紫薇星上的SSM——整合SSM框架

技术2022-07-12 81

SSM框架分为Spring、Spring MVC、Mybatis，去前面我们分别学习了这三个部分，现在我们来整理一下如何成功的整合这三部分以达到完整的SSM框架。

0.环境

首先来配一下环境，IDEA2020，Maven项目，这些就不说了，主要看一下依赖：

<dependencies> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.34</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.4</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>2.0.4</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.2.6.RELEASE</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>3.0-alpha-1</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>5.2.6.RELEASE</version> </dependency> <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter-api</artifactId> <version>5.7.0-M1</version> <scope>test</scope> </dependency> <dependency> <groupId>javax.servlet.jsp</groupId> <artifactId>jsp-api</artifactId> <version>2.2.1-b03</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.9.5</version> </dependency> <dependency> <groupId>com.mchange</groupId> <artifactId>c3p0</artifactId> <version>0.9.5.5</version> </dependency> </dependencies>

1.前期配置

配置applicationContext.xml

这里我们先什么都不配，来看下一步，在src下建立controller、mapper、pojo、service四个包，分别对应Servlet、Dao、DoMain、Service这四个部分。

简单的Demo

因为处理事务的原因，所以简单的写一个Demo用来说明，我们需要一个数据库，Demo用来实现图书数据的增删改查。

数据库准备

首先建立一个数据库，以及数据：

SET NAMES utf8mb4; SET FOREIGN_KEY_CHECKS = 0; -- ---------------------------- -- Table structure for books -- ---------------------------- DROP TABLE IF EXISTS `books`; CREATE TABLE `books` ( `bookID` int(10) NOT NULL AUTO_INCREMENT, `bookName` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL, `bookCounts` int(11) NOT NULL, `detail` varchar(200) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL, PRIMARY KEY (`bookID`) USING BTREE ) ENGINE = InnoDB AUTO_INCREMENT = 4 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Compact; -- ---------------------------- -- Records of books -- ---------------------------- INSERT INTO `books` VALUES (1, 'Java', 1, '从入门到放弃'); INSERT INTO `books` VALUES (2, 'Mysql', 10, '从入门到放弃'); INSERT INTO `books` VALUES (3, 'Linux', 5, '从入门到放弃'); SET FOREIGN_KEY_CHECKS = 1;

pojo准备

接下来在pojo包中建立Books类：

package com.test.pojo; public class Books { private int bookID; private String bookName; private int bookCounts; private String detail; public Books() { } public Books(int bookID, String bookName, int bookCounts, String detail) { this.bookID = bookID; this.bookName = bookName; this.bookCounts = bookCounts; this.detail = detail; } public int getBookID() { return bookID; } public void setBookID(int bookID) { this.bookID = bookID; } public String getBookName() { return bookName; } public void setBookName(String bookName) { this.bookName = bookName; } public int getBookCounts() { return bookCounts; } public void setBookCounts(int bookCounts) { this.bookCounts = bookCounts; } public String getDetail() { return detail; } public void setDetail(String detail) { this.detail = detail; } @Override public String toString() { return "Books{" + "bookID=" + bookID + ", bookName='" + bookName + '\'' + ", bookCounts=" + bookCounts + ", detail='" + detail + '\'' + '}'; } }

前期准备就绪，现在我们可以开始整合了。

2.整合Mybatis

Mapper接口

有了pojo实体类后就应该编写接口来定义方法：

package com.test.mapper; import com.test.pojo.Books; import org.apache.ibatis.annotations.Param; import java.util.List; public interface BookMapper { public int addBook(Books books); public int deleteBookById(@Param("bookID") int id); public int updateBook(Books books); public List<Books> queryBooks(); public Books queryBooksById(@Param("bookID")int id); }

我们简简单单的编写五个方法，实现增删改查的功能。

mybatis-config.xml

有了接口接下来我们需要建立mybatis-config.xml注册接口，因为使用Spring，所以mybatis-config的大部分工作交给Spring去做，mybatis-config中只需要注册mapper接口和实现别名就可以：

<?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> <typeAliases> <package name="com.test.pojo"/> </typeAliases> <mappers> <mapper class="com.test.mapper.BookMapper"/> </mappers> </configuration>

数据库配置文件

编写database.properties文件：

jdbc.driver=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3306/ssmbuild?useSSL=true&useUnicode=true&charsetEncoding=utf8 jdbc.username=#你的账号# jdbc.password=#你的密码#

Spring接管mybatis

使用Spring接管Mybatis的大部分工作，建立spring-mapper.xml：

<?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" 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">  <context:property-placeholder location="classpath:database.properties"/>   <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="driverClass" value="${jdbc.driver}"/> <property name="jdbcUrl" value="${jdbc.url}"/> <property name="user" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/>  <property name="maxPoolSize" value="30"/> <property name="minPoolSize" value="10"/>  <property name="autoCommitOnClose" value="false"/>  <property name="checkoutTimeout" value="10000"/>  <property name="acquireRetryAttempts" value="2"/> </bean>  <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"/>  <property name="configLocation" value="classpath:mybatis-config.xml"/> </bean>  <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">  <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>  <property name="basePackage" value="com.test.mapper"/> </bean> </beans>

