Here you can find the source of readFileBytes(String filePath)
public static byte[] readFileBytes(String filePath) throws IOException
//package com.java2s; /**/* ww w. j ava2s .com*/ * Copyright 2016 William Van Woensel 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. * * * @author wvw * */ import java.io.ByteArrayOutputStream; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; public class Main { public static byte[] readFileBytes(String filePath) throws IOException { InputStream fin = getFileInputStream(filePath); byte[] b = new byte[1024]; int len = 0; ByteArrayOutputStream bOut = new ByteArrayOutputStream(); while ((len = fin.read(b)) != -1) bOut.write(b, 0, len); return bOut.toByteArray(); } public static InputStream getFileInputStream(String filePath) throws IOException { return new FileInputStream(filePath); } }