文章所用例子参考相关课程。

使用IDEA创建一个maven的webapp项目，建好相应的项目结构。

• main

  • java：java源码

    • com.dct.seckillDemo：包名，一般为groupId+artifactId

      • dao：Data Access Object，数据访问对象，主要数据库操作相关方法。
      • dto：主要是自定义的pojo，用于service层与web层之间的数据传输
      • entity：实体包，是简单的java对象（pojo），与数据库中的表对应。
      • service：主要的业务逻辑层
      • web：即控制器层，接受请求并调用服务，返回数据和视图。

  • resources

    • mapper：与mybatis数据库操作相关的xml文件
    • spring：spring相关配置文件

  • webapp

    • resources：项目的静态资源，如js css images等。
    • WEB-INF：外部浏览器无法访问，只有内部才能访问

• test

  • java:java测试相关代码
  • resources：测试所需资源文件

然后导入项目依赖的jar包

pom.xml

      
     
      4.0.0
       
     
      com.dct
       
     
      seckillDemo
       
     
      war
       
     
      1.0-SNAPSHOT
       
     
      seckillDemo Maven Webapp
       
     
      http://maven.apache.org
       
         
            
       
        junit
             
       
        junit
             
       
        4.11
             
       
        test
           
          
          
          
            
       
        org.slf4j
             
       
        slf4j-api
             
       
        1.7.12
           
          
            
       
        ch.qos.logback
             
       
        logback-core
             
       
        1.1.1
           
          
          
            
       
        ch.qos.logback
             
       
        logback-classic
             
       
        1.1.1
           
          
          
            
       
        mysql
             
       
        mysql-connector-java
             
       
        5.1.35
             
       
        runtime
           
          
            
       
        c3p0
             
       
        c3p0
             
       
        0.9.1.2
           
          
          
            
       
        org.mybatis
             
       
        mybatis
             
       
        3.3.0
           
          
          
            
       
        org.mybatis
             
       
        mybatis-spring
             
       
        1.2.3
           
          
          
            
       
        taglibs
             
       
        standard
             
       
        1.1.2
           
          
            
       
        jstl
             
       
        jstl
             
       
        1.2
           
          
            
       
        com.fasterxml.jackson.core
             
       
        jackson-databind
             
       
        2.5.4
           
          
            
       
        javax.servlet
             
       
        javax.servlet-api
             
       
        3.1.0
           
          
          
          
            
       
        org.springframework
             
       
        spring-core
             
       
        4.1.7.RELEASE
           
          
            
       
        org.springframework
             
       
        spring-beans
             
       
        4.1.7.RELEASE
           
          
            
       
        org.springframework
             
       
        spring-context
             
       
        4.1.7.RELEASE
           
          
          
            
       
        org.springframework
             
       
        spring-jdbc
             
       
        4.1.7.RELEASE
           
          
            
       
        org.springframework
             
       
        spring-tx
             
       
        4.1.7.RELEASE
           
          
          
            
       
        org.springframework
             
       
        spring-web
             
       
        4.1.7.RELEASE
           
          
            
       
        org.springframework
             
       
        spring-webmvc
             
       
        4.1.7.RELEASE
           
          
          
            
       
        org.springframework
             
       
        spring-test
             
       
        4.1.7.RELEASE
           
        
       
         
      
       seckillDemo
        
     
    

下面开始进行整合SSM，首进行mybatis和spring的整合。

在resources下新建jdbc.properties和mybatis-config.xml文件。

jdbc.properties（数据库连接相关参数）

jdbc.driver=com.mysql.jdbc.Driverjdbc.url=jdbc:mysql://localhost:3306/seckill?useUnicode=true&characterEncoding=utf-8jdbc.username=rootjdbc.password=root

mybatis-config.xml（mybatis全局属性的配置）

然后在spring包下新建spring-dao.xml文件，进行spring和mybatis的整合配置。

spring-dao.xml

在spring包下新建spring-service.xml文件，配置service层。

spring-service.xml

在spring包下新建spring-web.xml文件，配置控制器层。

spring-web.xml

配置web.xml文件

web.xml

      
       
