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手把手整合SSM框架#yyds干货盘点#

IT知识SSM框架手把手

赋料扬雄敌，诗看子建亲。这篇文章主要讲述手把手整合SSM框架#yyds干货盘点#相关的知识，希望能为你提供帮助。
前言@[toc]
搭建整合 SSM 之 HelloWorld 开发环境

  • idea
  • mysql5.x
  • jdk8
  • maven
目录
手把手整合SSM框架#yyds干货盘点#

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目录包括 main、resources、mapper、webapp，不一一介绍，不熟悉查看前面文章。
环境搭建
新建项目这里使用的是 IDEA 编辑器，新建一个 Maven 工程，选择 web 项目。
手把手整合SSM框架#yyds干货盘点#

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导入依赖使用 Maven 管理项目 jar ，只需要在 pom.xml 加如相关依赖即可。
< ?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/xsd/maven-4.0.0.xsd"> < modelVersion> 4.0.0< /modelVersion> < groupId> javapub.rodert.github< /groupId> < artifactId> ssm_helloword_web< /artifactId> < version> 1.0-SNAPSHOT< /version> < packaging> war< /packaging> < url> < /url> < !--源码：https://github.com/Rodert/JavaPub--> < properties> < project.build.sourceEncoding> UTF-8< /project.build.sourceEncoding> < spring.version> 4.3.6.RELEASE< /spring.version> < /properties> < dependencies> < !-- 单元测试 --> < dependency> < groupId> junit< /groupId> < artifactId> junit< /artifactId> < version> 4.12< /version> < /dependency> < !-- 1.日志 --> < !-- 实现slf4j接口并整合 --> < dependency> < groupId> ch.qos.logback< /groupId> < artifactId> logback-classic< /artifactId> < version> 1.1.1< /version> < /dependency> < !-- 2.数据库 --> < dependency> < groupId> mysql< /groupId> < artifactId> mysql-connector-java< /artifactId> < version> 5.1.37< /version> < scope> runtime< /scope> < /dependency> < dependency> < groupId> c3p0< /groupId> < artifactId> c3p0< /artifactId> < version> 0.9.1.2< /version> < /dependency> < !-- DAO: MyBatis --> < dependency> < groupId> org.mybatis< /groupId> < artifactId> mybatis< /artifactId> < version> 3.3.0< /version> < /dependency> < dependency> < groupId> org.mybatis< /groupId> < artifactId> mybatis-spring< /artifactId> < version> 1.2.3< /version> < /dependency> < !-- 3.Servlet web --> < dependency> < groupId> taglibs< /groupId> < artifactId> standard< /artifactId> < version> 1.1.2< /version> < /dependency> < dependency> < groupId> jstl< /groupId> < artifactId> jstl< /artifactId> < version> 1.2< /version> < /dependency> < dependency> < groupId> com.fasterxml.jackson.core< /groupId> < artifactId> jackson-databind< /artifactId> < version> 2.5.4< /version> < /dependency> < dependency> < groupId> javax.servlet< /groupId> < artifactId> javax.servlet-api< /artifactId> < version> 3.1.0< /version> < /dependency> < !-- 4.Spring --> < !-- 1)Spring核心 --> < dependency> < groupId> org.springframework< /groupId> < artifactId> spring-core< /artifactId> < version> ${spring.version}< /version> < /dependency> < dependency> < groupId> org.springframework< /groupId> < artifactId> spring-beans< /artifactId> < version> ${spring.version}< /version> < /dependency> < dependency> < groupId> org.springframework< /groupId> < artifactId> spring-context< /artifactId> < version> ${spring.version}< /version> < /dependency> < !-- 2)Spring DAO层 --> < dependency> < groupId> org.springframework< /groupId> < artifactId> spring-jdbc< /artifactId> < version> ${spring.version}< /version> < /dependency> < dependency> < groupId> org.springframework< /groupId> < artifactId> spring-tx< /artifactId> < version> ${spring.version}< /version> < /dependency> < !-- 3)Spring web --> < dependency> < groupId> org.springframework< /groupId> < artifactId> spring-web< /artifactId> < version> ${spring.version}< /version> < /dependency> < dependency> < groupId> org.springframework< /groupId> < artifactId> spring-webmvc< /artifactId> < version> ${spring.version}< /version> < /dependency> < !-- 4)Spring test --> < dependency> < groupId> org.springframework< /groupId> < artifactId> spring-test< /artifactId> < version> ${spring.version}< /version> < /dependency> < !-- redis客户端:Jedis --> < dependency> < groupId> redis.clients< /groupId> < artifactId> jedis< /artifactId> < version> 2.7.3< /version> < /dependency> < dependency> < groupId> com.dyuproject.protostuff< /groupId> < artifactId> protostuff-core< /artifactId> < version> 1.0.8< /version> < /dependency> < dependency> < groupId> com.dyuproject.protostuff< /groupId> < artifactId> protostuff-runtime< /artifactId> < version> 1.0.8< /version> < /dependency> < !-- Map工具类 --> < dependency> < groupId> commons-collections< /groupId> < artifactId> commons-collections< /artifactId> < version> 3.2< /version> < /dependency> < !--注解--> < !-- https://mvnrepository.com/artifact/org.projectlombok/lombok --> < dependency> < groupId> org.projectlombok< /groupId> < artifactId> lombok< /artifactId> < version> 1.18.12< /version> < scope> provided< /scope> < /dependency> < /dependencies> < build> < finalName> ssm_helloword_web< /finalName> < plugins> < plugin> < groupId> org.apache.maven.plugins< /groupId> < artifactId> maven-compiler-plugin< /artifactId> < configuration> < source> 7< /source> < target> 7< /target> < /configuration> < /plugin> < /plugins> < /build> < /project> < !--源码：https://github.com/Rodert/JavaPub-->

