Load File as byte array : Byte Array « File Input Output « Java






Load File as byte array

      

/*
    GNU LESSER GENERAL PUBLIC LICENSE
    Copyright (C) 2006 The Lobo Project

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Contact info: lobochief@users.sourceforge.net
*/
/*
 * Created on Mar 19, 2005
 */

import java.io.*;

/**
 * @author J. H. S.
 */
public class IORoutines {
  public static final byte[] LINE_BREAK_BYTES = { (byte) 13, (byte) 10 }; 
  
  public static String loadAsText(InputStream in, String encoding) throws IOException {
    return loadAsText(in, encoding, 4096);
  }
  
  public static String loadAsText(InputStream in, String encoding, int bufferSize) throws IOException {
    InputStreamReader reader = new InputStreamReader(in, encoding);
      char[] buffer = new char[bufferSize];
      int offset = 0;
      for(;;) {
        int remain = buffer.length - offset;
        if(remain <= 0) {
          char[] newBuffer = new char[buffer.length * 2];
          System.arraycopy(buffer, 0, newBuffer, 0, offset);                    
          buffer = newBuffer;
          remain = buffer.length - offset;
        }
          int numRead = reader.read(buffer, offset, remain);
          if(numRead == -1) {
            break;
          }
        offset += numRead;
      }
      return new String(buffer, 0, offset);
  }
  
    public static byte[] load(File file) throws IOException {
        long fileLength = file.length();
        if(fileLength > Integer.MAX_VALUE) {
            throw new IOException("File '" + file.getName() + "' too big");
        }
        InputStream in = new FileInputStream(file);
        try {
          return loadExact(in, (int) fileLength);
        } finally {
            in.close();
        }
    }
    
    public static byte[] load(InputStream in) throws IOException {
        return load(in, 4096);
    }
    public static byte[] load(InputStream in, int initialBufferSize) throws IOException {
      if(initialBufferSize == 0) {
        initialBufferSize = 1;
      }
      byte[] buffer = new byte[initialBufferSize];
      int offset = 0;
      for(;;) {
        int remain = buffer.length - offset;
        if(remain <= 0) {
          int newSize = buffer.length * 2;
          byte[] newBuffer = new byte[newSize];
          System.arraycopy(buffer, 0, newBuffer, 0, offset);                    
          buffer = newBuffer;
          remain = buffer.length - offset;
        }
          int numRead = in.read(buffer, offset, remain);
          if(numRead == -1) {
            break;
          }
        offset += numRead;
      }
      if(offset < buffer.length) {
        byte[] newBuffer = new byte[offset];
        System.arraycopy(buffer, 0, newBuffer, 0, offset);                    
        buffer = newBuffer;
      }
      return buffer;
    }
    
    public static byte[] loadExact(InputStream in, int length) throws IOException {
      byte[] buffer = new byte[length];
      int offset = 0;
      for(;;) {
        int remain = length - offset;
        if(remain <= 0) {
          break;
        }
        int numRead = in.read(buffer, offset, remain);
        if(numRead == -1) {
          throw new IOException("Reached EOF, read " + offset + " expecting " + length);
        }
      offset += numRead;
      }
      return buffer;
    }

    public static boolean equalContent(File file, byte[] content) throws IOException {
      long length = file.length();
      if(length > Integer.MAX_VALUE) {
        throw new IOException("File '" + file + "' too big");
      }
      InputStream in = new FileInputStream(file);
      try {
        byte[] fileContent = loadExact(in, (int) length);
        return java.util.Arrays.equals(content, fileContent);
      } finally {
        in.close();
      }
    }
    
    public static void save(File file, byte[] content) throws IOException {
      FileOutputStream out = new FileOutputStream(file);
      try {
        out.write(content);
      } finally {
        out.close();
      }
    }
    
    /**
     * Reads line without buffering.
     */
    public static String readLine(InputStream in) throws IOException {
      int b;
      StringBuffer sb = null;
      OUTER:
      while((b = in.read()) != -1) {
        if(sb == null) {
          sb = new StringBuffer();
        }
        switch(b) {
          case (byte) '\n':
            break OUTER;
          case (byte) '\r':
            break;
          default:
            sb.append((char) b);
            break;
        }
      }
      return sb == null ? null : sb.toString();
    }
    
    public static void touch(File file) {
      file.setLastModified(System.currentTimeMillis());
    }
    
    public static void saveStrings(File file, java.util.Collection list) throws IOException {
      BufferedOutputStream bout = new BufferedOutputStream(new FileOutputStream(file));
      try {
        PrintWriter writer = new PrintWriter(bout);
        java.util.Iterator i = list.iterator();
        while(i.hasNext()) {
          String text = (String) i.next();
          writer.println(text);
        }
        writer.flush();
      } finally {
        bout.close();
      }
    }
    
    public static java.util.List loadStrings(File file) throws IOException {
      java.util.List list = new java.util.LinkedList();
      InputStream in = new FileInputStream(file);
      try {
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
        String line;
        while((line = reader.readLine()) != null) {
          list.add(line);
        }
        return list;
      } finally {
        in.close();
      }
    }
    
}

   
    
    
    
    
    
  








Related examples in the same category

1.Load file to byte array
2.Manages fixed-length byte arrays
3.Byte-Array Conversion Utility Functions
4.ByteArray wraps java byte arrays (byte[]) to allow byte arrays to be used as keys in hashtables.
5.Returns a object from the given byte array.
6.Gets an array of bytes corresponding to the given object
7.An implementation of a virtual file, whose contents are kept in memory
8.Given a hexstring this will return the byte array corresponding to string
9.Decode byte array
10.Compare two byte[] for differences, either may be null
11.Convert the bytes within the specified range of the given byte array into a String
12.Convert the bytes within the specified range of the given byte array into a signed integer
13.Convert the bytes within the specified range of the given byte array into a signed integer in the given radix
14.Convert the bytes within the specified range of the given byte array into a signed long
15.Converts a byte array into a hexadecimal string
16.Converts a byte array into hexadecimal characters which are written as ASCII to the given output stream.
17.Convert byte array into a printable format: a String of hexadecimal digit characters (two per byte).
18.Convert hexadecimal digits into byte array by encoding each two hexadecimal digits as a byte.
19.Get Hex from byte arrayGet Hex from byte array
20.Read file to byte array
21.Invert the endianness of words (4 bytes) in the given byte array starting at the given offset and repeating length/4 times.
22.Returns a hexadecimal representation of the given byte array.
23.Converts a hex string representation to a byte array.
24.extracts floats from byte array
25.Extracts ints from byte array
26.extracts longs from byte array
27.Extracts short ints from byte array
28.writes doubles to byte array
29.writes floats to byte array
30.writes ints to byte array
31.writes longs to byte array
32.writes short ints to byte array
33.Convert a string of hex digits to a byte array, with the first byte in the array being the MSB.
34.Byte Array
35.This class provides encoding of byte arrays into Base64-encoded strings, and decoding the other way.
36.Byte Array for Android
37.Convert byte array to Hex string
38.implements an output stream in which the data is written into a byte array. The buffer automatically grows as data is written to it.
39.Convert a TCP/IP address string into a byte array
40.Read file to byte array and save byte array to file
41.Convert object to byte array and convert byte array to object
42.Byte ArrayList
43.converts an int integer array to a byte array.
44.Compress byte array
45.Utility method to convert byte array to hex-encoded string.
46.InputStream to String and Byte array
47.Fast Byte Array InputStream
48.Fast Byte Array OutputStream