Class ExceptionUtils
- java.lang.Object
-
- org.codehaus.plexus.util.ExceptionUtils
-
public class ExceptionUtils extends Object
ExceptionUtilsprovides utilities for manipulatingThrowableobjects.- Since:
- 1.0
- Author:
- Daniel Rall, Dmitri Plotnikov, Stephen Colebourne
-
-
Field Summary
Fields Modifier and Type Field Description protected static String[]CAUSE_METHOD_NAMESThe names of methods commonly used to access a wrapped exception.
-
Constructor Summary
Constructors Modifier Constructor Description protectedExceptionUtils()Constructs a newExceptionUtils.
-
Method Summary
All Methods Static Methods Concrete Methods Modifier and Type Method Description static voidaddCauseMethodName(String methodName)Adds to the list of method names used in the search forThrowableobjects.static ThrowablegetCause(Throwable throwable)Introspects the specifiedThrowableto obtain the cause.static ThrowablegetCause(Throwable throwable, String[] methodNames)Introspects the specifiedThrowableto obtain the cause using a supplied array of method names.static StringgetFullStackTrace(Throwable t)A way to get the entire nested stack-trace of an throwable.static ThrowablegetRootCause(Throwable throwable)Walks through the exception chain to the last element -- the "root" of the tree -- usinggetCause(Throwable), and returns that exception.static String[]getRootCauseStackTrace(Throwable t)Creates a compact stack trace for the root cause of the supplied throwable.static String[]getStackFrames(Throwable t)Captures the stack trace associated with the specifiedThrowableobject, decomposing it into a list of stack frames.static StringgetStackTrace(Throwable t)A convenient way of extracting the stack trace from an exception.static intgetThrowableCount(Throwable throwable)Returns the number ofThrowableobjects in the exception chain.static Throwable[]getThrowables(Throwable throwable)Returns the list ofThrowableobjects in the exception chain.static intindexOfThrowable(Throwable throwable, Class type)Delegates toindexOfThrowable(Throwable, Class, int), starting the search at the beginning of the exception chain.static intindexOfThrowable(Throwable throwable, Class type, int fromIndex)Returns the (zero based) index, of the firstThrowablethat matches the specified type in the exception chain ofThrowableobjects with an index greater than or equal to the specified index, or-1if the type is not found.static booleanisNestedThrowable(Throwable throwable)Whether an Throwable is considered nested or not.static voidprintRootCauseStackTrace(Throwable t)Equivalent to printRootCauseStackTrace(t, System.err)static voidprintRootCauseStackTrace(Throwable t, PrintStream stream)Prints a compact stack trace for the root cause of a throwable.static voidprintRootCauseStackTrace(Throwable t, PrintWriter writer)Same as printRootCauseStackTrace(t, stream), except it takes a PrintWriter as an argument.
-
-
-
Field Detail
-
CAUSE_METHOD_NAMES
protected static String[] CAUSE_METHOD_NAMES
The names of methods commonly used to access a wrapped exception.
-
-
Method Detail
-
addCauseMethodName
public static void addCauseMethodName(String methodName)
Adds to the list of method names used in the search for
Throwableobjects.- Parameters:
methodName- the methodName to add to the list, null and empty strings are ignored
-
getCause
public static Throwable getCause(Throwable throwable)
Introspects the specified
Throwableto obtain the cause.The method searches for methods with specific names that return a
Throwableobject. This will pick up most wrapping exceptions, including those from JDK 1.4, and The method names can be added to usingaddCauseMethodName(String). The default list searched for are:getCause()getNextException()getTargetException()getException()getSourceException()getRootCause()getCausedByException()getNested()
In the absence of any such method, the object is inspected for a
detailfield assignable to aThrowable.If none of the above is found, returns
null.- Parameters:
throwable- The exception to introspect for a cause.- Returns:
- The cause of the
Throwable. - Throws:
NullPointerException- if the throwable is null
-
getCause
public static Throwable getCause(Throwable throwable, String[] methodNames)
Introspects the specified
Throwableto obtain the cause using a supplied array of method names.- Parameters:
throwable- The exception to introspect for a cause.methodNames- the methods names to match- Returns:
- The cause of the
Throwable. - Throws:
NullPointerException- if the method names array is null or contains nullNullPointerException- if the throwable is null
-
getRootCause
public static Throwable getRootCause(Throwable throwable)
Walks through the exception chain to the last element -- the "root" of the tree -- using
getCause(Throwable), and returns that exception.- Parameters:
throwable- the throwable to get the root cause for- Returns:
- The root cause of the
Throwable.
