-// StringBuffer.java - Growable strings.
+/* StringBuffer.java -- Growable strings
+ Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
+ Free Software Foundation, Inc.
-/* Copyright (C) 1998, 1999, 2000 Red Hat
+This file is part of GNU Classpath.
- This file is part of libgcj.
+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.
-This software is copyrighted work licensed under the terms of the
-Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
-details. */
+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.lang;
+
import java.io.Serializable;
/**
- * @author Tom Tromey <tromey@cygnus.com>
- * @date October 23, 1998.
+ * <code>StringBuffer</code> represents a changeable <code>String</code>.
+ * It provides the operations required to modify the
+ * <code>StringBuffer</code>, including insert, replace, delete, append,
+ * and reverse. It is thread-safe; meaning that all modifications to a buffer
+ * are in synchronized methods.
+ *
+ * <p><code>StringBuffer</code>s are variable-length in nature, so even if
+ * you initialize them to a certain size, they can still grow larger than
+ * that. <em>Capacity</em> indicates the number of characters the
+ * <code>StringBuffer</code> can have in it before it has to grow (growing
+ * the char array is an expensive operation involving <code>new</code>).
+ *
+ * <p>Incidentally, compilers often implement the String operator "+"
+ * by using a <code>StringBuffer</code> operation:<br>
+ * <code>a + b</code><br>
+ * is the same as<br>
+ * <code>new StringBuffer().append(a).append(b).toString()</code>.
+ *
+ * <p>Classpath's StringBuffer is capable of sharing memory with Strings for
+ * efficiency. This will help when a StringBuffer is converted to a String
+ * and the StringBuffer is not changed after that (quite common when performing
+ * string concatenation).
+ *
+ * @author Paul Fisher
+ * @author John Keiser
+ * @author Tom Tromey
+ * @author Eric Blake (ebb9@email.byu.edu)
+ * @see String
+ * @since 1.0
+ * @status updated to 1.4
*/
+public final class StringBuffer implements Serializable, CharSequence
+{
+ /**
+ * Compatible with JDK 1.0+.
+ */
+ private static final long serialVersionUID = 3388685877147921107L;
-/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
- */
+ /**
+ * Index of next available character (and thus the size of the current
+ * string contents). Note that this has permissions set this way so that
+ * String can get the value.
+ *
+ * @serial the number of characters in the buffer
+ */
+ int count;
-public final class StringBuffer implements Serializable
-{
- public StringBuffer append (boolean bool)
- {
- return append (String.valueOf(bool));
- }
-
- public synchronized StringBuffer append (char ch)
- {
- ensureCapacity (count + 1);
- value[count++] = ch;
- return this;
- }
-
- public StringBuffer append (int inum)
- {
- return append (String.valueOf(inum));
- }
-
- public StringBuffer append (long lnum)
- {
- return append (String.valueOf(lnum));
- }
-
- public StringBuffer append (float fnum)
- {
- return append (String.valueOf(fnum));
- }
-
- public StringBuffer append (double dnum)
- {
- return append (String.valueOf(dnum));
- }
-
- public StringBuffer append (Object obj)
- {
- return append (String.valueOf(obj));
- }
-
- public synchronized StringBuffer append (String str)
- {
- if (str == null)
- str = "null";
- int len = str.length();
- ensureCapacity (count + len);
- str.getChars(0, len, value, count);
- count += len;
- return this;
- }
-
- public StringBuffer append (char[] data)
- {
- return append (data, 0, data.length);
- }
-
- public synchronized StringBuffer append (char[] data, int offset, int count)
- {
- ensureCapacity (this.count + count);
- System.arraycopy(data, offset, value, this.count, count);
- this.count += count;
- return this;
- }
-
- public int capacity ()
- {
- return value.length;
- }
-
- public synchronized char charAt (int index)
- {
- if (index >= count)
- throw new StringIndexOutOfBoundsException (index);
- return value[index];
- }
-
- public synchronized void ensureCapacity (int minimumCapacity)
- {
- if (shared || minimumCapacity > value.length)
- {
- // We don't want to make a larger vector when `shared' is
- // set. If we do, then setLength becomes very inefficient
- // when repeatedly reusing a StringBuffer in a loop.
