From ccaab5d0b312b28ab15833ab8f11dd809ec93aab Mon Sep 17 00:00:00 2001 From: Samuel Tardieu Date: Wed, 14 Sep 2011 23:54:46 +0200 Subject: Convert to Unix end-of-line format --- .../commons/lang3/exception/ExceptionUtils.java | 1394 ++++++++++---------- 1 file changed, 697 insertions(+), 697 deletions(-) (limited to 'src/org/apache/commons/lang3/exception/ExceptionUtils.java') diff --git a/src/org/apache/commons/lang3/exception/ExceptionUtils.java b/src/org/apache/commons/lang3/exception/ExceptionUtils.java index 68d3e53..9adfcd9 100644 --- a/src/org/apache/commons/lang3/exception/ExceptionUtils.java +++ b/src/org/apache/commons/lang3/exception/ExceptionUtils.java @@ -1,697 +1,697 @@ -/* - * Licensed to the Apache Software Foundation (ASF) under one or more - * contributor license agreements. See the NOTICE file distributed with - * this work for additional information regarding copyright ownership. - * The ASF licenses this file to You under the Apache License, Version 2.0 - * (the "License"); you may not use this file except in compliance with - * the License. You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ -package org.apache.commons.lang3.exception; - -import java.io.PrintStream; -import java.io.PrintWriter; -import java.io.StringWriter; -import java.lang.reflect.InvocationTargetException; -import java.lang.reflect.Method; -import java.util.ArrayList; -import java.util.List; -import java.util.StringTokenizer; - -import org.apache.commons.lang3.ArrayUtils; -import org.apache.commons.lang3.ClassUtils; -import org.apache.commons.lang3.StringUtils; -import org.apache.commons.lang3.SystemUtils; - -/** - *

Provides utilities for manipulating and examining - * Throwable objects.

- * - * @since 1.0 - * @version $Id: ExceptionUtils.java 1144929 2011-07-10 18:26:16Z ggregory $ - */ -public class ExceptionUtils { - - /** - *

Used when printing stack frames to denote the start of a - * wrapped exception.

- * - *

Package private for accessibility by test suite.

- */ - static final String WRAPPED_MARKER = " [wrapped] "; - - /** - *

The names of methods commonly used to access a wrapped exception.

- */ - // TODO: Remove in Lang 4.0 - private static final String[] CAUSE_METHOD_NAMES = { - "getCause", - "getNextException", - "getTargetException", - "getException", - "getSourceException", - "getRootCause", - "getCausedByException", - "getNested", - "getLinkedException", - "getNestedException", - "getLinkedCause", - "getThrowable", - }; - - /** - *

- * Public constructor allows an instance of ExceptionUtils to be created, although that is not - * normally necessary. - *

- */ - public ExceptionUtils() { - super(); - } - - //----------------------------------------------------------------------- - /** - *

Returns the default names used when searching for the cause of an exception.

- * - *

This may be modified and used in the overloaded getCause(Throwable, String[]) method.

- * - * @return cloned array of the default method names - * @since 3.0 - * @deprecated This feature will be removed in Lang 4.0 - */ - @Deprecated - public static String[] getDefaultCauseMethodNames() { - return ArrayUtils.clone(CAUSE_METHOD_NAMES); - } - - //----------------------------------------------------------------------- - /** - *

Introspects the Throwable to obtain the cause.

- * - *

The method searches for methods with specific names that return a - * Throwable object. This will pick up most wrapping exceptions, - * including those from JDK 1.4. - * - *

The default list searched for are:

- * - * - *

If none of the above is found, returns null.

- * - * @param throwable the throwable to introspect for a cause, may be null - * @return the cause of the Throwable, - * null if none found or null throwable input - * @since 1.0 - * @deprecated This feature will be removed in Lang 4.0 - */ - @Deprecated - public static Throwable getCause(Throwable throwable) { - return getCause(throwable, CAUSE_METHOD_NAMES); - } - - /** - *

Introspects the Throwable to obtain the cause.

- * - *

A null set of method names means use the default set. - * A null in the set of method names will be ignored.

- * - * @param throwable the throwable to introspect for a cause, may be null - * @param methodNames the method names, null treated as default set - * @return the cause of the Throwable, - * null if none found or null throwable input - * @since 1.0 - * @deprecated This feature will be removed in Lang 4.0 - */ - @Deprecated - public static Throwable getCause(Throwable throwable, String[] methodNames) { - if (throwable == null) { - return null; - } - - if (methodNames == null) { - methodNames = CAUSE_METHOD_NAMES; - } - - for (String methodName : methodNames) { - if (methodName != null) { - Throwable cause = getCauseUsingMethodName(throwable, methodName); - if (cause != null) { - return cause; - } - } - } - - return null; - } - - /** - *

Introspects the Throwable to obtain the root cause.

- * - *

This method walks through the exception chain to the last element, - * "root" of the tree, using {@link #getCause(Throwable)}, and - * returns that exception.

- * - *

From version 2.2, this method handles recursive cause structures - * that might otherwise cause infinite loops. If the throwable parameter - * has a cause of itself, then null will be returned. If the throwable - * parameter cause chain loops, the last element in the chain before the - * loop is returned.

