Here you can find the source of readFile(File file)
public static String readFile(File file) throws IOException
//package com.java2s; //License from project: Open Source License import java.io.Closeable; import java.io.File; import java.io.FileInputStream; import java.io.IOException; public class Main { public static String readFile(File file) throws IOException { FileInputStream in = null; try {/*from ww w . j av a 2 s .co m*/ in = new FileInputStream(file); byte[] buf = new byte[in.available()]; in.read(buf); return new String(buf, "UTF-8"); } finally { closeQuietly(in); } } public static void closeQuietly(Closeable closeable) { if (closeable != null) { try { closeable.close(); } catch (Exception ex) { } } } }