* java/io/ByteArrayOutputStream.java: Merged with Classpath.

From-SVN: r35736

1 files changed, 158 insertions, 10 deletions

diff --git a/libjava/java/io/ByteArrayOutputStream.java b/libjava/java/io/ByteArrayOutputStream.java
index 901312f..5fba5c5 100644
--- a/libjava/java/io/ByteArrayOutputStream.java
+++ b/libjava/java/io/ByteArrayOutputStream.java
@@ -1,6 +1,6 @@
 // ByteArrayOutputStream.java - Write bytes to an array.
 
-/* Copyright (C) 1998, 1999  Free Software Foundation
+/* Copyright (C) 1998, 1999, 2000  Free Software Foundation
 
    This file is part of libgcj.
 
@@ -10,39 +10,103 @@ details.  */
 
 package java.io;
 
-/**
- * @author Tom Tromey <tromey@cygnus.com>
- * @date September 24, 1998 
- */
-
 /* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
  * "The Java Language Specification", ISBN 0-201-63451-1
  * Status:  Complete to version 1.1.
  */
 
+/**
+  * This class allows data to be written to a byte array buffer and
+  * and then retrieved by an application.   The internal byte array
+  * buffer is dynamically resized to hold all the data written.  Please
+  * be aware that writing large amounts to data to this stream will
+  * cause large amounts of memory to be allocated.
+  * <p>
+  * The size of the internal buffer defaults to 32 and it is resized
+  * by doubling the size of the buffer.  This default size can be
+  * overridden by using the
+  * <code>gnu.java.io.ByteArrayOutputStream.initialBufferSize</code>
+  * property.
+  * <p>
+  * There is a constructor that specified the initial buffer size and
+  * that is the preferred way to set that value because it it portable
+  * across all Java class library implementations.
+  * <p>
+  * Note that this class also has methods that convert the byte array
+  * buffer to a <code>String</code> using either the system default or an
+  * application specified character encoding.  Thus it can handle 
+  * multibyte character encodings.
+  *
+  * @version 0.0
+  *
+  * @author Aaron M. Renn (arenn@urbanophile.com)
+  * @author Tom Tromey <tromey@cygnus.com>
+  * @date September 24, 1998 
+  */
 public class ByteArrayOutputStream extends OutputStream
 {
+  /**
+   * This method initializes a new <code>ByteArrayOutputStream</code>
+   * with the default buffer size of 32 bytes.  If a different initial
+   * buffer size is desired, see the constructor
+   * <code>ByteArrayOutputStream(int size)</code>.  For applications
+   * where the source code is not available, the default buffer size
+   * can be set using the system property
+   * <code>gnu.java.io.ByteArrayOutputStream.initialBufferSize</code>
+   */
   public ByteArrayOutputStream ()
   {
-    this (32);
+    this (initial_buffer_size);
   }
 
+  /**
+   * This method initializes a new <code>ByteArrayOutputStream</code> with
+   * a specified initial buffer size.
+   *
+   * @param size The initial buffer size in bytes
+   */
   public ByteArrayOutputStream (int size)
   {
     buf = new byte[size];
     count = 0;
   }
 
+  /**
+   * This method discards all of the bytes that have been written to
+   * the internal buffer so far by setting the <code>count</code>
+   * variable to 0.  The internal buffer remains at its currently
+   * allocated size.
+   */
   public synchronized void reset ()
   {
     count = 0;
   }
 
+  /**
+   * This method returns the number of bytes that have been written to
+   * the buffer so far.  This is the same as the value of the protected
+   * <code>count</code> variable.  If the <code>reset</code> method is
+   * called, then this value is reset as well.  Note that this method does
+   * not return the length of the internal buffer, but only the number
+   * of bytes that have been written to it.
+   *
+   * @return The number of bytes in the internal buffer
+   *
+   * @see reset
+   */
   public int size ()
   {
     return count;
   }
 
+  /**
+   * This method returns a byte array containing the bytes that have been
+   * written to this stream so far.  This array is a copy of the valid
+   * bytes in the internal buffer and its length is equal to the number of
+   * valid bytes, not necessarily to the the length of the current 
+   * internal buffer.  Note that since this method allocates a new array,
+   * it should be used with caution when the internal buffer is very large.
+   */
   public synchronized byte[] toByteArray ()
   {
     byte[] ret = new byte[count];
@@ -50,17 +114,56 @@ public class ByteArrayOutputStream extends OutputStream
     return ret;
   }
 
