隨筆檔案(496)

1.把浮點數寫入文件

import java.io.*;

public class FileOutputDemo
{
public static void main(String[] args)
{
?? FileOutputStream out;
?? DataOutputStream p;

?? try
?? {
??? out = new FileOutputStream("myfile.txt");
??? p = new DataOutputStream(out);
??? p.writeDouble(3);
??? p.writeDouble(4);
??? p.writeDouble(5);
??? p.close();
?? }
?? catch(Exception e)
?? {
??? System.err.println("Error writing to file");
?? }
}
}

2.從文件中讀取浮點數

import java.io.*;

public class FileInputDemo
{
public static void main(String[] args)
{
?? if(args.length==1)
?? {
??? try
??? {
???? FileInputStream f = new FileInputStream(args[0]);
???? DataInputStream in = new DataInputStream(f);
???? while(in.available() != 0)
???? {
????? System.out.println(String.valueOf(in.readDouble()));
???? }
???? in.close();
??? }
??? catch(Exception e)
??? {
???? System.out.println("File input Erroe!");
??? }
?? }
?? else
??? System.out.println("Invalid parametres");
}
}