编码
配置文件 spring-dao.xml
  • 先在spring文件夹里新建spring-dao.xml文件，我们这里分三层，分别是dao service web。
  1. 加载数据库配置
  2. 配置数据库连接池
  3. 配置 SqlSessionFactory 对象（MyBatis）
  4. 配置扫描 dao 层接口，动态代理实现 Dao 实现类，执行 sql 写在 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 http://www.springframework.org/schema/context/spring-context.xsd"> < !-- 配置整合mybatis过程 --> < !-- 1.配置数据库相关参数properties的属性：${url} --> < context:property-placeholder location="classpath:jdbc.properties" /> < !-- 2.数据库连接池 --> < bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> < !-- 配置连接池属性 --> < property name="driverClass" value="https://www.songbingjia.com/android/${jdbc.driver}" /> < property name="jdbcUrl" value="https://www.songbingjia.com/android/${jdbc.url}" /> < property name="user" value="https://www.songbingjia.com/android/${jdbc.username}" /> < property name="password" value="https://www.songbingjia.com/android/${jdbc.password}" /> < !-- c3p0连接池的私有属性 --> < property name="maxPoolSize" value="https://www.songbingjia.com/android/30" /> < property name="minPoolSize" value="https://www.songbingjia.com/android/10" /> < !-- 关闭连接后不自动commit --> < property name="autoCommitOnClose" value="https://www.songbingjia.com/android/false" /> < !-- 获取连接超时时间 --> < property name="checkoutTimeout" value="https://www.songbingjia.com/android/10000" /> < !-- 当获取连接失败重试次数 --> < property name="acquireRetryAttempts" value="https://www.songbingjia.com/android/2" /> < /bean> < !-- 3.配置SqlSessionFactory对象 --> < bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> < !-- 注入数据库连接池 --> < property name="dataSource" ref="dataSource" /> < !-- 配置MyBaties全局配置文件:mybatis-config.xml --> < property name="configLocation" value="https://www.songbingjia.com/android/classpath:Mybatis-config.xml" /> < !-- 扫描entity包 使用别名 --> < property name="typeAliasesPackage" value="https://www.songbingjia.com/android/javapub.rodert.github.entity" /> < !-- 扫描sql配置文件:mapper需要的xml文件 --> < property name="mapperLocations" value="https://www.songbingjia.com/android/classpath:mapper/*.xml" /> < /bean> < !-- 4.配置扫描Dao接口包，动态实现Dao接口，注入到spring容器中 --> < bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> < !-- 注入sqlSessionFactory --> < property name="sqlSessionFactoryBeanName" value="https://www.songbingjia.com/android/sqlSessionFactory" /> < !-- 给出需要扫描Dao接口包 --> < property name="basePackage" value="https://www.songbingjia.com/android/javapub.rodert.github.dao" /> < /bean> < /beans>

jdbc.properties数据库配置，在 resources 文件夹里新建一个 jdbc.properties 文件，注意自己的password。
jdbc.driver=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3306/ssm1?useUnicode=true& characterEncoding=utf8 jdbc.username=root jdbc.password=

