SSM-Spring-22：Spring+Mybatis+JavaWeb的整合
------------吾亦无他,唯手熟尔，谦卑若愚，好学若饥-------------
众所周知，框架Spring来整合别的框架，但是Mybatis出现的晚，Spring就没有给他提供支持，那怎么办呢？Mybatis说，我吃点亏，我给你提供整合的jar，所以那个整合的jar包就叫mabatis-spring。jar
由于SpringMVC和Spring天然集成，所以，Spring整合了Mabatis就证明你ssm整合就搞定了
整合并不只是jar包的堆砌，而是一个框架的部分功能要交给另外一个框架进行完成，调度
写个案例，购买添加图书的Spring+Mabatis+JavaWeb的案例
步骤开始：
1.引入jar包，修改build节点：
我之前案例的节点，可能这个案例用不到，但是也一块扔上来了
<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"> <parent> <artifactId>Y2167DAWNALLDEMO</artifactId> <groupId>cn.dawn</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>02Spring</artifactId> <packaging>war</packaging> <name>02Spring Maven Webapp</name> <url>http://maven.apache.org</url> <dependencies> <!--单元测试的依赖 ctrl+shif+/--> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>test</scope> </dependency> <!--Spring--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>4.2.0.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>4.2.0.RELEASE</version> </dependency> <!--aop使用的jar--> <dependency> <groupId> org.aspectj</groupId > <artifactId> aspectjweaver</artifactId > <version> 1.8.7</version> </dependency> <!--spring jdbc--> <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>4.2.0.RELEASE</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.39</version> </dependency> <!-- https://mvnrepository.com/artifact/c3p0/c3p0 --> <dependency> <groupId>c3p0</groupId> <artifactId>c3p0</artifactId> <version>0.9.1.2</version> </dependency> <!-- https://mvnrepository.com/artifact/org.apache.commons/commons-dbcp2 --> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-dbcp2</artifactId> <version>2.1.1</version> </dependency> <!-- https://mvnrepository.com/artifact/com.alibaba/druid --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.1.6</version> </dependency> <!--mybatis jar包--> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.2.2</version> </dependency> <!--Mybatis+Spring整合--> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>1.2.1</version> </dependency> <!-- Spring整合JavaWeb的包 --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>4.2.0.RELEASE</version> </dependency> <!--javaee jar--> <dependency> <groupId>javaee</groupId> <artifactId>javaee-api</artifactId> <version>5</version> </dependency> <!--jstl表达式--> <dependency> <groupId>jstl</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> </dependencies> <build> <resources> <resource> <directory>src/main/java</directory> <includes> <include>**/*.xml</include> </includes> </resource> </resources> </build> </project>
2.准备数据库：
3.分层开发开始：
3.1entity层
Book实体类
package cn.dawn.day23ssm.entity; public class Book { private Integer bookID; private String bookName; private String bookAuthor; private Integer bookPrice; public Book() { } public Book(String bookName, String bookAuthor, Integer bookPrice) { this.bookName = bookName; this.bookAuthor = bookAuthor; this.bookPrice = bookPrice; } public Integer getBookID() { return this.bookID; } public void setBookID(Integer bookID) { this.bookID = bookID; } public String getBookName() { return this.bookName; } public void setBookName(String bookName) { this.bookName = bookName; } public String getBookAuthor() { return this.bookAuthor; } public void setBookAuthor(String bookAuthor) { this.bookAuthor = bookAuthor; } public Integer getBookPrice() { return this.bookPrice; } public void setBookPrice(Integer bookPrice) { this.bookPrice = bookPrice; } }
3.2dao层
接口IBookDAO
package cn.dawn.day23ssm.dao; import cn.dawn.day23ssm.entity.Book; /** * Created by Dawn on 2018/3/17. */ public interface IBookDAO { //添加 public int insertBook(Book book) throws Exception; }
同名的IBookDAO.xml配置文件
<?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="cn.dawn.day23ssm.dao.IBookDAO"> <insert id="insertBook"> INSERT INTO book(bookname,bookauthor,bookprice) VALUES (#{bookName},#{bookAuthor},#{bookPrice}) </insert> </mapper>
3.3service层
IBookService接口：
package cn.dawn.day23ssm.service; import cn.dawn.day23ssm.entity.Book; /** * Created by Dawn on 2018/3/17. */ public interface IBookService { //添加 public int insertBook(Book book) throws Exception; }
BookServiceImpl刚才那个接口的实现类
package cn.dawn.day23ssm.service; import cn.dawn.day23ssm.dao.IBookDAO; import cn.dawn.day23ssm.entity.Book; import org.springframework.transaction.annotation.Transactional; /** * Created by Dawn on 2018/3/17. */ public class BookServiceImpl implements IBookService { private IBookDAO dao; //开启事务 @Transactional public int insertBook(Book book) throws Exception { return dao.insertBook(book); } public IBookDAO getDao() { return dao; } public void setDao(IBookDAO dao) { this.dao = dao; } }
此处我做了事务的开启
3.我的习惯是在此处开始写配置文件，走个单测再去和javaweb打交道
所以此处的步骤就是三个大配置文件
3.1jdbc.properties
jdbc.driver=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql:///s2228 jdbc.username=root jdbc.password=
3.2mybatis-config.xml
<?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="cn.dawn.day23ssm.entity"></package> </typeAliases> </configuration>
此处的mybatis只做了别名，但是这个案例中没有用，只是提一下，如果做查询的时候，别名从这儿设置，我一会也给把加入spring的地方也标出来
它的mappers，properties都不从这儿设置，这就印证了我之前的一句话，整合并不只是jar包的堆砌，而是一个框架的部分功能要交给另外一个框架进行完成，调度
