Java by API/java.nio.charset/Charset

Charset: aliases()

 
import java.nio.charset.Charset;
import java.util.Iterator;
import java.util.Map;
public class Main {
  public static void main(String[] args) {
    Map charsets = Charset.availableCharsets();
    Iterator iterator = charsets.values().iterator();
    while (iterator.hasNext()) {
      Charset cs = (Charset) iterator.next();
      System.out.print(cs.displayName());
      if (cs.isRegistered()) {
        System.out.print(" (registered): ");
      } else {
        System.out.print(" (unregistered): ");
      }
      System.out.print(cs.name());
      Iterator names = cs.aliases().iterator();
      while (names.hasNext()) {
        System.out.print(", ");
        System.out.print(names.next());
      }
      System.out.println();
    }
  }
}

Charset: availableCharsets()

 
import java.nio.charset.Charset;
import java.util.Iterator;
import java.util.Set;
import java.util.SortedMap;
public class Main {
  static public void main(String args[]) throws Exception {
    SortedMap charsets = Charset.availableCharsets();
    Set names = charsets.keySet();
    for (Iterator e = names.iterator(); e.hasNext();) {
      String name = (String) e.next();
      Charset charset = (Charset) charsets.get(name);
      System.out.println(charset);
      Set aliases = charset.aliases();
      for (Iterator ee = aliases.iterator(); ee.hasNext();) {
        System.out.println("    " + ee.next());
      }
    }
  }
}

Charset: defaultCharset()

 
 
 
/*
 * Copyright (c) 1995 - 2008 Sun Microsystems, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Sun Microsystems nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
import static java.lang.System.out;
import java.io.Console;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.nio.charset.Charset;
public class Main {
  public static void main(String... args) {
    Constructor[] ctors = Console.class.getDeclaredConstructors();
    Constructor ctor = null;
    for (int i = 0; i < ctors.length; i++) {
      ctor = ctors[i];
      if (ctor.getGenericParameterTypes().length == 0)
        break;
    }
    try {
      ctor.setAccessible(true);
      Console c = (Console) ctor.newInstance();
      Field f = c.getClass().getDeclaredField("cs");
      f.setAccessible(true);
      out.format("Console charset         :  %s%n", f.get(c));
      out.format("Charset.defaultCharset():  %s%n", Charset.defaultCharset());
      // production code should handle these exceptions more gracefully
    } catch (InstantiationException x) {
      x.printStackTrace();
    } catch (InvocationTargetException x) {
      x.printStackTrace();
    } catch (IllegalAccessException x) {
      x.printStackTrace();
    } catch (NoSuchFieldException x) {
      x.printStackTrace();
    }
  }
}

Charset: displayName()

 
import java.nio.charset.Charset;
import java.util.Iterator;
import java.util.Map;
public class Main {
  public static void main(String[] args) {
    Map charsets = Charset.availableCharsets();
    Iterator iterator = charsets.values().iterator();
    while (iterator.hasNext()) {
      Charset cs = (Charset) iterator.next();
      System.out.print(cs.displayName());
      if (cs.isRegistered()) {
        System.out.print(" (registered): ");
      } else {
        System.out.print(" (unregistered): ");
      }
      System.out.print(cs.name());
      Iterator names = cs.aliases().iterator();
      while (names.hasNext()) {
        System.out.print(", ");
        System.out.print(names.next());
      }
      System.out.println();
    }
  }
}

Charset: forName(String charsetName)

 
import java.nio.CharBuffer;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
public class MainClass {
  public static void main(String[] args) throws Exception{
    CharsetEncoder encoder = Charset.forName("US-ASCII").newEncoder();
    ServerSocketChannel server = ServerSocketChannel.open();
    server.socket().bind(new java.net.InetSocketAddress(8000));
    for (;;) { // This server runs forever
      SocketChannel client = server.accept();
      String response = new java.util.Date().toString() + "\r\n";
      client.write(encoder.encode(CharBuffer.wrap(response)));
      client.close();
    }
  }
}

Charset: isRegistered()

 
import java.nio.charset.Charset;
import java.util.Iterator;
import java.util.Map;
public class Main {
  public static void main(String[] args) {
    Map charsets = Charset.availableCharsets();
    Iterator iterator = charsets.values().iterator();
    while (iterator.hasNext()) {
      Charset cs = (Charset) iterator.next();
      System.out.print(cs.displayName());
      if (cs.isRegistered()) {
        System.out.print(" (registered): ");
      } else {
        System.out.print(" (unregistered): ");
      }
      System.out.print(cs.name());
      Iterator names = cs.aliases().iterator();
      while (names.hasNext()) {
        System.out.print(", ");
        System.out.print(names.next());
      }
      System.out.println();
    }
  }
}

Charset: name()

 
import java.nio.charset.Charset;
import java.util.Iterator;
import java.util.Map;
public class Main {
  public static void main(String[] args) {
    Map charsets = Charset.availableCharsets();
    Iterator iterator = charsets.values().iterator();
    while (iterator.hasNext()) {
      Charset cs = (Charset) iterator.next();
      System.out.print(cs.displayName());
      if (cs.isRegistered()) {
        System.out.print(" (registered): ");
      } else {
        System.out.print(" (unregistered): ");
      }
      System.out.print(cs.name());
      Iterator names = cs.aliases().iterator();
      while (names.hasNext()) {
        System.out.print(", ");
        System.out.print(names.next());
      }
      System.out.println();
    }
  }
}

Charset: newDecoder()

 
import java.io.File;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;
public class Main {
  static public void main(String args[]) throws Exception {
    File infile = new File("inFilename");
    File outfile = new File("outFilename");
    RandomAccessFile inraf = new RandomAccessFile(infile, "r");
    RandomAccessFile outraf = new RandomAccessFile(outfile, "rw");
    FileChannel finc = inraf.getChannel();
    FileChannel foutc = outraf.getChannel();
    MappedByteBuffer inmbb = finc.map(FileChannel.MapMode.READ_ONLY, 0, (int) infile.length());
    Charset inCharset = Charset.forName("UTF8");
    Charset outCharset = Charset.forName("UTF16");
    CharsetDecoder inDecoder = inCharset.newDecoder();
    CharsetEncoder outEncoder = outCharset.newEncoder();
    CharBuffer cb = inDecoder.decode(inmbb);
    ByteBuffer outbb = outEncoder.encode(cb);
    foutc.write(outbb);
    inraf.close();
    outraf.close();
  }
}

Charset: newEncoder()

 
import java.nio.CharBuffer;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
public class MainClass {
  public static void main(String[] args) throws Exception{
    CharsetEncoder encoder = Charset.forName("US-ASCII").newEncoder();
    ServerSocketChannel server = ServerSocketChannel.open();
    server.socket().bind(new java.net.InetSocketAddress(8000));
    for (;;) { // This server runs forever
      SocketChannel client = server.accept();
      String response = new java.util.Date().toString() + "\r\n";
      client.write(encoder.encode(CharBuffer.wrap(response)));
      client.close();
    }
  }
}