mybatis-config.xmlMyBatis 核心文件，在recources文件夹里新建mybatis-config.xml文件。
  1. 使用自增主键
  2. 使用列别名
  3. 开启驼峰命名转换 create_time -> createTime
< ?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="https://www.songbingjia.com/android/true" /> < !-- 使用列别名替换列名 默认:true --> < setting name="useColumnLabel" value="https://www.songbingjia.com/android/true" /> < !-- 开启驼峰命名转换:Table{create_time} -> Entity{createTime} --> < setting name="mapUnderscoreToCamelCase" value="https://www.songbingjia.com/android/true" /> < /settings> < /configuration>

spring-service.xml在 spring 文件夹里新建 spring-service.xml 文件。
  1. 扫描 service 包所有注解 @Service
  2. 配置事务管理器，把事务管理交由 spring 来完成
  3. 基于注解的 声明式事务，可以直接在方法上 @Transaction
< ?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: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/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"> < !-- 扫描service包下所有使用注解的类型 --> < context:component-scan base-package="javapub.rodert.github.service" /> < !-- 配置事务管理器 --> < bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> < !-- 注入数据库连接池 --> < property name="dataSource" ref="dataSource" /> < /bean> < !-- 配置基于注解的声明式事务 --> < tx:annotation-driven transaction-manager="transactionManager" /> < /beans>

spring-web.xmlweb 层，在 spring 文件夹里新建 spring-web.xml 文件。
  1. 开启SpringMVC注解模式，可以使用@RequestMapping，@PathVariable，@ResponseBody等
  2. 对静态资源处理，如js，css，jpg等
  3. 配置jsp 显示ViewResolver，及渲染后的 JSP
  4. 扫描web层 @Controller
< ?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/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd"> < !-- 配置SpringMVC --> < !-- 1.开启SpringMVC注解模式 --> < !-- 简化配置： (1)自动注册DefaultAnootationHandlerMapping,AnotationMethodHandlerAdapter (2)提供一些列：数据绑定，数字和日期的format @NumberFormat, @DateTimeFormat, xml,json默认读写支持 --> < mvc:annotation-driven /> < !-- 2.静态资源默认servlet配置 (1)加入对静态资源的处理：js,gif,png (2)允许使用"/"做整体映射 --> < mvc:default-servlet-handler/> < !-- 3.配置jsp 显示ViewResolver --> < bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> < property name="viewClass" value="https://www.songbingjia.com/android/org.springframework.web.servlet.view.JstlView" /> < !--< property name="contentType" value="https://www.songbingjia.com/android/text/html"/> --> < property name="prefix" value="https://www.songbingjia.com/WEB-INF/jsp/" /> < property name="suffix" value="https://www.songbingjia.com/android/.jsp" /> < /bean> < !-- 4.扫描web相关的bean --> < context:component-scan base-package="javapub.rodert.github.web" /> < /beans>

web.xml修改 web.xml 文件了，它在 webapp 的 WEB-INF 下。也可以在这里配置过滤器、监听器等。
< 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_3_1.xsd" version="3.1" metadata-complete="true"> < !-- 如果是用mvn命令生成的xml，需要修改servlet版本为3.1 --> < !-- 配置DispatcherServlet --> < servlet> < servlet-name> dispatcherServlet< /servlet-name> < servlet-class> org.springframework.web.servlet.DispatcherServlet< /servlet-class> < !-- 配置springMVC需要加载的配置文件 spring-dao.xml,spring-service.xml,spring-web.xml Mybatis - > spring -> springmvc --> < init-param> < param-name> contextConfigLocation< /param-name> < param-value> classpath:spring/spring-*.xml< /param-value> < /init-param> < load-on-startup> 1< /load-on-startup> < /servlet> < servlet-mapping> < servlet-name> dispatcherServlet< /servlet-name> < !-- 默认匹配所有的请求 --> < url-pattern> /< /url-pattern> < /servlet-mapping> < welcome-file-list> < welcome-file> index.jsp< /welcome-file> < /welcome-file-list> < /web-app>

日志配置一些简单的日志，使用 logback，在 resources 文件夹里新建logback.xml 文件。
< ?xml version="1.0" encoding="UTF-8"?> < configuration debug="true"> < appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"> < !-- encoders are by default assigned the type ch.qos.logback.classic.encoder.PatternLayoutEncoder --> < encoder> < pattern> %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n< /pattern> < /encoder> < /appender> < root level="debug"> < appender-ref ref="STDOUT" /> < /root> < /configuration>

