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Posted to dev@commons.apache.org by sc...@apache.org on 2006/01/07 02:12:31 UTC
svn commit: r366617 -
/jakarta/commons/proper/lang/trunk/src/java/org/apache/commons/lang/exception/ExceptionUtils.java
Author: scolebourne
Date: Fri Jan 6 17:12:28 2006
New Revision: 366617
URL: http://svn.apache.org/viewcvs?rev=366617&view=rev
Log:
Javadoc changes, with better description of trace methods
Modified:
jakarta/commons/proper/lang/trunk/src/java/org/apache/commons/lang/exception/ExceptionUtils.java
Modified: jakarta/commons/proper/lang/trunk/src/java/org/apache/commons/lang/exception/ExceptionUtils.java
URL: http://svn.apache.org/viewcvs/jakarta/commons/proper/lang/trunk/src/java/org/apache/commons/lang/exception/ExceptionUtils.java?rev=366617&r1=366616&r2=366617&view=diff
==============================================================================
--- jakarta/commons/proper/lang/trunk/src/java/org/apache/commons/lang/exception/ExceptionUtils.java (original)
+++ jakarta/commons/proper/lang/trunk/src/java/org/apache/commons/lang/exception/ExceptionUtils.java Fri Jan 6 17:12:28 2006
@@ -1,5 +1,5 @@
/*
- * Copyright 2002-2005 The Apache Software Foundation.
+ * Copyright 2002-2006 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
@@ -29,13 +29,13 @@
import java.util.StringTokenizer;
import org.apache.commons.lang.ArrayUtils;
+import org.apache.commons.lang.NullArgumentException;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.SystemUtils;
-import org.apache.commons.lang.NullArgumentException;
/**
* <p>Provides utilities for manipulating and examining
-<code>Throwable</code> objects.</p>
+ * <code>Throwable</code> objects.</p>
*
* @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a>
* @author Dmitri Plotnikov
@@ -74,16 +74,12 @@
};
/**
- * <p>
- * The Method object for Java 1.4 getCause.
- * </p>
+ * <p>The Method object for Java 1.4 getCause.</p>
*/
private static final Method THROWABLE_CAUSE_METHOD;
/**
- * <p>
- * The Method object for Java 1.4 initCause.
- * </p>
+ * <p>The Method object for Java 1.4 initCause.</p>
*/
private static final Method THROWABLE_INITCAUSE_METHOD;
@@ -149,16 +145,12 @@
}
/**
- * <p>
- * Sets the cause of a <code>Throwable</code> using introspection, allowing source code compatibility between
- * pre-1.4 and post-1.4 Java releases.
- * </p>
- *
- * <p>
- * The typical use of this method is inside a constructor as in the following example:
- * </p>
- *
- * <p>
+ * <p>Sets the cause of a <code>Throwable</code> using introspection, allowing
+ * source code compatibility between pre-1.4 and post-1.4 Java releases.</p>
+ *
+ * <p>The typical use of this method is inside a constructor as in
+ * the following example:</p>
+ *
* <pre>
* import org.apache.commons.lang.exception.ExceptionUtils;
*
@@ -167,20 +159,16 @@
* public MyException(String msg) {
* super(msg);
* }
- *
+ *
* public MyException(String msg, Throwable cause) {
* super(msg);
* ExceptionUtils.setCause(this, cause);
* }
- *
- * }
+ * }
* </pre>
- * </p>
- *
- * @param target
- * the target <code>Throwable</code>
- * @param cause
- * the <code>Throwable</code> to set in the target
+ *
+ * @param target the target <code>Throwable</code>
+ * @param cause the <code>Throwable</code> to set in the target
* @return a <code>true</code> if the target has been modified
* @since 2.2
*/
@@ -225,6 +213,7 @@
/**
* Returns {@link #CAUSE_METHOD_NAMES} as a List.
+ *
* @return {@link #CAUSE_METHOD_NAMES} as a List.