- int max = (minimumCapacity > value.length
- ? value.length*2+2
- : value.length);
- minimumCapacity = Math.max(minimumCapacity, max);
- char[] nb = new char[minimumCapacity];
- System.arraycopy(value, 0, nb, 0, count);
- value = nb;
- shared = false;
- }
- }
-
- public synchronized void getChars (int srcOffset, int srcEnd,
- char[] dst, int dstOffset)
- {
- if (srcOffset < 0 || srcOffset > srcEnd)
- throw new StringIndexOutOfBoundsException (srcOffset);
- int todo = srcEnd - srcOffset;
- if (srcEnd > count || dstOffset + todo > count)
- throw new StringIndexOutOfBoundsException (srcEnd);
- System.arraycopy(value, srcOffset, dst, dstOffset, todo);
- }
-
- public StringBuffer insert (int offset, boolean bool)
- {
- return insert (offset, bool ? "true" : "false");
- }
-
- public synchronized StringBuffer insert (int offset, char ch)
- {
- if (offset < 0 || offset > count)
- throw new StringIndexOutOfBoundsException (offset);
- ensureCapacity (count+1);
- System.arraycopy(value, offset, value, offset+1, count-offset);
- value[offset] = ch;
- count++;
- return this;
- }
-
- public StringBuffer insert (int offset, int inum)
- {
- return insert (offset, String.valueOf(inum));
- }
-
- public StringBuffer insert (int offset, long lnum)
- {
- return insert (offset, String.valueOf(lnum));
- }
-
- public StringBuffer insert (int offset, float fnum)
- {
- return insert (offset, String.valueOf(fnum));
- }
-
- public StringBuffer insert (int offset, double dnum)
- {
- return insert (offset, String.valueOf(dnum));
- }
-
- public StringBuffer insert (int offset, Object obj)
- {
- return insert (offset, String.valueOf(obj));
- }
-
- public synchronized StringBuffer insert (int offset, String str)
- {
- if (offset < 0 || offset > count)
- throw new StringIndexOutOfBoundsException (offset);
- // Note that using `null' is from JDK 1.2.
- if (str == null)
- str = "null";
- int len = str.length();
- ensureCapacity(count+len);
- System.arraycopy(value, offset, value, offset+len, count-offset);
- str.getChars(0, len, value, offset);
- count += len;
- return this;
- }
-
- public synchronized StringBuffer insert (int offset, char[] data)
- {
- if (offset < 0 || offset > count)
- throw new StringIndexOutOfBoundsException (offset);
- int len = data.length;
- ensureCapacity (count+len);
- System.arraycopy(value, offset, value, offset+len, count-offset);
- System.arraycopy(data, 0, value, offset, len);
- count += len;
- return this;
- }
-
- public int length ()
- {
- return count;
- }
-
- public synchronized StringBuffer reverse ()
- {
- for (int i = 0; i < count / 2; ++i)
- {
- char c = value[i];
- value[i] = value[count - i - 1];
- value[count - i - 1] = c;
- }
- return this;
- }
-
- public synchronized void setCharAt (int index, char ch)
- {
- if (index < 0 || index >= count)
- throw new StringIndexOutOfBoundsException (index);
- // Call ensureCapacity to enforce copy-on-write.
- ensureCapacity (count);
- value[index] = ch;
- }
-
- public synchronized void setLength (int newLength)
- {
- if (newLength < 0)
- throw new StringIndexOutOfBoundsException (newLength);
-
- ensureCapacity (newLength);
- for (int i = count; i < newLength; ++i)
- value[i] = '\0';
- count = newLength;
- }
-
- public StringBuffer ()
- {
- this (16);
- }
-
- public StringBuffer (int capacity)
- {
- count = 0;
- value = new char[capacity];
- shared = false;
- }
-
- public StringBuffer (String str)
- {
- // The documentation is not clear, but experimentation with
- // other implementations indicates that StringBuffer(null)
- // should throw a NullPointerException.