       
         
      
       seckill-dispatcher
          
      
       org.springframework.web.servlet.DispatcherServlet
          
          
            
       
        contextConfigLocation
             
       
        classpath:spring/spring-*.xml
           
        
       
         
      
       seckill-dispatcher
          
          
      
       /
        
       
       
         
      
       字符集过滤器
          
      
       encodingFilter
          
      
             org.springframework.web.filter.CharacterEncodingFilter    
          
            
       
        字符集编码
             
       
        encoding
             
       
        UTF-8
           
        
       
         
      
       encodingFilter
          
      
       /*
        
       
         
      
       index.jsp
        
     
    

目前为止，SSM整合工作就已经完成，项目目录结构如下。

---

SSM框架应用示例--秒杀系统

首先新建数据库及相应的数据表，在main下新建一个sql包，然后新建一个schema.sql文件

schema.sql

-- 数据库初始化脚本-- 创建数据库CREATE DATABASE seckill;-- 使用数据库，只有INNODb支持事务use seckill;CREATE TABLE seckill(  `seckill_id` BIGINT NOT NUll AUTO_INCREMENT COMMENT '商品库存ID',  `name` VARCHAR(120) NOT NULL COMMENT '商品名称',  `number` int NOT NULL COMMENT '库存数量',  `start_time` TIMESTAMP  NOT NULL COMMENT '秒杀开始时间',  `end_time`   TIMESTAMP   NOT NULL COMMENT '秒杀结束时间',  `create_time` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',  PRIMARY KEY (seckill_id),  key idx_start_time(start_time),  key idx_end_time(end_time),  key idx_create_time(create_time))ENGINE=INNODB AUTO_INCREMENT=10000 DEFAULT CHARSET=utf8 COMMENT='秒杀库存表';-- 初始化数据INSERT into seckill(name,number,start_time,end_time)VALUES  ('1000元秒杀iphone6',100,'2016-01-01 00:00:00','2016-01-02 00:00:00'),  ('800元秒杀ipad',200,'2016-01-01 00:00:00','2016-01-02 00:00:00'),  ('6600元秒杀mac book pro',300,'2016-01-01 00:00:00','2016-01-02 00:00:00'),  ('7000元秒杀iMac',400,'2016-01-01 00:00:00','2016-01-02 00:00:00');-- 秒杀成功明细表-- 用户登录认证相关信息(简化为手机号)CREATE TABLE success_killed(  `seckill_id` BIGINT NOT NULL COMMENT '秒杀商品ID',  `user_phone` BIGINT NOT NULL COMMENT '用户手机号',  `state` TINYINT NOT NULL DEFAULT -1 COMMENT '状态标识:-1:无效 0:成功 1:已付款 2:已发货',  `create_time` TIMESTAMP NOT NULL COMMENT '创建时间',  PRIMARY KEY(seckill_id,user_phone),/*联合主键*/  KEY idx_create_time(create_time))ENGINE=INNODB DEFAULT CHARSET=utf8 COMMENT='秒杀成功明细表';  -- SHOW CREATE TABLE seckill;#显示表的创建信息

dao层开发

在entity包中新建两个实体类，属性分别与数据表一一对应

Seckill.java

public class Seckill{    private long seckillId;    private String name;    private int number;    //该注解处理日期的格式化    @DateTimeFormat(pattern="yyyy-MM-dd HH:mm:ss")    private Date startTime;    @DateTimeFormat(pattern="yyyy-MM-dd HH:mm:ss")    private Date endTime;    @DateTimeFormat(pattern="yyyy-MM-dd HH:mm:ss")    private Date createTime;   public Seckill(){   }    public Seckill(String name, int number, Date startTime, Date endTime) {        this.name = name;        this.number = number;        this.startTime = startTime;        this.endTime = endTime;    }    public long getSeckillId() {        return seckillId;    }    public void setSeckillId(long seckillId) {        this.seckillId = seckillId;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public int getNumber() {        return number;    }    public void setNumber(int number) {        this.number = number;    }    public Date getStartTime() {        return startTime;    }    public void setStartTime(Date startTime) {        this.startTime = startTime;    }    public Date getEndTime() {        return endTime;    }    public void setEndTime(Date endTime) {        this.endTime = endTime;    }    public Date getCreateTime() {        return createTime;    }    public void setCreateTime(Date createTime) {        this.createTime = createTime;    }    @Override    public String toString() {        return "Seckill{" +                "seckillId=" + seckillId +                ", name='" + name + '\'' +                ", number=" + number +                ", startTime=" + startTime +                ", endTime=" + endTime +                ", createTime=" + createTime +                '}';    }}

