org.apache.commons.lang.exception.NestableException Maven / Gradle / Ivy
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/*
* 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.lang.exception;
import java.io.PrintStream;
import java.io.PrintWriter;
/**
* The base class of all exceptions which can contain other exceptions.
*
* It is intended to ease the debugging by carrying on the information
* about the exception which was caught and provoked throwing the
* current exception. Catching and rethrowing may occur multiple
* times, and provided that all exceptions except the first one
* are descendants of NestedException, when the
* exception is finally printed out using any of the
* printStackTrace() methods, the stack trace will contain
* the information about all exceptions thrown and caught on
* the way.
* Running the following program
*
* 1 import org.apache.commons.lang.exception.NestableException;
* 2
* 3 public class Test {
* 4 public static void main( String[] args ) {
* 5 try {
* 6 a();
* 7 } catch(Exception e) {
* 8 e.printStackTrace();
* 9 }
* 10 }
* 11
* 12 public static void a() throws Exception {
* 13 try {
* 14 b();
* 15 } catch(Exception e) {
* 16 throw new NestableException("foo", e);
* 17 }
* 18 }
* 19
* 20 public static void b() throws Exception {
* 21 try {
* 22 c();
* 23 } catch(Exception e) {
* 24 throw new NestableException("bar", e);
* 25 }
* 26 }
* 27
* 28 public static void c() throws Exception {
* 29 throw new Exception("baz");
* 30 }
* 31 }
*
* Yields the following stack trace:
*
* org.apache.commons.lang.exception.NestableException: foo
* at Test.a(Test.java:16)
* at Test.main(Test.java:6)
* Caused by: org.apache.commons.lang.exception.NestableException: bar
* at Test.b(Test.java:24)
* at Test.a(Test.java:14)
* ... 1 more
* Caused by: java.lang.Exception: baz
* at Test.c(Test.java:29)
* at Test.b(Test.java:22)
* ... 2 more
*
*
* @author Rafal Krzewski
* @author Daniel L. Rall
* @author Kasper Nielsen
* @author Steven Caswell
* @since 1.0
* @version $Id: NestableException.java 512889 2007-02-28 18:18:20Z dlr $
*/
public class NestableException extends Exception implements Nestable {
/**
* Required for serialization support.
*
* @see java.io.Serializable
*/
private static final long serialVersionUID = 1L;
/**
* The helper instance which contains much of the code which we
* delegate to.
*/
protected NestableDelegate delegate = new NestableDelegate(this);
/**
* Holds the reference to the exception or error that caused
* this exception to be thrown.
*/
private Throwable cause = null;
/**
* Constructs a new NestableException without specified
* detail message.
*/
public NestableException() {
super();
}
/**
* Constructs a new NestableException with specified
* detail message.
*
* @param msg The error message.
*/
public NestableException(String msg) {
super(msg);
}
/**
* Constructs a new NestableException with specified
* nested Throwable.
*
* @param cause the exception or error that caused this exception to be
* thrown
*/
public NestableException(Throwable cause) {
super();
this.cause = cause;
}
/**
* Constructs a new NestableException with specified
* detail message and nested Throwable.
*
* @param msg the error message
* @param cause the exception or error that caused this exception to be
* thrown
*/
public NestableException(String msg, Throwable cause) {
super(msg);
this.cause = cause;
}
/**
* {@inheritDoc}
*/
public Throwable getCause() {
return cause;
}
/**
* Returns the detail message string of this throwable. If it was
* created with a null message, returns the following:
* (cause==null ? null : cause.toString()).
*
* @return String message string of the throwable
*/
public String getMessage() {
if (super.getMessage() != null) {
return super.getMessage();
} else if (cause != null) {
return cause.toString();
} else {
return null;
}
}
/**
* {@inheritDoc}
*/
public String getMessage(int index) {
if (index == 0) {
return super.getMessage();
}
return delegate.getMessage(index);
}
/**
* {@inheritDoc}
*/
public String[] getMessages() {
return delegate.getMessages();
}
/**
* {@inheritDoc}
*/
public Throwable getThrowable(int index) {
return delegate.getThrowable(index);
}
/**
* {@inheritDoc}
*/
public int getThrowableCount() {
return delegate.getThrowableCount();
}
/**
* {@inheritDoc}
*/
public Throwable[] getThrowables() {
return delegate.getThrowables();
}
/**
* {@inheritDoc}
*/
public int indexOfThrowable(Class type) {
return delegate.indexOfThrowable(type, 0);
}
/**
* {@inheritDoc}
*/
public int indexOfThrowable(Class type, int fromIndex) {
return delegate.indexOfThrowable(type, fromIndex);
}
/**
* {@inheritDoc}
*/
public void printStackTrace() {
delegate.printStackTrace();
}
/**
* {@inheritDoc}
*/
public void printStackTrace(PrintStream out) {
delegate.printStackTrace(out);
}
/**
* {@inheritDoc}
*/
public void printStackTrace(PrintWriter out) {
delegate.printStackTrace(out);
}
/**
* {@inheritDoc}
*/
public final void printPartialStackTrace(PrintWriter out) {
super.printStackTrace(out);
}
}