-
getThrowableCount
public static int getThrowableCount(Throwable throwable)
Returns the number of
Throwableobjects in the exception chain.- Parameters:
throwable- the exception to inspect- Returns:
- The throwable count.
-
getThrowables
public static Throwable[] getThrowables(Throwable throwable)
Returns the list of
Throwableobjects in the exception chain.- Parameters:
throwable- the exception to inspect- Returns:
- The list of
Throwableobjects.
-
indexOfThrowable
public static int indexOfThrowable(Throwable throwable, Class type)
Delegates to
indexOfThrowable(Throwable, Class, int), starting the search at the beginning of the exception chain.- Parameters:
throwable- the exception to inspecttype-Classto look for- Returns:
- index of the stack matching the type
- See Also:
indexOfThrowable(Throwable, Class, int)
-
indexOfThrowable
public static int indexOfThrowable(Throwable throwable, Class type, int fromIndex)
Returns the (zero based) index, of the first
Throwablethat matches the specified type in the exception chain ofThrowableobjects with an index greater than or equal to the specified index, or-1if the type is not found.- Parameters:
throwable- the exception to inspecttype-Classto look forfromIndex- the (zero based) index of the starting position in the chain to be searched- Returns:
- the first occurrence of the type in the chain, or
-1if the type is not found - Throws:
IndexOutOfBoundsException- If thefromIndexargument is negative or not less than the count ofThrowables in the chain.
-
printRootCauseStackTrace
public static void printRootCauseStackTrace(Throwable t, PrintStream stream)
Prints a compact stack trace for the root cause of a throwable. The compact stack trace starts with the root cause and prints stack frames up to the place where it was caught and wrapped. Then it prints the wrapped exception and continues with stack frames until the wrapper exception is caught and wrapped again, etc.The method is equivalent to t.printStackTrace() for throwables that don't have nested causes.
- Parameters:
t- the exceptionstream- the stream
-
printRootCauseStackTrace
public static void printRootCauseStackTrace(Throwable t)
Equivalent to printRootCauseStackTrace(t, System.err)- Parameters:
t- the exception
-
printRootCauseStackTrace
public static void printRootCauseStackTrace(Throwable t, PrintWriter writer)
Same as printRootCauseStackTrace(t, stream), except it takes a PrintWriter as an argument.- Parameters:
t- the causewriter- the writer
-
getRootCauseStackTrace
public static String[] getRootCauseStackTrace(Throwable t)
Creates a compact stack trace for the root cause of the supplied throwable. SeeprintRootCauseStackTrace(Throwable t, PrintStream s)- Parameters:
t- the cause- Returns:
- the Stack
-
getStackTrace
public static String getStackTrace(Throwable t)
A convenient way of extracting the stack trace from an exception.- Parameters:
t- TheThrowable.- Returns:
- The stack trace as generated by the exception's
printStackTrace(PrintWriter)method.
-
getFullStackTrace
public static String getFullStackTrace(Throwable t)
A way to get the entire nested stack-trace of an throwable.- Parameters:
t- TheThrowable.- Returns:
- The nested stack trace, with the root cause first.
-
isNestedThrowable
public static boolean isNestedThrowable(Throwable throwable)
Whether an Throwable is considered nested or not.- Parameters:
throwable- TheThrowable.- Returns:
- boolean true/false
-
-