SuccessKilled.java

public class SuccessKilled{    private long seckillId;    private long userPhone;    private short state;    private Date createTime;    //省略getter，setter和toString方法 }

在dao包下新建两个接口,定义数据库操作相关方法

seckillDao.java

@Repositorypublic interface SeckillDao{    /**     * 减库存     * @param seckillId     * @param killTime     * @return 如果影响行数>1，表示更新库存的记录行数     */    int reduceNumber(@Param("seckillId") long seckillId, @Param("killTime") Date killTime);    /**     * 根据id查询秒杀的商品信息     * @param seckillId     * @return     */    Seckill queryById(long seckillId);    /**     * 根据偏移量查询秒杀商品列表     * @param offset     * @param limit     * @return     */    List
    
      queryAll(@Param("offset") int offset, @Param("limit") int limit);    //    添加秒杀物品    boolean addItem(Seckill seckill);    //    删除秒杀物品    boolean deleteById(long seckillId);    //    更新秒杀物品    boolean updateItem(Seckill seckill);    }
    

SuccessKilledDao.java

@Repositorypublic interface SuccessKilledDao {    /**     * 插入购买明细,可过滤重复     * @param seckillId     * @param userPhone     * @return插入的行数     */    int insertSuccessKilled(@Param("seckillId") long seckillId, @Param("userPhone") long userPhone);    /**     * 根据秒杀商品的id查询明细SuccessKilled对象(该对象携带了Seckill秒杀产品对象)     * @param seckillId     * @return     */    SuccessKilled queryByIdWithSeckill(@Param("seckillId") long seckillId, @Param("userPhone") long userPhone);}

在resources包下的mapper保重创建xml文件，实现dao包接口中的方法。

SeckillDao.xml

    
        
         
         
     
              UPDATE seckill        SET number = number-1        WHERE seckill_id=#{seckillId}        AND start_time  #{killTime}        AND end_time >= #{killTime}        AND number > 0;    
         
             SELECT *        FROM seckill        WHERE seckill_id=#{seckillId}        
             SELECT *        FROM seckill        ORDER BY create_time DESC        limit #{offset},#{limit}            
     
              INSERT INTO seckill(name,number,start_time,end_time)        VALUES (#{name},#{number},#{startTime},#{endTime})    
         
     
              DELETE FROM seckill        WHERE seckill_id=#{seckillId}    
         
     
              UPDATE seckill        set name=#{name},number=#{number},start_time=#{startTime},end_time=#{endTime}        WHERE seckill_id=#{seckillId}    
     
    

SuccessKilledDao.xml

        
             
              INSERT ignore INTO success_killed(seckill_id,user_phone,state)        VALUES (#{seckillId},#{userPhone},0)    
         
             
              
              
              SELECT            sk.seckill_id,            sk.user_phone,            sk.create_time,            sk.state,            s.seckill_id as "seckill.seckill_id",            s.name "seckill.name",            s.number "seckill.number",            s.start_time "seckill.start_time",            s.end_time "seckill.end_time",            s.create_time "seckill.create_time"        FROM success_killed sk        INNER JOIN seckill s ON sk.seckill_id=s.seckill_id        WHERE sk.seckill_id=#{seckillId} and sk.user_phone=#{userPhone}    
    

