求推荐一个 Android 系统上可以和电脑互传文件的应用

https://www.v2ex.com/t/689044

package com.example.genericparadigmdemo.paradigm.calculator;

public interface Calculator<T> {

//泛型
    public T add(T operand1, T operand2);

    public T addMany(T...operands);

    public T sub(T operand1, T operand2);

    public T multiplication(T...operands);
}

package com.example.genericparadigmdemo.paradigm.calculator;

import org.springframework.stereotype.Component;

@Component
public class IntegerCalculator implements Calculator<Integer> {
    @Override
    public Integer add(Integer operand1, Integer operand2) {
        return operand1 + operand2;
    }

    @Override
    public Integer addMany(Integer... operands) {
        Integer result = 0;
        for (Integer oper : operands) {
            result += oper;
        }
        return result;
    }

    @Override
    public Integer sub(Integer operand1, Integer operand2) {
        return operand1 - operand2;
    }

    @Override
    public Integer multiplication(Integer... operands) {
        Integer result = 1;
        for (Integer oper : operands) {
            result *= oper;
        }
        return result;
    }


    public static void main(String[] args) {
        IntegerCalculator c1 = new IntegerCalculator();
        System.out.println(c1.add(1, 2));

        Calculator<Integer> c2 = new IntegerCalculator();
        System.out.println(c2.add(3, 4));

        Calculator<Integer> c3 = new IntegerCalculator();
        System.out.println(c3.multiplication(3,2,2));

        Calculator<Integer> c4 = new IntegerCalculator();
        System.out.println(c4.addMany(1,2,311,412,3,21,3));
    }
}

package com.example.genericparadigmdemo.paradigm.calculator;

import com.example.genericparadigmdemo.paradigm.ParadigmFormatter;

public class IntervalCalculator implements Calculator<ParadigmFormatter<Integer>> {
    @Override
    public ParadigmFormatter<Integer> add(ParadigmFormatter<Integer> operand1, ParadigmFormatter<Integer> operand2) {
        int lower = operand1.getLower() + operand2.getLower();
        int upper = operand1.getUpper() + operand2.getUpper();
        return new ParadigmFormatter<Integer>(lower,upper);
    }

    public static void main(String[] args) {
        Calculator<ParadigmFormatter<Integer>> c = new IntervalCalculator();
        ParadigmFormatter<Integer> operand1 = new ParadigmFormatter<>(1,2);
        ParadigmFormatter<Integer> operand2 = new ParadigmFormatter<>(3,4);
        ParadigmFormatter<Integer> operand3 = c.add(operand1, operand2);
        System.out.println(operand3.getLower());
    }

    @Override
    public ParadigmFormatter<Integer> addMany(ParadigmFormatter<Integer>... operands) {
        return null;
    }

    @Override
    public ParadigmFormatter<Integer> sub(ParadigmFormatter<Integer> operand1, ParadigmFormatter<Integer> operand2) {
        return null;
    }

    @Override
    public ParadigmFormatter<Integer> multiplication(ParadigmFormatter<Integer>... operands) {
        return null;
    }
}

package com.example.genericparadigmdemo.paradigm.calculator;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class OperationController {


}

package com.example.genericparadigmdemo.paradigm;

public class ParadigmFormatter<T> {

    private T lower;
    private T upper;

    public ParadigmFormatter(T lower, T upper){
        this.lower = lower;
        this.upper = upper;
    }

    public T getLower(){
        return lower;
    }

    public T getUpper(){
        return upper;
    }

}