java - 通过随机访问文件保存日期变量

Question

如何在 Java 中使用 RandomAccesFile 编写日期变量？我知道日期变量是 7 个字节，但我不知道如何编写它。

Answer 1

以下是如何使用日期和文件的一些示例。

import java.util.*;
import java.text.*;
import java.io.*;
import java.nio.*;

public class DateExample {

     public static void main(String []args) throws IOException, ParseException {
        /* convert string to Date */
        String time = "May 08 2015 05:19:34";
        DateFormat df = new SimpleDateFormat("MMM dd yyyy HH:mm:ss");
        Date outDate = df.parse(time);

        /* write to file */
        System.out.println(outDate + " in one number is " + outDate.getTime());
        RandomAccessFile outFile = new RandomAccessFile("date-file", "rw");
        outFile.write(ByteBuffer.allocate(8).putLong(outDate.getTime()).array());
        outFile.close();

        /* read from file */
        Date inDate = new Date(); 
        RandomAccessFile inFile = new RandomAccessFile("date-file", "r");
        long t = inFile.readLong();
        inDate.setTime(t);
        outFile.close();
        System.out.println("number " + t + " is "+ inDate);
     }

}