Application: gvSIG desktop » Library: org.gvsig.tools

package org.gvsig.tools.util;

/**

 * A task that returns a result and may throw an exception. 

 * Implementors define a single method with no arguments called call.

 * 

 * This interface is similar to the same interface of java 1.5 and this

 * is here for java 1.4 compatibility.

 *  

 * @author gvSIG Team - jjdelcerro

 *

 */

public interface Callable {

	/**

	 * Computes a result, or throws an exception if unable to do so.

	 * 

	 * @return computed result

	 * @throws Exception if unable to compute a result

	 */

	public Object call() throws Exception;

}

package org.gvsig.tools.util.impl;

import java.util.ArrayList;

import java.util.Iterator;

import java.util.List;

import org.gvsig.tools.util.Callable;

import org.gvsig.tools.util.Caller;

public class DefaultCaller implements Caller {

	private boolean collectExceptions;

	private List callables;

	private List exceptions;

	public DefaultCaller() {

		this.collectExceptions = true;

		this.callables = new ArrayList();

		this.exceptions = null;

	}

	public boolean call() {

        List exceptions = new ArrayList();

        Iterator it = this.callables.iterator();

        while( it.hasNext() ) {

        	Callable callable = (Callable)(it.next());

        	try {

				callable.call();

			} catch (Exception e) {

				exceptions.add(e);

			}

        }

        if( exceptions.size()>0 ) {

        	this.exceptions = exceptions;

        	return false;

        }

        return true;

	}

	public boolean getCollectExceptions() {

		return this.collectExceptions;

	}

	public void setCollectExceptions(boolean collectExceptions) {

		this.collectExceptions = collectExceptions;

	}

	public void add(Callable callable) {

		this.callables.add(callable);

	}

	public List getExceptions() {

		return this.exceptions;

	}

}

package org.gvsig.tools.util;

import java.util.List;

/**

 * 

 * This is a utility class for call a list of callables.

 * 

 * It can collect exceptions and continue to call the next 

 * callable in the list. 

 * 

 * @author gvSIG Team - jjdelcerro

 *

 */

public interface Caller {

	/**

	 * Get if the Caller can collect exceptions or

	 * exit in the first exception produced.

	 * 

	 * @return boolean that indicate that collect exceptions.

	 */

	public boolean getCollectExceptions();

	/**

	 * Set in the caller the behabior of collect al exceptions

	 * and continue calling the next callable in the list of our

	 * callables.

	 * 

	 * @param collectExceptions

	 */

	public void setCollectExceptions(boolean collectExceptions);

	/**

	 * Add a callable to the list of callables of the caller.

	 * @param callable

	 */

	public void add(Callable callable);

	/**

	 * Return the list of collected exceptions or null.

	 * 

	 * @return list of exceptions

	 */

	public List getExceptions();

	/**

	 * Call all callables in the list of callables of the caller.

	 * 

	 * @return true if no exceptions produced

	 */

	public boolean call();

}