- * - * @param throwable the throwable to get the root cause for, may be null - * @return the root cause of the Throwable, - * null if none found or null throwable input - */ - public static Throwable getRootCause(Throwable throwable) { - List list = getThrowableList(throwable); - return (list.size() < 2 ? null : (Throwable)list.get(list.size() - 1)); - } - - /** - *

Finds a Throwable by method name.

- * - * @param throwable the exception to examine - * @param methodName the name of the method to find and invoke - * @return the wrapped exception, or null if not found - */ - // TODO: Remove in Lang 4.0 - private static Throwable getCauseUsingMethodName(Throwable throwable, String methodName) { - Method method = null; - try { - method = throwable.getClass().getMethod(methodName); - } catch (NoSuchMethodException ignored) { // NOPMD - // exception ignored - } catch (SecurityException ignored) { // NOPMD - // exception ignored - } - - if (method != null && Throwable.class.isAssignableFrom(method.getReturnType())) { - try { - return (Throwable) method.invoke(throwable); - } catch (IllegalAccessException ignored) { // NOPMD - // exception ignored - } catch (IllegalArgumentException ignored) { // NOPMD - // exception ignored - } catch (InvocationTargetException ignored) { // NOPMD - // exception ignored - } - } - return null; - } - - //----------------------------------------------------------------------- - /** - *

Counts the number of Throwable objects in the - * exception chain.

- * - *

A throwable without cause will return 1. - * A throwable with one cause will return 2 and so on. - * A null throwable will return 0.

- * - *

From version 2.2, this method handles recursive cause structures - * that might otherwise cause infinite loops. The cause chain is - * processed until the end is reached, or until the next item in the - * chain is already in the result set.

- * - * @param throwable the throwable to inspect, may be null - * @return the count of throwables, zero if null input - */ - public static int getThrowableCount(Throwable throwable) { - return getThrowableList(throwable).size(); - } - - /** - *

Returns the list of Throwable objects in the - * exception chain.

- * - *

A throwable without cause will return an array containing - * one element - the input throwable. - * A throwable with one cause will return an array containing - * two elements. - the input throwable and the cause throwable. - * A null throwable will return an array of size zero.

- * - *

From version 2.2, this method handles recursive cause structures - * that might otherwise cause infinite loops. The cause chain is - * processed until the end is reached, or until the next item in the - * chain is already in the result set.

- * - * @see #getThrowableList(Throwable) - * @param throwable the throwable to inspect, may be null - * @return the array of throwables, never null - */ - public static Throwable[] getThrowables(Throwable throwable) { - List list = getThrowableList(throwable); - return list.toArray(new Throwable[list.size()]); - } - - /** - *

Returns the list of Throwable objects in the - * exception chain.

- * - *

A throwable without cause will return a list containing - * one element - the input throwable. - * A throwable with one cause will return a list containing - * two elements. - the input throwable and the cause throwable. - * A null throwable will return a list of size zero.

- * - *

This method handles recursive cause structures that might - * otherwise cause infinite loops. The cause chain is processed until - * the end is reached, or until the next item in the chain is already - * in the result set.

- * - * @param throwable the throwable to inspect, may be null - * @return the list of throwables, never null - * @since Commons Lang 2.2 - */ - public static List getThrowableList(Throwable throwable) { - List list = new ArrayList(); - while (throwable != null && list.contains(throwable) == false) { - list.add(throwable); - throwable = ExceptionUtils.getCause(throwable); - } - return list; - } - - //----------------------------------------------------------------------- - /** - *

Returns the (zero based) index of the first Throwable - * that matches the specified class (exactly) in the exception chain. - * Subclasses of the specified class do not match - see - * {@link #indexOfType(Throwable, Class)} for the opposite.

- * - *

A null throwable returns -1. - * A null type returns -1. - * No match in the chain returns -1.

- * - * @param throwable the throwable to inspect, may be null - * @param clazz the class to search for, subclasses do not match, null returns -1 - * @return the index into the throwable chain, -1 if no match or null input - */ - public static int indexOfThrowable(Throwable throwable, Class clazz) { - return indexOf(throwable, clazz, 0, false); - } - - /** - *

Returns the (zero based) index of the first Throwable - * that matches the specified type in the exception chain from - * a specified index. - * Subclasses of the specified class do not match - see - * {@link #indexOfType(Throwable, Class, int)} for the opposite.

- * - *

A null throwable returns -1. - * A null type returns -1. - * No match in the chain returns -1. - * A negative start index is treated as zero. - * A start index greater than the number of throwables returns -1.

- * - * @param throwable the throwable to inspect, may be null - * @param clazz the class to search for, subclasses do not match, null returns -1 - * @param fromIndex the (zero based) index of the starting position, - * negative treated as zero, larger than chain size returns -1 - * @return the index into the throwable chain, -1 if no match or null input - */ - public static int indexOfThrowable(Throwable throwable, Class clazz, int fromIndex) { - return indexOf(throwable, clazz, fromIndex, false); - } - - //----------------------------------------------------------------------- - /** - *

Returns the (zero based) index of the first Throwable - * that matches the specified class or subclass in the exception chain. - * Subclasses of the specified class do match - see - * {@link #indexOfThrowable(Throwable, Class)} for the opposite.

