手把手整合SSM框架

前言

如果看过前几篇文章，对 Spring 和 MyBatis 有了肯定理解，肯定想上手试试。这篇文章从 0 到 1，手把手整合 SSM (Spring、Spring MVC、MyBatis)。

本篇是代码篇，在 PC 端浏览更佳，源码在文末

[toc]

搭建整合 SSM 之 HelloWorld

开发环境

idea
MySql5.x
jdk8
maven

对应的技术入门在公众号 历史文章 都能够找到

环境搭建

新建我的项目

这里应用的是 IDEA 编辑器，新建一个 Maven 工程，抉择 web 我的项目。

导入依赖

应用 Maven 治理我的项目 jar ，只须要在 pom.xml 加如相干依赖即可。

<?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外围 -->        <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，咱们这里分三层，别离是dao service web。

加载数据库配置
配置数据库连接池
配置 SqlSessionFactory 对象（MyBatis）
配置扫描 dao 层接口，动静代理实现 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.配置数据库相干参数properties的属性：${url} -->    <context:property-placeholder location="classpath:jdbc.properties" />    <!-- 2.数据库连接池 -->    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">        <!-- 配置连接池属性 -->        <property name="driverClass" value="${jdbc.driver}" />        <property name="jdbcUrl" value="${jdbc.url}" />        <property name="user" value="${jdbc.username}" />        <property name="password" value="${jdbc.password}" />        <!-- c3p0连接池的公有属性 -->        <property name="maxPoolSize" value="30" />        <property name="minPoolSize" value="10" />        <!-- 敞开连贯后不主动commit -->        <property name="autoCommitOnClose" value="false" />        <!-- 获取连贯超时工夫 -->        <property name="checkoutTimeout" value="10000" />        <!-- 当获取连贯失败重试次数 -->        <property name="acquireRetryAttempts" value="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="classpath:Mybatis-config.xml" />        <!-- 扫描entity包 应用别名 -->        <property name="typeAliasesPackage" value="javapub.rodert.github.entity" />        <!-- 扫描sql配置文件:mapper须要的xml文件 -->        <property name="mapperLocations" value="classpath:mapper/*.xml" />    </bean>    <!-- 4.配置扫描Dao接口包，动静实现Dao接口，注入到spring容器中 -->    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">        <!-- 注入sqlSessionFactory -->        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />        <!-- 给出须要扫描Dao接口包 -->        <property name="basePackage" value="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，留神本人的明码。

jdbc.driver=com.mysql.jdbc.Driverjdbc.url=jdbc:mysql://localhost:3306/ssm1?useUnicode=true&characterEncoding=utf8jdbc.username=rootjdbc.password=

mybatis-config.xml

MyBatis 外围文件，在recources文件夹里新建mybatis-config.xml文件。

应用自增主键
应用列别名
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>        <!-- 应用jdbc的getGeneratedKeys获取数据库自增主键值 -->        <setting name="useGeneratedKeys" value="true" />        <!-- 应用列别名替换列名 默认:true -->        <setting name="useColumnLabel" value="true" />        <!-- 开启驼峰命名转换:Table{create_time} -> Entity{createTime} -->        <setting name="mapUnderscoreToCamelCase" value="true" />    </settings></configuration>

spring-service.xml

在 spring 文件夹里新建 spring-service.xml 文件。

扫描 service 包所有注解 @Service
配置事务管理器，把事务管理交由 spring 来实现
基于注解的申明式事务，能够间接在办法上 @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包下所有应用注解的类型 -->    <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>    <!-- 配置基于注解的申明式事务 -->    <tx:annotation-driven transaction-manager="transactionManager" /></beans>

spring-web.xml

web 层，在 spring 文件夹里新建 spring-web.xml 文件。

开启SpringMVC注解模式，能够应用@RequestMapping，@PathVariable，@ResponseBody等
对动态资源解决，如js，css，jpg等
配置jsp 显示ViewResolver，及渲染后的 JSP
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)主动注册DefaultAnootationHandlerMapping,AnotationMethodHandlerAdapter        (2)提供一些列：数据绑定，数字和日期的format @NumberFormat, @DateTimeFormat, xml,json默认读写反对    -->    <mvc:annotation-driven />    <!-- 2.动态资源默认servlet配置        (1)退出对动态资源的解决：js,gif,png        (2)容许应用"/"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="org.springframework.web.servlet.view.JstlView" /><!--        <property name="contentType" value="text/html"/>-->        <property name="prefix" value="/WEB-INF/jsp/" />        <property name="suffix" value=".jsp" />    </bean>    <!-- 4.扫描web相干的bean -->    <context:component-scan base-package="javapub.rodert.github.web" /></beans>

web.xml

批改 web.xml 文件了，它在 webapp 的 WEB-INF 下。也能够在这里配置过滤器、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，须要批改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须要加载的配置文件        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>    <!-- 默认匹配所有的申请 -->    <url-pattern>/</url-pattern>  </servlet-mapping>  <welcome-file-list>    <welcome-file>index.jsp</welcome-file>  </welcome-file-list></web-app>

