Create Error Log File In Java
Contents |
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business how to create log file in java using log4j Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs how to create log file in java using log4j example Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just how to create a log file in java code like you, helping each other. Join them; it only takes a minute: Sign up Creating a log file only when an error or exceptions occured without using log4j up vote 1 down vote favorite 1 I want
Generate Log File In Java
to maintain a log file or txt file ,where I am able to maintain the exception details as well as some other details either in txt or log file.The scenario is like this try { ....... } catch(exception e) { here the file should be created } what will be the best optimize solution for this without using logging frameworks. Could this work for me? try { // something } catch (Exception ex) { ex.printStackTrace(new how to write into a log file in java PrintStream(new File("error.log"))); } java file exception logging error-handling share|improve this question edited Nov 9 '12 at 7:08 assylias 174k23332478 asked Nov 9 '12 at 6:50 arvin_codeHunk 1,12052238 1 can you elaborate a bit further why logging frameworks are out of the question? but well, if you insist on going without them, then you'd need to roll your own. There is no one "best optimize solution". –eis Nov 9 '12 at 6:54 what do you mean by elaborate, see I have to just write the exception details into a file when an exception occurs,thats it, is'nt it clear –arvin_codeHunk Nov 9 '12 at 7:00 I like using a simple FileWriter : construct in the constructor of the class, and just call for each write method in the catch exceptions. Might not be the best way, but it is pretty easy to implement. –Vineet Kosaraju Nov 9 '12 at 7:11 add a comment| 4 Answers 4 active oldest votes up vote 1 down vote accepted I don't know why you not like to use logger Framework. Ok so One thing you can do create FileWritter object on the top level and use it in your class where you want. BufferedWriter bw = null; String path = "your//file//path//where u want to save your log"; try { bw = new BufferedWr
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn how to write log file in java using log4j more about Stack Overflow the company Business Learn more about hiring developers or posting
Java Filehandler
ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community
How To Create Log File In Java Web Application
Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up How to write error log or exception into file in http://stackoverflow.com/questions/13303441/creating-a-log-file-only-when-an-error-or-exceptions-occured-without-using-log4j java up vote 11 down vote favorite 9 Is there any way to write error log or exception into a file in java. i have gone through Log4j. I googled about it but diidnt find a good solution. I have written a simple code catch (Exception e) { PrintWriter pw = new PrintWriter(new FileOutputStream("Log")); e.printStackTrace(pw); } Is there any other way to log the errors or exception? can http://stackoverflow.com/questions/9362574/how-to-write-error-log-or-exception-into-file-in-java any body provide me wwith sample example of Log4j? java log4j error-log share|improve this question edited Apr 12 at 11:50 Ashish Aggarwal 2,41511232 asked Feb 20 '12 at 14:15 adesh 3983819 add a comment| 5 Answers 5 active oldest votes up vote 19 down vote accepted First read log4j Manual, it's easy to configure a rolling log file. You do not have to do any explicit file operations. #SET LEVEL of ROOT-LOGGER, you will like to have Debug in local, but in prod you may just want WARN and ABOVE. This setting is done here! log4j.rootLogger=debug, stdout, R log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.layout=org.apache.log4j.PatternLayout # Pattern to output the caller's file name and line number. (basically, format of log) log4j.appender.stdout.layout.ConversionPattern=%5p [%t] (%F:%L) - %m%n # THIS IS WHERE YOU WILL HAVE ALL THE LOG WRITTEN log4j.appender.R=org.apache.log4j.RollingFileAppender log4j.appender.R.File=/var/log/applogs/example.log # Maximum size of log file, usually we keep 10MB log4j.appender.R.MaxFileSize=100KB # Keep one backup file, usually we keep 10 log4j.appender.R.MaxBackupIndex=1 log4j.appender.R.layout=org.apache.log4j.PatternLayout log4j.appender.R.layout.ConversionPattern=%p %t %c - %m%n Second, whenever you catch an exception, do like this public class MyClass{ private static Logger logger = Logger.getLogger(MyClass.class); public ReturnType myMethod(Param p, Param2 p2) { .... .... try { .. } catch(MyException e) { logger.log("Exceptions happen!", e); //this will put all the de
Implemented Interfaces: java.io.Serializable Direct Known Subclasses: TestLog public class ErrorLogextends java.lang.Objectimplements java.io.Serializable ErrorLog is a simple way of handling warnings and errors in your programs. Rather than having 20 lines of error http://www.javaranch.com/doc/com/javaranch/common/ErrorLog.html handling for each occurance of an error, you can have just one. When the time comes to handle your errors a different way, you don't have to find a thousand https://www.loggly.com/blog/logging-exceptions-in-java/ error locations and rewrite the handling: just change the ErrorLog initialization. To use ErrorLog, create a log instance: ErrorLog log = new ErrorLog(); and then when the error occurs: log.add( log file "file " + fileName + " corrupted at byte " + pos ); The time and date will be added to your message and written to System.err. FILE LOGGING To activate this feature, use the setLogFile() method. To deactivate this feature, or to complete file logging, use the setLogFileOff() method. When activated, all error messages will be copied to a log file in text file (using the name provided in setLogFile()). By default, this feature is off. Example: ErrorLog log = new ErrorLog(); log.setLogFile( "errors.txt" ); // turn on text file logging ... log.add( "file " + fileName + " corrupted at byte " + pos ); // this error message is sent to the console and copied to the file "errors.txt" ... // end of the program log.setLogFileOff(); Note that a "file flush" is performed after each error message is processed. This is in case your program is prematurely terminated: the file will still contain all of the messages you sent (instead of having them in a buffer in memory waiting for the file to be closed). Note also that setLogFileOff() does not have to be called when your program finishes, although it is good programming practice. In other words, you will not lose any data from your file if you do not call setLogFileOff(). INTERNAL LOGGING To activate/deactivate this feature, use the setInternalLog() method. When activated, all error messages will be stored inside the ErrorLog object. By default, this feature
Whether or not you recover from an exception, logging the problem can help you identify the cause of – and ultimately the solution to – potential problems in your application. In this post, we'll look at common approaches to exception handling and logging. The examples use Log4j2, but the concepts apply to almost all modern logging frameworks. When to Log an Exception One of the first questions that often comes up when logging exceptions is: Where should I put the logging code? Logging can take place in the method where the exception occurred, or it can follow the exception up the call stack until it's eventually handled by one of the calling methods. Choosing one option over the other depends mostly on how your application is structured. In either case, the logger will need enough information to record the cause of the error. Log at the Source Logging close to the source of the error provides as much detail about the error as possible. For example, imagine we have a program that writes a string to a file. In our program, we have a class that opens a file, writes to it, and then closes it. In this class, we catch and log any IOExceptions: While this approach lets us create specific log messages, it limits the available context. We have access to the stack trace, but we don't know what particular course of action triggered the exception. Logging close to the source also adds complexity to the application, since it requires each component to provide its own logging implementation. This can be mitigated with frameworks such as SLF4J, but it still ends up adding redundancy and overhead. Log Further up the Stack Rather than log directly at the source, we can pass the exception up the stack and log it at a point where we have more contextual information. This can take place in the middle of the call stack, or even by an umbrella handler at the top. This can even be done using Thread.setD