- * - *

A null throwable returns -1. - * A null type returns -1. - * No match in the chain returns -1.

- * - * @param throwable the throwable to inspect, may be null - * @param type the type to search for, subclasses match, null returns -1 - * @return the index into the throwable chain, -1 if no match or null input - * @since 2.1 - */ - public static int indexOfType(Throwable throwable, Class type) { - return indexOf(throwable, type, 0, true); - } - - /** - *

Returns the (zero based) index of the first Throwable - * that matches the specified type in the exception chain from - * a specified index. - * Subclasses of the specified class do match - see - * {@link #indexOfThrowable(Throwable, Class)} for the opposite.

- * - *

A null throwable returns -1. - * A null type returns -1. - * No match in the chain returns -1. - * A negative start index is treated as zero. - * A start index greater than the number of throwables returns -1.

- * - * @param throwable the throwable to inspect, may be null - * @param type the type to search for, subclasses match, null returns -1 - * @param fromIndex the (zero based) index of the starting position, - * negative treated as zero, larger than chain size returns -1 - * @return the index into the throwable chain, -1 if no match or null input - * @since 2.1 - */ - public static int indexOfType(Throwable throwable, Class type, int fromIndex) { - return indexOf(throwable, type, fromIndex, true); - } - - /** - *

Worker method for the indexOfType methods.

- * - * @param throwable the throwable to inspect, may be null - * @param type the type to search for, subclasses match, null returns -1 - * @param fromIndex the (zero based) index of the starting position, - * negative treated as zero, larger than chain size returns -1 - * @param subclass if true, compares with {@link Class#isAssignableFrom(Class)}, otherwise compares - * using references - * @return index of the type within throwables nested withing the specified throwable - */ - private static int indexOf(Throwable throwable, Class type, int fromIndex, boolean subclass) { - if (throwable == null || type == null) { - return -1; - } - if (fromIndex < 0) { - fromIndex = 0; - } - Throwable[] throwables = ExceptionUtils.getThrowables(throwable); - if (fromIndex >= throwables.length) { - return -1; - } - if (subclass) { - for (int i = fromIndex; i < throwables.length; i++) { - if (type.isAssignableFrom(throwables[i].getClass())) { - return i; - } - } - } else { - for (int i = fromIndex; i < throwables.length; i++) { - if (type.equals(throwables[i].getClass())) { - return i; - } - } - } - return -1; - } - - //----------------------------------------------------------------------- - /** - *

Prints a compact stack trace for the root cause of a throwable - * to System.err.

- * - *

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 output of this method is consistent across JDK versions. - * Note that this is the opposite order to the JDK1.4 display.

- * - *

The method is equivalent to printStackTrace for throwables - * that don't have nested causes.

- * - * @param throwable the throwable to output - * @since 2.0 - */ - public static void printRootCauseStackTrace(Throwable throwable) { - printRootCauseStackTrace(throwable, System.err); - } - - /** - *

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 output of this method is consistent across JDK versions. - * Note that this is the opposite order to the JDK1.4 display.

- * - *

The method is equivalent to printStackTrace for throwables - * that don't have nested causes.

- * - * @param throwable the throwable to output, may be null - * @param stream the stream to output to, may not be null - * @throws IllegalArgumentException if the stream is null - * @since 2.0 - */ - public static void printRootCauseStackTrace(Throwable throwable, PrintStream stream) { - if (throwable == null) { - return; - } - if (stream == null) { - throw new IllegalArgumentException("The PrintStream must not be null"); - } - String trace[] = getRootCauseStackTrace(throwable); - for (String element : trace) { - stream.println(element); - } - stream.flush(); - } - - /** - *

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 output of this method is consistent across JDK versions. - * Note that this is the opposite order to the JDK1.4 display.

- * - *

The method is equivalent to printStackTrace for throwables - * that don't have nested causes.

- * - * @param throwable the throwable to output, may be null - * @param writer the writer to output to, may not be null - * @throws IllegalArgumentException if the writer is null - * @since 2.0 - */ - public static void printRootCauseStackTrace(Throwable throwable, PrintWriter writer) { - if (throwable == null) { - return; - } - if (writer == null) { - throw new IllegalArgumentException("The PrintWriter must not be null"); - } - String trace[] = getRootCauseStackTrace(throwable); - for (String element : trace) { - writer.println(element); - } - writer.flush(); - } - - //----------------------------------------------------------------------- - /** - *

Creates a compact stack trace for the root cause of the supplied - * Throwable.

- * - *

The output of this method is consistent across JDK versions. - * It consists of the root exception followed by each of its wrapping - * exceptions separated by '[wrapped]'. Note that this is the opposite - * order to the JDK1.4 display.

