用Java写一个简单的加减乘除计算器

好的，为您提供一个简单的Java实现的加减乘除计算器：

import java.util.Scanner;

public class Calculator {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.print("请输入第一个数字：");
        double num1 = scanner.nextDouble();

        System.out.print("请输入操作符（+,-,*,/）：");
        char operator = scanner.next().charAt(0);

        System.out.print("请输入第二个数字：");
        double num2 = scanner.nextDouble();

        double result = 0;

        switch (operator) {
            case '+':
                result = num1 + num2;
                break;
            case '-':
                result = num1 - num2;
                break;
            case '*':
                result = num1 * num2;
                break;
            case '/':
                if (num2 == 0) {
                    System.out.println("除数不能为0！");
                    return;
                }
                result = num1 / num2;
                break;
            default:
                System.out.println("请输入正确的操作符！");
                return;
        }

        System.out.println(num1 + " " + operator + " " + num2 + " = " + result);
    }
}

希望能够对您有所帮助！