com.sun.grizzly.suspendable.Suspendable Maven / Gradle / Ivy

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 * 
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
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package com.sun.grizzly.suspendable;

import java.nio.channels.SelectionKey;

/**
 * An Object representing the result of an suspendable operation like {@link SuspendableFilter@#suspend}
 * An instance of that class can be used to resume or cancel a suspended connection.
 * See {@link SuspendableFilter} for more information.
 * 
 * @author Jeanfrancois Arcand
 */
public class Suspendable {

    private SuspendableFilter suspendableFilter;
    private SelectionKey key;
    private boolean isResumed = false;

    protected Suspendable(SuspendableFilter suspendableFilter) {
        this.suspendableFilter = suspendableFilter;
    }

    
    /**
     * Resume a suspended connection. If the connection has been resumed, calling
     * resume with produce an {@link IllegalStateException}.
     * @return true is resumed.
     */
    public boolean resume() {
        if (getKey() == null){
            isResumed = true;
            return isResumed;
        }
        
        isResumed = suspendableFilter.resume(getKey());
        return isResumed;
    }

    
    /**
     * Return true if the connection associated with this instance has been {@link #resumed}
     * 
     * @return true if resumed.
     */
    public boolean isResumed() {
        return isResumed;
    }

    
    /**
     * Cancel a suspended connection. If the connection has been  {@link #resumed}, calling
     * resume with produce an {@link IllegalStateException}.
     * @return true is resumed.
     */
    public void cancel(){
        if (isResumed) {
            throw new IllegalStateException("Already cancelled");
        }
        
        if (getKey() == null){
            isResumed = true;
            return;
        }
                
        suspendableFilter.cancel(getKey());
    }

    
    /**
     * Return the underlying SelectionKey representing the connection.
     * @return the underlying SelectionKey representing the connection.
     */
    protected SelectionKey getKey() {
        return key;
    }

    
    /**
     * Set the underlying SelectionKey.
     * @param key  the underlying SelectionKey.
     */
    protected void setKey(SelectionKey key) {
        this.key = key;
    }
}