Here you can find the source of getInputStream(String file)
public static DataInputStream getInputStream(String file) throws IOException
//package com.java2s; import java.io.*; public class Main { /**/*from w w w . ja va2 s .c o m*/ * Return a buffered data input stream for file. */ public static DataInputStream getInputStream(String file) throws IOException { return getInputStream(new File(file)); } /** * Return a buffered data input stream for f. */ public static DataInputStream getInputStream(File f) throws IOException { return new DataInputStream(new BufferedInputStream(new FileInputStream(f), 32676)); } }