org.apache.sshd.common.util.ExceptionUtils Maven / Gradle / Ivy
/*
* 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.sshd.common.util;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.UndeclaredThrowableException;
import java.util.concurrent.ExecutionException;
import javax.management.MBeanException;
import javax.management.ReflectionException;
/**
* @author Apache MINA SSHD Project
*/
public final class ExceptionUtils {
private ExceptionUtils() {
throw new UnsupportedOperationException("No instance");
}
public static void rethrowAsIoException(Throwable e) throws IOException {
if (e instanceof IOException) {
throw (IOException) e;
} else if (e instanceof RuntimeException) {
throw (RuntimeException) e;
} else if (e instanceof Error) {
throw (Error) e;
} else {
throw new IOException(e);
}
}
/**
* Used to "accumulate" exceptions of the same type. If the current exception is {@code null} then
* the new one becomes the current, otherwise the new one is added as a suppressed exception to the current
* one
*
* @param The exception type
* @param current The current exception
* @param extra The extra/new exception
* @return The resolved exception
* @see Throwable#addSuppressed(Throwable)
*/
public static T accumulateException(T current, T extra) {
if (current == null) {
return extra;
}
if ((extra == null) || (extra == current)) {
return current;
}
current.addSuppressed(extra);
return current;
}
/**
* @param t The original {@link Throwable} - ignored if {@code null}
* @return If {@link Throwable#getCause()} is non-{@code null} then the cause, otherwise the original exception -
* {@code null} if the original exception was {@code null}
*/
public static Throwable resolveExceptionCause(Throwable t) {
if (t == null) {
return t;
}
Throwable c = t.getCause();
if (c == null) {
return t;
} else {
return c;
}
}
/**
* Attempts to get to the "effective" exception being thrown, by taking care of some known exceptions that
* wrap the original thrown one.
*
* @param t The original {@link Throwable} - ignored if {@code null}
* @return The effective exception - same as input if not a wrapper
*/
public static Throwable peelException(Throwable t) {
// NOTE: check order is important - e.g., InvocationTargetException extends ReflectiveOperationException
if (t == null) {
return t;
} else if (t instanceof UndeclaredThrowableException) {
Throwable wrapped = ((UndeclaredThrowableException) t).getUndeclaredThrowable();
// according to the Javadoc it may be null, in which case 'getCause'
// might contain the information we need
if (wrapped != null) {
return peelException(wrapped);
}
wrapped = t.getCause();
if (wrapped != t) { // make sure it is a real cause
return peelException(wrapped);
}
} else if (t instanceof InvocationTargetException) {
Throwable target = ((InvocationTargetException) t).getTargetException();
if (target != null) {
return peelException(target);
}
} else if (t instanceof ReflectionException) {
Throwable target = ((ReflectionException) t).getTargetException();
if (target != null) {
return peelException(target);
}
} else if (t instanceof ExecutionException) {
Throwable wrapped = resolveExceptionCause(t);
if (wrapped != null) {
return peelException(wrapped);
}
} else if (t instanceof MBeanException) {
Throwable target = ((MBeanException) t).getTargetException();
if (target != null) {
return peelException(target);
}
}
return t; // no special handling required or available
}
/**
* Converts a thrown generic exception to a {@link RuntimeException}
*
* @param t The original thrown exception
* @param peelThrowable Whether to determine the root cause by "peeling" any enclosing exceptions
* @return The thrown cause if already a runtime exception, otherwise a runtime exception of the
* resolved exception as its cause
* @see #peelException(Throwable)
*/
public static RuntimeException toRuntimeException(Throwable t, boolean peelThrowable) {
Throwable e = peelThrowable ? peelException(t) : t;
if (e instanceof RuntimeException) {
return (RuntimeException) e;
}
return new RuntimeException(e);
}
public static RuntimeException toRuntimeException(Throwable t) {
return toRuntimeException(t, true);
}
}