配置说明以上配置是整合 SSM 的基础配置，目录结构如图所示：
手把手整合SSM框架#yyds干货盘点#

文章图片

SSM实例-图书管理系统 sql新建俩张表，图书表 book 和 预约图书表 appointment，并初始化数据。
/* Navicat MySQL Data TransferSource Server: localhost Source Server Version : 50716 Source Host: localhost:3306 Source Database: ssm1Target Server Type: MYSQL Target Server Version : 50716 File Encoding: 65001Date: 2020-07-12 16:50:43 */SET FOREIGN_KEY_CHECKS=0; -- ---------------------------- -- Table structure for appointment -- ---------------------------- DROP TABLE IF EXISTS `appointment`; CREATE TABLE `appointment` ( `book_id` bigint(20) NOT NULL COMMENT 图书ID, `student_id` bigint(20) NOT NULL COMMENT 学号, `appoint_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT 预约时间, PRIMARY KEY (`book_id`,`student_id`), KEY `idx_appoint_time` (`appoint_time`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT=预约图书表; -- ---------------------------- -- Records of appointment -- ------------------------------ ---------------------------- -- Table structure for book -- ---------------------------- DROP TABLE IF EXISTS `book`; CREATE TABLE `book` ( `book_id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT 图书ID, `name` varchar(100) NOT NULL COMMENT 图书名称, `number` int(11) NOT NULL COMMENT 馆藏数量, PRIMARY KEY (`book_id`) ) ENGINE=InnoDB AUTO_INCREMENT=1004 DEFAULT CHARSET=utf8 COMMENT=图书表; -- ---------------------------- -- Records of book -- ---------------------------- INSERT INTO `book` VALUES (2000, Java程序设计, 20); INSERT INTO `book` VALUES (2001, 数据结构, 7); INSERT INTO `book` VALUES (2002, 设计模式, 20); INSERT INTO `book` VALUES (2003, 编译原理, 20);

实体在 entity 包下新建实体 Book 和 Appointment
  • Book.java
package javapub.rodert.github.entity; import lombok.Getter; import lombok.Setter; import lombok.ToString; /** * @author wangshiyu rodert * @date 2020/7/6 20:58 * @description * * @Data 注解，简化代码，自动添加get set toSting 方法 * @Getter * @Setter * @ToString */ @Getter @Setter @ToString public class Book {private long bookId; // 图书IDprivate String name; // 图书名称private int number; // 馆藏数量// 省略构造方法，getter和setter方法，toString方法}

  • Appointment.java
package javapub.rodert.github.entity; /** * @author wangshiyu rodert * @date 2020/7/6 20:58 * @description */import lombok.Data; import lombok.Getter; import lombok.Setter; import lombok.ToString; import java.util.Date; /** * 预约图书实体 * @Data 注解，简化代码，自动添加get set toSting 方法 */ @Data public class Appointment {private long bookId; // 图书IDprivate long studentId; // 学号private Date appointTime; // 预约时间// 多对一的复合属性 private Book book; // 图书实体// 省略构造方法，getter和setter方法，toString方法}

dao接口在dao包新建接口 BookDao.java 和 Appointment.java
  • BookDao.java
package javapub.rodert.github.dao; /** * @author wangshiyu rodert * @date 2020/7/6 21:01 * @description */import javapub.rodert.github.entity.Book; import org.apache.ibatis.annotations.Param; import java.util.List; public interface BookDao {/** * 通过ID查询单本图书 * * @param id * @return */ Book queryById(long id); /** * 查询所有图书 * * @param offset 查询起始位置 * @param limit 查询条数 * @return */ List< Book> queryAll(@Param("offset") int offset, @Param("limit") int limit); /** * 减少馆藏数量 * * @param bookId * @return 如果影响行数等于> 1，表示更新的记录行数 */ int reduceNumber(long bookId); }

  • AppointmentDao.java
package javapub.rodert.github.dao; /** * @author wangshiyu rodert * @date 2020/7/6 21:01 * @description */import javapub.rodert.github.entity.Appointment; import org.apache.ibatis.annotations.Param; public interface AppointmentDao {/** * 插入预约图书记录 * * @param bookId * @param studentId * @return 插入的行数 */ int insertAppointment(@Param("bookId") long bookId, @Param("studentId") long studentId); /** * 通过主键查询预约图书记录，并且携带图书实体 * * @param bookId * @param studentId * @return */ Appointment queryByKeyWithBook(@Param("bookId") long bookId, @Param("studentId") long studentId); }

