Here you can find the source of readFile(String filename)
public static byte[] readFile(String filename) throws IOException
//package com.java2s; /*/*from ww w. j a va 2 s .c o m*/ * Copyright 2005 PB Consult Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * */ import java.io.*; public class Main { public static byte[] readFile(String filename) throws IOException { File file = new File(filename); long len = file.length(); byte data[] = new byte[(int) len]; FileInputStream fin = new FileInputStream(file); int r = fin.read(data); if (r != len) { throw new IOException("Only read " + r + " of " + len + " for " + file); } fin.close(); return data; } }