一步步教你整合SSM框架（Spring MVC+Spring+MyBatis）详细教程

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemalocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
 <modelversion>4.0.0</modelversion>
 <groupid>com.soecode.ssm</groupid>
 ssm</artifactid>
 <packaging>war</packaging>
 <version>0.0.1-SNAPSHOT</version>
 <name>ssm Maven Webapp</name>
 <url>http://github.com/liyifeng1994/ssm</url>
 <dependencies>
 <!-- 单元测试 -->
 <dependency>
 <groupid>junit</groupid>
 junit</artifactid>
 <version>4.11</version>
 </dependency>
 
 <!-- 1.日志 -->
 <!-- 实现slf4j接口并整合 -->
 <dependency>
 <groupid>ch.qos.logback</groupid>
 logback-classic</artifactid>
 <version>1.1.1</version>
 </dependency>
 
 <!-- 2.数据库 -->
 <dependency>
 <groupid>mysql</groupid>
 mysql-connector-java</artifactid>
 <version>5.1.37</version>
 <scope>runtime</scope>
 </dependency>
 <dependency>
 <groupid>c3p0</groupid>
 c3p0</artifactid>
 <version>0.9.1.2</version>
 </dependency>
 
 <!-- DAO: MyBatis -->
 <dependency>
 <groupid>org.mybatis</groupid>
 mybatis</artifactid>
 <version>3.3.0</version>
 </dependency>
 <dependency>
 <groupid>org.mybatis</groupid>
 mybatis-spring</artifactid>
 <version>1.2.3</version>
 </dependency>
 
 <!-- 3.Servlet web -->
 <dependency>
 <groupid>taglibs</groupid>
 standard</artifactid>
 <version>1.1.2</version>
 </dependency>
 <dependency>
 <groupid>jstl</groupid>
 jstl</artifactid>
 <version>1.2</version>
 </dependency>
 <dependency>
 <groupid>com.fasterxml.jackson.core</groupid>
 jackson-databind</artifactid>
 <version>2.5.4</version>
 </dependency>
 <dependency>
 <groupid>javax.servlet</groupid>
 javax.servlet-api</artifactid>
 <version>3.1.0</version>
 </dependency>
 
 <!-- 4.Spring -->
 <!-- 1)Spring核心 -->
 <dependency>
 <groupid>org.springframework</groupid>
 spring-core</artifactid>
 <version>4.1.7.RELEASE</version>
 </dependency>
 <dependency>
 <groupid>org.springframework</groupid>
 spring-beans</artifactid>
 <version>4.1.7.RELEASE</version>
 </dependency>
 <dependency>
 <groupid>org.springframework</groupid>
 spring-context</artifactid>
 <version>4.1.7.RELEASE</version>
 </dependency>
 <!-- 2)Spring DAO层 -->
 <dependency>
 <groupid>org.springframework</groupid>
 spring-jdbc</artifactid>
 <version>4.1.7.RELEASE</version>
 </dependency>
 <dependency>
 <groupid>org.springframework</groupid>
 spring-tx</artifactid>
 <version>4.1.7.RELEASE</version>
 </dependency>
 <!-- 3)Spring web -->
 <dependency>
 <groupid>org.springframework</groupid>
 spring-web</artifactid>
 <version>4.1.7.RELEASE</version>
 </dependency>
 <dependency>
 <groupid>org.springframework</groupid>
 spring-webmvc</artifactid>
 <version>4.1.7.RELEASE</version>
 </dependency>
 <!-- 4)Spring test -->
 <dependency>
 <groupid>org.springframework</groupid>
 spring-test</artifactid>
 <version>4.1.7.RELEASE</version>
 </dependency>
 
 <!-- redis客户端:Jedis -->
 <dependency>
 <groupid>redis.clients</groupid>
 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>
 </dependencies>
 <build>
 <finalname>ssm</finalname>
 </build>
</project>

<?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="com.soecode.lyf.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="com.soecode.lyf.dao" />
 </bean>
</beans>

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3307/ssm?useUnicode=true&characterEncoding=utf8
jdbc.username=root
jdbc.password=

<?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>

<?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="com.soecode.lyf.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>

<?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="prefix" value="/WEB-INF/jsp/" />
 <property name="suffix" value=".jsp" />
 </bean>