提示：这里为什么要给方法的参数添加 @Param注解呢？是因为该方法有两个或以上的参数，一定要加，不然 mybatis 识别不了。上面的 BookDao 接口的 queryById 方法和 reduceNumber 方法只有一个参数 book_id ，所以可以不用加 @Param 注解。
dao接口xml这里不需要写 dao接口 的实现类，mybatis会帮我们动态实现，上面我们已经在 spring-dao.xml 配置了动态扫描。现在需要编写相应的 mapper。
在 mapper 目录里新建两个文件 BookDao.xml 和 AppointmentDao.xml ，分别对应上面两个dao接口。
  • BookDao.xml
< ?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="javapub.rodert.github.dao.BookDao"> < !-- 目的：为dao接口方法提供sql语句配置 --> < select id="queryById" resultType="Book" parameterType="long"> < !-- 具体的sql --> SELECT book_id, name, number FROM book WHERE book_id = #{bookId} < /select> < select id="queryAll" resultType="Book"> SELECT book_id, name, number FROM book ORDER BY book_id LIMIT #{offset}, #{limit} < /select> < update id="reduceNumber"> UPDATE book SET number = number - 1 WHERE book_id = #{bookId} AND number > 0 < /update> < /mapper>

  • AppointmentDao.xml
< ?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="javapub.rodert.github.dao.AppointmentDao"> < insert id="insertAppointment"> < !-- ignore 主键冲突，报错 --> INSERT ignore INTO appointment (book_id, student_id) VALUES (#{bookId}, #{studentId}) < /insert> < select id="queryByKeyWithBook" resultType="Appointment"> < !-- 如何告诉MyBatis把结果映射到Appointment同时映射book属性 --> < !-- 可以自由控制SQL --> SELECT a.book_id, a.student_id, a.appoint_time, b.book_id "book.book_id", b.`name` "book.name", b.number "book.number" FROM appointment a INNER JOIN book b ON a.book_id = b.book_id WHERE a.book_id = #{bookId} AND a.student_id = #{studentId} < /select> < /mapper>

mapper 说明：namespace 是 xml 对应的接口全名，select 和 update 中的 id 对应方法名（唯一），resultType 是返回值类型，parameterType 是参数类型（这个其实可选），#{...} 中填写的是方法的参数
dao接口测试现在的写法是从数据库层向前（web）写，现在测试一下 dao 接口，编写测试类。
因为每次测试都要加载配置文件，所有抽离一个类（BaseTest），每次测试方法都继承它。
  • BaseTest.java
package javapub.rodert.github; /** * @author wangshiyu rodert * @date 2020/7/6 21:07 * @description */import org.junit.runner.RunWith; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; /** * 配置spring和junit整合，junit启动时加载springIOC容器 spring-test,junit */ @RunWith(SpringJUnit4ClassRunner.class) // 告诉junit spring配置文件 @ContextConfiguration({ "classpath:spring/spring-dao.xml", "classpath:spring/spring-service.xml" }) public class BaseTest {}

新建 BookDaoTest.java 和 AppointmentDaoTest.java 两个 dao 测试文件。
  • BookDao.java
package javapub.rodert.github.dao; /** * @author wangshiyu rodert * @date 2020/7/6 21:08 * @description */import javapub.rodert.github.BaseTest; import javapub.rodert.github.entity.Book; import org.junit.Test; import org.springframework.beans.factory.annotation.Autowired; import java.util.List; public class BookDaoTest extends BaseTest {@Autowired private BookDao bookDao; @Test public void testQueryById() throws Exception { long bookId = 1000; Book book = bookDao.queryById(bookId); System.out.println(book); }@Test public void testQueryAll() throws Exception { List< Book> books = bookDao.queryAll(0, 4); for (Book book : books) { System.out.println(book); } }@Test public void testReduceNumber() throws Exception { long bookId = 1000; int update = bookDao.reduceNumber(bookId); System.out.println("update=" + update); }}

  • AppointmentDaoTest.java
package javapub.rodert.github.dao; /** * @author wangshiyu rodert * @date 2020/7/6 21:18 * @description */import javapub.rodert.github.BaseTest; import javapub.rodert.github.entity.Appointment; import org.junit.Test; import org.springframework.beans.factory.annotation.Autowired; public class AppointmentDaoTest extends BaseTest {@Autowired private AppointmentDao appointmentDao; @Test public void testInsertAppointment() throws Exception { long bookId = 1000; long studentId = 12345678910L; int insert = appointmentDao.insertAppointment(bookId, studentId); System.out.println("insert=" + insert); }@Test public void testQueryByKeyWithBook() throws Exception { long bookId = 1000; long studentId = 12345678910L; Appointment appointment = appointmentDao.queryByKeyWithBook(bookId, studentId); System.out.println(appointment); System.out.println(appointment.getBook()); }}

  • BookDaoTest.java -- > testQueryById()
手把手整合SSM框架#yyds干货盘点#

文章图片

业务层-结果集封装到这里，我们的 dao 层，及数据库接口操作都没有问题，下面开始业务层编写。
如果你有实战项目经验，那一定会发现，对于后端接口，我们都会定义一个统一的返回格式，及定义一个返回标准方便前端解析，如下：
{ "code":200, "message":"成功", "result":{}, "isSuccess":true }

