operationfactory.java

面向对象设计的Java计算器

public class OperationFactory {
	public static Operation createOperate(String operate)
	{
		Operation oper=null;
		if(operate.equals("+"))
			oper=new OperationAdd();
		if(operate.equals("-"))
			oper=new OperationSub();
		if(operate.equals("*"))
			oper=new OperationMul();
		if(operate.equals("/"))
			oper=new OperationDiv();
		return oper;
	}
}