In parallel, use Redis to prevent repeated data insertions (the database is not set to table fields only)

@Controller @requestmapping ("/mytest") public class testcontroller {    @ Autowired (Required = false)     private TestService testService;          @Autowired     private RedisUtil  redisutil;     @RequestMapping ("Add")     public void add ( Httpservletrequest request)  throws Exception {         list<course> clist = testservice.querybyname ("AAAAA");//Query          system.out.println (Thread.CurrentThread (). GetName () + "Clist.size:" +clist.size ());         if (Clist.size ()  == 0) {             if (Redisutil.setnx ("name_" + "AAAAA",  "AAAAA")  == 1) {// Returns 0 if the data exists, does not exist return 1                course course =  New course ();                 course.setcname ("AAAAA");                 try{               &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;TESTSERVICE.ADD1 (course);//Insert                  }catch  (exception e)  {                      Redisutil.del ("name_" + "AAAAA");//Insert Exception Delete                      throw e;                 }                 system.out.println (Thread.CurrentThread (). GetName () + "success");                 redisutil.expire ("name_" + "AAAAA",  3);// Set failure time 3 seconds             }else{                 system.out.println ( Thread.CurrentThread (). GetName () + "exists");             }        }else{             system.out.println (Thread.CurrentThread (). GetName () + "false");         }    }}

redisutil tools can be searched online

The following test code:

public class test {    /**     *  @param   args     *  @throws  ioexception      * @ Throws httpexception      */    public static  void main (String[] args)  throws Exception {         for (int i=0;i<10;i++) {             try {                 thread.sleep (            } catch);   (interruptedexception e)  {                 // TODO Auto-generated catch block         &nbsP;       e.printstacktrace ();             }            new  thread (new runnable ()  {                  @Override                  public void run ()  {                     // todo auto-generated  method stub                     post ();                 }            }). Start (); &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSp;  }    }        public static  void post () {        httpclient client = new  httpclient ();         client.getparams (). SetContentCharset ("UTF-8 ");         postmethod method = new postmethod (" Http://localhost:8080/practice/myTest/add.do?time= "+new date (). GetTime ());         method.setrequestheader ("ContentType", "application/x-www-form-urlencoded;charset=utf-8");         try {             client.executemethod (method);        }  catch  (httpexception e)  {             // todo auto-generated catch block             E.printstacktrace ();        } catch  (IOException e)  {            // TODO  auto-generated catch block             E.printstacktrace ();         }    }}

In parallel, use Redis to prevent repeated data insertions (the database is not set to table fields only)