Use threadlocal to record logs

Use threadlocal to record logs Original reverocean (Participation score: 9727, expert score: 822) published: Version: 1.0 read:353Times

It is necessary to record logs in a project, but it is often recorded by logger. debug ("... "). logs are recorded when the program runs, especially in multi-threaded or web applications. Different logs may be recorded in the same file at the same time, when an error occurs, you cannot determine which information you want to care about. therefore, if we start logging at the beginning of a program, but this log is not recorded in the log file, but saved in a threadlocal, when an error occurs, all these logs can be output to the log file for easy search. The Code is as follows:     Import java. util. arraylist; Import java. util. List; Public class debuglogger { /** * @ Param ARGs */ Public static void main (string [] ARGs ){ // Test and use. A new debuglogger can be created at the beginning of a method. Debuglogger logger = new debuglogger (); // Simulate the ten logs to be recorded and record them to the debuglogger at a time. For (INT I = 0; I <10; I ++ ){ // Modify the following code to record logs Logger. Put ("log Info" + I ); }   // When the method ends or an exception occurs, extract the recorded log String [] strings = logger. Get (); // Record the obtained logs to the log file once. For (INT I = 0; I <strings. length; I ++ ){ System. Out. println (strings [I]); } // Enter the log Content recorded in debuglogger. Logger. Clear (); { String [] strings1 = logger. Get (); For (INT I = 0; I <strings1.length; I ++ ){ System. Out. println (strings1 [I]); } } }   // Internal static class, inherited to threadlocal Private Static class threadlocallist extends threadlocal { // An arraylist object is returned when the get () method is called. Public object initialvalue (){ Return new arraylist (); } // Returns the list stored in threadlocal. Public list getlist (){ Return (list) Super. Get (); } }   Private threadlocallist list = new threadlocallist (); Private Static string [] stringarray = new string [0]; // Clear the recorded logs Public void clear (){ List. getlist (). Clear (); } // Save the log content to be recorded Public void put (string text ){ List. getlist (). Add (text ); } // Return the logs to be recorded Public String [] Get (){ Return (string []) List. getlist (). toarray (stringarray ); } }   In the code, you can call debuglogger. put () to save information about what your program is doing, and, if necessary later (for example, an error occurs), you can easily retrieve debugging information related to a specific thread. This technology is much easier than simply dumping all the information to a log file and then trying to find out which log records come from which thread (and worry about thread contention for log record objects, and more effective.