Package Torello.Java

Class EXCC

  • public class EXCC
extends java.lang.Object
    'Exception Cause Chain' helps convert exception messages whose Throwable.cause() method returns a non-null cause, thereby unrolling (and printing) this chain of exceptions into a readable String.

    EXCC: Exception Cause Chain

    In Java, there are exceptions that may have been thrown by a different thread. In Java, Exception's thrown by a different thread will often be wrapped into another Exception, with the original 'cause' Exception is kept by the Surrounding / 'Wrapping' Exception. It may be retrieved using the Throwable Method getCause().

    Java does not expect every exception throw to provide a "cause" - quite the contrary, most do not. There are also a number of java Exception's that do not even allow for a "cause throwable" in any of the provided constructors. Multi-threaded code is on source of "exception chaining" - but code there are also instances where simple try-catchblocks will catch an exceptions and wrap it (and throw the new Exception instance) in order to give the Exception a different name, and also to provide more detailed information about the error that has occurred.

    Either way, printing such information is easier to read if there is a standardized formatting for such information, which is the purpose behind class 'EXCC'

    To view both stack-traces, invoke the following:

    1. ex.printStackTrace();
    2. ex.getCause().printStackTrace();

    If viewing the "getCause()" of an exception is important, this class will help print the cause-exception (and even the causes' cause - recursively). The String-Methods in this class use recursion to traverse through each "parent exception", adding indentations, until a null is returned when invoking getCause().



    Stateless Class:
    This class neither contains any program-state, nor can it be instantiated. The @StaticFunctional Annotation may also be called 'The Spaghetti Report'. Static-Functional classes are, essentially, C-Styled Files, without any constructors or non-static member fields. It is a concept very similar to the Java-Bean's @Stateless Annotation.

    • 1 Constructor(s), 1 declared private, zero-argument constructor
    • 8 Method(s), 8 declared static
    • 0 Field(s)


    • Method Summary

       
      Print Exception and, recursively, all causes to a String
      Modifier and Type Method
      static String toString​(Throwable t)
      static String toString​(Throwable t, int indentation)
       
      Print Exceptions recursively, but do not print Stack-Traces
      Modifier and Type Method
      static String toStringNoST​(Throwable t)
      static String toStringNoST​(Throwable t, int indentation)
       
      Print Exceptions recursively, and limit number of Stack-Trace Entries to Print
      Modifier and Type Method
      static String toStringMaxTraces​(Throwable t, int maxNumInvocations)
      static String toStringMaxTraces​(Throwable t, int maxNumInvocations, int indentation)
       
      Protected Helpers: Handle Legacy Exception Cause Printing
      Modifier and Type Method
      protected static Throwable legacyCause​(Throwable t)
      protected static String legacyMsg​(Throwable t)

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Method Detail

      • toString

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static java.lang.String toString​(java.lang.Throwable t)
        Prints the Exception-message and Exception-stack trace to an output String, and invokes, recursively, this method with any cause-Throwable's that are present in this Throwable.
        Parameters:
        t - Any Java Throwable. Java Throwable's with one or 'cause' Throwable's will utilize more fully the printing-features of this class, 'EXCC' - though any Throwable will be properly printed.
        Returns:
        This method doesn't actually print anything to the screen or terminal, it just returns a String that you may print yourself - or write to a class StringBuilder, or any variation of text-output you wish.
        Code:
        Exact Method Body:
         // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
 // Initialize the Variables
 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

 final StackTraceElement[]   steArr          = t.getStackTrace();
 final StringBuilder         sb              = new StringBuilder();
 final Throwable             cause           = t.getCause();
 final Throwable             legacyCause     = legacyCause(t);
 final boolean               hasCause        = (cause != null);
 final boolean               hasLegacyCause  = (legacyCause != null) && (legacyCause != cause);

 String msg          = t.getMessage();
 String localMsg     = t.getLocalizedMessage();
 String legacyMsg    = (hasLegacyCause) ? legacyMsg(t) : null;

 final boolean hasMessage    = (msg != null)         && (msg.length() > 0);
 final boolean hasLocalMsg   = (localMsg != null)    && (localMsg.length() > 0);

 if (hasMessage)     msg         = StrIndent.indent(msg, 1, false, true);
 if (hasLocalMsg)    localMsg    = StrIndent.indent(localMsg, 1, false, true);