- * - * @param throwable the throwable to examine, may be null - * @return an array of stack trace frames, never null - * @since 2.0 - */ - public static String[] getRootCauseStackTrace(Throwable throwable) { - if (throwable == null) { - return ArrayUtils.EMPTY_STRING_ARRAY; - } - Throwable throwables[] = getThrowables(throwable); - int count = throwables.length; - List frames = new ArrayList(); - List nextTrace = getStackFrameList(throwables[count - 1]); - for (int i = count; --i >= 0;) { - List trace = nextTrace; - if (i != 0) { - nextTrace = getStackFrameList(throwables[i - 1]); - removeCommonFrames(trace, nextTrace); - } - if (i == count - 1) { - frames.add(throwables[i].toString()); - } else { - frames.add(WRAPPED_MARKER + throwables[i].toString()); - } - for (int j = 0; j < trace.size(); j++) { - frames.add(trace.get(j)); - } - } - return frames.toArray(new String[frames.size()]); - } - - /** - *

Removes common frames from the cause trace given the two stack traces.

- * - * @param causeFrames stack trace of a cause throwable - * @param wrapperFrames stack trace of a wrapper throwable - * @throws IllegalArgumentException if either argument is null - * @since 2.0 - */ - public static void removeCommonFrames(List causeFrames, List wrapperFrames) { - if (causeFrames == null || wrapperFrames == null) { - throw new IllegalArgumentException("The List must not be null"); - } - int causeFrameIndex = causeFrames.size() - 1; - int wrapperFrameIndex = wrapperFrames.size() - 1; - while (causeFrameIndex >= 0 && wrapperFrameIndex >= 0) { - // Remove the frame from the cause trace if it is the same - // as in the wrapper trace - String causeFrame = causeFrames.get(causeFrameIndex); - String wrapperFrame = wrapperFrames.get(wrapperFrameIndex); - if (causeFrame.equals(wrapperFrame)) { - causeFrames.remove(causeFrameIndex); - } - causeFrameIndex--; - wrapperFrameIndex--; - } - } - - //----------------------------------------------------------------------- - /** - *

Gets the stack trace from a Throwable as a String.

- * - *

The result of this method vary by JDK version as this method - * uses {@link Throwable#printStackTrace(java.io.PrintWriter)}. - * On JDK1.3 and earlier, the cause exception will not be shown - * unless the specified throwable alters printStackTrace.

- * - * @param throwable the Throwable to be examined - * @return the stack trace as generated by the exception's - * printStackTrace(PrintWriter) method - */ - public static String getStackTrace(Throwable throwable) { - StringWriter sw = new StringWriter(); - PrintWriter pw = new PrintWriter(sw, true); - throwable.printStackTrace(pw); - return sw.getBuffer().toString(); - } - - /** - *

Captures the stack trace associated with the specified - * Throwable object, decomposing it into a list of - * stack frames.

- * - *

The result of this method vary by JDK version as this method - * uses {@link Throwable#printStackTrace(java.io.PrintWriter)}. - * On JDK1.3 and earlier, the cause exception will not be shown - * unless the specified throwable alters printStackTrace.

- * - * @param throwable the Throwable to examine, may be null - * @return an array of strings describing each stack frame, never null - */ - public static String[] getStackFrames(Throwable throwable) { - if (throwable == null) { - return ArrayUtils.EMPTY_STRING_ARRAY; - } - return getStackFrames(getStackTrace(throwable)); - } - - //----------------------------------------------------------------------- - /** - *

Returns an array where each element is a line from the argument.

- * - *

The end of line is determined by the value of {@link SystemUtils#LINE_SEPARATOR}.

- * - * @param stackTrace a stack trace String - * @return an array where each element is a line from the argument - */ - static String[] getStackFrames(String stackTrace) { - String linebreak = SystemUtils.LINE_SEPARATOR; - StringTokenizer frames = new StringTokenizer(stackTrace, linebreak); - List list = new ArrayList(); - while (frames.hasMoreTokens()) { - list.add(frames.nextToken()); - } - return list.toArray(new String[list.size()]); - } - - /** - *

Produces a List of stack frames - the message - * is not included. Only the trace of the specified exception is - * returned, any caused by trace is stripped.

- * - *

This works in most cases - it will only fail if the exception - * message contains a line that starts with: - * "   at".

- * - * @param t is any throwable - * @return List of stack frames - */ - static List getStackFrameList(Throwable t) { - String stackTrace = getStackTrace(t); - String linebreak = SystemUtils.LINE_SEPARATOR; - StringTokenizer frames = new StringTokenizer(stackTrace, linebreak); - List list = new ArrayList(); - boolean traceStarted = false; - while (frames.hasMoreTokens()) { - String token = frames.nextToken(); - // Determine if the line starts with at - int at = token.indexOf("at"); - if (at != -1 && token.substring(0, at).trim().length() == 0) { - traceStarted = true; - list.add(token); - } else if (traceStarted) { - break; - } - } - return list; - } - - //----------------------------------------------------------------------- - /** - * Gets a short message summarising the exception. - *

- * The message returned is of the form - * {ClassNameWithoutPackage}: {ThrowableMessage} - * - * @param th the throwable to get a message for, null returns empty string - * @return the message, non-null - * @since Commons Lang 2.2 - */ - public static String getMessage(Throwable th) { - if (th == null) { - return ""; - } - String clsName = ClassUtils.getShortClassName(th, null); - String msg = th.getMessage(); - return clsName + ": " + StringUtils.defaultString(msg); - } - - //----------------------------------------------------------------------- - /** - * Gets a short message summarising the root cause exception. - *