完成了dao层开发，接下来对到dao方法进行测试。点击我们要测试的类，快捷键ctrl+shift+t，创建新的测试，选择测试的路径及所要测试的方法。

SeckillDaoTest.java

/** * Created by codingBoy on 16/11/27. * 配置spring和junit整合，这样junit在启动时就会加载springIOC容器 */@RunWith(SpringJUnit4ClassRunner.class)//告诉junit spring的配置文件@ContextConfiguration({"classpath:spring/spring-dao.xml"})public class SeckillDaoTest {    //注入Dao实现类依赖    @Resource    private SeckillDao seckillDao;    @Test    public void reduceNumber() throws Exception {        long seckillId=10000;        Date date=new Date();        int updateCount=seckillDao.reduceNumber(seckillId,date);        System.out.println(updateCount);    }    @Test    public void queryById() throws Exception {        long seckillId=10000;        Seckill seckill=seckillDao.queryById(seckillId);        System.out.println(seckill.getName());        System.out.println(seckill);    }    @Test    public void queryAll() throws Exception {        List
    
      seckills=seckillDao.queryAll(0,100);        for (Seckill seckill : seckills)        {            System.out.println(seckill);        }    }    @Test    public void addItem() throws Exception {        Seckill seckill = new Seckill("222",300,new Date(),new Date());        seckillDao.addItem(seckill);    }    @Test    public void deleteById() throws Exception {        seckillDao.deleteById(10011);    }    @Test    public void updateItem() throws Exception {        Seckill seckill = seckillDao.queryById(10018);        seckill.setNumber(500);        seckillDao.updateItem(seckill);    }}
    

dao层开发过程中的注意点

1. 主要xml文件与dao接口中的方法一一对应
2. 对于与数据表对应的实体类，mybatis提供了自动生成的工具，详见

---

对所有的dao包中的方法进行测试后，就可进入service层方法的开发。

service层为主要的业务逻辑层，也是最复杂的部分，一般在service下新建一个接口，然后在impl包下放接口的实现类。SeckillService.java

/**业务接口:站在使用者(程序员)的角度设计接口 * 三个方面:1.方法定义粒度，方法定义的要非常清楚2.参数，要越简练越好 * 3.返回类型(return 类型一定要友好/或者return异常，我们允许的异常) * Created by codingBoy on 16/11/27. */public interface SeckillService {    /**     * 查询全部的秒杀记录     * @return     */    List
    
      getSeckillList();    /**     *查询单个秒杀记录     * @param seckillId     * @return     */    Seckill getById(long seckillId);    //再往下，是我们最重要的行为的一些接口    /**     * 在秒杀开启时输出秒杀接口的地址，否则输出系统时间和秒杀时间     * @param seckillId     */    Exposer exportSeckillUrl(long seckillId);    /**     * 执行秒杀操作，有可能失败，有可能成功，所以要抛出我们允许的异常     * @param seckillId     * @param userPhone     * @param md5     * @return     */    SeckillExecution executeSeckill(long seckillId, long userPhone, String md5)            throws SeckillException,RepeatKillException,SeckillCloseException;    void addItem(Seckill seckill);    void deleteItemById(long seckillId);    void updateItemById(Seckill seckill);}
    

SeckillServiceImpl.java

@Servicepublic class SeckillServiceImpl implements SeckillService{    //日志对象    private Logger logger= LoggerFactory.getLogger(this.getClass());    //加入一个混淆字符串(秒杀接口)的salt，为了我避免用户猜出我们的md5值，值任意给，越复杂越好    private final String salt="shsdssljdd'l.";    //注入Service依赖    @Autowired //@Resource    private SeckillDao seckillDao;    @Autowired //@Resource    private SuccessKilledDao successKilledDao;    public List
    
      getSeckillList() {        return seckillDao.queryAll(0,100);    }    public Seckill getById(long seckillId) {        return seckillDao.queryById(seckillId);    }    public Exposer exportSeckillUrl(long seckillId) {        Seckill seckill = seckillDao.queryById(seckillId);        if (seckill == null){            return new Exposer(false,seckillId);        }        //若是秒杀未开启        Date startTime=seckill.getStartTime();        Date endTime=seckill.getEndTime();        //系统当前时间        Date nowTime=new Date();        if (startTime.getTime()>nowTime.getTime() || endTime.getTime()
    