- count = str.length();
- // JLS: The initial capacity of the string buffer is 16 plus the
- // length of the argument string.
- value = new char[count + 16];
- str.getChars(0, count, value, 0);
- shared = false;
- }
-
- public String toString ()
- {
- shared = true;
- return new String (this);
- }
-
- // The buffer. Note that this has permissions set this way so that
- // String can get the value.
+ /**
+ * The buffer. Note that this has permissions set this way so that String
+ * can get the value.
+ *
+ * @serial the buffer
+ */
char[] value;
- // Index of next available character. Note that this has
- // permissions set this way so that String can get the value.
- int count;
+ /**
+ * True if the buffer is shared with another object (StringBuffer or
+ * String); this means the buffer must be copied before writing to it again.
+ * Note that this has permissions set this way so that String can get the
+ * value.
+ *
+ * @serial whether the buffer is shared
+ */
+ boolean shared;
+
+ /**
+ * The default capacity of a buffer.
+ */
+ private static final int DEFAULT_CAPACITY = 16;
+
+ /**
+ * Create a new StringBuffer with default capacity 16.
+ */
+ public StringBuffer()
+ {
+ this(DEFAULT_CAPACITY);
+ }
+
+ /**
+ * Create an empty <code>StringBuffer</code> with the specified initial
+ * capacity.
+ *
+ * @param capacity the initial capacity
+ * @throws NegativeArraySizeException if capacity is negative
+ */
+ public StringBuffer(int capacity)
+ {
+ value = new char[capacity];
+ }
+
+ /**
+ * Create a new <code>StringBuffer</code> with the characters in the
+ * specified <code>String</code>. Initial capacity will be the size of the
+ * String plus 16.
+ *
+ * @param str the <code>String</code> to convert
+ * @throws NullPointerException if str is null
+ */
+ public StringBuffer(String str)
+ {
+ // Unfortunately, because the size is 16 larger, we cannot share.
+ count = str.count;
+ value = new char[count + DEFAULT_CAPACITY];
+ str.getChars(0, count, value, 0);
+ }
+
+ /**
+ * Create a new <code>StringBuffer</code> with the characters from the
+ * specified <code>CharSequence</code>. Initial capacity will be the
+ * size of the CharSequence plus 16.
+ *
+ * @param sequence the <code>String</code> to convert
+ * @throws NullPointerException if str is null
+ *
+ * @since 1.5
+ */
+ public StringBuffer(CharSequence sequence)
+ {
+ count = Math.max(0, sequence.length());
+ value = new char[count + DEFAULT_CAPACITY];
+ for (int i = 0; i < count; ++i)
+ value[i] = sequence.charAt(i);
+ }
+
+ /**
+ * Get the length of the <code>String</code> this <code>StringBuffer</code>
+ * would create. Not to be confused with the <em>capacity</em> of the
+ * <code>StringBuffer</code>.
+ *
+ * @return the length of this <code>StringBuffer</code>
+ * @see #capacity()
+ * @see #setLength(int)
+ */
+ public synchronized int length()
+ {
+ return count;
+ }
+
+ /**
+ * Get the total number of characters this <code>StringBuffer</code> can
+ * support before it must be grown. Not to be confused with <em>length</em>.
+ *
+ * @return the capacity of this <code>StringBuffer</code>
+ * @see #length()
+ * @see #ensureCapacity(int)
+ */
+ public synchronized int capacity()
+ {
+ return value.length;
+ }
+
+ /**
+ * Increase the capacity of this <code>StringBuffer</code>. This will
+ * ensure that an expensive growing operation will not occur until
+ * <code>minimumCapacity</code> is reached. The buffer is grown to the
+ * larger of <code>minimumCapacity</code> and
+ * <code>capacity() * 2 + 2</code>, if it is not already large enough.
