Question

编写一个Java程序将111,112,113,114,115 这5个数写入到Dest.txt文件中，并以相反的顺序读出显示在屏幕上

Answer 1

import java.io.*;
import java.util.ArrayList;
import java.util.List;

public class DestTxt {

    public static void writeTo(String filename) throws IOException {
        FileOutputStream fout = new FileOutputStream(filename);
        DataOutputStream dout = new DataOutputStream(fout);
        for (int i=1; i<= 5; i++)
            dout.writeInt(110 + i);
        dout.close();
        fout.close();
    }
    public static void readFrom(String filename) throws  IOException
    {
        FileInputStream fin = new FileInputStream(filename);
        DataInputStream din = new DataInputStream(fin);
        System.out.println(filename + ": ");
        List list = new ArrayList();
        while (true)
            try {
                list.add(0, din.readInt());
            } catch (EOFException e) {
                break;
            }
        for(Object o : list)
            System.out.println(o);
        din.close();
        fin.close();
    }

    public static void main(String[] args) throws IOException {
        writeTo("dest.txt");
        readFrom("dest.txt");
    }
}