以上代码中用到了dto、enums、exception包中自定义的类。

dto包下三个类

//省略getter,setter和toString方法public class Exposer {    //是否开启秒杀    private boolean exposed;    //加密措施    private String md5;    private long seckillId;    //系统当前时间(毫秒)    private long now;    //秒杀的开启时间    private long start;    //秒杀的结束时间    private long end;    public Exposer(boolean exposed, String md5, long seckillId) {        this.exposed = exposed;        this.md5 = md5;        this.seckillId = seckillId;    }    public Exposer(boolean exposed, long seckillId,long now, long start, long end) {        this.exposed = exposed;        this.seckillId=seckillId;        this.now = now;        this.start = start;        this.end = end;    }    public Exposer(boolean exposed, long seckillId) {        this.exposed = exposed;        this.seckillId = seckillId;    }  }

//省略getter,setter和toString方法public class SeckillExecution {    private long seckillId;    //秒杀执行结果的状态    private int state;    //状态的明文标识    private String stateInfo;    //当秒杀成功时，需要传递秒杀成功的对象回去    private SuccessKilled successKilled;    //秒杀成功返回所有信息    public SeckillExecution(long seckillId, SeckillStatEnum statEnum, SuccessKilled successKilled) {        this.seckillId = seckillId;        this.state = statEnum.getState();        this.stateInfo = statEnum.getInfo();        this.successKilled = successKilled;    }    //秒杀失败    public SeckillExecution(long seckillId, SeckillStatEnum statEnum) {        this.seckillId = seckillId;        this.state = statEnum.getState();        this.stateInfo = statEnum.getInfo();    }  }

//将所有的ajax请求返回类型，全部封装成json数据public class SeckillResult
    
      {    //请求是否成功    private boolean success;    private T data;    private String error;    public SeckillResult(boolean success, T data) {        this.success = success;        this.data = data;    }    public SeckillResult(boolean success, String error) {        this.success = success;        this.error = error;    }   }
    

新建enums存放枚举类型

public enum SeckillStatEnum {    SUCCESS(1,"秒杀成功"),    END(0,"秒杀结束"),    REPEAT_KILL(-1,"重复秒杀"),    INNER_ERROR(-2,"系统异常"),    DATE_REWRITE(-3,"数据篡改");    private int state;    private String info;    SeckillStatEnum(int state, String info) {        this.state = state;        this.info = info;    }    public int getState() {        return state;    }    public String getInfo() {        return info;    }    public static SeckillStatEnum stateOf(int index)    {        for (SeckillStatEnum state : values())        {            if (state.getState()==index)            {                return state;            }        }        return null;    }}

新建exception存放自定义的异常类

public class RepeatKillException extends SeckillException {    public RepeatKillException(String message) {        super(message);    }    public RepeatKillException(String message, Throwable cause) {        super(message, cause);    }}

public class SeckillException extends RuntimeException {    public SeckillException(String message) {        super(message);    }    public SeckillException(String message, Throwable cause) {        super(message, cause);    }}

public class SeckillCloseException extends SeckillException{    public SeckillCloseException(String message) {        super(message);    }    public SeckillCloseException(String message, Throwable cause) {        super(message, cause);    }}

完成service层，进行测试

---

控制层开发

在web包下新建控制类

SeckillController.java

/** /seckill/list    获取列表* /seckill/{seckillId}/detail   物品详情* /seckill/{seckillId}/exposer   获取物品秒杀地址* /seckill/{seckillId}/{md5}/execution   执行物品秒杀** /seckill/add  get获取添加页面* /seckill/add  post向数据库中添加记录* /seckill/{seckillId}/update  get获取更新页面* /seckill/update  post更新数据* /seckill//{seckillId}delete  删除数据* */@Controller@RequestMapping("/seckill")//url:模块/资源/{}/细分public class SeckillController{    @Autowired    private SeckillService seckillService;    @RequestMapping(value = "/list",method = RequestMethod.GET)    public String list(Model model)    {        //list.jsp+mode=ModelAndView        //获取列表页        List
    