+ *
+ * @param minimumCapacity the new capacity
+ * @see #capacity()
+ */
+ public synchronized void ensureCapacity(int minimumCapacity)
+ {
+ ensureCapacity_unsynchronized(minimumCapacity);
+ }
+
+ /**
+ * Set the length of this StringBuffer. If the new length is greater than
+ * the current length, all the new characters are set to '\0'. If the new
+ * length is less than the current length, the first <code>newLength</code>
+ * characters of the old array will be preserved, and the remaining
+ * characters are truncated.
+ *
+ * @param newLength the new length
+ * @throws IndexOutOfBoundsException if the new length is negative
+ * (while unspecified, this is a StringIndexOutOfBoundsException)
+ * @see #length()
+ */
+ public synchronized void setLength(int newLength)
+ {
+ if (newLength < 0)
+ throw new StringIndexOutOfBoundsException(newLength);
+
+ int valueLength = value.length;
+
+ /* Always call ensureCapacity_unsynchronized in order to preserve
+ copy-on-write semantics. */
+ ensureCapacity_unsynchronized(newLength);
+
+ if (newLength < valueLength)
+ {
+ /* If the StringBuffer's value just grew, then we know that
+ value is newly allocated and the region between count and
+ newLength is filled with '\0'. */
+ count = newLength;
+ }
+ else
+ {
+ /* The StringBuffer's value doesn't need to grow. However,
+ we should clear out any cruft that may exist. */
+ while (count < newLength)
+ value[count++] = '\0';
+ }
+ }
+
+ /**
+ * Get the character at the specified index.
+ *
+ * @param index the index of the character to get, starting at 0
+ * @return the character at the specified index
+ * @throws IndexOutOfBoundsException if index is negative or >= length()
+ */
+ public synchronized char charAt(int index)
+ {
+ if (index < 0 || index >= count)
+ throw new StringIndexOutOfBoundsException(index);
+ return value[index];
+ }
+
+ /**
+ * Get the code point at the specified index. This is like #charAt(int),
+ * but if the character is the start of a surrogate pair, and the
+ * following character completes the pair, then the corresponding
+ * supplementary code point is returned.
+ * @param index the index of the codepoint to get, starting at 0
+ * @return the codepoint at the specified index
+ * @throws IndexOutOfBoundsException if index is negative or >= length()
+ * @since 1.5
+ */
+ public synchronized int codePointAt(int index)
+ {
+ return Character.codePointAt(value, index, count);
+ }
+
+ /**
+ * Get the code point before the specified index. This is like
+ * #codePointAt(int), but checks the characters at <code>index-1</code> and
+ * <code>index-2</code> to see if they form a supplementary code point.
+ * @param index the index just past the codepoint to get, starting at 0
+ * @return the codepoint at the specified index
+ * @throws IndexOutOfBoundsException if index is negative or >= length()
+ * @since 1.5
+ */
+ public synchronized int codePointBefore(int index)
+ {
+ // Character.codePointBefore() doesn't perform this check. We
+ // could use the CharSequence overload, but this is just as easy.
+ if (index >= count)
+ throw new IndexOutOfBoundsException();
+ return Character.codePointBefore(value, index, 1);
+ }
+
+ /**
+ * Get the specified array of characters. <code>srcOffset - srcEnd</code>
+ * characters will be copied into the array you pass in.
