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From-SVN: r102074

1 files changed, 406 insertions, 0 deletions

diff --git a/libjava/classpath/java/nio/charset/Charset.java b/libjava/classpath/java/nio/charset/Charset.java
new file mode 100644
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+/* Charset.java -- 
+   Copyright (C) 2002, 2004, 2005  Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath 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
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package java.nio.charset;
+
+import gnu.classpath.SystemProperties;
+
+import gnu.java.nio.charset.Provider;
+import gnu.java.nio.charset.iconv.IconvProvider;
+
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.net.URL;
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.spi.CharsetProvider;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.LinkedHashSet;
+import java.util.Locale;
+import java.util.Set;
+import java.util.SortedMap;
+import java.util.TreeMap;
+
+/**
+ * @author Jesse Rosenstock
+ * @since 1.4
+ * @status updated to 1.5
+ */
+public abstract class Charset implements Comparable
+{
+  private CharsetEncoder cachedEncoder;
+  private CharsetDecoder cachedDecoder;
+ 
+  /**
+   * Charset providers.
+   */
+  private static CharsetProvider[] providers;
+  
+  private final String canonicalName;
+  private final String[] aliases;
+  
+  protected Charset (String canonicalName, String[] aliases)
+  {
+    checkName (canonicalName);
+    if (aliases != null)
+      {
+        int n = aliases.length;
+        for (int i = 0; i < n; ++i)
+            checkName (aliases[i]);
+      }
+
+    cachedEncoder = null;
+    cachedDecoder = null;
+    this.canonicalName = canonicalName;
+    this.aliases = aliases;
+  }
+
+  /**
+   * @throws IllegalCharsetNameException  if the name is illegal
+   */
+  private static void checkName (String name)
+  {
+    int n = name.length ();
+
+    if (n == 0)
+      throw new IllegalCharsetNameException (name);
+
+    char ch = name.charAt (0);
+    if (!(('A' <= ch && ch <= 'Z')
+          || ('a' <= ch && ch <= 'z')
+          || ('0' <= ch && ch <= '9')))
+      throw new IllegalCharsetNameException (name);
+
+    for (int i = 1; i < n; ++i)
+      {
+        ch = name.charAt (i);
+        if (!(('A' <= ch && ch <= 'Z')
+              || ('a' <= ch && ch <= 'z')
+              || ('0' <= ch && ch <= '9')
+              || ch == '-' || ch == '.' || ch == ':' || ch == '_'))
+          throw new IllegalCharsetNameException (name);
+      }
+  }
+
+  /**
+   * Returns the system default charset.
+   *
+   * This may be set by the user or VM with the file.encoding
+   * property.
+   */
+  public static Charset defaultCharset()
+  {
+    String encoding;
+    
+    try 
+      {
+	encoding = SystemProperties.getProperty("file.encoding");
+      }
+    catch(SecurityException e)
+      {
+	// Use fallback.
+	encoding = "ISO-8859-1";
+      }
+    catch(IllegalArgumentException e)
+      {
+	// Use fallback.
+	encoding = "ISO-8859-1";
+      }
+
+    try
+      {
+	return forName(encoding);
+      }
+    catch(UnsupportedCharsetException e)
+      {
+	// Ignore.
+      }
+    catch(IllegalCharsetNameException e)
+      {
+	// Ignore.
+      }
+    catch(IllegalArgumentException e)
+      {
+	// Ignore.
+      }
+    
+    throw new IllegalStateException("Can't get default charset!");
+  }
+
+  public static boolean isSupported (String charsetName)
+  {
+    return charsetForName (charsetName) != null;
+  }
+
+  /**
+   * Returns the Charset instance for the charset of the given name.
+   * 
+   * @param charsetName
+   * @return
+   * @throws UnsupportedCharsetException if this VM does not support
+   * the charset of the given name.
+   * @throws IllegalCharsetNameException if the given charset name is
+   * legal.
+   * @throws IllegalArgumentException if <code>charsetName</code> is null.
+   */
+  public static Charset forName (String charsetName)
+  {
+    // Throws IllegalArgumentException as the JDK does.
+    if(charsetName == null)
+        throw new IllegalArgumentException("Charset name must not be null.");
+    
+    Charset cs = charsetForName (charsetName);
+    if (cs == null)
+      throw new UnsupportedCharsetException (charsetName);
+    return cs;
+  }
+
+  /**
+   * Retrieves a charset for the given charset name.
+   *
+   * @return A charset object for the charset with the specified name, or
+   * <code>null</code> if no such charset exists.