 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
 // Print the "Top Part" / "Header Part" / Error-Message to the Return-Output StringBuilder
 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

 sb.append(BRED + "THROWN: " + t.getClass().getCanonicalName() + RESET + "\n");

 if (hasMessage)
 {
     sb.append(BCYAN + "Throwable.getMessage():\n" + RESET + msg + "\n");

     if (hasLocalMsg && (! msg.equals(localMsg)))
         sb.append(BCYAN + "Throwable.getLocalizedMessage():\n" + RESET + localMsg + "\n");
 }

 else if (hasLocalMsg)
     sb.append(BCYAN + "Throwable.getLocalizedMessage():\n" + RESET + localMsg + "\n");

 else
     sb.append(BYELLOW + "No Exception Messages Provided.\n" + RESET);


 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
 // Print the Stack-Trace
 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

 sb.append(BCYAN + "StackTrace:\n" + RESET);

 int temp, maxLN = 0;

 for (StackTraceElement ste : steArr)
     if ((temp = ste.getLineNumber()) > maxLN)
         maxLN = temp;

 final int base10 =
     2 + // 2: colon + space
     ((int) Math.ceil(Math.log10(maxLN)));

 for (int k=0; k < steArr.length; k++) sb.append(
     '\t' + StringParse.rightSpacePad(steArr[k].getLineNumber() + ":", base10) +
     steArr[k].getClassName() + "." +
     steArr[k].getMethodName() + "()\n"
 );


 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
 // Build the StringBuilder & Return / Exit
 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

 return
     sb.toString() +
     (hasCause       ? StrIndent.indentTabs(toString(cause), 1)                      : "") +
     (hasLegacyCause ? (legacyMsg + StrIndent.indentTabs(toString(legacyCause), 1))  : "");

      • toStringMaxTraces

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static java.lang.String toStringMaxTraces​(java.lang.Throwable t,
                                                 int maxNumInvocations)
        Prints the Exception-message and Exception-stack trace to an output String, and invokes, recursively, this method with any cause-Throwable's that are present in this Throwable.
        Parameters:
        t - Any Java Throwable. Java Throwable's with one or 'cause' Throwable's will utilize more fully the printing-features of this class, 'EXCC' - though any Throwable will be properly printed.
        maxNumInvocations - Each of the Throwable's printed shall have, at most, 'maxNumInvocations' of their Stack-Traces printed into the output String.
        Returns:
        This method doesn't actually print anything to the screen or terminal, it just returns a String that you may print yourself - or write to a class StringBuilder, or any variation of text-output you wish.
        Code:
        Exact Method Body:
         // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
 // Initialize the Variables
 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

 StackTraceElement[] steArr = t.getStackTrace();

 final StringBuilder sb              = new StringBuilder();
 final Throwable     cause           = t.getCause();
 final Throwable     legacyCause     = legacyCause(t);
 final boolean       hasCause        = (cause != null);
 final boolean       hasLegacyCause  = (legacyCause != null) && (legacyCause != cause);

 String msg          = t.getMessage();
 String localMsg     = t.getLocalizedMessage();
 String legacyMsg    = (hasLegacyCause) ? legacyMsg(t) : null;

 final boolean hasMessage    = (msg != null)         && (msg.length() > 0);
 final boolean hasLocalMsg   = (localMsg != null)    && (localMsg.length() > 0);

 if (hasMessage)     msg         = StrIndent.indent(msg, 1, false, true);
 if (hasLocalMsg)    localMsg    = StrIndent.indent(localMsg, 1, false, true);


 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
 // Print the "Top Part" / "Header Part" / Error-Message to the Return-Output StringBuilder
 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

 sb.append(BRED + "THROWN: " + t.getClass().getCanonicalName() + RESET + "\n");

 if (hasMessage)
 {
     sb.append(BCYAN + "Throwable.getMessage():\n" + RESET + msg + "\n");

     if (hasLocalMsg && (! msg.equals(localMsg)))
         sb.append(BCYAN + "Throwable.getLocalizedMessage():\n" + RESET + localMsg + "\n");
 }

 else if (hasLocalMsg)
     sb.append(BCYAN + "Throwable.getLocalizedMessage():\n" + RESET + localMsg + "\n");

 else
     sb.append(BYELLOW + "No Exception Messages Provided.\n" + RESET);


 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
 // Print the Stack-Trace
 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

 sb.append(BCYAN + "StackTrace:\n" + RESET);

 int temp, maxLN = 0, stTruncated = 0;

 if (steArr.length > maxNumInvocations)
 {
     stTruncated = steArr.length - maxNumInvocations;
     steArr      = Arrays.copyOf(steArr, maxNumInvocations);
 }

 for (StackTraceElement ste : steArr)
     if ((temp = ste.getLineNumber()) > maxLN)
         maxLN = temp;

 final int base10 =
     2 + // 2: colon + space
     ((int) Math.ceil(Math.log10(maxLN)));


