Java implementation of Java process mutex using Filelock

Principle:
The Filelock in the JDK's NIO package implements a file lock similar to the Linux fcntl , allowing the file to be accessed by the process mutex. With this feature, a powerful Java process mutex can be implemented to ensure that only the unique jar application process is running at the same time at the application level ! avoid certain factors that cause the jar to execute repeatedly, competing with multiple processes, and destroying business data. (Of course, you can do the same thing with Ubuntu-like upstart scripts or ps-p <pid>.)
Realize:

2. Package test;
4. Import Java.io.File;
6. Import java.io.IOException;
8. Import Java.io.RandomAccessFile;
10. Import Java.nio.channels.FileChannel;
12. Import Java.nio.channels.FileLock;
14. Import java.util.concurrent.Callable;
16. Import Java.util.concurrent.TimeUnit;
18. public class Filelocktest {
20. public static void Main (string[] args) throws Exception {
22. Exclusivewithfilelock (New callable<void> () {
24. @Override
26. Public Void Call () throws Exception {
28. TimeUnit.SECONDS.sleep (10); Simulating business logic with hibernation
30. return null;
32. }
34. });
36. }
38. public static <V> V Exclusivewithfilelock (callable<v> caller)
40. Throws Exception {
42. File LockFile = new file ("/tmp/" +filelocktest.class.getcanonicalname ());//Use class name as filename
44. if (!lockfile.exists ()) {
46. if (!lockfile.getparentfile (). exists ()) {
48. Lockfile.getparentfile (). Mkdirs ();
50. }
52. if (!lockfile.createnewfile ()) {
54. throw new IOException ("Create lock File failed!");
56. }
58. }
60. FileChannel FC = null;
62. try {
64. FC = new Randomaccessfile (lockFile, "RW"). Getchannel ();
66. Filelock lck = Fc.trylock ();
68. if (lck = = null) {
70. System.out.println ("File is lock by another programme");
72. System.exit (1);
74. } else {
76. System.out.println ("Do your ...");
78. return Caller.call ();
80. }
82. } finally {
84. if (FC! = null) {
86. Fc.close ();
88. }
90. }
92. return null;
94. }
96. }

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Results:

1. [Email protected]:~/myworkspace/source/jademo/src$ java test. Filelocktest
2. File is lock by another programme
3. [Email protected]:~/myworkspace/source/jademo/src$ java test. Filelocktest
4. Do your ...

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Advantage:
1. Simple to implement and powerful in function.

Java implementation of Java process mutex using Filelock