sadhijhqwui</jdbc.username> <jdbc.password>zxczkchwihcznk=</jdbc.password> </properties> </profile> </profiles> </project>
注意:
- 所有的注意點:都在注釋中
-
上述<build>中的resource的配置是為了是spring.xml可以讀取pom.xml文件的內容,具體的注意點,查看注釋
- profiles的配置是為了配置多套環境(在這里配置了三套env,開發,預上線和線上環境),具體的注意點,查看注釋
2.2.2、ssmm0-data
pom.xml
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <!-- 指定父模塊 --> <parent> <groupId>com.xxx</groupId> <artifactId>ssmm0</artifactId> <version>1.0-SNAPSHOT</version> </parent> <groupId>com.xxx.ssmm0</groupId> <artifactId>ssmm0-data</artifactId> <name>ssmm0-data</name> <packaging>jar</packaging><!-- 只是作為其他模塊使用的工具 --> <!-- 引入實際依賴 --> <dependencies> <!-- mysql --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <!-- 數據源 --> <dependency> <groupId>org.apache.tomcat</groupId> <artifactId>tomcat-jdbc</artifactId> </dependency> <!-- mybatis --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> </dependency> </dependencies> </project>
注意:<package>為jar
com.xxx.model.userManagement.Admin
package com.xxx.model.userManagement; /** * 管理員 */ public class Admin { private int id; private String username; private String password; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } }
com.xxx.mapper.userManagement.AdminMapper
package com.xxx.mapper.userManagement; import org.apache.ibatis.annotations.Insert; import org.apache.ibatis.annotations.Param; import org.apache.ibatis.annotations.Result; import org.apache.ibatis.annotations.Results; import org.apache.ibatis.annotations.Select; import com.xxx.model.userManagement.Admin; /** * 管理員Mapper */ public interface AdminMapper { @Insert("INSERT INTO userinfo(username, password) VALUES(#{username},#{password})") public int insertAdmin(Admin admin); @Select("SELECT * FROM userinfo WHERE username = #{username} AND password = #{password}") @Results(value = { @Result(id = true, column = "id", property = "id"), @Result(column = "username", property = "username"), @Result(column = "password", property = "password") }) public Admin selectAdmin(@Param("username") String username, @Param("password") String password); }
com.xxx.dao.userManagement.AdminDao
package com.xxx.dao.userManagement; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Repository; import com.xxx.mapper.userManagement.AdminMapper; import com.xxx.model.userManagement.Admin; /** * 管理員DAO */ @Repository public class AdminDao { @Autowired private AdminMapper adminMapper; public boolean register(Admin admin){ return adminMapper.insertAdmin(admin)==1?true:false; } public Admin login(String username ,String password){ return adminMapper.selectAdmin(username, password); } }
com.xxx.service.userManagement.AdminService
package com.xxx.service.userManagement; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import com.xxx.dao.userManagement.AdminDao; import com.xxx.model.userManagement.Admin; /** * 管理員service */ @Service public class AdminService { @Autowired private AdminDao adminDao; public boolean register(Admin admin){ return adminDao.register(admin); } public Admin login(String username, String password) { return adminDao.login(username, password); } }
代碼很簡單,與之前的基本一樣,只是名字換了而已。
值得注意的是包名:com.xxx.mapper.userManagement而非com.xxx.userManagement.mapper。
2.2.3、ssmm0-userManagement
pom.xml