+ *
+ * @param srcOffset the index to start copying from (inclusive)
+ * @param srcEnd the index to stop copying from (exclusive)
+ * @param dst the array to copy into
+ * @param dstOffset the index to start copying into
+ * @throws NullPointerException if dst is null
+ * @throws IndexOutOfBoundsException if any source or target indices are
+ * out of range (while unspecified, source problems cause a
+ * StringIndexOutOfBoundsException, and dest problems cause an
+ * ArrayIndexOutOfBoundsException)
+ * @see System#arraycopy(Object, int, Object, int, int)
+ */
+ public synchronized void getChars(int srcOffset, int srcEnd,
+ char[] dst, int dstOffset)
+ {
+ if (srcOffset < 0 || srcEnd > count || srcEnd < srcOffset)
+ throw new StringIndexOutOfBoundsException();
+ System.arraycopy(value, srcOffset, dst, dstOffset, srcEnd - srcOffset);
+ }
+
+ /**
+ * Set the character at the specified index.
+ *
+ * @param index the index of the character to set starting at 0
+ * @param ch the value to set that character to
+ * @throws IndexOutOfBoundsException if index is negative or >= length()
+ * (while unspecified, this is a StringIndexOutOfBoundsException)
+ */
+ public synchronized void setCharAt(int index, char ch)
+ {
+ if (index < 0 || index >= count)
+ throw new StringIndexOutOfBoundsException(index);
+ // Call ensureCapacity to enforce copy-on-write.
+ ensureCapacity_unsynchronized(count);
+ value[index] = ch;
+ }
+
+ /**
+ * Append the <code>String</code> value of the argument to this
+ * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+ * to <code>String</code>.
+ *
+ * @param obj the <code>Object</code> to convert and append
+ * @return this <code>StringBuffer</code>
+ * @see String#valueOf(Object)
+ * @see #append(String)
+ */
+ public StringBuffer append(Object obj)
+ {
+ return append(obj == null ? "null" : obj.toString());
+ }
+
+ /**
+ * Append the <code>String</code> to this <code>StringBuffer</code>. If
+ * str is null, the String "null" is appended.
+ *
+ * @param str the <code>String</code> to append
+ * @return this <code>StringBuffer</code>
+ */
+ public synchronized StringBuffer append(String str)
+ {
+ if (str == null)
+ str = "null";
+ int len = str.count;
+ ensureCapacity_unsynchronized(count + len);
+ str.getChars(0, len, value, count);
+ count += len;
+ return this;
+ }
+
+ /**
+ * Append the <code>StringBuffer</code> value of the argument to this
+ * <code>StringBuffer</code>. This behaves the same as
+ * <code>append((Object) stringBuffer)</code>, except it is more efficient.
+ *
+ * @param stringBuffer the <code>StringBuffer</code> to convert and append
+ * @return this <code>StringBuffer</code>
+ * @see #append(Object)
+ * @since 1.4
+ */
+ public synchronized StringBuffer append(StringBuffer stringBuffer)
+ {
+ if (stringBuffer == null)
+ return append("null");
+ synchronized (stringBuffer)
+ {
+ int len = stringBuffer.count;
+ ensureCapacity_unsynchronized(count + len);
+ System.arraycopy(stringBuffer.value, 0, value, count, len);
+ count += len;
+ }
+ return this;
+ }
+
+ /**
+ * Append the <code>CharSequence</code> value of the argument to this
+ * <code>StringBuffer</code>.
+ *
+ * @param sequence the <code>CharSequence</code> to append
+ * @return this <code>StringBuffer</code>
+ * @see #append(Object)
+ * @since 1.5
+ */
+ public synchronized StringBuffer append(CharSequence sequence)
+ {
+ if (sequence == null)
+ sequence = "null";
+ return append(sequence, 0, sequence.length());
+ }
+
+ /**
+ * Append the specified subsequence of the <code>CharSequence</code>
+ * argument to this <code>StringBuffer</code>.