      list=seckillService.getSeckillList();        model.addAttribute("list",list);        return "list";    }    @RequestMapping(value = "/{seckillId}/detail",method = RequestMethod.GET)    public String detail(@PathVariable("seckillId") Long seckillId, Model model)    {        if (seckillId == null)        {            return "redirect:/seckill/list";        }        Seckill seckill=seckillService.getById(seckillId);        if (seckill==null)        {            return "forward:/seckill/list";        }        model.addAttribute("seckill",seckill);        return "detail";    }    @RequestMapping(value = "/add",method = {RequestMethod.GET})    public String addItemUI(){        return "add";    }    @RequestMapping(value = "/add",method = {RequestMethod.POST})    public String addItemInfo(Seckill seckill){        seckillService.addItem(seckill);        return "redirect:/seckill/list";    }    @RequestMapping(value = "/{sk.seckillId}/delete",method = {RequestMethod.GET})    public String deleteItem(@PathVariable("sk.seckillId") Long seckillId){        seckillService.deleteItemById(seckillId);        return "redirect:/seckill/list";    }    @RequestMapping(value = "/{sk.seckillId}/update",method = {RequestMethod.GET})    public String updateItemUI(@PathVariable("sk.seckillId") Long seckillId,Model model){        Seckill seckill = seckillService.getById(seckillId);        model.addAttribute("item",seckill);        return "update";    }    @RequestMapping(value = "/update",method = {RequestMethod.POST})    public String updateItem(Seckill seckill){        seckillService.updateItemById(seckill);        return "redirect:/seckill/list";    }    //ajax ,json暴露秒杀接口的方法    @RequestMapping(value = "/{seckillId}/exposer",                    method = RequestMethod.GET,                    produces = {"application/json;charset=UTF-8"})    @ResponseBody    public SeckillResult
     
       exposer(@PathVariable("seckillId") Long seckillId)    {        SeckillResult
      
        result;        try{            Exposer exposer=seckillService.exportSeckillUrl(seckillId);            result=new SeckillResult
       
        (true,exposer);        }catch (Exception e)        {            e.printStackTrace();            result=new SeckillResult
        
         (false,e.getMessage());        }        return result;    }    @RequestMapping(value = "/{seckillId}/{md5}/execution",            method = RequestMethod.POST,            produces = {"application/json;charset=UTF-8"})    @ResponseBody    public SeckillResult
         
           execute(@PathVariable("seckillId") Long seckillId, @PathVariable("md5") String md5, @CookieValue(value = "userPhone",required = false) Long userPhone) { if (userPhone==null) { return new SeckillResult
          
           (false,"未注册"); } SeckillResult
           
             result; try { SeckillExecution execution = seckillService.executeSeckill(seckillId, userPhone, md5); return new SeckillResult
            
             (true, execution); }catch (RepeatKillException e1) { SeckillExecution execution=new SeckillExecution(seckillId, SeckillStatEnum.REPEAT_KILL); return new SeckillResult
             
              (true,execution); }catch (SeckillCloseException e2) { SeckillExecution execution=new SeckillExecution(seckillId, SeckillStatEnum.END); return new SeckillResult
              
               (true,execution); } catch (Exception e) { SeckillExecution execution=new SeckillExecution(seckillId, SeckillStatEnum.INNER_ERROR); return new SeckillResult
               
                (true,execution); } } //获取系统时间 @RequestMapping(value = "/time/now",method = RequestMethod.GET) @ResponseBody public SeckillResult
                
                  time() { Date now=new Date(); return new SeckillResult
                 
                  (true,now.getTime()); }}
                 
                
               
              
             
            
           
          
         
        
       
      
     
    

web层开发过程中的注意点

1. 注意类级别与方法级别路径映射的区别
2. 返回页面和返回json类型数据不同的注解方式
3. 方法中参数的获取

目前为止，秒杀系统后端服务全部完成，前端相关代码就不在此贴出来，全部代码见