1 <?xml version="1.0" encoding="UTF-8"?> 2 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 3 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> 4 5 <modelVersion>4.0.0</modelVersion> 6 7 <!-- 指定父模塊 --> 8 <parent> 9 <groupId>com.xxx</groupId> 10 <artifactId>ssmm0</artifactId> 11 <version>1.0-SNAPSHOT</version> 12 </parent> 13 14 <groupId>com.xxx.ssmm0</groupId> 15 <artifactId>ssmm0-userManagement</artifactId> 16 <!--<version>1.0-SNAPSHOT</version>--><!-- 父模塊已經指定了版本號,這里就不用了--> 17 18 <name>ssmm0-userManagement</name> 19 <packaging>war</packaging><!-- 需要部署的模塊 --> 20 21 <!-- 引入實際依賴 --> 22 <dependencies> 23 <!-- 將ssmm0-data項目作為一個jar引入項目中 --> 24 <dependency> 25 <groupId>com.xxx.ssmm0</groupId> 26 <artifactId>ssmm0-data</artifactId> 27 <version>1.0-SNAPSHOT</version> 28 </dependency> 29 <!-- servlet --> 30 <dependency> 31 <groupId>javax.servlet</groupId> 32 <artifactId>javax.servlet-api</artifactId> 33 </dependency> 34 <!-- spring mvc --> 35 <dependency> 36 <groupId>org.springframework</groupId> 37 <artifactId>spring-web</artifactId> 38 </dependency> 39 <dependency> 40 <groupId>org.springframework</groupId> 41 <artifactId>spring-webmvc</artifactId> 42 </dependency> 43 <!-- 這個是使用velocity的必備包 --> 44 <dependency> 45 <groupId>org.springframework</groupId> 46 <artifactId>spring-context-support</artifactId> 47 </dependency> 48 <!-- velocity --> 49 <dependency> 50 <groupId>org.apache.velocity</groupId> 51 <artifactId>velocity</artifactId> 52 </dependency> 53 <dependency> 54 <groupId>velocity-tools</groupId> 55 <artifactId>velocity-tools-generic</artifactId> 56 </dependency> 57 </dependencies> 58 </project>
注意:將ssmm0-data作為普通的jar引入即可。
spring.xml
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:context="http://www.springframework.org/schema/context" 4 xmlns:mvc="http://www.springframework.org/schema/mvc" 5 xsi:schemaLocation="http://www.springframework.org/schema/beans 6 http://www.springframework.org/schema/beans/spring-beans-3.2.xsd 7 http://www.springframework.org/schema/context 8 http://www.springframework.org/schema/context/spring-context-3.2.xsd 9 http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd"> 10 11 <!-- 注解掃描 --> 12 <context:component-scan base-package="com.xxx" /> 13 14 <!-- 配置fastjson轉換器 --> 15 <mvc:annotation-driven> 16 <mvc:message-converters register-defaults="true"> 17 <bean class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter"></bean> 18 </mvc:message-converters> 19 </mvc:annotation-driven> 20 21 <!-- 引入數據源,這里變量的讀取都是從ssmm0的pom.xml中讀取的 --> 22 <bean id="xxxDataSource" class="org.apache.tomcat.jdbc.pool.DataSource" destroy-method="close"> 23 <property name="driverClassName" value="${jdbc.driverClassName}" /> 24 <property name="url" value="${jdbc.url}" /> 25 <property name="username" value="${jdbc.username}" /> 26 <property name="password" value="${jdbc.password}" /> 27 </bean> 28 29 <!-- 引入mybatis --> 30 <bean id="xxxSqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> 31 <property name="dataSource" ref="xxxDataSource" /> 32 </bean> 33 <bean id="xxxMapperScannerConfigurer" class="org.mybatis.spring.mapper.MapperScannerConfigurer"> 34 <!-- 35 這里就是包名為什么就做com.xxx.mapper.user而非com.xxx.user.mapper, 36 這樣的話,比如說有兩個項目com.xxx.mapper.user和com.xxx.mapper.hotel,value只需寫作com.xxx.mapper即可 37 否則,value就要寫作com.xxx.user.mapper,com.xxx.hotel.mapper 38 --> 39 <property name="basePackage" value="com.xxx.mapper" /> 40 <property name="sqlSessionFactoryBeanName" value="xxxSqlSessionFactory" /> 41 </bean> 42 43 <!-- 配置velocity --> 44 <bean id="velocityConfigurer" class="org.springframework.web.servlet.view.velocity.VelocityConfigurer"> 45 <property name="resourceLoaderPath"> 46 <value>WEB-INF/templates/</value> 47 </property> 48 <property name="velocityProperties"> 49 <props> 50 <prop key="input.encoding">UTF-8</prop> 51 <prop key="output.encoding">UTF-8</prop> 52 </props> 53 </property> 54 </bean> 55 <bean id="viewResolver" class="org.springframework.web.servlet.view.velocity.VelocityViewResolver"> 56 <property name="suffix" value=".vm" /> 57 <property name="contentType" value="text/html;charset=utf-8" /> 58 <property name="dateToolAttribute" value="date"/> 59 <property name="numberToolAttribute" value="number"/> 60 </bean> 61 </beans>