- * The message returned is of the form - * {ClassNameWithoutPackage}: {ThrowableMessage} - * - * @param th the throwable to get a message for, null returns empty string - * @return the message, non-null - * @since Commons Lang 2.2 - */ - public static String getRootCauseMessage(Throwable th) { - Throwable root = ExceptionUtils.getRootCause(th); - root = (root == null ? th : root); - return getMessage(root); - } - -} +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.commons.lang3.exception; + +import java.io.PrintStream; +import java.io.PrintWriter; +import java.io.StringWriter; +import java.lang.reflect.InvocationTargetException; +import java.lang.reflect.Method; +import java.util.ArrayList; +import java.util.List; +import java.util.StringTokenizer; + +import org.apache.commons.lang3.ArrayUtils; +import org.apache.commons.lang3.ClassUtils; +import org.apache.commons.lang3.StringUtils; +import org.apache.commons.lang3.SystemUtils; + +/** + *

Provides utilities for manipulating and examining + * Throwable objects.

+ * + * @since 1.0 + * @version $Id: ExceptionUtils.java 1144929 2011-07-10 18:26:16Z ggregory $ + */ +public class ExceptionUtils { + + /** + *

Used when printing stack frames to denote the start of a + * wrapped exception.

+ * + *

Package private for accessibility by test suite.

+ */ + static final String WRAPPED_MARKER = " [wrapped] "; + + /** + *

The names of methods commonly used to access a wrapped exception.

+ */ + // TODO: Remove in Lang 4.0 + private static final String[] CAUSE_METHOD_NAMES = { + "getCause", + "getNextException", + "getTargetException", + "getException", + "getSourceException", + "getRootCause", + "getCausedByException", + "getNested", + "getLinkedException", + "getNestedException", + "getLinkedCause", + "getThrowable", + }; + + /** + *

+ * Public constructor allows an instance of ExceptionUtils to be created, although that is not + * normally necessary. + *

+ */ + public ExceptionUtils() { + super(); + } + + //----------------------------------------------------------------------- + /** + *

Returns the default names used when searching for the cause of an exception.

+ * + *

This may be modified and used in the overloaded getCause(Throwable, String[]) method.

+ * + * @return cloned array of the default method names + * @since 3.0 + * @deprecated This feature will be removed in Lang 4.0 + */ + @Deprecated + public static String[] getDefaultCauseMethodNames() { + return ArrayUtils.clone(CAUSE_METHOD_NAMES); + } + + //----------------------------------------------------------------------- + /** + *

Introspects the Throwable to obtain the cause.

+ * + *

The method searches for methods with specific names that return a + * Throwable object. This will pick up most wrapping exceptions, + * including those from JDK 1.4. + * + *

The default list searched for are:

+ *
    + *
  • getCause()
    • + *
  • getNextException()
    • + *
  • getTargetException()
    • + *
  • getException()
    • + *
  • getSourceException()
    • + *
  • getRootCause()
    • + *
  • getCausedByException()
    • + *
  • getNested()
    • + *
+ * + *

If none of the above is found, returns null.

+ * + * @param throwable the throwable to introspect for a cause, may be null + * @return the cause of the Throwable, + * null if none found or null throwable input + * @since 1.0 + * @deprecated This feature will be removed in Lang 4.0 + */ + @Deprecated + public static Throwable getCause(Throwable throwable) { + return getCause(throwable, CAUSE_METHOD_NAMES); + } + + /** + *

Introspects the Throwable to obtain the cause.

+ * + *

A null set of method names means use the default set. + * A null in the set of method names will be ignored.

+ * + * @param throwable the throwable to introspect for a cause, may be null + * @param methodNames the method names, null treated as default set + * @return the cause of the Throwable, + * null if none found or null throwable input + * @since 1.0 + * @deprecated This feature will be removed in Lang 4.0 + */ + @Deprecated + public static Throwable getCause(Throwable throwable, String[] methodNames) { + if (throwable == null) { + return null; + } + + if (methodNames == null) { + methodNames = CAUSE_METHOD_NAMES; + } + + for (String methodName : methodNames) { + if (methodName != null) { + Throwable cause = getCauseUsingMethodName(throwable, methodName); + if (cause != null) { + return cause; + } + } + } + + return null; + } + + /** + *

Introspects the Throwable to obtain the root cause.

+ * + *

This method walks through the exception chain to the last element, + * "root" of the tree, using {@link #getCause(Throwable)}, and + * returns that exception.

+ * + *

From version 2.2, this method handles recursive cause structures + * that might otherwise cause infinite loops. If the throwable parameter + * has a cause of itself, then null will be returned. If the throwable + * parameter cause chain loops, the last element in the chain before the + * loop is returned.

+ * + * @param throwable the throwable to get the root cause for, may be null + * @return the root cause of the Throwable, + * null if none found or null throwable input + */ + public static Throwable getRootCause(Throwable throwable) { + List list = getThrowableList(throwable); + return (list.size() < 2 ? null : (Throwable)list.get(list.size() - 1)); + } + + /** + *

Finds a Throwable by method name.

