java实现四则运算

代码示例：

public class Test
{

	public static void main(String[] args)
	{
		try
		{
			System.out.println(calc("-5*(10/(2*4.5-4)+(-3/1.5+4)*(-2))/(-2/1-(-1))+12"));
		}
		catch (javax.script.ScriptException se)
		{

		}
	}

	public static double calc(String s) throws javax.script.ScriptException
	{
		Object o = new javax.script.ScriptEngineManager().getEngineByName(
				"JavaScript").eval(s);
		return (Double) o;
	}
}