Java基础之写文件——通过缓冲流写文件（StreamOutputToFile）

控制台程序，生成一些二进制整型值并且将它们写入到文件中。

 import java.nio.file.*;
 import java.nio.*;
 import java.io.*;

 public class StreamOutputToFile {

   public static void main(String[] args) {
     final int count = 50;                                              // Number of values
     long[] fiboNumbers = {0L,0L};                                      // Array of 2 elements
     int index = 0;                                                     // Index to fibonumbers
     ByteBuffer buf = ByteBuffer.allocate(count*8);                     // Buffer for output
     LongBuffer longBuf = buf.asLongBuffer();                           // View buffer for type long
     Path file = Paths.get(System.getProperty("user.home")).resolve("Beginning Java Struff").resolve("fibonnaci.bin");
     try {
       // Create parent directory if it doesn't exist
       Files.createDirectories(file.getParent());
     } catch(IOException e) {
       System.err.println("Error creating directory: " + file.getParent());
       e.printStackTrace();
       System.exit(1);
     }

     try(BufferedOutputStream fileOut = new BufferedOutputStream(Files.newOutputStream(file))){
       // Generate Fibonacci numbers in buffer
       for(int i = 0 ; i < count ; ++i) {
         if(i < 2)
           fiboNumbers[index] = i;
         else
           fiboNumbers[index] = fiboNumbers[0] + fiboNumbers[1];
         longBuf.put(fiboNumbers[index]);
         index = ++index%2;
       }
     // Write the numbers to the file
     fileOut.write(buf.array(), 0, buf.capacity());
     System.out.println("File written.");
     } catch(IOException e) {
       System.err.println("Error writing file: " + file);
       e.printStackTrace();
     }
   }
 }