+ * + * @param throwable the exception to examine + * @param methodName the name of the method to find and invoke + * @return the wrapped exception, or null if not found + */ + // TODO: Remove in Lang 4.0 + private static Throwable getCauseUsingMethodName(Throwable throwable, String methodName) { + Method method = null; + try { + method = throwable.getClass().getMethod(methodName); + } catch (NoSuchMethodException ignored) { // NOPMD + // exception ignored + } catch (SecurityException ignored) { // NOPMD + // exception ignored + } + + if (method != null && Throwable.class.isAssignableFrom(method.getReturnType())) { + try { + return (Throwable) method.invoke(throwable); + } catch (IllegalAccessException ignored) { // NOPMD + // exception ignored + } catch (IllegalArgumentException ignored) { // NOPMD + // exception ignored + } catch (InvocationTargetException ignored) { // NOPMD + // exception ignored + } + } + return null; + } + + //----------------------------------------------------------------------- + /** + *

Counts the number of Throwable objects in the + * exception chain.

+ * + *

A throwable without cause will return 1. + * A throwable with one cause will return 2 and so on. + * A null throwable will return 0.

+ * + *

From version 2.2, this method handles recursive cause structures + * that might otherwise cause infinite loops. The cause chain is + * processed until the end is reached, or until the next item in the + * chain is already in the result set.

+ * + * @param throwable the throwable to inspect, may be null + * @return the count of throwables, zero if null input + */ + public static int getThrowableCount(Throwable throwable) { + return getThrowableList(throwable).size(); + } + + /** + *

Returns the list of Throwable objects in the + * exception chain.

+ * + *

A throwable without cause will return an array containing + * one element - the input throwable. + * A throwable with one cause will return an array containing + * two elements. - the input throwable and the cause throwable. + * A null throwable will return an array of size zero.

+ * + *

From version 2.2, this method handles recursive cause structures + * that might otherwise cause infinite loops. The cause chain is + * processed until the end is reached, or until the next item in the + * chain is already in the result set.

+ * + * @see #getThrowableList(Throwable) + * @param throwable the throwable to inspect, may be null + * @return the array of throwables, never null + */ + public static Throwable[] getThrowables(Throwable throwable) { + List list = getThrowableList(throwable); + return list.toArray(new Throwable[list.size()]); + } + + /** + *

Returns the list of Throwable objects in the + * exception chain.

+ * + *

A throwable without cause will return a list containing + * one element - the input throwable. + * A throwable with one cause will return a list containing + * two elements. - the input throwable and the cause throwable. + * A null throwable will return a list of size zero.

+ * + *

This method handles recursive cause structures that might + * otherwise cause infinite loops. The cause chain is processed until + * the end is reached, or until the next item in the chain is already + * in the result set.

+ * + * @param throwable the throwable to inspect, may be null + * @return the list of throwables, never null + * @since Commons Lang 2.2 + */ + public static List getThrowableList(Throwable throwable) { + List list = new ArrayList(); + while (throwable != null && list.contains(throwable) == false) { + list.add(throwable); + throwable = ExceptionUtils.getCause(throwable); + } + return list; + } + + //----------------------------------------------------------------------- + /** + *

Returns the (zero based) index of the first Throwable + * that matches the specified class (exactly) in the exception chain. + * Subclasses of the specified class do not match - see + * {@link #indexOfType(Throwable, Class)} for the opposite.

+ * + *

A null throwable returns -1. + * A null type returns -1. + * No match in the chain returns -1.

+ * + * @param throwable the throwable to inspect, may be null + * @param clazz the class to search for, subclasses do not match, null returns -1 + * @return the index into the throwable chain, -1 if no match or null input + */ + public static int indexOfThrowable(Throwable throwable, Class clazz) { + return indexOf(throwable, clazz, 0, false); + } + + /** + *

Returns the (zero based) index of the first Throwable + * that matches the specified type in the exception chain from + * a specified index. + * Subclasses of the specified class do not match - see + * {@link #indexOfType(Throwable, Class, int)} for the opposite.

+ * + *

A null throwable returns -1. + * A null type returns -1. + * No match in the chain returns -1. + * A negative start index is treated as zero. + * A start index greater than the number of throwables returns -1.

+ * + * @param throwable the throwable to inspect, may be null + * @param clazz the class to search for, subclasses do not match, null returns -1 + * @param fromIndex the (zero based) index of the starting position, + * negative treated as zero, larger than chain size returns -1 + * @return the index into the throwable chain, -1 if no match or null input + */ + public static int indexOfThrowable(Throwable throwable, Class clazz, int fromIndex) { + return indexOf(throwable, clazz, fromIndex, false); + } + + //----------------------------------------------------------------------- + /** + *

Returns the (zero based) index of the first Throwable + * that matches the specified class or subclass in the exception chain. + * Subclasses of the specified class do match - see + * {@link #indexOfThrowable(Throwable, Class)} for the opposite.

+ * + *

A null throwable returns -1. + * A null type returns -1. + * No match in the chain returns -1.

+ * + * @param throwable the throwable to inspect, may be null + * @param type the type to search for, subclasses match, null returns -1 + * @return the index into the throwable chain, -1 if no match or null input + * @since 2.1 + */ + public static int indexOfType(Throwable throwable, Class type) { + return indexOf(throwable, type, 0, true); + } + + /** + *

Returns the (zero based) index of the first Throwable + * that matches the specified type in the exception chain from + * a specified index. + * Subclasses of the specified class do match - see + * {@link #indexOfThrowable(Throwable, Class)} for the opposite.