*/
private static ArrayList getCauseMethodNameList() {
@@ -246,7 +235,7 @@
/**
* <p>Introspects the <code>Throwable</code> to obtain the cause.</p>
- *
+ *
* <p>The method searches for methods with specific names that return a
* <code>Throwable</code> object. This will pick up most wrapping exceptions,
* including those from JDK 1.4, and
@@ -267,7 +256,7 @@
*
* <p>In the absence of any such method, the object is inspected for a
* <code>detail</code> field assignable to a <code>Throwable</code>.</p>
- *
+ *
* <p>If none of the above is found, returns <code>null</code>.</p>
*
* @param throwable the throwable to introspect for a cause, may be null
@@ -281,13 +270,13 @@
/**
* <p>Introspects the <code>Throwable</code> to obtain the cause.</p>
- *
+ *
* <ol>
* <li>Try known exception types.</li>
* <li>Try the supplied array of method names.</li>
* <li>Try the field 'detail'.</li>
* </ol>
- *
+ *
* <p>A <code>null</code> set of method names means use the default set.
* A <code>null</code> in the set of method names will be ignored.</p>
*
@@ -325,7 +314,7 @@
/**
* <p>Introspects the <code>Throwable</code> to obtain the root cause.</p>
- *
+ *
* <p>This method walks through the exception chain to the last element,
* "root" of the tree, using {@link #getCause(Throwable)}, and
* returns that exception.</p>
@@ -369,7 +358,7 @@
/**
* <p>Finds a <code>Throwable</code> by method name.</p>
- *
+ *
* @param throwable the exception to examine
* @param methodName the name of the method to find and invoke
* @return the wrapped exception, or <code>null</code> if not found
@@ -400,7 +389,7 @@
/**
* <p>Finds a <code>Throwable</code> by field name.</p>
- *
+ *
* @param throwable the exception to examine
* @param fieldName the name of the attribute to examine
* @return the wrapped exception, or <code>null</code> if not found
@@ -430,9 +419,9 @@
//-----------------------------------------------------------------------
/**
* <p>Checks if the Throwable class has a <code>getCause</code> method.</p>
- *
+ *
* <p>This is true for JDK 1.4 and above.</p>
- *
+ *
* @return true if Throwable is nestable
* @since 2.0
*/
@@ -442,7 +431,7 @@
/**
* <p>Checks whether this <code>Throwable</code> class can store a cause.</p>
- *
+ *
* <p>This method does <b>not</b> check whether it actually does store a cause.<p>
*
* @param throwable the <code>Throwable</code> to examine, may be null
@@ -496,11 +485,11 @@
/**
* <p>Counts the number of <code>Throwable</code> objects in the
* exception chain.</p>
- *
+ *
* <p>A throwable without cause will return <code>1</code>.
* A throwable with one cause will return <code>2</code> and so on.
* A <code>null</code> throwable will return <code>0</code>.</p>
- *
+ *
* @param throwable the throwable to inspect, may be null
* @return the count of throwables, zero if null input
*/
@@ -516,7 +505,7 @@
/**
* <p>Returns the list of <code>Throwable</code> objects in the
* exception chain.</p>
- *
+ *
* <p>A throwable without cause will return an array containing
* one element - the input throwable.
* A throwable with one cause will return an array containing
@@ -541,7 +530,7 @@
* 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.</p>
- *
+ *
* <p>A <code>null</code> throwable returns <code>-1</code>.
* A <code>null</code> type returns <code>-1</code>.
* No match in the chain returns <code>-1</code>.</p>
@@ -560,7 +549,7 @@
* a specified index.
* Subclasses of the specified class do not match - see
* {@link #indexOfType(Throwable, Class, int)} for the opposite.</p>
- *
+ *
* <p>A <code>null</code> throwable returns <code>-1</code>.
* A <code>null</code> type returns <code>-1</code>.
* No match in the chain returns <code>-1</code>.
@@ -583,7 +572,7 @@
* 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.</p>
- *
+ *
* <p>A <code>null</code> throwable returns <code>-1</code>.
* A <code>null</code> type returns <code>-1</code>.
* No match in the chain returns <code>-1</code>.</p>
@@ -603,7 +592,7 @@
* a specified index.
* Subclasses of the specified class do match - see
* {@link #indexOfThrowable(Throwable, Class)} for the opposite.</p>
- *
+ *
* <p>A <code>null</code> throwable returns <code>-1</code>.
* A <code>null</code> type returns <code>-1</code>.
* No match in the chain returns <code>-1</code>.
@@ -623,7 +612,7 @@
/**
* <p>Worker method for the <code>indexOfType</code> methods.</p>
- *
+ *
* @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,
@@ -663,15 +652,18 @@
/**
* <p>Prints a compact stack trace for the root cause of a throwable
* to <code>System.err</code>.</p>
- *
+ *
* <p>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.</p>
*
+ * <p>The output of this method is consistent across JDK versions.