+ *
+ * @param sequence the <code>CharSequence</code> to append
+ * @param start the starting index
+ * @param end one past the ending index
+ * @return this <code>StringBuffer</code>
+ * @see #append(Object)
+ * @since 1.5
+ */
+ public synchronized StringBuffer append(CharSequence sequence,
+ int start, int end)
+ {
+ if (sequence == null)
+ sequence = "null";
+ if (start < 0 || end < 0 || start > end || end > sequence.length())
+ throw new IndexOutOfBoundsException();
+ ensureCapacity_unsynchronized(this.count + end - start);
+ for (int i = start; i < end; ++i)
+ value[count++] = sequence.charAt(i);
+ return this;
+ }
+
+ /**
+ * Append the <code>char</code> array to this <code>StringBuffer</code>.
+ * This is similar (but more efficient) than
+ * <code>append(new String(data))</code>, except in the case of null.
+ *
+ * @param data the <code>char[]</code> to append
+ * @return this <code>StringBuffer</code>
+ * @throws NullPointerException if <code>str</code> is <code>null</code>
+ * @see #append(char[], int, int)
+ */
+ public StringBuffer append(char[] data)
+ {
+ return append(data, 0, data.length);
+ }
+
+ /**
+ * Append part of the <code>char</code> array to this
+ * <code>StringBuffer</code>. This is similar (but more efficient) than
+ * <code>append(new String(data, offset, count))</code>, except in the case
+ * of null.
+ *
+ * @param data the <code>char[]</code> to append
+ * @param offset the start location in <code>str</code>
+ * @param count the number of characters to get from <code>str</code>
+ * @return this <code>StringBuffer</code>
+ * @throws NullPointerException if <code>str</code> is <code>null</code>
+ * @throws IndexOutOfBoundsException if offset or count is out of range
+ * (while unspecified, this is a StringIndexOutOfBoundsException)
+ */
+ public synchronized StringBuffer append(char[] data, int offset, int count)
+ {
+ if (offset < 0 || count < 0 || offset > data.length - count)
+ throw new StringIndexOutOfBoundsException();
+ ensureCapacity_unsynchronized(this.count + count);
+ System.arraycopy(data, offset, value, this.count, count);
+ this.count += count;
+ return this;
+ }
+
+ /**
+ * Append the <code>String</code> value of the argument to this
+ * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+ * to <code>String</code>.
+ *
+ * @param bool the <code>boolean</code> to convert and append
+ * @return this <code>StringBuffer</code>
+ * @see String#valueOf(boolean)
+ */
+ public StringBuffer append(boolean bool)
+ {
+ return append(bool ? "true" : "false");
+ }
+
+ /**
+ * Append the <code>char</code> to this <code>StringBuffer</code>.
+ *
+ * @param ch the <code>char</code> to append
+ * @return this <code>StringBuffer</code>
+ */
+ public synchronized StringBuffer append(char ch)
+ {
+ ensureCapacity_unsynchronized(count + 1);
+ value[count++] = ch;
+ return this;
+ }
+
+ /**
+ * Append the code point to this <code>StringBuffer</code>.
+ * This is like #append(char), but will append two characters
+ * if a supplementary code point is given.
+ *
+ * @param code the code point to append
+ * @return this <code>StringBuffer</code>
+ * @see Character#toChars(int, char[], int)
+ * @since 1.5
+ */
+ public synchronized StringBuffer appendCodePoint(int code)
+ {
+ int len = Character.charCount(code);
+ ensureCapacity_unsynchronized(count + len);
+ Character.toChars(code, value, count);
+ count += len;
+ return this;
+ }
+
+ /**
+ * Append the <code>String</code> value of the argument to this
+ * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+ * to <code>String</code>.
+ *
+ * @param inum the <code>int</code> to convert and append
+ * @return this <code>StringBuffer</code>
+ * @see String#valueOf(int)
+ */
+ // GCJ LOCAL: this is native for efficiency.
+ public native StringBuffer append (int inum);
+
+ /**
+ * Append the <code>String</code> value of the argument to this
+ * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+ * to <code>String</code>.
+ *
+ * @param lnum the <code>long</code> to convert and append
+ * @return this <code>StringBuffer</code>
+ * @see String#valueOf(long)
+ */
+ public StringBuffer append(long lnum)
+ {
+ return append(Long.toString(lnum, 10));
+ }
+
+ /**
+ * Append the <code>String</code> value of the argument to this
+ * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+ * to <code>String</code>.
