手把手整合SSM框架
前言
如果看过前几篇文章,对
Spring
和MyBatis
有了一定了解,一定想上手试试。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
文章目录
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 都可以找到
目录
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。
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。
- 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:${url} -->
<context:property-placeholder location="classpath:jdbc.properties" />
<!-- 2.数据库连接池 -->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<!-- 配置连接池属性 -->
<property name="driverClass" value="${jdbc.driver}" />
<property name="jdbcUrl" value="${jdbc.url}" />
<property name="user" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
<!-- c3p0连接池的私有属性 -->
<property name="maxPoolSize" value="30" />
<property name="minPoolSize" value="10" />
<!-- 关闭连接后不自动commit -->
<property name="autoCommitOnClose" value="false" />
<!-- 获取连接超时时间 -->
<property name="checkoutTimeout" value="10000" />
<!-- 当获取连接失败重试次数 -->
<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 使用别名 -->
<property name="typeAliasesPackage" value="javapub.rodert.github.entity" />
<!-- 扫描sql配置文件:mapper需要的xml文件 -->
<property name="mapperLocations" value="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="sqlSessionFactory" />
<!-- 给出需要扫描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,注意自己的密码。
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssm1?useUnicode=true&characterEncoding=utf8
jdbc.username=root
jdbc.password=
mybatis-config.xml
MyBatis
核心文件,在recources文件夹里新建mybatis-config.xml文件。
- 使用自增主键
- 使用列别名
- 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>
<!-- 使用jdbc的getGeneratedKeys获取数据库自增主键值 -->
<setting name="useGeneratedKeys" value="true" />
<!-- 使用列别名替换列名 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 来完成
- 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.xml
web 层,在 spring 文件夹里新建 spring-web.xml
文件。
- 开启SpringMVC注解模式,可以使用@RequestMapping,@PathVariable,@ResponseBody等
- 对静态资源处理,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)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="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:
SSM实例-图书管理系统
sql
以上部分整个 SSM 框架就已经搭建好了,下面是一个 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 Transfer
Source Server : localhost
Source Server Version : 50716
Source Host : localhost:3306
Source Database : ssm1
Target Server Type : MYSQL
Target Server Version : 50716
File Encoding : 65001
Date: 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ID
private 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ID
private 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*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()
测试方法都验证过,没有问题,不一一测试了
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:
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 = 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 = "/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);//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:
curl -H “Accept: application/json; charset=utf-8” -d “studentId=1234567890” localhost:8080/book/1003/appoint
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。
启动成功后:
这里对前端代码只写较少部分,具体可参考 BookController
--> book/test
接口,有需要帮助请留言。
- 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。
完整代码地址:https://github.com/Rodert/JavaPub/code/ssm_helloworld_web/
最后:知识点总结
文章底部都有对应原创PDF,持续更新中,
教程纯手打,致力于最实用教程,微信搜:JavaPub
,无套路领取免费原创 PDF 、学习路线图,后台回复【666】。
- 51页MyBatis
- 19页Maven
- 14页zookeeper
- 10页Git
- 18页spring
- 8页布隆过滤器
- 50页排序算法
- redis系列文章
- dubbo
- nginx
- ffmpeg
- Jenkins
- http
- …
觉得文章内容不错,记得点赞或在看都行,这是对我最大的鼓励!
推荐阅读
-
Spring集成redis(SSM框架) 博客分类: spring
-
SSH整合 Spring Struts Hibernate三大框架 博客分类: Sping springstrutshibernate框架ssh
-
Spring集成redis(SSM框架) 博客分类: spring
-
一步步教你整合SSM框架(Spring MVC+Spring+MyBatis)详细教程
-
SSM框架——详细整合教程(Spring+SpringMVC+MyBatis)
-
【Spring框架家族】SpringBoot整合第三方
-
手把手编写自己的 PHP MVC 框架实例教程 mvc php 案例 php mvc教程 php mvc开发实
-
CI框架整合smarty步骤详解_php实例
-
SpringBoot2 整合ElasticJob框架,定制化管理流程
-
ASP.NET Core应用中与第三方IoC/DI框架的整合