开始写我们的代码，新建枚举类，用来定义预约业务的数据字典。如果不太明白，先看代码，后面在 JavaPub 微信公众号文章索引中查找对应文章。
新建一个包叫 enums，在里面新建一个枚举类 AppointStateEnum.java。
  • AppointStateEnum.java
package javapub.rodert.github.enums; /** * @author wangshiyu rodert * @date 2020/7/6 21:20 * @description *//** * 使用枚举表述常量数据字典 */ public enum AppointStateEnum {SUCCESS(1, "预约成功"), NO_NUMBER(0, "库存不足"), REPEAT_APPOINT(-1, "重复预约"), INNER_ERROR(-2, "系统异常"); private int state; private String stateInfo; private AppointStateEnum(int state, String stateInfo) { this.state = state; this.stateInfo = stateInfo; }public int getState() { return state; }public String getStateInfo() { return stateInfo; }public static AppointStateEnum stateOf(int index) { for (AppointStateEnum state : values()) { if (state.getState() == index) { return state; } } return null; }}

在 dto 包下新建 AppointExecution.java 用来存储我们执行预约操作的返回结果。
  • AppointExecution.java
package javapub.rodert.github.dto; /** * @author wangshiyu rodert * @date 2020/7/7 16:26 * @description */import javapub.rodert.github.entity.Appointment; import javapub.rodert.github.enums.AppointStateEnum; import lombok.Data; /** * 封装预约执行后结果 */ @Data public class AppointExecution {// 图书ID private long bookId; // 秒杀预约结果状态 private int state; // 状态标识 private String stateInfo; // 预约成功对象 private Appointment appointment; public AppointExecution() { }// 预约失败的构造器 public AppointExecution(long bookId, AppointStateEnum stateEnum) { this.bookId = bookId; this.state = stateEnum.getState(); this.stateInfo = stateEnum.getStateInfo(); }// 预约成功的构造器 public AppointExecution(long bookId, AppointStateEnum stateEnum, Appointment appointment) { this.bookId = bookId; this.state = stateEnum.getState(); this.stateInfo = stateEnum.getStateInfo(); this.appointment = appointment; }// 省略getter和setter方法，toString方法}

在 exception 包下新建三个文件
NoNumberException.java
RepeatAppointException.java
AppointException.java
预约业务异常类（都需要继承 RuntimeException ---运行时异常类），分别是无库存异常、重复预约异常、预约未知错误异常，用于业务层非成功情况下的返回（即成功返回结果，失败抛出异常）。为事务做准备。
  • AppointException.java
package javapub.rodert.github.exception; /** * @author wangshiyu rodert * @date 2020/7/7 16:31 * @description *//** * 预约业务异常 */ public class AppointException extends RuntimeException {public AppointException(String message) { super(message); }public AppointException(String message, Throwable cause) { super(message, cause); }}

  • NoNumberException.java
/** * @author wangshiyu rodert * @date 2020/7/7 16:30 * @description */ package javapub.rodert.github.exception; /** * 库存不足异常 */ public class NoNumberException extends RuntimeException {public NoNumberException(String message) { super(message); }public NoNumberException(String message, Throwable cause) { super(message, cause); }}

  • RepeatAppointException.java
/** * @author wangshiyu rodert * @date 2020/7/7 16:31 * @description */ package javapub.rodert.github.exception; /** * 重复预约异常 */ public class RepeatAppointException extends RuntimeException {public RepeatAppointException(String message) { super(message); }public RepeatAppointException(String message, Throwable cause) { super(message, cause); }}

Service 业务接口代码在service包下新建BookService.java图书业务接口。
  • BookService.java
/** * @author wangshiyu rodert * @date 2020/7/7 16:32 * @description */ package javapub.rodert.github.service; import javapub.rodert.github.dto.AppointExecution; import javapub.rodert.github.entity.Book; import java.util.List; /** * 业务接口：站在"使用者"角度设计接口 三个方面：方法定义粒度，参数，返回类型（return 类型/异常） */ public interface BookService {/** * 查询一本图书 * * @param bookId * @return */ Book getById(long bookId); /** * 查询所有图书 * * @return */ List< Book> getList(); /** * 预约图书 * * @param bookId * @param studentId * @return */ AppointExecution appoint(long bookId, long studentId); }