日志

配置一些简略的日志，应用 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>

配置阐明

以上配置是整合 SSM 的根底配置，目录构造如图所示：

SSM实例-图书管理系统

sql

以上局部整个 SSM 框架就曾经搭建好了，上面是一个 Demo ，供参考。

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         : localhostSource Server Version : 50716Source Host           : localhost:3306Source Database       : ssm1Target Server Type    : MYSQLTarget Server Version : 50716File 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 '预约工夫',  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，主动增加get set toSting 办法 * @Getter * @Setter * @ToString */@Getter@Setter@ToStringpublic class Book {    private long bookId;// 图书ID    private String name;// 图书名称    private int number;// 馆藏数量    // 省略构造方法，getter和setter办法，toString办法}

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，主动增加get set toSting 办法 */@Datapublic class Appointment {    private long bookId;// 图书ID    private long studentId;// 学号    private Date appointTime;// 预约工夫    // 多对一的复合属性    private Book book;// 图书实体    // 省略构造方法，getter和setter办法，toString办法}

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查问单本图书     *     * @param id     * @return     */    Book queryById(long id);    /**     * 查问所有图书     *     * @param offset 查问起始地位     * @param limit 查问条数     * @return     */    List<Book> queryAll(@Param("offset") int offset, @Param("limit") int limit);    /**     * 缩小馆藏数量     *     * @param bookId     * @return 如果影响行数等于>1，示意更新的记录行数     */    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);    /**     * 通过主键查问预约图书记录，并且携带图书实体     *     * @param bookId     * @param studentId     * @return     */    Appointment queryByKeyWithBook(@Param("bookId") long bookId, @Param("studentId") long studentId);}

提醒：这里为什么要给办法的参数增加 @Param注解呢？是因为该办法有两个或以上的参数，肯定要加，不然 mybatis 辨认不了。下面的 BookDao 接口的 queryById 办法和 reduceNumber 办法只有一个参数 book_id ，所以能够不必加 @Param 注解。

dao接口xml

这里不须要写 dao接口 的实现类，mybatis会帮咱们动静实现，下面咱们曾经在 spring-dao.xml 配置了动静扫描。当初须要编写相应的 mapper。
在 mapper 目录里新建两个文件 BookDao.xml 和 AppointmentDao.xml ，别离对应下面两个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">    <!-- 目标：为dao接口办法提供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 主键抵触，报错 -->        INSERT ignore INTO appointment (book_id, student_id)        VALUES (#{bookId}, #{studentId})    </insert>    <select id="queryByKeyWithBook" resultType="Appointment">        <!-- 如何通知MyBatis把后果映射到Appointment同时映射book属性 -->        <!-- 能够自在管制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 阐明：namespace 是 xml 对应的接口全名，select 和 update 中的 id 对应办法名（惟一），resultType 是返回值类型，parameterType 是参数类型（这个其实可选），#{...} 中填写的是办法的参数

dao接口测试

当初的写法是从数据库层向前（web）写，当初测试一下 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)// 通知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()

测试方法都验证过，没有问题，不一一测试了

业务层-后果集封装

到这里，咱们的 dao 层，及数据库接口操作都没有问题，上面开始业务层编写。

如果你有实战我的项目教训，那肯定会发现，对于后端接口，咱们都会定义一个对立的返回格局，及定义一个返回规范不便前端解析，如下：

{    "code":200,    "message":"胜利",    "result":{},    "isSuccess":true}

开始写咱们的代码，新建枚举类，用来定义预约业务的数据字典。如果不太明确，先看代码，前面在 JavaPub 微信公众号文章索引中查找对应文章。

新建一个包叫 enums，在外面新建一个枚举类 AppointStateEnum.java。

AppointStateEnum.java

package javapub.rodert.github.enums;/** * @author wangshiyu rodert * @date 2020/7/6 21:20 * @description *//** * 应用枚举表述常量数据字典 */public enum AppointStateEnum {    SUCCESS(1, "预约胜利"), NO_NUMBER(0, "库存有余"), REPEAT_APPOINT(-1, "反复预约"), INNER_ERROR(-2, "零碎异样");    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 用来存储咱们执行预约操作的返回后果。

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;/** * 封装预约执行后后果 */@Datapublic class AppointExecution {    // 图书ID    private long bookId;    // 秒杀预约后果状态    private int state;    // 状态标识    private String stateInfo;    // 预约胜利对象    private Appointment appointment;    public AppointExecution() {    }    // 预约失败的结构器    public AppointExecution(long bookId, AppointStateEnum stateEnum) {        this.bookId = bookId;        this.state = stateEnum.getState();        this.stateInfo = stateEnum.getStateInfo();    }    // 预约胜利的结构器    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办法，toString办法}

