Caculater_1

Main

package caculater;

import java.util.ArrayList;
import java.util.List;

public class Caculater_1 {
    public static void main(String[] args) {
        Double res = 0.0;
        while(true){
            List<Double> Num = new ArrayList<Double>();
            List<Integer> Ope = new ArrayList<Integer>();
            Object[] Inp = {null,-1};
            boolean NorO = true;
            while(true){
                Inp = Input_1.Inp();
                if(Inp[1].equals(-2)){
                    System.out.println("Error input");
                    continue;
                }
                if(NorO==true){
                    if(Inp[1].equals(-1)){
                        Num.add((Double) Inp[0]);
                        NorO = false;
                    }else{
                        if(Ope.size()==0){
                            Ope.set(0, (Integer) Inp[1]);
                            if(Ope.get(Ope.size()-1)==0){
                                break;
                            }
                        }else{
                            Ope.set(Ope.size()-1, (Integer) Inp[1]);
                            if(Ope.get(Ope.size()-1)==0){
                                break;
                            }
                        }
                    }
                }else{if(Inp[1].equals(-1)){
                    Num.removeAll(Num);
                    Num.add((Double) Inp[0]);
                }else{
                    Ope.add((Integer) Inp[1]);
                    if(Ope.get(Ope.size()-1)==0){
                        break;
                    }
                    NorO = true;
                }
                }
            }
            for(int i =0;i<Ope.size()-1;i++){
                if(Ope.get(i)==3&&Ope.get(i)==4){
                    if(Ope.get(i)==3){
                        Num.set(i,Compute_1.Mul(Num.get(i),Num.get(i+1)));
                        Ope.remove(i);
                        Num.remove(i+1);
                        i--;
                    }else if(Ope.get(i)==0){
                        break;
                    }else{
                        Num.set(i,Compute_1.Div(Num.get(i),Num.get(i+1)));
                        Ope.remove(i);
                        Num.remove(i+1);
                        i--;
                    }
                }
            }
            for(int i =0;i<Ope.size()-1;i++){
                if(Ope.get(i)==1){
                    Num.set(i,Compute_1.Add(Num.get(i),Num.get(i+1)));
                    Ope.remove(i);
                    Num.remove(i+1);
                    i--;
                }else if(Ope.get(i)==0){
                    break;
                }else{
                    Num.set(i,Compute_1.Sub(Num.get(i),Num.get(i+1)));
                    Ope.remove(i);
                    Num.remove(i+1);
                    i--; 
                }
            }
            res = Num.get(0);
            System.out.println(res);
        }
    }
}

输入检测

package caculater;
import java.util.Scanner;

public class Input_1 {
    public static Object[] Inp(){
        Double num = null;
        Object[] Inp ={num,-1};
        @SuppressWarnings("resource")
        Scanner sc = new Scanner(System.in);
        String Input = sc.nextLine();
        String[]opt ={"=","+","-","*","/"};
        try {
            Inp[0]=Double.parseDouble(Input);
        } catch (NumberFormatException e) {
            for(int i=0;i<5;i++){
                if(Input.equals(opt[i])){
                    Inp[1] = i;
                    break;
                }else{
                    Inp[1] = -2;
                }
            }
        }
        return Inp;
    }
}

计算

package caculater;

public class Compute_1 {
    public static double Add(double a,double b){
        return a+b;
    }
    public static double Sub(double a,double b){
        return a-b;
    }
    public static double Mul(double a,double b){
        return a+b;
    }
    public static double Div(double a,double b){
        return a+b;
    }
}