/*
* RHQ Management Platform
* Copyright (C) 2005-2008 Red Hat, Inc.
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation, and/or the GNU Lesser
* General Public License, version 2.1, also as published by the Free
* Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License and the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License
* and the GNU Lesser General Public License along with this program;
* if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
package org.rhq.core.util.exception;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import java.sql.SQLException;
import java.util.ArrayList;
/**
* Utilities for working with throwables and their messages.
*
* @author John Mazzitelli
*/
public class ThrowableUtil {
private static final String EXCEPTION_WAS_NULL = ">> exception was null <<";
private static final String DOTS = " ... ";
private static final String ARROW = " -> ";
/**
* Prevent instantiation.
*/
private ThrowableUtil() {
}
/**
* Returns all the messages for the throwable and all of its causes in one long string. This is useful for logging
* an exception when you don't want to dump the entire stack trace but you still want to see the throwable and all
* of its causes.
*
* @param t the top throwable (may be <code>null</code>)
* @param includeExceptionName if <code>true</code>, the exception name will prefix all messages
*
* @return string containing the throwable's message and its causes' messages in the order of the causes (the lowest
* nested throwable's message appears last in the string)
*/
public static String getAllMessages(Throwable t, boolean includeExceptionName) {
StringBuffer ret_message = new StringBuffer();
if (t != null) {
String[] msgs = getAllMessagesArray(t, includeExceptionName);
ret_message.append(msgs[0]);
for (int i = 1; i < msgs.length; i++) {
ret_message.append(ARROW);
ret_message.append(msgs[i]);
}
} else {
ret_message.append(EXCEPTION_WAS_NULL);
}
return ret_message.toString();
}
/**
* Generates a string with all exception messages similarly to {@link #getAllMessages(Throwable, boolean)}
* but limits the length of the string to the provided limit.
* The messages are left out of the resulting string in the following manner:
* <ul>
* <li>The last message (i.e. the ultimate cause) is *always* in the output, regardless the maxSize
* <li>The first throwable is output, then the second, etc. up until the point where appending the
* next message *AND* the last message would make the output longer than maxSize.
* <li>An ellipsis is appended if the ultimate cause isn't the direct cause of the
* throwable which was last output according to the above algo.
* </ul>
* @param t
* @param includeExceptionNames
* @param maxSize the maximum size of the message. If < 0, the output is not limited.
* @return
*/
public static final String getAllMessages(Throwable t, boolean includeExceptionNames, int maxSize) {
if (maxSize < 0) {
return getAllMessages(t, includeExceptionNames);
}
if (t == null) {
return EXCEPTION_WAS_NULL;
}
int arrowLength = ARROW.length();
int dotsLength = DOTS.length();
StringBuilder bld = new StringBuilder();
String[] msgs = getAllMessagesArray(t, includeExceptionNames);
//reduce the max size by the length of the last message
int maxDottedSize = maxSize - msgs[msgs.length - 1].length() - dotsLength;
// the dots and arrow have different lengths so we have to specialize for
//the case where the output actually fits in the maxSize
int maxFullSize = maxDottedSize + dotsLength - arrowLength;
if (msgs.length == 1 || maxDottedSize < 0) {
return msgs[msgs.length - 1];
}
int maxIdx = msgs.length - 1;
int lastIdx = maxIdx - 1;
int curLen = msgs[0].length();
if (curLen <= maxDottedSize) {
bld.append(msgs[0]);
}
int curIdx = 1;
for(; curIdx < maxIdx; ++curIdx) {
int lenIncr = arrowLength + msgs[curIdx].length();
if (curIdx == lastIdx) {
if (curLen + lenIncr > maxFullSize) {
break;
}
} else {
if (curLen + lenIncr > maxDottedSize) {
break;
}
}
bld.append(ARROW);
bld.append(msgs[curIdx]);
curLen += lenIncr;
}
if (curIdx < msgs.length - 1) {
bld.append(DOTS);
} else {
bld.append(ARROW);
}
bld.append(msgs[msgs.length - 1]);
return bld.toString();
}
/**
* Same as {@link #getAllMessages(Throwable, boolean)} with the "include exception name" parameter set to <code>
* true</code>.
*
* @param t the top throwable (may be <code>null</code>)
*
* @return string containing the throwable's message and its causes' messages in the order of the causes (the lowest
* nested throwable's message appears last in the string)
*/
public static String getAllMessages(Throwable t) {
return getAllMessages(t, true);
}
/**
* Returns all the messages for the throwable and all of its causes.
*
* @param t the top throwable (may be <code>null</code>)
* @param includeExceptionName if <code>true</code>, the exception name will prefix all messages
*
* @return array of strings containing the throwable's message and its causes' messages in the order of the causes
* (the lowest nested throwable's message appears last)
*/
public static String[] getAllMessagesArray(Throwable t, boolean includeExceptionName) {
ArrayList<String> list = new ArrayList<String>();
if (t != null) {
String msg;
String tMessage = t.getMessage();
if (includeExceptionName) {
msg = t.getClass().getName() + ":" + tMessage;
} else {
msg = (tMessage != null) ? tMessage : t.getClass().getName();
}
if (t instanceof SQLException) {
msg += "[SQLException=" + getAllSqlExceptionMessages((SQLException) t, false) + "]";
}
list.add(msg);
while ((t.getCause() != null) && (t != t.getCause())) {
t = t.getCause();
tMessage = t.getMessage();
if (includeExceptionName) {
msg = t.getClass().getName() + ":" + tMessage;
} else {
msg = (tMessage != null) ? tMessage : t.getClass().getName();
}
if (t instanceof SQLException) {
msg += "[SQLException=" + getAllSqlExceptionMessages((SQLException) t, false) + "]";
}
list.add(msg);
}
}
return list.toArray(new String[list.size()]);
}
/**
* Same as {@link #getAllMessagesArray(Throwable, boolean)} with the "include exception name" parameter set to
* <code>true</code>.