+ * + *

A null throwable returns -1. + * A null type returns -1. + * No match in the chain returns -1. + * A negative start index is treated as zero. + * A start index greater than the number of throwables returns -1.

+ * + * @param throwable the throwable to inspect, may be null + * @param type the type to search for, subclasses match, null returns -1 + * @param fromIndex the (zero based) index of the starting position, + * negative treated as zero, larger than chain size returns -1 + * @return the index into the throwable chain, -1 if no match or null input + * @since 2.1 + */ + public static int indexOfType(Throwable throwable, Class type, int fromIndex) { + return indexOf(throwable, type, fromIndex, true); + } + + /** + *

Worker method for the indexOfType methods.

+ * + * @param throwable the throwable to inspect, may be null + * @param type the type to search for, subclasses match, null returns -1 + * @param fromIndex the (zero based) index of the starting position, + * negative treated as zero, larger than chain size returns -1 + * @param subclass if true, compares with {@link Class#isAssignableFrom(Class)}, otherwise compares + * using references + * @return index of the type within throwables nested withing the specified throwable + */ + private static int indexOf(Throwable throwable, Class type, int fromIndex, boolean subclass) { + if (throwable == null || type == null) { + return -1; + } + if (fromIndex < 0) { + fromIndex = 0; + } + Throwable[] throwables = ExceptionUtils.getThrowables(throwable); + if (fromIndex >= throwables.length) { + return -1; + } + if (subclass) { + for (int i = fromIndex; i < throwables.length; i++) { + if (type.isAssignableFrom(throwables[i].getClass())) { + return i; + } + } + } else { + for (int i = fromIndex; i < throwables.length; i++) { + if (type.equals(throwables[i].getClass())) { + return i; + } + } + } + return -1; + } + + //----------------------------------------------------------------------- + /** + *

Prints a compact stack trace for the root cause of a throwable + * to System.err.

+ * + *

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 output of this method is consistent across JDK versions. + * Note that this is the opposite order to the JDK1.4 display.

+ * + *

The method is equivalent to printStackTrace for throwables + * that don't have nested causes.

+ * + * @param throwable the throwable to output + * @since 2.0 + */ + public static void printRootCauseStackTrace(Throwable throwable) { + printRootCauseStackTrace(throwable, System.err); + } + + /** + *

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 output of this method is consistent across JDK versions. + * Note that this is the opposite order to the JDK1.4 display.

+ * + *

The method is equivalent to printStackTrace for throwables + * that don't have nested causes.

+ * + * @param throwable the throwable to output, may be null + * @param stream the stream to output to, may not be null + * @throws IllegalArgumentException if the stream is null + * @since 2.0 + */ + public static void printRootCauseStackTrace(Throwable throwable, PrintStream stream) { + if (throwable == null) { + return; + } + if (stream == null) { + throw new IllegalArgumentException("The PrintStream must not be null"); + } + String trace[] = getRootCauseStackTrace(throwable); + for (String element : trace) { + stream.println(element); + } + stream.flush(); + } + + /** + *

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 output of this method is consistent across JDK versions. + * Note that this is the opposite order to the JDK1.4 display.

+ * + *

The method is equivalent to printStackTrace for throwables + * that don't have nested causes.

+ * + * @param throwable the throwable to output, may be null + * @param writer the writer to output to, may not be null + * @throws IllegalArgumentException if the writer is null + * @since 2.0 + */ + public static void printRootCauseStackTrace(Throwable throwable, PrintWriter writer) { + if (throwable == null) { + return; + } + if (writer == null) { + throw new IllegalArgumentException("The PrintWriter must not be null"); + } + String trace[] = getRootCauseStackTrace(throwable); + for (String element : trace) { + writer.println(element); + } + writer.flush(); + } + + //----------------------------------------------------------------------- + /** + *

Creates a compact stack trace for the root cause of the supplied + * Throwable.

+ * + *

The output of this method is consistent across JDK versions. + * It consists of the root exception followed by each of its wrapping + * exceptions separated by '[wrapped]'. Note that this is the opposite + * order to the JDK1.4 display.

+ * + * @param throwable the throwable to examine, may be null + * @return an array of stack trace frames, never null + * @since 2.0 + */ + public static String[] getRootCauseStackTrace(Throwable throwable) { + if (throwable == null) { + return ArrayUtils.EMPTY_STRING_ARRAY; + } + Throwable throwables[] = getThrowables(throwable); + int count = throwables.length; + List frames = new ArrayList(); + List nextTrace = getStackFrameList(throwables[count - 1]); + for (int i = count; --i >= 0;) { + List trace = nextTrace; + if (i != 0) { + nextTrace = getStackFrameList(throwables[i - 1]); + removeCommonFrames(trace, nextTrace); + } + if (i == count - 1) { + frames.add(throwables[i].toString()); + } else { + frames.add(WRAPPED_MARKER + throwables[i].toString()); + } + for (int j = 0; j < trace.size(); j++) { + frames.add(trace.get(j)); + } + } + return frames.toArray(new String[frames.size()]); + } + + /** + *

Removes common frames from the cause trace given the two stack traces.