+   *
+   * @throws IllegalCharsetNameException  if the name is illegal
+   */
+  private static Charset charsetForName(String charsetName)
+  {
+    checkName (charsetName);
+    Charset cs = null;
+    CharsetProvider[] providers = providers2();
+    for (int i = 0; i < providers.length; i++)
+      {
+        cs = providers[i].charsetForName(charsetName);
+        if (cs != null)
+	  break;
+      }
+    return cs;
+  }
+
+  public static SortedMap availableCharsets()
+  {
+    TreeMap charsets = new TreeMap(String.CASE_INSENSITIVE_ORDER);
+
+    CharsetProvider[] providers = providers2();
+    for (int j = 0; j < providers.length; j++)
+      {
+        for (Iterator i = providers[j].charsets(); i.hasNext(); )
+          {
+            Charset cs = (Charset) i.next();
+            charsets.put(cs.name(), cs);
+          }
+      }
+
+    return Collections.unmodifiableSortedMap(charsets);
+  }
+
+  private static CharsetProvider provider()
+  {
+    String useIconv = SystemProperties.getProperty
+      ("gnu.classpath.nio.charset.provider.iconv");
+
+    if (useIconv != null)
+      return IconvProvider.provider();
+
+    return Provider.provider();
+  }
+
+  /**
+   * We need to support multiple providers, reading them from
+   * java.nio.charset.spi.CharsetProvider in the resource directory
+   * META-INF/services.
+   */
+  private static CharsetProvider[] providers2()
+  {
+    if (providers == null)
+      {
+        try
+          {
+            Enumeration en = ClassLoader.getSystemResources
+	      ("META-INF/services/java.nio.charset.spi.CharsetProvider");
+            LinkedHashSet set = new LinkedHashSet();
+            set.add(provider());
+            while (en.hasMoreElements())
+              {
+                BufferedReader rdr = new BufferedReader(new InputStreamReader
+                  (((URL) (en.nextElement())).openStream()));
+                while (true)
+                  {
+                    String s = rdr.readLine();
+                    if (s == null)
+		      break;
+                    CharsetProvider p =
+		      (CharsetProvider) ((Class.forName(s)).newInstance());
+                    set.add(p);
+                  }
+               }
+
+            providers = new CharsetProvider[set.size()];
+            set.toArray(providers);
+          }
+        catch (Exception e)
+          {
+            throw new RuntimeException(e);
+          }
+      }
+    return providers;
+  }
+
+  public final String name ()
+  {
+    return canonicalName;
+  }
+
+  public final Set aliases ()
+  {
+    if (aliases == null)
+      return Collections.EMPTY_SET;
+
+    // should we cache the aliasSet instead?
+    int n = aliases.length;
+    HashSet aliasSet = new HashSet (n);
+    for (int i = 0; i < n; ++i)
+        aliasSet.add (aliases[i]);
+    return Collections.unmodifiableSet (aliasSet);
+  }
+
+  public String displayName ()
+  {
+    return canonicalName;
+  }
+
+  public String displayName (Locale locale)
+  {
+    return canonicalName;
+  }
+
+  public final boolean isRegistered ()
+  {
+    return (!canonicalName.startsWith ("x-")
+            && !canonicalName.startsWith ("X-"));
+  }
+
+  public abstract boolean contains (Charset cs);
+
+  public abstract CharsetDecoder newDecoder ();
+
+  public abstract CharsetEncoder newEncoder ();
+
+  public boolean canEncode ()
+  {
+    return true;
+  }
+
+  // NB: This implementation serializes different threads calling
+  // Charset.encode(), a potential performance problem.  It might
+  // be better to remove the cache, or use ThreadLocal to cache on
+  // a per-thread basis.
+  public final synchronized ByteBuffer encode (CharBuffer cb)
+  {
+    try
+      {
+	if (cachedEncoder == null)
+	  {
+	    cachedEncoder = newEncoder ()
+	      .onMalformedInput (CodingErrorAction.REPLACE)
+	      .onUnmappableCharacter (CodingErrorAction.REPLACE);
+	  } else
+	  cachedEncoder.reset();
+	return cachedEncoder.encode (cb);
+      }
+    catch (CharacterCodingException e)
+      {
+        throw new AssertionError (e);
+      }
+  }
+  
+  public final ByteBuffer encode (String str)
+  {
+    return encode (CharBuffer.wrap (str));
+  }
+
+  // NB: This implementation serializes different threads calling
+  // Charset.decode(), a potential performance problem.  It might
+  // be better to remove the cache, or use ThreadLocal to cache on
+  // a per-thread basis.
+  public final synchronized CharBuffer decode (ByteBuffer bb)
+  {
+    try
+      {
+	if (cachedDecoder == null)
+	  {
+	    cachedDecoder = newDecoder ()
+	      .onMalformedInput (CodingErrorAction.REPLACE)
+	      .onUnmappableCharacter (CodingErrorAction.REPLACE);
+	  } else
+	  cachedDecoder.reset();
+
+	return cachedDecoder.decode (bb);
+      }
+    catch (CharacterCodingException e)
+      {
+        throw new AssertionError (e);
+      }
+  }
+
+  public final int compareTo (Object ob)
+  {
+    return canonicalName.compareToIgnoreCase (((Charset) ob).canonicalName);
+  }
+
+  public final int hashCode ()
+  {
+    return canonicalName.hashCode ();
+  }
+
+  public final boolean equals (Object ob)
+  {
+    if (ob instanceof Charset)
+      return canonicalName.equalsIgnoreCase (((Charset) ob).canonicalName);
+    else
+      return false;
+  }
+
+  public final String toString ()
+  {
+    return canonicalName;
+  }
+}