FileHandler.java

package apes.lib;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.nio.ByteBuffer;

import javax.swing.JFileChooser;
import javax.swing.JPanel;


/**
 * A helper class to load and save files from and to the disk.
 * 
 * @author Simon Holm
 */
public class FileHandler
{

  /**
   * Loads a file from the disk and stores the data into a ByteBuffer.
   * 
   * @param path The path to the folder with the file to be loaded.
   * @param fileName The name of the file to be loaded.
   * @return Returns a ByteBuffer with all the data from the file.
   * @throws IOException Throws an IOException if something unexpected happens.
   */
  public static ByteBuffer loadFile(String path, String fileName) throws IOException
  {
    File file = new File(path, fileName);
    FileInputStream iStream = new FileInputStream(file);
    byte[] buffer = new byte[(int)file.length()];
    iStream.read(buffer);

    return ByteBuffer.wrap(buffer);
  }

  /**
   * Loads a file at the root path from the disk and stores the data into a
   * ByteBuffer.
   * 
   * @param fileName The name of the file to be loaded.
   * @return Returns a ByteBuffer with all the data from the file
   * @throws IOException Throws an IOException if something unexpected happens.
   */
  public static ByteBuffer loadFile(String fileName) throws IOException
  {
    return loadFile(".", fileName);
  }

  /**
   * Saves data to a file.
   * 
   * @param path The path to the folder were the file will be save.
   * @param fileName The name of the file to be saved.
   * @param data The data to be saved.
   * @throws IOException Throws an IOException if something unexpected happens.
   */
  public static void saveToFile(String path, String fileName, byte[] data) throws IOException
  {
    File file = new File(path + "/" + fileName);
    file.createNewFile();
    FileOutputStream oStream = new FileOutputStream(file);
    oStream.write(data);
  }

  /**
   * Saves data to a file in the folder ".".
   * 
   * @param fileName The name of the file.
   * @param data The data to be saved.
   * @throws IOException Throws an IOException if something unexpected happens.
   */
  public static void saveToFile(String fileName, byte[] data) throws IOException
  {
    saveToFile(".", fileName, data);
  }

  /**
   * Saves an object to a file.
   * 
   * @param path The path to were the file will be saved.
   * @param fileName The name of the file.
   * @param data The object to be saved.
   * @throws IOException Throws an IOException if something unexpected happens.
   */
  public static void saveObjectToFile(String path, String fileName, Object data) throws IOException
  {
    File file = new File(path + "/" + fileName);
    file.createNewFile();
    FileOutputStream oStream = new FileOutputStream(file);

    ObjectOutputStream obj_out = new ObjectOutputStream(oStream);
    obj_out.writeObject(data);
  }

  /**
   * Saves an object to a file in the folder ".".
   * 
   * @param fileName The name of the file.
   * @param data The object to be saved.
   * @throws IOException Throws an IOException if something unexpected happens.
   */
  public static void saveObjectToFile(String fileName, Object data) throws IOException
  {
    saveObjectToFile(".", fileName, data);
  }

  /**
   * Loads an object from a file.
   * 
   * @param path The path to the folder were to load the file.
   * @param fileName The name of the file to be loaded.
   * @return Returns the loaded object.
   * @throws IOException Throws an IOException if something unexpected happens.
   * @throws ClassNotFoundException Throws an ClassNotFoundException if
   *           something unexpected happens.
   */
  public static Object loadObjectFile(String path, String fileName) throws IOException, ClassNotFoundException
  {
    File file = new File(path + "/" + fileName);
    FileInputStream iStream = new FileInputStream(file);

    ObjectInputStream obj_in = new ObjectInputStream(iStream);

    return obj_in.readObject();
  }

  /**
   * Loads an object form the folder ".".
   * 
   * @param fileName The name of the file to be loaded.
   * @return Returns the loaded object.
   * @throws IOException Throws an IOException if something unexpected happens.
   * @throws ClassNotFoundException Throws an ClassNotFoundException if
   *           something unexpected happens.
   */
  public static Object loadObjectFile(String fileName) throws IOException, ClassNotFoundException
  {
    return loadObjectFile(".", fileName);
  }

  // /////////////////////////////////////////////////////

  /**
   * Loads a file from the disk and stores the data into a ByteBuffer with a
   * dialogbox.
   * 
   * @return Returns a ByteBuffer with all the data from the file.
   * @throws IOException Throws an IOException if something unexpected happens.
   */
  public static ByteBuffer loadFileGraphical() throws IOException
  {
    final JFileChooser fc = new JFileChooser();
    fc.setCurrentDirectory(new File("."));
    fc.showOpenDialog(new JPanel());
    File file = fc.getSelectedFile();
    FileInputStream iStream = new FileInputStream(file);
    byte[] buffer = new byte[(int)file.length()];
    iStream.read(buffer);

    return ByteBuffer.wrap(buffer);
  }

  /**
   * Saves data to a file with a dialogbox.
   * 
   * @param path The path to the folder were the file will be save.
   * @param fileName The name of the file to be saved.
   * @param data The data to be saved.
   * @throws IOException Throws an IOException if something unexpected happens.
   */
  public static void saveToFileGraphical(String path, String fileName, byte[] data) throws IOException
  {
    File file = new File(path + "/" + fileName);
    file.createNewFile();
    FileOutputStream oStream = new FileOutputStream(file);
    oStream.write(data);
  }

  /**
   * Saves an object to a file with a dialogbox.
   * 
   * @param path The path to were the file will be saved.
   * @param fileName The name of the file.
   * @param data The object to be saved.
   * @throws IOException Throws an IOException if something unexpected happens.
   */
  public static void saveObjectToFileGraphical(String path, String fileName, Object data) throws IOException
  {
    File file = new File(path + "/" + fileName);
    file.createNewFile();
    FileOutputStream oStream = new FileOutputStream(file);

    ObjectOutputStream obj_out = new ObjectOutputStream(oStream);
    obj_out.writeObject(data);
  }

  /**
   * Loads an object from a file with a dialogbox.
   * 
   * @param path The path to the folder were to load the file.
   * @param fileName The name of the file to be loaded.
   * @return Returns the loaded object.
   * @throws IOException Throws an IOException if something unexpected happens.
   * @throws ClassNotFoundException Throws an ClassNotFoundException if
   *           something unexpected happens.
   */
  public static Object loadObjectFileGraphical(String path, String fileName) throws IOException, ClassNotFoundException
  {
    File file = new File(path + "/" + fileName);
    FileInputStream iStream = new FileInputStream(file);

    ObjectInputStream obj_in = new ObjectInputStream(iStream);

    return obj_in.readObject();
  }
}