我们并没有使用Spring自带的DriverManagerDataSource来做连接池，而是使用了c3p0，这是因为c3p0比较方便。

BookMapper.xml文件

接下来就可以编写sql语句了：

<?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.test.mapper.BookMapper"> <insert id="addBook" parameterType="Books"> insert into ssmbuild.books (bookID, bookName, bookCounts, detail) values (#{bookID}, #{bookName}, #{bookCounts}, #{detail}); </insert> <delete id="deleteBookById" parameterType="int"> delete from ssmbuild.books where bookID = #{id}; </delete> <update id="updateBook" parameterType="Books"> update ssmbuild.books set bookName = #{bookName}, bookCounts = #{bookCounts}, detail = #{detail} where bookID = #{bookID}; </update> <select id="queryBooks" resultType="Books"> select * from ssmbuild.books; </select> <select id="queryBookById" parameterType="int" resultType="Books"> select * from ssmbuild.books where bookID = #{bookID}; </select> </mapper>

3.整合service

service接口

有了DAO层，接下来就是Service层，同样的，建立接口：

package com.test.service; import com.test.pojo.Books; import java.util.List; public interface BookService { public int addBook(Books books); public int deleteBookById(int id); public int updateBook(Books books); public List<Books> queryBooks(); public Books queryBooksById(int id); }

接口实现类

有了接口就要建立实现类：

package com.test.service; import com.test.mapper.BookMapper; import com.test.pojo.Books; import java.util.List; public class BookServiceImpl implements BookService { //service层调DAO层 private BookMapper mapper; public BookServiceImpl() { } public BookServiceImpl(BookMapper mapper) { this.mapper = mapper; } public BookMapper getMapper() { return mapper; } public void setMapper(BookMapper mapper) { this.mapper = mapper; } @Override public String toString() { return "BookServiceImpl{" + "mapper=" + mapper + '}'; } public int addBook(Books books) { return mapper.addBook(books); } public int deleteBookById(int id) { return mapper.deleteBookById(id); } public int updateBook(Books books) { return mapper.updateBook(books); } public List<Books> queryBooks() { return mapper.queryBooks(); } public Books queryBooksById(int id) { return mapper.queryBooksById(id); } }

Spring注入Service

有了Service就可以使用Spring来做注入：

配置applicationContext.xml

不要忘记applicationContext.xml需要修改，不然dataSource注入不了：

<?xml version="1.0" encoding="UTF-8" ?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <import resource="classpath:spring-mapper.xml"/> <import resource="classpath:spring-service.xml"/> </beans>

4.整合SpringMVC

配置web.xml

首先将普通的Maven项目变成一个Web项目，添加Web Framework support，变为web项目后来配置web.xml：

<?xml version="1.0" encoding="UTF-8"?> <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"> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:applicationContext.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <filter> <filter-name>encoding</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>encoding</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <session-config> <session-timeout>15</session-timeout> </session-config> </web-app>

配置spring-mvc.xml

在web.xml中配置DispatcherServlet，filter，session，接下来配置mvc：

配置applicationContext.xml

当然配置后就要修改applicationContext.xml：

BookController

最后就到了Controller层：

package com.test.controller; import com.test.pojo.Books; import com.test.service.BookService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; import java.util.List; @Controller @RequestMapping("/book") public class BookController { //controller层调service层 @Autowired @Qualifier("BookServiceImpl") private BookService bookService; @RequestMapping("/allBook") public String list(Model model){ List<Books> books = bookService.queryBooks(); model.addAttribute("list", books); return "allBook"; } }

直接使用@Qualifier注入Service，接下来该写页面了。

jsp页面

因为Demo主要是为了整合SSM框架，所以页面功能就不做细节，简单实现就可，首先是allBook.jsp：

<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>书籍展示</title> </head> <body> <h1>书籍展示</h1> ${list} </body> </html>

接下来是index.jsp入口页面：

<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>首页</title> </head> <body> <h3> <a href="${pageContext.request.contextPath}/book/allBook">进入书籍页面</a> </h3> </body> </html>

5.细节

这里有几个小细节，我们要注意一下：

Not used ‘webapp’

我们使用的是普通Maven项目+web framework support，这样做的好处是基本不会出错，一切都可以根据我们自己来选，但是这样也会有问题，就是artifacts目录下的WEB-INF目录中没有lib目录，所以我们要手动添加：

然后将所有的jar全部添加，apply，ok，就可以了。

配置Tomcat

最后就是配置Tomcat：

6.总结

结构

这是最后的文件结构，大家可以核对一下自己的：

效果

以及最终的效果：

SSM整合就这么多东西，其余的如拦截器，功能实现，前端页面等，都可以直接把这个框架拿过去修改，完全没有问题，接下来就该找时间将上次给我爸做的那个商品管理系统使用SSM重构一下，我们下次见👋

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