 <!-- 4.扫描web相关的bean -->
 <context:component-scan base-package="com.soecode.lyf.web" />
</beans>

<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>seckill-dispatcher</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>
 </servlet>
 <servlet-mapping>
 <servlet-name>seckill-dispatcher</servlet-name>
 <!-- 默认匹配所有的请求 -->
 <url-pattern>/</url-pattern>
 </servlet-mapping>
</web-app>

<?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>

-- 创建图书表
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=1000 DEFAULT CHARSET=utf8 COMMENT='图书表'

-- 初始化图书数据
INSERT INTO `book` (`book_id`, `name`, `number`)
VALUES
 (1000, 'Java程序设计', 10),
 (1001, '数据结构', 10),
 (1002, '设计模式', 10),
 (1003, '编译原理', 10)

-- 创建预约图书表
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`),
 INDEX `idx_appoint_time` (`appoint_time`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='预约图书表'

package com.soecode.lyf.entity;

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

}

package com.soecode.lyf.entity;

import java.util.Date;

/**
 * 预约图书实体
 */
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

}

package com.soecode.lyf.dao;

import java.util.List;

import com.soecode.lyf.entity.Book;

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);
}

package com.soecode.lyf.dao;

import org.apache.ibatis.annotations.Param;

import com.soecode.lyf.entity.Appointment;

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);

}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
 PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
 "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.soecode.lyf.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>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
 PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
 "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.soecode.lyf.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>

package com.soecode.lyf;

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 {

}

package com.soecode.lyf.dao;

import java.util.List;

import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;

import com.soecode.lyf.BaseTest;
import com.soecode.lyf.entity.Book;

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);
 }

}

package com.soecode.lyf.dao;

import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;

import com.soecode.lyf.BaseTest;
import com.soecode.lyf.entity.Appointment;

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());
 }

}

package com.soecode.lyf.enums;

/**
 * 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;
 }

}

package com.soecode.lyf.dto;

import com.soecode.lyf.entity.Appointment;
import com.soecode.lyf.enums.AppointStateEnum;

/**
 * 封装预约执行后结果
 */
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

}

package com.soecode.lyf.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);
 }

}

package com.soecode.lyf.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);
 }

}

package com.soecode.lyf.exception;

/**
 * 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);
 }

}

package com.soecode.lyf.service;

import java.util.List;

import com.soecode.lyf.dto.AppointExecution;
import com.soecode.lyf.entity.Book;

/**
 * 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);

}

package com.soecode.lyf.service.impl;

import java.util.List;

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 com.soecode.lyf.dao.AppointmentDao;
import com.soecode.lyf.dao.BookDao;
import com.soecode.lyf.dto.AppointExecution;
import com.soecode.lyf.entity.Appointment;
import com.soecode.lyf.entity.Book;
import com.soecode.lyf.enums.AppointStateEnum;
import com.soecode.lyf.exception.AppointException;
import com.soecode.lyf.exception.NoNumberException;
import com.soecode.lyf.exception.RepeatAppointException;
import com.soecode.lyf.service.BookService;

@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");
 } 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 e1) {
 throw e1;
 } catch (RepeatAppointException e2) {
 throw e2;
 } 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());
 }
 }

}

package com.soecode.lyf.service.impl;

import static org.junit.Assert.fail;

import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;

import com.soecode.lyf.BaseTest;
import com.soecode.lyf.dto.AppointExecution;
import com.soecode.lyf.service.BookService;

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);
 }

}

package com.soecode.lyf.dto;

/**
 * 封装json对象，所有返回结果都使用它
 */
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
}

package com.soecode.lyf.web;

import java.util.List;

import org.apache.ibatis.annotations.Param;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

import com.soecode.lyf.dto.AppointExecution;
import com.soecode.lyf.dto.Result;
import com.soecode.lyf.entity.Book;
import com.soecode.lyf.enums.AppointStateEnum;
import com.soecode.lyf.exception.NoNumberException;
import com.soecode.lyf.exception.RepeatAppointException;
import com.soecode.lyf.service.BookService;

@Controller
@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 = "/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
 @RequestMapping(value = "/{bookId}/appoint", method = RequestMethod.POST, 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);
 }

}