Java RuntimeException Create toRuntimeException(Throwable t)

Description

Always returns a RuntimeException using this sequential logic:

1. if t == null, returns a new RuntimeException which has a null cause
2. else if t is an instanceof Error, returns a new RuntimeException which has t as its cause
3. else if t is an instanceof RuntimeException, returns t itself
4. else if t is an instanceof Exception, then it must be a checked Exception, so it returns a new RuntimeException which has t as its cause
5. else t is an actual Throwable instance (or some unknown subclass), so it returns a new RuntimeException which has t as its cause

This method is usually called to convert checked Exceptions into unchecked ones.

License

Open Source License

Parameter

Parameter	Description
t	the original cause; may be null

Declaration

public static RuntimeException toRuntimeException(Throwable t) 

Method Source Code

//package com.java2s;
/*//from   w  ww .  j ava2  s.c o  m
Copyright ? 2008 Brent Boyer
    
This program is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
    
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 Lesser GNU General Public License for more details.
    
You should have received a copy of the Lesser GNU General Public License along with this program (see the license directory in this project).  If not, see <http://www.gnu.org/licenses/>.
*/

public class Main {
    /**
    * Always returns a RuntimeException using this sequential logic:
    * <ol>
    *  <li>if t == null, returns a new RuntimeException which has a null cause</li>
    *  <li>else if t is an instanceof Error, returns a new RuntimeException which has t as its cause</li>
    *  <li>else if t is an instanceof RuntimeException, returns t <i>itself</i></li>
    *  <li>
    *      else if t is an instanceof Exception, then it must be a checked Exception,
    *      so it returns a new RuntimeException which has t as its cause
    *  </li>
    *  <li>
    *      else t is an actual Throwable instance (or some unknown subclass),
    *      so it returns a new RuntimeException which has t as its cause
    *  </li>
    * </ol>
    * <p>
    * This method is usually called to convert checked Exceptions into unchecked ones.
    * <p>
    * One example where this is useful is if you want to initialize a field by calling a method:
    * it turns out that such a method cannot throw a checked Exception,
    * so it must have a try-catch block,
    * and it may be convenient for the catch to simply pass whatever it catches to this method and rethrow the result.
    * <p>
    * @param t the original cause; may be null
    */
    public static RuntimeException toRuntimeException(Throwable t) {
        if (t == null)
            return new RuntimeException("This RuntimeException wraps a null cause");
        else if (t instanceof Error)
            return new RuntimeException("This RuntimeException wraps an underlying Error (see cause)", t);
        else if (t instanceof RuntimeException)
            return (RuntimeException) t;
        else if (t instanceof Exception)
            return new RuntimeException("This RuntimeException wraps an underlying checked Exception (see cause)",
                    t);
        else
            return new RuntimeException("This RuntimeException wraps an underlying Throwable (see cause)", t);
    }
}

Related

1. toRuntimeException(Exception e)
2. toRuntimeException(Exception ex)
3. toRuntimeException(final Throwable e)
4. toRuntimeException(Throwable e)
5. toRuntimeException(Throwable t)
6. toRuntimeException(Throwable throwable)
7. toRuntimeException(Throwable throwable)
8. toRuntimeExceptionOr(Class exClass, Throwable throwable)