ThrowableTask.java

/**
 * Copyright 2015 Santhosh Kumar Tekuri
 *
 * The JLibs authors license 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 jlibs.core.lang;

/**
 * @author Santhosh Kumar T
 */
public abstract class ThrowableTask<R, E extends Exception>{
    private Class<E> exceptionClass;
    
    private R r;
    private Exception ex;

    public ThrowableTask(Class<E> exceptionClass){
        this.exceptionClass = exceptionClass;
    }

    public abstract R run() throws E;
    
    @SuppressWarnings({"unchecked"})
    public R getResult() throws E{
        if(exceptionClass.isInstance(ex))
            throw (E)ex;
        else if(ex!=null)
            throw new RuntimeException(ex);
        return r;
    }
    
    public Exception getException(){
        return ex;
    }

    public Runnable asRunnable(){
        return new Runnable(){
            public void run(){
                try{
                    r = ThrowableTask.this.run();
                }catch(Exception ex){
                    ThrowableTask.this.ex = ex;
                }
            }
        };
    }
}