在 service.impl 包下新建 BookServiceImpl.java 使用 BookService 接口，并实现里面的方法。
  • BookServiceImpl.java
/** * @author wangshiyu rodert * @date 2020/7/7 16:39 * @description */ package javapub.rodert.github.service.impl; import javapub.rodert.github.dao.AppointmentDao; import javapub.rodert.github.dao.BookDao; import javapub.rodert.github.dto.AppointExecution; import javapub.rodert.github.entity.Appointment; import javapub.rodert.github.entity.Book; import javapub.rodert.github.enums.AppointStateEnum; import javapub.rodert.github.exception.AppointException; import javapub.rodert.github.exception.NoNumberException; import javapub.rodert.github.exception.RepeatAppointException; import javapub.rodert.github.service.BookService; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Transactional; import java.util.List; @Service public class BookServiceImpl implements BookService {private Logger logger = LoggerFactory.getLogger(this.getClass()); // 注入Service依赖 @Autowired private BookDao bookDao; @Autowired private AppointmentDao appointmentDao; @Override public Book getById(long bookId) { return bookDao.queryById(bookId); }@Override public List< Book> getList() { return bookDao.queryAll(0, 1000); }@Override @Transactional /** * 使用注解控制事务方法的优点： * 1.开发团队达成一致约定，明确标注事务方法的编程风格 * 2.保证事务方法的执行时间尽可能短，不要穿插其他网络操作，RPC/HTTP请求或者剥离到事务方法外部 * 3.不是所有的方法都需要事务，如只有一条修改操作，只读操作不需要事务控制 */ public AppointExecution appoint(long bookId, long studentId) { try { // 减库存 int update = bookDao.reduceNumber(bookId); if (update < = 0) {// 库存不足 //return new AppointExecution(bookId, AppointStateEnum.NO_NUMBER); //错误写法 throw new NoNumberException("no number"); // 抛出异常，保证触发事务执行 } else { // 执行预约操作 int insert = appointmentDao.insertAppointment(bookId, studentId); if (insert < = 0) {// 重复预约 //return new AppointExecution(bookId, AppointStateEnum.REPEAT_APPOINT); //错误写法 throw new RepeatAppointException("repeat appoint"); } else {// 预约成功 Appointment appointment = appointmentDao.queryByKeyWithBook(bookId, studentId); return new AppointExecution(bookId, AppointStateEnum.SUCCESS, appointment); } } // 要先于catch Exception异常前先catch住再抛出，不然自定义的异常也会被转换为AppointException，导致控制层无法具体识别是哪个异常 } catch (NoNumberException | RepeatAppointException e1) { throw e1; } catch (Exception e) { logger.error(e.getMessage(), e); // 所有编译期异常转换为运行期异常 //return new AppointExecution(bookId, AppointStateEnum.INNER_ERROR); //错误写法 throw new AppointException("appoint inner error:" + e.getMessage()); } }}

实现类使用了我们上边定义的异常方法 RepeatAppointException ，用于业务层非成功情况下的返回（即成功返回结果，失败抛出异常）。触发事务。
测试一下业务层代码，这里演示预约图书业务。
  • BookServiceImplTest.java
/** * @author wangshiyu rodert * @date 2020/7/7 16:40 * @description */ package javapub.rodert.github.service.impl; import javapub.rodert.github.BaseTest; import javapub.rodert.github.dto.AppointExecution; import javapub.rodert.github.service.BookService; import org.junit.Test; import org.springframework.beans.factory.annotation.Autowired; public class BookServiceImplTest extends BaseTest {@Autowired private BookService bookService; @Test public void testAppoint() throws Exception { long bookId = 1001; long studentId = 12345678910L; AppointExecution execution = bookService.appoint(bookId, studentId); System.out.println(execution); }}

测试结果：
手把手整合SSM框架#yyds干货盘点#

文章图片

首次执行是“预约成功”，如果再次执行的话，应该会出现“重复预约”，至此，我们所有的后台代码都通过单元测试啦~~ 是不是很开心~
咱们还需要在dto包里新建一个封装json返回结果的类Result.java，设计成泛型。
  • Result.java
package javapub.rodert.github.dto; /** * @author wangshiyu rodert * @date 2020/7/7 21:00 * @description */import lombok.Data; /** * 封装json对象，所有返回结果都使用它 */ @Data public class Result< T> {private boolean success; // 是否成功标志private T data; // 成功时返回的数据private String error; // 错误信息public Result() { }// 成功时的构造器 public Result(boolean success, T data) { this.success = success; this.data = https://www.songbingjia.com/android/data; }// 错误时的构造器 public Result(boolean success, String error) { this.success = success; this.error = error; }// 省略getter和setter方法 使用注解代替 }