+ * Note that this is the opposite order to the JDK1.4 display.</p>
+ *
* <p>The method is equivalent to <code>printStackTrace</code> for throwables
* that don't have nested causes.</p>
- *
+ *
* @param throwable the throwable to output
* @since 2.0
*/
@@ -687,9 +679,12 @@
* Then it prints the wrapped exception and continues with stack frames
* until the wrapper exception is caught and wrapped again, etc.</p>
*
+ * <p>The output of this method is consistent across JDK versions.
+ * Note that this is the opposite order to the JDK1.4 display.</p>
+ *
* <p>The method is equivalent to <code>printStackTrace</code> for throwables
* that don't have nested causes.</p>
- *
+ *
* @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 <code>null</code>
@@ -717,9 +712,12 @@
* Then it prints the wrapped exception and continues with stack frames
* until the wrapper exception is caught and wrapped again, etc.</p>
*
+ * <p>The output of this method is consistent across JDK versions.
+ * Note that this is the opposite order to the JDK1.4 display.</p>
+ *
* <p>The method is equivalent to <code>printStackTrace</code> for throwables
* that don't have nested causes.</p>
- *
+ *
* @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 <code>null</code>
@@ -743,7 +741,12 @@
/**
* <p>Creates a compact stack trace for the root cause of the supplied
* <code>Throwable</code>.</p>
- *
+ *
+ * <p>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.</p>
+ *
* @param throwable the throwable to examine, may be null
* @return an array of stack trace frames, never null
* @since 2.0
@@ -776,7 +779,7 @@
/**
* <p>Removes common frames from the cause trace given the two stack traces.</p>
- *
+ *
* @param causeFrames stack trace of a cause throwable
* @param wrapperFrames stack trace of a wrapper throwable
* @throws IllegalArgumentException if either argument is null
@@ -805,6 +808,11 @@
/**
* <p>Gets the stack trace from a Throwable as a String.</p>
*
+ * <p>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.</p>
+ *
* @param throwable the <code>Throwable</code> to be examined
* @return the stack trace as generated by the exception's
* <code>printStackTrace(PrintWriter)</code> method
@@ -819,6 +827,9 @@
/**
* <p>A way to get the entire nested stack-trace of an throwable.</p>
*
+ * <p>The result of this method is highly dependent on the JDK version
+ * and whether the exceptions override printStackTrace or not.</p>
+ *
* @param throwable the <code>Throwable</code> to be examined
* @return the nested stack trace, with the root cause first
* @since 2.0
@@ -842,6 +853,11 @@
* <code>Throwable</code> object, decomposing it into a list of
* stack frames.</p>
*
+ * <p>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.</p>
+ *
* @param throwable the <code>Throwable</code> to examine, may be null
* @return an array of strings describing each stack frame, never null
*/
@@ -853,21 +869,16 @@
}
/**
- * <p>
- * Returns an array where each element is a line from the argument.
- * </p>
- * <p>
- * The end of line is determined by the value of {@link SystemUtils#LINE_SEPARATOR}.
- * </p>
- *
- * <p>
- * Functionality shared between the <code>getStackFrames(Throwable)</code> methods of this and the
- * {@link org.apache.commons.lang.exception.NestableDelegate} classes.
- * </p>
- *
- * @param stackTrace
- * A stack trace String.
- * @return an array where each element is a line from the argument.
+ * <p>Returns an array where each element is a line from the argument.</p>
+ *
+ * <p>The end of line is determined by the value of {@link SystemUtils#LINE_SEPARATOR}.</p>
+ *
+ * <p>Functionality shared between the
+ * <code>getStackFrames(Throwable)</code> methods of this and the
+ * {@link org.apache.commons.lang.exception.NestableDelegate} classes.</p>
+ *
+ * @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;
@@ -881,7 +892,8 @@
/**
* <p>Produces a <code>List</code> of stack frames - the message
- * is not included.</p>
+ * is not included. Only the trace of the specified exception is
+ * returned, any caused by trace is stripped.</p>
*
* <p>This works in most cases - it will only fail if the exception
* message contains a line that starts with:
@@ -909,5 +921,5 @@
}
return list;
}
-
+
}
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