从文件获取字节
/*n o w j a v a . c o m 提供*/ //package com.nowjava; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; public class Main { public static void main(String[] argv) throws Exception { File file = new File("Main.java"); System.out.println(java.util.Arrays .toString(getBytesFromFile(file))); } public static byte[] getBytesFromFile(File file) throws IOException { InputStream is = new FileInputStream(file); long length = file.length(); if (length > Integer.MAX_VALUE) { // File is too large/*时 代 J a v a 公 众 号 - nowjava.com 提供*/ } byte[] bytes = new byte[(int) length]; int offset = 0; int numRead = 0; while (offset < bytes.length && (numRead = is.read(bytes, offset, bytes.length - offset)) >= 0) { offset += numRead; }