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();
     }
   }
 }