+  /**
+   * Returns the bytes in the internal array as a <code>String</code>.  The
+   * bytes in the buffer are converted to characters using the system default
+   * encoding.  There is an overloaded <code>toString()</code> method that
+   * allows an application specified character encoding to be used.
+   *
+   * @return A <code>String</code> containing the data written to this
+   * stream so far
+   */
   public String toString ()
   {
     return new String (buf, 0, count);
   }
 
+  /**
+   * Returns the bytes in the internal array as a <code>String</code>.  The
+   * bytes in the buffer are converted to characters using the specified
+   * encoding. 
+   *
+   * @param enc The name of the character encoding to use
+   *
+   * @return A <code>String</code> containing the data written to this
+   * stream so far
+   *
+   * @exception UnsupportedEncodingException If the named encoding is
+   * not available
+   */
   public String toString (String enc) throws UnsupportedEncodingException
   {
     return new String (buf, 0, count, enc);
   }
 
-  // This is deprecated in the JCL book.
+  /**
+   * This method returns the bytes in the internal array as a
+   * <code>String</code>.  It uses each byte in the array as the low
+   * order eight bits of the Unicode character value and the passed in
+   * parameter as the high eight bits.
+   * <p>
+   * This method does not convert bytes to characters in the proper way and
+   * so is deprecated in favor of the other overloaded <code>toString</code>
+   * methods which use a true character encoding.
+   *
+   * @param hibyte The high eight bits to use for each character in
+   * the <code>String</code> 
+   *
+   * @return A <code>String</code> containing the data written to this
+   * stream so far
+   *
+   * @deprecrated
+   */
   public String toString (int hibyte)
   {
     return new String (buf, 0, count, hibyte);
@@ -80,12 +183,27 @@ public class ByteArrayOutputStream extends OutputStream
       }
   }
 
+  /**
+   * This method writes the writes the specified byte into the internal
+   * buffer.
+   *
+   * @param oneByte The byte to be read passed as an int
+   */
   public synchronized void write (int oneByte)
   {
     resize (1);
     buf[count++] = (byte) oneByte;
   }
 
+  /**
+   * This method writes <code>len</code> bytes from the passed in array 
+   * <code>buf</code> starting at index <code>offset</code> into the
+   * internal buffer.
+   *
+   * @param buffer The byte array to write data from
+   * @param offset The index into the buffer to start writing data from
+   * @param add The number of bytes to write
+   */
   public synchronized void write (byte[] buffer, int offset, int add)
   {
     // If ADD < 0 then arraycopy will throw the appropriate error for
@@ -96,13 +214,43 @@ public class ByteArrayOutputStream extends OutputStream
     count += add;
   }
 
+  /**
+   * This method writes all the bytes that have been written to this stream
+   * from the internal buffer to the specified <code>OutputStream</code>.
+   *
+   * @param out The <code>OutputStream</code> to write to
+   *
+   * @exception IOException If an error occurs
+   */
   public synchronized void writeTo (OutputStream out) throws IOException
   {
     out.write(buf, 0, count);
   }
 
-  // The byte buffer.
+  /**
+   * The internal buffer where the data written is stored
+   */
   protected byte[] buf;
-  // Number of valid bytes in buffer.
+
+  /**
+   * The number of bytes that have been written to the buffer
+   */
   protected int count;
+
+  /**
+   * The default initial buffer size.  Specified by the JCL.
+   */
+  private static final int DEFAULT_INITIAL_BUFFER_SIZE = 32;
+
+  // The default buffer size which can be overridden by the user.
+  private static final int initial_buffer_size;
+
+  static
+  {
+    initial_buffer_size
+      = Integer.getInteger ("gnu.java.io.ByteArrayOutputStream.initialBufferSize",
+			    DEFAULT_INITIAL_BUFFER_SIZE).intValue ();
+    if (initial_buffer_size <= 0)
+      initial_buffer_size = DEFAULT_INITIAL_BUFFER_SIZE;
+  }
 }