Java基础之读文件——使用输入流读取二进制文件（StreamInputFromFile）

控制台程序，读取Java基础之读文件部分（StreamOutputToFile）写入的50个fibonacci数字。

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

public class StreamInputFromFile {
  public static void main(String[] args) {

    Path file = Paths.get(System.getProperty("user.home")).resolve("Beginning Java Struff").resolve("fibonnaci.bin");

    if(!Files.exists(file)) {
      System.out.println(file + " does not exist. Terminating program.");
      System.exit(1);
    }

    final int count = 6;                                               // Number of values to be read each time

    // Buffer to hold count values
    ByteBuffer buf = ByteBuffer.allocate(8*count);

    LongBuffer values = buf.asLongBuffer();
    byte[] bytes = buf.array();                                        // Backing array for buf
    int totalRead = 0;                                                 // Total value read
    try(BufferedInputStream fileIn = new BufferedInputStream(Files.newInputStream(file))){
      int numberRead = 0;
      while(true) {
        numberRead = fileIn.read(bytes, 0, bytes.length);
        if(numberRead == -1)                                           // EOF reached
          break;
        totalRead += numberRead/8;                                     // Increment total

        for(int i = 0 ; i < numberRead/8 ; ++i)                        // Access as many as there are
          System.out.format("%12d", values.get());

        System.out.println();                                          // New line
        values.flip();                                                 // Reset for next input
      }
    System.out.format("%d  values read.%n", totalRead);
    } catch(IOException e) {
      System.err.println("Error writing file: " + file);
      e.printStackTrace();
    }
  }
}