postfixevaluationconsole.java

这个是一个计算表达式的java包

/*
Created 2 Dec 2006 - Richard Morris
*/
package com.singularsys.jepexamples.consoles;

import com.singularsys.jep.JepException;
import com.singularsys.jep.parser.Node;
import com.singularsys.jep.walkers.PostfixEvaluator;

public class PostfixEvaluationConsole extends Console {
	private static final long serialVersionUID = 1L;
	PostfixEvaluator pfe; 
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Console c = new PostfixEvaluationConsole();
		c.run(args);
	}

	public void initialise() {
		super.initialise();
		pfe = new PostfixEvaluator();
	}

	public void processEquation(Node node) throws JepException {
		Object result;
		try {
			//Node processed = ((XJep) j).preprocess(node);
			result = pfe.evaluate(node);
			System.out.println(result);
		} catch (Exception e) {
			System.out.println(e.getMessage());
		}
	}

}