注意:這里對包名的體現,由於直接使用spring.xml去讀ssmm0的 pom.xml了,所以jdbc.properties文件就不要了,在spring.xml中,指定文件位置的<context:property-placeholder>標簽就刪掉了
web.xml
1 <?xml version="1.0" encoding="utf-8"?> 2 <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> 5 6 <servlet> 7 <servlet-name>dispatcherServlet</servlet-name> 8 <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> 9 <init-param> 10 <param-name>contextConfigLocation</param-name> 11 <param-value>classpath:spring.xml</param-value> 12 </init-param> 13 <load-on-startup>1</load-on-startup> 14 </servlet> 15 <servlet-mapping> 16 <servlet-name>dispatcherServlet</servlet-name> 17 <url-pattern>/</url-pattern> 18 </servlet-mapping> 19 20 <filter> 21 <filter-name>encodingFilter</filter-name> 22 <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> 23 <init-param> 24 <param-name>encoding</param-name> 25 <param-value>UTF-8</param-value> 26 </init-param> 27 <init-param> 28 <param-name>forceEncoding</param-name> 29 <param-value>true</param-value> 30 </init-param> 31 </filter> 32 <filter-mapping> 33 <filter-name>encodingFilter</filter-name> 34 <url-pattern>/*</url-pattern> 35 </filter-mapping> 36 37 <welcome-file-list> 38 <welcome-file>/index.jsp</welcome-file> 39 </welcome-file-list> 40 </web-app>
com.xxx.web.admin.AdminController
1 package com.xxx.web.admin; 2 3 import org.springframework.beans.factory.annotation.Autowired; 4 import org.springframework.stereotype.Controller; 5 import org.springframework.web.bind.annotation.RequestMapping; 6 import org.springframework.web.bind.annotation.RequestParam; 7 import org.springframework.web.bind.annotation.ResponseBody; 8 import org.springframework.web.servlet.ModelAndView; 9 10 import com.xxx.model.userManagement.Admin; 11 import com.xxx.service.userManagement.AdminService; 12 13 /** 14 * adminController 15 */ 16 @Controller 17 @RequestMapping("/admin") 18 public class AdminController { 19 20 @Autowired 21 private AdminService adminService; 22 23 /** 24 * 管理員注冊 25 */ 26 @ResponseBody 27 @RequestMapping("/register") 28 public boolean register(@RequestParam("username") String username, 29 @RequestParam("password") String password){ 30 Admin admin = new Admin(); 31 admin.setUsername(username); 32 admin.setPassword(password); 33 34 boolean isRegisterSuccess = adminService.register(admin); 35 36 return isRegisterSuccess; 37 } 38 39 /** 40 * 管理員登錄 41 */ 42 @RequestMapping("/login") 43 public ModelAndView login(@RequestParam("username") String username, 44 @RequestParam("password") String password){ 45 Admin admin = adminService.login(username, password); 46 47 ModelAndView modelAndView = new ModelAndView(); 48 if(admin == null){ 49 modelAndView.addObject("message", "用戶不存在或者密碼錯誤!請重新輸入"); 50 modelAndView.setViewName("error"); 51 }else{ 52 modelAndView.addObject("admin", admin); 53 modelAndView.setViewName("userinfo"); 54 } 55 56 return modelAndView; 57 } 58 }
error.vm
1 <!DOCTYPE html> 2 <html lang="zh-cn"> 3 <head> 4 <meta charset="UTF-8"> 5 <title>登錄失敗</title> 6 </head> 7 <body> 8 <div> 9 $message 10 </div> 11 </body> 12 </html>
userinfo.vm
1 <!DOCTYPE html> 2 <html lang="zh-cn"> 3 <head> 4 <meta charset="UTF-8"> 5 <title>登錄成功</title> 6 </head> 7 <body> 8 <div> 9 id:$admin.id 10 username:$admin.username 11 password:$admin.password 12 </div> 13 </body> 14 </html>
具體測試過程:
- 直接運行jetty的話,會發現連不上數據庫服務器99.99.99.999,這是因為默認啟動服務器之后,我們使用的是prod的一套env,這套env中的數據庫服務器是我自己亂寫的:99.99.99.999
- 這時候,在ssmm0-userManagement項目上右擊-->"Build Path"-->"Configure Build Path"-->"Maven"-->修改env,如下圖所示,這樣就切換到了dev的env下,之后再運行jetty,如果依舊不行的話,就采用ssmm0的pom.xml文件中我寫的那塊注釋的方法。

這樣,一個基本上就是企業中開發常用的結構的項目就完成了,這個項目非常重要,一定自己試着去寫一個,一定要仔細看其中的每一條注釋。