*
* @param t the top throwable (may be <code>null</code>)
*
* @return string containing the throwable's message and its causes' messages in the order of the causes (the lowest
* nested throwable's message appears last in the string)
*/
public static String[] getAllMessagesArray(Throwable t) {
return getAllMessagesArray(t, true);
}
/**
* Returns all the messages for the SQL Exception and all of its next exceptions in one long string.
*
* @param t the top SQL Exception (may be <code>null</code>)
* @param includeExceptionName if <code>true</code>, the exception name will prefix all messages
*
* @return string containing the SQL Exception's message and its next exception's messages in order
*/
public static String getAllSqlExceptionMessages(SQLException t, boolean includeExceptionName) {
StringBuffer ret_message = new StringBuffer();
if (t != null) {
String[] msgs = getAllSqlExceptionMessagesArray(t, includeExceptionName);
ret_message.append(msgs[0]);
for (int i = 1; i < msgs.length; i++) {
ret_message.append(ARROW);
ret_message.append(msgs[i]);
}
} else {
ret_message.append(">> sql exception was null <<");
}
return ret_message.toString();
}
/**
* Same as {@link #getAllSqlExceptionMessages(Throwable, boolean)} with the "include exception name" parameter set
* to <code>true</code>.
*
* @param t the top sql exception (may be <code>null</code>)
*
* @return string containing the SQL Exception's message and its next exception's messages in order
*/
public static String getAllSqlExceptionMessages(SQLException t) {
return getAllSqlExceptionMessages(t, true);
}
/**
* Returns all the messages for the SQL Exception and all of its causes.
*
* @param t the top SQL Exception (may be <code>null</code>)
* @param includeExceptionName if <code>true</code>, the exception name will prefix all messages
*
* @return strings containing the SQL Exception's message and its next exception's messages in order
*/
public static String[] getAllSqlExceptionMessagesArray(SQLException t, boolean includeExceptionName) {
ArrayList<String> list = new ArrayList<String>();
if (t != null) {
String tMessage = t.getMessage();
if (includeExceptionName) {
list.add(t.getClass().getName() + ":" + tMessage);
} else {
list.add((tMessage != null) ? tMessage : t.getClass().getName());
}
while ((t.getNextException() != null) && (t != t.getNextException())) {
String msg;
t = t.getNextException();
tMessage = t.getMessage();
if (includeExceptionName) {
msg = t.getClass().getName() + ":" + tMessage;
} else {
msg = (tMessage != null) ? tMessage : t.getClass().getName();
}
list.add(msg + "(error-code=" + t.getErrorCode() + ",sql-state=" + t.getSQLState() + ")");
}
}
return list.toArray(new String[list.size()]);
}
/**
* Same as {@link #getAllSqlExceptionMessagesArray(SQLException, boolean)} with the "include exception name"
* parameter set to <code>true</code>.
*
* @param t the top sql exception (may be <code>null</code>)
*
* @return strings containing the SQL Exception's message and its next exception's messages in order
*/
public static String[] getAllSqlExceptionMessagesArray(SQLException t) {
return getAllSqlExceptionMessagesArray(t, true);
}
public static String getStackAsString(Throwable t) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
t.printStackTrace(new PrintStream(baos));
return baos.toString();
}
/**
* The same as calling <code>getFilteredStackAsString(t, "org.rhq")</code>
*
* @param t
* @return the filtered stack, as a String
*/
public static String getFilteredStackAsString(Throwable t) {
return getFilteredStackAsString(t, "org.rhq");
}
/**
* Returns the stack for <code>t</code>, filtering out all <code>StackTraceElement</code>'s that don't start
* with <code>filter</code>.
*
* @param t
* @param filter Not Null
* @return the filtered stack, as a String
*/
public static String getFilteredStackAsString(Throwable t, String filter) {
StringBuilder smallStack = new StringBuilder();
StackTraceElement[] stack = (null == t) ? new Exception().getStackTrace() : t.getStackTrace();
for (int i = 1; i < stack.length; i++) {
StackTraceElement ste = stack[i];
if (ste.getClassName().startsWith(filter)) {
smallStack.append(ste.toString());
smallStack.append("\n");
}
}
return smallStack.toString();
}
public static String getRootMessage(Throwable t) {
t = getRootCause(t);
String rootMessage = t.getMessage();
return (rootMessage != null) ? rootMessage : t.getClass().getName();
}
public static Throwable getRootCause(Throwable t) {
while ((t.getCause() != null) && (t != t.getCause())) {
t = t.getCause();
}
return t;
}
}