compliermain.java

用JAVA写的计算一段数学表达式的程序

package net.csksoft.util.expcomp;
import org.omg.CORBA.*;
import javax.swing.*;

//Finish CodeFans.net
public class ComplierMain{

	
	public static void main(String[] args) {
		
		ExpComplier comp = new ExpComplier();
		String exp=JOptionPane.showInputDialog("Please Input the expression:","12.11+23*2-2*-3*(4.4+3/4)");
		
		if (exp==null) return;
		comp.SetExpression(exp);
		if (!comp.Complie())
		{
			JOptionPane.showMessageDialog(null, "Compile err:\n" +comp.GetLastError() );
		
			return;
		}
		
		DoubleHolder ansHolder = new DoubleHolder();
		if (!comp.calc(ansHolder))
		{
			JOptionPane.showMessageDialog(null, "Exec err:\n" +comp.GetLastError() );
			
		}
		else
		{
			String tmpStr = new String();
			tmpStr = "The Answer of \"" + comp.GetExpression() +"\" is :";
			tmpStr += ansHolder.value;
			JOptionPane.showMessageDialog(null, tmpStr);
		}
		
	}
	
	
}