+ * + * @param causeFrames stack trace of a cause throwable + * @param wrapperFrames stack trace of a wrapper throwable + * @throws IllegalArgumentException if either argument is null + * @since 2.0 + */ + public static void removeCommonFrames(List causeFrames, List wrapperFrames) { + if (causeFrames == null || wrapperFrames == null) { + throw new IllegalArgumentException("The List must not be null"); + } + int causeFrameIndex = causeFrames.size() - 1; + int wrapperFrameIndex = wrapperFrames.size() - 1; + while (causeFrameIndex >= 0 && wrapperFrameIndex >= 0) { + // Remove the frame from the cause trace if it is the same + // as in the wrapper trace + String causeFrame = causeFrames.get(causeFrameIndex); + String wrapperFrame = wrapperFrames.get(wrapperFrameIndex); + if (causeFrame.equals(wrapperFrame)) { + causeFrames.remove(causeFrameIndex); + } + causeFrameIndex--; + wrapperFrameIndex--; + } + } + + //----------------------------------------------------------------------- + /** + *

Gets the stack trace from a Throwable as a String.

+ * + *

The result of this method vary by JDK version as this method + * uses {@link Throwable#printStackTrace(java.io.PrintWriter)}. + * On JDK1.3 and earlier, the cause exception will not be shown + * unless the specified throwable alters printStackTrace.

+ * + * @param throwable the Throwable to be examined + * @return the stack trace as generated by the exception's + * printStackTrace(PrintWriter) method + */ + public static String getStackTrace(Throwable throwable) { + StringWriter sw = new StringWriter(); + PrintWriter pw = new PrintWriter(sw, true); + throwable.printStackTrace(pw); + return sw.getBuffer().toString(); + } + + /** + *

Captures the stack trace associated with the specified + * Throwable object, decomposing it into a list of + * stack frames.

+ * + *

The result of this method vary by JDK version as this method + * uses {@link Throwable#printStackTrace(java.io.PrintWriter)}. + * On JDK1.3 and earlier, the cause exception will not be shown + * unless the specified throwable alters printStackTrace.

+ * + * @param throwable the Throwable to examine, may be null + * @return an array of strings describing each stack frame, never null + */ + public static String[] getStackFrames(Throwable throwable) { + if (throwable == null) { + return ArrayUtils.EMPTY_STRING_ARRAY; + } + return getStackFrames(getStackTrace(throwable)); + } + + //----------------------------------------------------------------------- + /** + *

Returns an array where each element is a line from the argument.

+ * + *

The end of line is determined by the value of {@link SystemUtils#LINE_SEPARATOR}.

+ * + * @param stackTrace a stack trace String + * @return an array where each element is a line from the argument + */ + static String[] getStackFrames(String stackTrace) { + String linebreak = SystemUtils.LINE_SEPARATOR; + StringTokenizer frames = new StringTokenizer(stackTrace, linebreak); + List list = new ArrayList(); + while (frames.hasMoreTokens()) { + list.add(frames.nextToken()); + } + return list.toArray(new String[list.size()]); + } + + /** + *

Produces a List of stack frames - the message + * is not included. Only the trace of the specified exception is + * returned, any caused by trace is stripped.

+ * + *

This works in most cases - it will only fail if the exception + * message contains a line that starts with: + * "   at".

+ * + * @param t is any throwable + * @return List of stack frames + */ + static List getStackFrameList(Throwable t) { + String stackTrace = getStackTrace(t); + String linebreak = SystemUtils.LINE_SEPARATOR; + StringTokenizer frames = new StringTokenizer(stackTrace, linebreak); + List list = new ArrayList(); + boolean traceStarted = false; + while (frames.hasMoreTokens()) { + String token = frames.nextToken(); + // Determine if the line starts with at + int at = token.indexOf("at"); + if (at != -1 && token.substring(0, at).trim().length() == 0) { + traceStarted = true; + list.add(token); + } else if (traceStarted) { + break; + } + } + return list; + } + + //----------------------------------------------------------------------- + /** + * Gets a short message summarising the exception. + *

+ * The message returned is of the form + * {ClassNameWithoutPackage}: {ThrowableMessage} + * + * @param th the throwable to get a message for, null returns empty string + * @return the message, non-null + * @since Commons Lang 2.2 + */ + public static String getMessage(Throwable th) { + if (th == null) { + return ""; + } + String clsName = ClassUtils.getShortClassName(th, null); + String msg = th.getMessage(); + return clsName + ": " + StringUtils.defaultString(msg); + } + + //----------------------------------------------------------------------- + /** + * Gets a short message summarising the root cause exception. + *

+ * The message returned is of the form + * {ClassNameWithoutPackage}: {ThrowableMessage} + * + * @param th the throwable to get a message for, null returns empty string + * @return the message, non-null + * @since Commons Lang 2.2 + */ + public static String getRootCauseMessage(Throwable th) { + Throwable root = ExceptionUtils.getRootCause(th); + root = (root == null ? th : root); + return getMessage(root); + } + +} -- cgit v1.1