The variables within the 2.1.1 method are thread safe

A non-thread-safe problem exists in an instance variable, and if it is a private variable inside a method, there is no non-thread-safe problem, so it is thread-safe.

Test

1  PackageCom.cky.bean;2 3 /**4 * Created by Chenkaiyang on 2017/12/4.5  */6  Public classSelfprivatenum {7 8      Public voidAddi (String usrname) {9         Try {Ten             intNum =0; One             if(Usrname.equals ("a")) { ANum =100; -System.out.println ("A Over"); -Thread.Sleep (2000); the}Else { -Num= 200; -System.out.println ("B over"); -  +             } -System.out.println (usrname + "num=" +num); +}Catch(interruptedexception e) { A e.printstacktrace (); at         } -     } -}

1  PackageCom.cky.thread;2 3 ImportCom.cky.bean.SelfPrivateNum;4 5 /**6 * Created by Chenkaiyang on 2017/12/4.7  */8  Public classThreadaextendsthread{9     Privateselfprivatenum sn;Ten      PublicThreada (selfprivatenum sn) { One          This. SN =SN; A     } - @Override -      Public voidrun () { the         Super. Run (); -Sn.addi ("a"); -     } -}

1  PackageCom.cky.thread;2 3 ImportCom.cky.bean.SelfPrivateNum;4 5 /**6 * Created by Chenkaiyang on 2017/12/4.7  */8  Public classThreadbextendsthread{9     Privateselfprivatenum sn;Ten      Publicthreadb (selfprivatenum sn) { One          This. SN =SN; A     } - @Override -      Public voidrun () { the         Super. Run (); -Sn.addi ("B"); -     } -}

1  Packagecom.cky.test;2 3 ImportCom.cky.bean.SelfPrivateNum;4 ImportCom.cky.thread.ThreadA;5 ImportCom.cky.thread.ThreadB;6 7 /**8 * Created by Chenkaiyang on 2017/12/2.9  */Ten  Public classTest { One      Public Static voidMain (string[] args) { ASelfprivatenum sn =Newselfprivatenum (); -Threada Threada =NewThreada (SN); -THREADB threadb =Newthreadb (SN); the Threada.start (); - Threadb.start (); -     } -}

d:\it\jdk1.8\bin\java-didea.launcher.port=7532 "-didea.launcher.bin.path=d:\it\idea\intellij idea 2016.3.3\bin"- Dfile.encoding=utf-8-classpath "d:\it\jdk1.8\jre\lib\charsets.jar;d:\it\jdk1.8\jre\lib\deploy.jar;d:\it\jdk1.8\ Jre\lib\ext\access-bridge-64.jar;d:\it\jdk1.8\jre\lib\ext\cldrdata.jar;d:\it\jdk1.8\jre\lib\ext\dnsns.jar;d:\ It\jdk1.8\jre\lib\ext\jaccess.jar;d:\it\jdk1.8\jre\lib\ext\jfxrt.jar;d:\it\jdk1.8\jre\lib\ext\localedata.jar;d : \it\jdk1.8\jre\lib\ext\nashorn.jar;d:\it\jdk1.8\jre\lib\ext\sunec.jar;d:\it\jdk1.8\jre\lib\ext\sunjce_ Provider.jar;d:\it\jdk1.8\jre\lib\ext\sunmscapi.jar;d:\it\jdk1.8\jre\lib\ext\sunpkcs11.jar;d:\it\jdk1.8\jre\ Lib\ext\zipfs.jar;d:\it\jdk1.8\jre\lib\javaws.jar;d:\it\jdk1.8\jre\lib\jce.jar;d:\it\jdk1.8\jre\lib\jfr.jar;d : \it\jdk1.8\jre\lib\jfxswt.jar;d:\it\jdk1.8\jre\lib\jsse.jar;d:\it\jdk1.8\jre\lib\management-agent.jar;d:\it\ Jdk1.8\jre\lib\plugin.jar;d:\it\jdk1.8\jre\lib\resources.jar;d:\it\jdk1.8\jre\lib\rt.jar; F:\springboot\threaddemo\out\productiOn\threaddemo;d:\it\idea\intellij idea 2016.3.3\lib\idea_rt.jar " com.intellij.rt.execution.application.AppMain com.cky.test.Testa overb overb num=200a num=100

Results Analysis:

There is no non-thread-safe problem in the method variable, which is always thread-safe, which is caused by the method's internal variables being private.

The variables within the 2.1.1 method are thread safe