这个简单的Java程序是用来输入客户名称，产品编号，产品价格和项目name.Then将检查的TextField，使所有字段都必须填写在“添加项目”和“提交”按钮可以使用。然后，它将把打印输出和信息面板计算总价。-This simple java program is used to input customer name,item id,item price and item name.Then it will check the textField so that all field must be filled before "add item" and "submit" button can be used. Then,it will print the output into the info panel and calculate the total price.