 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
 // Build the StringBuilder & Return / Exit
 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

 for (int k=0; k < steArr.length; k++) sb.append(
     '\t' + StringParse.rightSpacePad(steArr[k].getLineNumber() + ":", base10) +
     steArr[k].getClassName() + "." +
     steArr[k].getMethodName() + "()\n"
 );

 if (stTruncated > 0)
     sb.append("\t... and " + stTruncated + " more invocations.\n");


 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
 // Build the StringBuilder & Return / Exit
 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

 return
     sb.toString() +
     (hasCause       ? StrIndent.indentTabs(toString(cause), 1)                      : "") +
     (hasLegacyCause ? (legacyMsg + StrIndent.indentTabs(toString(legacyCause), 1))  : "");

      • toStringNoST

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static java.lang.String toStringNoST​(java.lang.Throwable t)
        Prints the Exception-message to an output String. Invokes, recursively, this method with any cause-Throwable's that are present in this Throwable.

        This method differs from toString(Throwable), in that it does not print the StackTrace's to the output-return String.
        Parameters:
        t - Any Java Throwable. Java Throwable's with one or 'cause' Throwable's will utilize more fully the printing-features of this class, 'EXCC' - though any Throwable will be properly printed.
        Returns:
        This method doesn't actually print anything to the screen or terminal, it just returns a String that you may print yourself - or write to a class StorageBuffer, or any variation of logging you wish.
        Code:
        Exact Method Body:
         // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
 // Initialize the Variables
 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

 final StringBuilder sb              = new StringBuilder();
 final Throwable     cause           = t.getCause();
 final Throwable     legacyCause     = legacyCause(t);
 final boolean       hasCause        = (cause != null);
 final boolean       hasLegacyCause  = (legacyCause != null) && (legacyCause != cause);

 String msg          = t.getMessage();
 String localMsg     = t.getLocalizedMessage();
 String legacyMsg    = (hasLegacyCause) ? legacyMsg(t) : null;

 final boolean hasMessage    = (msg != null)         && (msg.length() > 0);
 final boolean hasLocalMsg   = (localMsg != null)    && (localMsg.length() > 0);

 if (hasMessage)     msg         = StrIndent.indent(msg, 1, false, true);
 if (hasLocalMsg)    localMsg    = StrIndent.indent(localMsg, 1, false, true);


 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
 // Print the "Top Part" / "Header Part" / Error-Message to the Return-Output StringBuilder
 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

 sb.append(BRED + "THROWN: " + t.getClass().getCanonicalName() + RESET + "\n");

 if (hasMessage)
 {
     sb.append(BCYAN + "Throwable.getMessage():\n" + RESET + msg + "\n");

     if (hasLocalMsg && (! msg.equals(localMsg)))
         sb.append(BCYAN + "Throwable.getLocalizedMessage():\n" + RESET + localMsg + "\n");
 }

 else if (hasLocalMsg)
     sb.append(BCYAN + "Throwable.getLocalizedMessage():\n" + RESET + localMsg + "\n");

 else
     sb.append(BYELLOW + "No Exception Messages Provided.\n" + RESET);


 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
 // Build the StringBuilder & Return / Exit
 // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

 return
     sb.toString() +
     (hasCause
         ? StrIndent.indentTabs(toStringNoST(cause), 1)
         : "") +
     (hasLegacyCause
         ? (legacyMsg + StrIndent.indentTabs(toStringNoST(legacyCause), 1))
         : "");

      • legacyCause

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        protected static java.lang.Throwable legacyCause​(java.lang.Throwable t)
        Helper Method for retrieving exceptions that function in a very similar fashion to a 'cause' exception.
        Parameters:
        t - Any Java Throwable
        Returns:
        For legacy exception classes, this will return the 'cause', using the older method for extracting that cause.
        Code:
        Exact Method Body:
         if (t instanceof InvocationTargetException)
     return ((InvocationTargetException) t).getTargetException();

 if (t instanceof ExceptionInInitializerError)
     return ((ExceptionInInitializerError) t).getException();

 return null;

      • legacyMsg

        🡅  ⇈  ⮫ 🗕  🗗  🗖 
        protected static java.lang.String legacyMsg​(java.lang.Throwable t)
        Generates a simple descriptive String whenever there is a cause exception present that has been extracted from one of the older exception classes that can produce such legacy causes.
        Parameters:
        t -
        Returns:
        A descriptive String explaining the legacy cause feature
        Code:
        Exact Method Body:
         if (t instanceof InvocationTargetException)
     return "InvocationTargetException.getTargetException():\n";

 if (t instanceof ExceptionInInitializerError)
     return "ExceptionInInitializerError.getException():\n";

 return null;