// Copyright (c) 2003-2012, Jodd Team (jodd.org). All Rights Reserved.
package jodd.exception;
import java.io.StringWriter;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
import java.sql.SQLException;
import java.lang.reflect.InvocationTargetException;
/**
* Few exception utilities.
*/
public class ExceptionUtil {
/**
* Returns current stack trace in form of array of stack trace elements.
* First stack trace element is removed.
* Since an exception is thrown internally, this method is slow.
*/
@SuppressWarnings({"ThrowCaughtLocally"})
public static StackTraceElement[] getCurrentStackTrace() {
StackTraceElement[] ste = new Exception().getStackTrace();
if (ste.length > 1) {
StackTraceElement[] result = new StackTraceElement[ste.length - 1];
System.arraycopy(ste, 1, result, 0, ste.length - 1);
return result;
} else {
return ste;
}
}
// ---------------------------------------------------------------- exception stack trace
/**
* Returns stack trace filtered by class names.
*/
public static StackTraceElement[] getStackTrace(Throwable t, String[] allow, String[] deny) {
StackTraceElement[] st = t.getStackTrace();
ArrayList<StackTraceElement> result = new ArrayList<StackTraceElement>(st.length);
elementLoop:
for (StackTraceElement element : st) {
String className = element.getClassName();
if (allow != null) {
boolean validElemenet = false;
for (String filter : allow) {
if (className.indexOf(filter) != -1) {
validElemenet = true;
break;
}
}
if (validElemenet == false) {
continue;
}
}
if (deny != null) {
for (String filter : deny) {
if (className.indexOf(filter) != -1) {
continue elementLoop;
}
}
}
result.add(element);
}
st = new StackTraceElement[result.size()];
return result.toArray(st);
}
/**
* Returns stack trace chain filtered by class names.
*/
public static StackTraceElement[][] getStackTraceChain(Throwable t, String[] allow, String[] deny) {
ArrayList<StackTraceElement[]> result = new ArrayList<StackTraceElement[]>();
while (t != null) {
StackTraceElement[] stack = getStackTrace(t, allow, deny);
result.add(stack);
t = t.getCause();
}
StackTraceElement[][] allStacks = new StackTraceElement[result.size()][];
for (int i = 0; i < allStacks.length; i++) {
allStacks[i] = result.get(i);
}
return allStacks;
}
/**
* Returns exception chain starting from top up to root cause.
*/
public static Throwable[] getExceptionChain(Throwable throwable) {
ArrayList<Throwable> list = new ArrayList<Throwable>();
list.add(throwable);
while ((throwable = throwable.getCause()) != null) {
list.add(throwable);
}
Throwable[] result = new Throwable[list.size()];
return list.toArray(result);
}
// ---------------------------------------------------------------- exception to string
/**
* Prints stack trace into a String.
*/
public static String exceptionToString(Throwable t) {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw, true);
t.printStackTrace(pw);
pw.flush();
sw.flush();
return sw.toString();
}
/**
* Prints full exception stack trace, from top to root cause, into a String.
*/
public static String exceptionChainToString(Throwable t) {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw, true);
while (t != null) {
t.printStackTrace(pw);
t = t.getCause();
}
pw.flush();
sw.flush();
return sw.toString();
}
/**
* Build a message for the given base message and its cause.
*/
public static String buildMessage(String message, Throwable cause) {
if (cause != null) {
cause = getRootCause(cause);
StringBuilder buf = new StringBuilder();
if (message != null) {
buf.append(message).append("; ");
}
buf.append("<--- ").append(cause);
return buf.toString();
} else {
return message;
}
}
// ---------------------------------------------------------------- root cause
/**
* Introspects the <code>Throwable</code> to obtain the root cause.
* <p>
* This method walks through the exception chain to the last element,
* "root" of the tree, and returns that exception. If no root cause found
* returns provided throwable.
*/
public static Throwable getRootCause(Throwable throwable) {
Throwable cause = throwable.getCause();
if (cause == null) {
return throwable;
}
throwable = cause;
while ((throwable = throwable.getCause()) != null) {
cause = throwable;
}
return cause;
}
/**
* Finds throwing cause in exception stack. Returns throwable object if cause class is matched.
* Otherwise, returns <code>null</code>.
*/
@SuppressWarnings({"unchecked"})
public static <T extends Throwable> T findCause(Throwable throwable, Class<T> cause) {
while (throwable != null) {
if (throwable.getClass().equals(cause)) {
return (T) throwable;
}
throwable = throwable.getCause();
}
return null;
}
// ---------------------------------------------------------------- sql
/**
* Rolls up SQL exceptions by taking each proceeding exception
* and making it a child of the previous using the <code>setNextException</code>
* method of SQLException.
*/
public static SQLException rollupSqlExceptions(List<SQLException> exceptions) {
SQLException parent = null;
for (SQLException exception : exceptions) {
if (parent != null) {
exception.setNextException(parent);
}
parent = exception;
}
return parent;
}
// ---------------------------------------------------------------- misc
/**
* Throws target of <code>InvocationTargetException</code> if it is exception.
*/
public static void throwTargetException(InvocationTargetException itex) throws Exception {
throw extractTargetException(itex);
}
public static Exception extractTargetException(InvocationTargetException itex) {
Throwable target = itex.getTargetException();
return target instanceof Exception ? (Exception) target : itex;
}
/**
* Throws checked exceptions in un-checked manner.
* Uses deprecated method.
* @see #throwException(Throwable)
*/
@SuppressWarnings({"deprecation"})
public static void throwExceptionAlt(Throwable throwable) {
if (throwable instanceof RuntimeException) {
throw (RuntimeException) throwable;
}
Thread.currentThread().stop(throwable);
}
/**
* Throws checked exceptions in un-checked manner.
* @see #throwException(Throwable)
*/
public static void throwException(Throwable throwable) {
if (throwable instanceof RuntimeException) {
throw (RuntimeException) throwable;
}
// can't handle these types
if ((throwable instanceof IllegalAccessException) || (throwable instanceof InstantiationException)) {
throw new IllegalArgumentException(throwable);
}
try {
synchronized (ThrowableThrower.class) {
ThrowableThrower.throwable = throwable;
ThrowableThrower.class.newInstance();
}
} catch (InstantiationException iex) {
throw new RuntimeException(iex);
} catch (IllegalAccessException iex) {
throw new RuntimeException(iex);
} finally {
ThrowableThrower.throwable = null;
}
}
private static class ThrowableThrower {
private static Throwable throwable;
ThrowableThrower() throws Throwable {
throw throwable;
}
}
}
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