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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 package com.android.contacts.vcard;
     17 
     18 import java.util.concurrent.ExecutorService;
     19 import java.util.concurrent.Future;
     20 import java.util.concurrent.RunnableFuture;
     21 import java.util.concurrent.TimeUnit;
     22 
     23 /**
     24  * A base processor class. One instance processes vCard one import/export request (imports a given
     25  * vCard or exports a vCard). Expected to be used with {@link ExecutorService}.
     26  *
     27  * This instance starts itself with {@link #run()} method, and can be cancelled with
     28  * {@link #cancel(boolean)}. Users can check the processor's status using {@link #isCancelled()}
     29  * and {@link #isDone()} asynchronously.
     30  *
     31  * {@link #get()} and {@link #get(long, TimeUnit)}, which are form {@link Future}, aren't
     32  * supported and {@link UnsupportedOperationException} will be just thrown when they are called.
     33  */
     34 public abstract class ProcessorBase implements RunnableFuture<Object> {
     35 
     36     /**
     37      * @return the type of the processor. Must be {@link VCardService#TYPE_IMPORT} or
     38      * {@link VCardService#TYPE_EXPORT}.
     39      */
     40     public abstract int getType();
     41 
     42     @Override
     43     public abstract void run();
     44 
     45     /**
     46      * Cancels this operation.
     47      *
     48      * @param mayInterruptIfRunning ignored. When this method is called, the instance
     49      * stops processing and finish itself even if the thread is running.
     50      *
     51      * @see Future#cancel(boolean)
     52      */
     53     @Override
     54     public abstract boolean cancel(boolean mayInterruptIfRunning);
     55     @Override
     56     public abstract boolean isCancelled();
     57     @Override
     58     public abstract boolean isDone();
     59 
     60     /**
     61      * Just throws {@link UnsupportedOperationException}.
     62      */
     63     @Override
     64     public final Object get() {
     65         throw new UnsupportedOperationException();
     66     }
     67 
     68     /**
     69      * Just throws {@link UnsupportedOperationException}.
     70      */
     71     @Override
     72     public final Object get(long timeout, TimeUnit unit) {
     73         throw new UnsupportedOperationException();
     74     }
     75 }