web层web 层，也就是 controller 层，我们在web包下新建BookController.java文件。
  • BookController.java
package javapub.rodert.github.web; /** * @author wangshiyu rodert * @date 2020/7/7 21:05 * @description */import javapub.rodert.github.dto.AppointExecution; import javapub.rodert.github.dto.Result; import javapub.rodert.github.entity.Book; import javapub.rodert.github.enums.AppointStateEnum; import javapub.rodert.github.exception.NoNumberException; import javapub.rodert.github.exception.RepeatAppointException; import javapub.rodert.github.service.BookService; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.*; import org.springframework.web.servlet.ModelAndView; import java.util.List; @RestController @RequestMapping("/book") // url:/模块/资源/{id}/细分 /seckill/list public class BookController {private Logger logger = LoggerFactory.getLogger(this.getClass()); @Autowired private BookService bookService; @RequestMapping(value = "https://www.songbingjia.com/test") public ModelAndView test(){ ModelAndView modelAndView = new ModelAndView(); modelAndView.setViewName("book/test"); modelAndView.addObject("key","welcome javaPub"); return modelAndView; }@RequestMapping(value = "https://www.songbingjia.com/list", method = RequestMethod.GET) private String list(Model model) { List< Book> list = bookService.getList(); model.addAttribute("list", list); // list.jsp + model = ModelAndView return "list"; // WEB-INF/jsp/"list".jsp }@RequestMapping(value = "https://www.songbingjia.com/{bookId}/detail", method = RequestMethod.GET) private String detail(@PathVariable("bookId") Long bookId, Model model) { if (bookId == null) { return "redirect:/book/list"; } Book book = bookService.getById(bookId); if (book == null) { return "forward:/book/list"; } model.addAttribute("book", book); return "detail"; }//ajax json //method = RequestMethod.POST, @RequestMapping(value = "https://www.songbingjia.com/{bookId}/appoint",produces = { "application/json; charset=utf-8" }) @ResponseBody private Result< AppointExecution> appoint(@PathVariable("bookId") Long bookId, @RequestParam("studentId") Long studentId) { if (studentId == null || studentId.equals("")) { return new Result< > (false, "学号不能为空"); } //AppointExecution execution = bookService.appoint(bookId, studentId); //错误写法，不能统一返回，要处理异常（失败）情况 AppointExecution execution = null; try { execution = bookService.appoint(bookId, studentId); } catch (NoNumberException e1) { execution = new AppointExecution(bookId, AppointStateEnum.NO_NUMBER); } catch (RepeatAppointException e2) { execution = new AppointExecution(bookId, AppointStateEnum.REPEAT_APPOINT); } catch (Exception e) { execution = new AppointExecution(bookId, AppointStateEnum.INNER_ERROR); } return new Result< AppointExecution> (true, execution); }}

目前大多项目都是前后端分离，我们作为服务端，一般和前端通过接口数据交互（json），像接口方法 appoint ，应该添加 @ResponseBody 注解。
测试 controller --> appoint 方法可以通过 curl ，如：
运行项目现在整个项目全部完成，配置tomcat，通过左上角引入 tomcat ，选择我们的项目 ssm。
手把手整合SSM框架#yyds干货盘点#

文章图片

启动成功后：
手把手整合SSM框架#yyds干货盘点#

文章图片

这里对前端代码只写较少部分，具体可参考 BookController --> book/test 接口，有需要帮助请留言。
  • BookController.java --> book/test
@RequestMapping(value = "https://www.songbingjia.com/test") public ModelAndView test(){ ModelAndView modelAndView = new ModelAndView(); modelAndView.setViewName("book/test"); modelAndView.addObject("key","welcome javaPub"); return modelAndView; }

  • test.jsp
< %@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> < !DOCTYPE HTML> < html> < head> < %@ page isELIgnored="false"%> < meta charset="UTF-8"> < meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0,maximum-scale=1.0,user-scalable=no"/> < title> news detail< /title> < /head> < body class="fn-pd24"> 大家好 ${key}< a rel="nofollow" href="https://mp.weixin.qq.com/s/kfyRAPnRDp8LLktjgd658Q"> JavaPub知识清单< /a> < /body> < /html>

通过 ModelAndView 将我们需要渲染的数据存储传输到对应视图，由 Sping MVC 定义好的视图解析器对该对象解析，最后将结果数据显示到指定页面。
【手把手整合SSM框架#yyds干货盘点#】
手把手整合SSM框架#yyds干货盘点#

文章图片

完整代码地址：https://github.com/Rodert/JavaPub/
(文末公众号回复：【github】，更多Java技术栈资源)
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