Add custom message to thrown exception while maintaining stack trace in Java

Question

I have a small piece of code that runs through some transactions for processing  Each transaction is marked with a transaction number  which is generated by an outside program and is not necessarily sequenced  When I catch an Exception in the processing code I am throwing it up to the main class and logging it for review later  I d like to add the transaction number to this thrown Exception  Is it possible to do this while still maintaining the correct stack trace   For Example   public static void main String   args        try          processMessage         catch Exception E           E printStackTrace              private static void processMessage   throws Exception      String transNbr           try          transNbr    2345           throw new Exception         catch Exception E           if  transNbr equals                     stack trace originates from here  not from actual exception             throw new Exception  transction      transNbr             else                stack trace gets passed correctly but no custom message available             throw E

User · Accepted Answer

Try   throw new Exception  transction      transNbr  E

User · Answer

you can use super while extending Exception  if  pass length    lt  minPassLength      throw new InvalidPassException  The password provided is too short       catch  NullPointerException e        throw new InvalidPassException  No password provided   e           A custom business exception class InvalidPassException extends Exception    InvalidPassException         InvalidPassException String message        super message     InvalidPassException String message  Throwable cause       super message  cause             source

User · Answer

There is an Exception constructor that takes also the cause argument  Exception String message  Throwable t     You can use it to propagate the stacktrace   try             catch Exception E       if  transNbr equals               throw new Exception  transaction      transNbr  E

User · Answer

Exceptions are usually immutable  you can t change their message after they ve been created  What you can do  though  is chain exceptions   throw new TransactionProblemException transNbr  originalException     The stack trace will look like  TransactionProblemException   transNbr at     at     caused by OriginalException     at     at

User · Answer

You can use your exception message by -   public class MyNullPointException extends NullPointerException            private ExceptionCodes exceptionCodesCode           public MyNullPointException ExceptionCodes code                this exceptionCodesCode code                     Override         public String getMessage                 return exceptionCodesCode getCode                   public class enum ExceptionCodes       COULD NOT SAVE RECORD   cityId 001 could not save record         NULL POINT EXCEPTION RECORD   cityId 002 null point exception record         COULD NOT DELETE RECORD   cityId 003 could not delete record          private String code       private ExceptionCodes String code            this code   code             public String getCode             return code

User · Answer

Following code is a simple example that worked for me Let me call the function main as parent function and divide as child function  Basically i am throwing a new exception with my custom message  for the parent s call  if an exception occurs in child function by catching the Exception in the child first     class Main       public static void main String args              try              long ans divide 0               System out println  answer   ans                     catch Exception e               System out println  got exception   e getMessage                           public static long divide int num  throws Exception          long x -1          try               x 5 num                    catch  Exception e               throw new Exception  Error occured in divide for number   num  Error   e getMessage                       return x              the last line return x will not run if error occurs somewhere in between

[java] Add custom message to thrown exception while maintaining stack trace in Java

Examples related to java

Examples related to exception

Examples related to exception-handling