在 exception 包下新建三个文件

NoNumberException.java
RepeatAppointException.java
AppointException.java

预约业务异样类（都须要继承 RuntimeException ---运行时异样类），别离是无库存异样、反复预约异样、预约未知谬误异样，用于业务层非胜利状况下的返回（即胜利返回后果，失败抛出异样）。为事务做筹备。

AppointException.java

package javapub.rodert.github.exception;/** * @author wangshiyu rodert * @date 2020/7/7 16:31 * @description *//** * 预约业务异样 */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;/** * 库存有余异样 */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;/** * 反复预约异样 */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：办法定义粒度，参数，返回类型（return 类型/异样） */public interface BookService {    /**     * 查问一本图书     *     * @param bookId     * @return     */    Book getById(long bookId);    /**     * 查问所有图书     *     * @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 应用 BookService 接口，并实现外面的办法。

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;@Servicepublic 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    /**     * 应用注解管制事务办法的长处：     * 1.开发团队达成统一约定，明确标注事务办法的编程格调     * 2.保障事务办法的执行工夫尽可能短，不要交叉其余网络操作，RPC/HTTP申请或者剥离到事务办法内部     * 3.不是所有的办法都须要事务，如只有一条批改操作，只读操作不须要事务管制     */    public AppointExecution appoint(long bookId, long studentId) {        try {            // 减库存            int update = bookDao.reduceNumber(bookId);            if (update <= 0) {// 库存有余                //return new AppointExecution(bookId, AppointStateEnum.NO_NUMBER);//谬误写法                throw new NoNumberException("no number");// 抛出异样，保障触发事务执行            } else {                // 执行预约操作                int insert = appointmentDao.insertAppointment(bookId, studentId);                if (insert <= 0) {// 反复预约                    //return new AppointExecution(bookId, AppointStateEnum.REPEAT_APPOINT);//谬误写法                    throw new RepeatAppointException("repeat appoint");                } else {// 预约胜利                    Appointment appointment = appointmentDao.queryByKeyWithBook(bookId, studentId);                    return new AppointExecution(bookId, AppointStateEnum.SUCCESS, appointment);                }            }            // 要先于catch Exception异样前先catch住再抛出，不然自定义的异样也会被转换为AppointException，导致管制层无奈具体辨认是哪个异样        } catch (NoNumberException | RepeatAppointException e1) {            throw e1;        } catch (Exception e) {            logger.error(e.getMessage(), e);            // 所有编译期异样转换为运行期异样            //return new AppointExecution(bookId, AppointStateEnum.INNER_ERROR);//谬误写法            throw new AppointException("appoint inner error:" + e.getMessage());        }    }}

实现类应用了咱们上边定义的异样办法 RepeatAppointException ，用于业务层非胜利状况下的返回（即胜利返回后果，失败抛出异样）。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);    }}

测试后果：

首次执行是“预约胜利”，如果再次执行的话，应该会呈现“反复预约”，至此，咱们所有的后盾代码都通过单元测试啦~~ 是不是很开心~

咱们还须要在dto包里新建一个封装json返回后果的类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，所有返回后果都应用它 */@Datapublic class Result<T> {    private boolean success;// 是否胜利标记    private T data;// 胜利时返回的数据    private String error;// 错误信息    public Result() {    }    // 胜利时的结构器    public Result(boolean success, T data) {        this.success = success;        this.data = data;    }    // 谬误时的结构器    public Result(boolean success, String error) {        this.success = success;        this.error = error;    }    // 省略getter和setter办法 应用注解代替}

web层

web 层，也就是 controller 层，咱们在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/listpublic class BookController {    private Logger logger = LoggerFactory.getLogger(this.getClass());    @Autowired    private BookService bookService;    @RequestMapping(value = "/test")    public ModelAndView test(){        ModelAndView modelAndView = new ModelAndView();        modelAndView.setViewName("book/test");        modelAndView.addObject("key","welcome javaPub");        return modelAndView;    }    @RequestMapping(value = "/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 = "/{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 = "/{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);//谬误写法，不能对立返回，要解决异样（失败）状况        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);    }}

目前大多我的项目都是前后端拆散，咱们作为服务端，个别和前端通过接口数据交互（json），像接口办法 appoint ，应该增加 @ResponseBody 注解。
测试 controller --> appoint 办法能够通过 curl ，如：

curl -H “Accept: application/json; charset=utf-8” -d “studentId=1234567890” localhost:8080/book/1003/appoint

运行我的项目

当初整个我的项目全副实现，配置tomcat，通过左上角引入 tomcat ，抉择咱们的我的项目 ssm。

启动胜利后：

这里对前端代码只写较少部分，具体可参考 BookController --> book/test 接口，有须要帮忙请留言。

BookController.java --> book/test

    @RequestMapping(value = "/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"><h1>大家好 ${key}</h1><a href="https://mp.weixin.qq.com/s/kfyRAPnRDp8LLktjgd658Q">JavaPub常识清单</a></body></html>

通过 ModelAndView 将咱们须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，最初将后果数据显示到指定页面。

残缺代码地址：https://github.com/Rodert/Jav...

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