Util.java Source code

Introduction

Here is the source code for Util.java

Source

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

public class Util {
    /** 
    * Read bytes from a File into a byte[].
    * 
    * @param file The File to read.
    * @return A byte[] containing the contents of the File.
    * @throws IOException Thrown if the File is too long to read or couldn't be
    * read fully.
    */
    public static byte[] readBytesFromFile(File file) throws IOException {
        InputStream is = new FileInputStream(file);

        // Get the size of the file
        long length = file.length();

        // You cannot create an array using a long type.
        // It needs to be an int type.
        // Before converting to an int type, check
        // to ensure that file is not larger than Integer.MAX_VALUE.
        if (length > Integer.MAX_VALUE) {
            throw new IOException("Could not completely read file " + file.getName() + " as it is too long ("
                    + length + " bytes, max supported " + Integer.MAX_VALUE + ")");
        }

        // Create the byte array to hold the data
        byte[] bytes = new byte[(int) length];

        // Read in the bytes
        int offset = 0;
        int numRead = 0;
        while (offset < bytes.length && (numRead = is.read(bytes, offset, bytes.length - offset)) >= 0) {
            offset += numRead;
        }

        // Ensure all the bytes have been read in
        if (offset < bytes.length) {
            throw new IOException("Could not completely read file " + file.getName());
        }

        // Close the input stream and return bytes
        is.close();
        return bytes;
    }

    /**
     * Writes the specified byte[] to the specified File path.
     * 
     * @param theFile File Object representing the path to write to.
     * @param bytes The byte[] of data to write to the File.
     * @throws IOException Thrown if there is problem creating or writing the 
     * File.
     */
    public static void writeBytesToFile(File theFile, byte[] bytes) throws IOException {
        BufferedOutputStream bos = null;

        try {
            FileOutputStream fos = new FileOutputStream(theFile);
            bos = new BufferedOutputStream(fos);
            bos.write(bytes);
        } finally {
            if (bos != null) {
                try {
                    //flush and close the BufferedOutputStream
                    bos.flush();
                    bos.close();
                } catch (Exception e) {
                }
            }
        }
    }
}