チャレンジプログラム4(JavaScript)

Calc.java

package main.java;

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

public class Calc {
	public static void main(String[] args) throws ScriptException {

		if (args.length == 1) {
			// 余計な文字を取り除く
			String arg0 = args[0].replaceAll("'", "").replace("\"", "");

			// 組み込みJavaScript Engine の Rhinoを使う
			ScriptEngine engine = new ScriptEngineManager()
					.getEngineByName("JavaScript");

			System.out.println(engine.eval(arg0));
		} else {
			System.out.println("usage 1: java -jar Calc.jar 1+2*3");
			System.out.println("usage 2: java -jar Cals.jar \"1 + 2*/3.0\"");
		}

	}
}