3.3ApplicationContext-day23ssm.xml(你们可以改这个名字的，一会调用的时候改掉就可以了，不要学死，灵活应变，举一反三)
<?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:aop="http://www.springframework.org/schema/aop" xmlns:p="http://www.springframework.org/schema/p" 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/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd"> <!--配置jdbc。properties--> <context:property-placeholder location="classpath:jdbc.properties"></context:property-placeholder> <!--阿里的Druid--> <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"> <property name="driverClassName" value="${jdbc.driver}"></property> <property name="url" value="${jdbc.url}"></property> <property name="username" value="${jdbc.username}"></property> <property name="password" value="${jdbc.password}"></property> </bean> <!--dao层--> <bean class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"></property> <!--这儿的mybatis配置文件中只做别名，其他的都由spring整合了--> <property name="configLocation" value="classpath:mybatis-config.xml"></property> </bean> <!--映射扫描器--> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="cn.dawn.day23ssm.dao"></property> </bean> <!--service--> <bean id="bookService" class="cn.dawn.day23ssm.service.BookServiceImpl"> <property name="dao" ref="IBookDAO"></property> </bean> <!--事务管理器--> <bean id="dataSourceTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"></property> </bean> <!--事务开启，注解版--> <tx:annotation-driven transaction-manager="dataSourceTransactionManager"></tx:annotation-driven> </beans>
4.jsp页面和servlet
4.1jsp页面
success.jsp
<%-- Created by IntelliJ IDEA. User: Dawn Date: 2018/3/17 Time: 14:39 To change this template use File | Settings | File Templates. --%> <%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %> <html> <head> <title>添加成功</title> </head> <body> <h2 style="text-align: center;color: red">添加${bookName}成功</h2> </body> </html>
addBook.jsp
<%-- Created by IntelliJ IDEA. User: Dawn Date: 2018/3/17 Time: 14:41 To change this template use File | Settings | File Templates. --%> <%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %> <html> <head> <title>添加图书页面</title> </head> <body> <form method="post" action="${pageContext.request.contextPath}/BookServlet"> 书名：<input type="text" name="bookName"> 作者：<input type="text" name="bookAuthor"> 价格：<input type="text" name="bookPrice"> <input type="submit" value="添加图书"> </form> </body> </html>
4.2servlet层
BookServlet
package cn.dawn.day23ssm.servlet; import cn.dawn.day23ssm.entity.Book; import cn.dawn.day23ssm.service.IBookService; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import org.springframework.web.context.support.WebApplicationContextUtils; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; /** * Created by Dawn on 2018/3/17. */ public class BookServlet extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //解决乱码 request.setCharacterEncoding("utf-8"); //获取书名 String bookName = request.getParameter("bookName"); //获取作者 String bookAuthor = request.getParameter("bookAuthor"); //获取价格 String bookPriceStr = request.getParameter("bookPrice"); Integer bookPrice=Integer.parseInt(bookPriceStr); //创建图书对象 Book book=new Book(bookName,bookAuthor,bookPrice); //创建service对象
//采用优雅的方式：
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
ApplicationContext applicationContext= WebApplicationContextUtils.getRequiredWebApplicationContext(this.getServletContext());
//ApplicationContext applicationContext=new ClassPathXmlApplicationContext("ApplicationContext-day23ssm.xml"); IBookService bookService = (IBookService)applicationContext.getBean("bookService"); //调用方法 try { int result = bookService.insertBook(book); //根据返回结果判断是否成功 if (result>0){ //把结果传过去 request.setAttribute("bookName",bookName); //成功，转发到Index页面 request.getRequestDispatcher("/success.jsp").forward(request,response); }else { //失败，重定向到刚才的页面 response.sendRedirect("/ssm/addBook.jsp"); } } catch (Exception e) { e.printStackTrace(); } } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } }
这儿有我之前埋的一个坑，我这儿用的javaee是5的版本，不是6.0，没法用注解版，所以还得到web.xml中配置一道
4.3web。xml
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd" > <web-app> <display-name>Archetype Created Web Application</display-name> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:ApplicationContext-day23ssm.xml</param-value> </context-param> <!--监听器--> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <servlet> <servlet-name>BookServlet</servlet-name> <servlet-class>cn.dawn.day23ssm.servlet.BookServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>BookServlet</servlet-name> <url-pattern>/BookServlet</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app>
这儿有一处之前没有见到过
servlet处的
ApplicationContext applicationContext= WebApplicationContextUtils.getRequiredWebApplicationContext(this.getServletContext());
和web.xml中的监听器和配置
这是什么呢？
这是一个优雅的方式，
总所周知，你将之前单测的那种方式你直接拖过来用，那在servlet中会造成什么后果呢？
就是每一次访问servlet你就对spring容器进行一次初始化工作，这里面的bean因为是单例的，所以都会生成一次，相当耗损性能
那么怎么办?
你想servletcontext就是在web容器中从一开始到结束过程中都可以访问到的，那么我们在web容器一启动的时候就将spring容器放到servletcontext中岂不美哉，之后就不用new了
-------笔者：晨曦Dawn-------
