生成算式并将他永久的保存到文件中

package update;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.util.Scanner;

public class complex {
    public static void main(String args[]) throws IOException {
        
        System.out.println("生成数量：");
        
        Scanner r=new Scanner(System.in);
        int count=r.nextInt();
        System.out.println("操作数范围：");
        Scanner r1=new Scanner(System.in);
        int fanwei=r1.nextInt();
    
        
        create(count,fanwei);
        
    }
    //生成算式
    public static void create(int count ,int fanwei) throws IOException {
    int[] result=new int[count];
    File f=new File("myout.txt");
        f.createNewFile();
        FileOutputStream fileOutputStream = new FileOutputStream(f);
        PrintStream printStream = new PrintStream(fileOutputStream);

        int i=0;
        for(i=0;i<count;i++) {
            int left_number=random( fanwei);
        
            int right_number=random(fanwei);
            String operate=fuhao();
            if((operate=="-")&&(left_number<right_number)) {
                int temp=0;
                temp=left_number;
                left_number=right_number;
                right_number=temp;
            
            }

        
            number num =new number(left_number, operate, right_number);
            
             result[i]=result( count, left_number, right_number, operate);
             System.setOut(printStream);
            System.out.println(num.left_number+num.operate+num.right_number+"=  ,");
            
        }
        System.out.println("查看答案0/1(否/是)：");
        Scanner r=new Scanner(System.in);
        int N=r.nextInt();
        if(N==1) {
            System.setOut(printStream);
            for( i=0;i<count;i++) {
                System.out.print(result[i]+",");
            }
        }
        
        
    }
    //产生随机数
    public static  int random(int fanwei){
        int a=0;
        a=(int)(Math.random()*fanwei)+1;
        return a;
        
    }
    //产生随机符号
    public static String fuhao() {
        int a=0;
        a=(int)(Math.random()*2);
        String fuhao = null;
        switch(a) {
        case 0:fuhao="+";break;
        case 1:fuhao="-";break;
        
        }
        return fuhao;
        
    }
    //计算结果
    public static int result(int count,int left_number,int right_number ,String operate) {
        
        
        int result=0;
        if(operate=="+") {
            result=left_number+right_number;
            
        }else if(operate=="-") {
            result=left_number-right_number;
            
        }
    return result;
        
    }

}

package update;

public class number {
    int left_number;//左操作数
    int right_number;//右操作数
    
    String operate;//符号
    public number(int left_number,String operate, int right_number) {
        this.left_number=left_number;
        this.right_number=right_number;
        this.operate=operate;
        
    }
    
    
     public int getLeft_number() {
            return left_number;
        }

        public void setLeft_number(int left_number) {
            this.left_number = left_number;
        }

        public int getRight_number() {
            return right_number;
        }

        public void setRight_number(int right_number) {
            this.right_number = right_number;
        }

        public String getOperate() {
            return operate;
        }

        public void setOperate(String operate) {
            this.operate = operate;
        }
       
}