+ *
+ * @param fnum the <code>float</code> to convert and append
+ * @return this <code>StringBuffer</code>
+ * @see String#valueOf(float)
+ */
+ public StringBuffer append(float fnum)
+ {
+ return append(Float.toString(fnum));
+ }
+
+ /**
+ * Append the <code>String</code> value of the argument to this
+ * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+ * to <code>String</code>.
+ *
+ * @param dnum the <code>double</code> to convert and append
+ * @return this <code>StringBuffer</code>
+ * @see String#valueOf(double)
+ */
+ public StringBuffer append(double dnum)
+ {
+ return append(Double.toString(dnum));
+ }
+
+ /**
+ * Delete characters from this <code>StringBuffer</code>.
+ * <code>delete(10, 12)</code> will delete 10 and 11, but not 12. It is
+ * harmless for end to be larger than length().
+ *
+ * @param start the first character to delete
+ * @param end the index after the last character to delete
+ * @return this <code>StringBuffer</code>
+ * @throws StringIndexOutOfBoundsException if start or end are out of bounds
+ * @since 1.2
+ */
+ public synchronized StringBuffer delete(int start, int end)
+ {
+ if (start < 0 || start > count || start > end)
+ throw new StringIndexOutOfBoundsException(start);
+ if (end > count)
+ end = count;
+ // This will unshare if required.
+ ensureCapacity_unsynchronized(count);
+ if (count - end != 0)
+ System.arraycopy(value, end, value, start, count - end);
+ count -= end - start;
+ return this;
+ }
+
+ /**
+ * Delete a character from this <code>StringBuffer</code>.
+ *
+ * @param index the index of the character to delete
+ * @return this <code>StringBuffer</code>
+ * @throws StringIndexOutOfBoundsException if index is out of bounds
+ * @since 1.2
+ */
+ public StringBuffer deleteCharAt(int index)
+ {
+ return delete(index, index + 1);
+ }
+
+ /**
+ * Replace characters between index <code>start</code> (inclusive) and
+ * <code>end</code> (exclusive) with <code>str</code>. If <code>end</code>
+ * is larger than the size of this StringBuffer, all characters after
+ * <code>start</code> are replaced.
+ *
+ * @param start the beginning index of characters to delete (inclusive)
+ * @param end the ending index of characters to delete (exclusive)
+ * @param str the new <code>String</code> to insert
+ * @return this <code>StringBuffer</code>
+ * @throws StringIndexOutOfBoundsException if start or end are out of bounds
+ * @throws NullPointerException if str is null
+ * @since 1.2
+ */
+ public synchronized StringBuffer replace(int start, int end, String str)
+ {
+ if (start < 0 || start > count || start > end)
+ throw new StringIndexOutOfBoundsException(start);
+
+ int len = str.count;
+ // Calculate the difference in 'count' after the replace.
+ int delta = len - (end > count ? count : end) + start;
+ ensureCapacity_unsynchronized(count + delta);
+
+ if (delta != 0 && end < count)
+ System.arraycopy(value, end, value, end + delta, count - end);
+
+ str.getChars(0, len, value, start);
+ count += delta;
+ return this;
+ }
+
+ /**
+ * Creates a substring of this StringBuffer, starting at a specified index
+ * and ending at the end of this StringBuffer.
+ *
+ * @param beginIndex index to start substring (base 0)
+ * @return new String which is a substring of this StringBuffer
+ * @throws StringIndexOutOfBoundsException if beginIndex is out of bounds
+ * @see #substring(int, int)
+ * @since 1.2
+ */
+ public String substring(int beginIndex)
+ {
+ return substring(beginIndex, count);
+ }
+
+ /**
+ * Creates a substring of this StringBuffer, starting at a specified index
+ * and ending at one character before a specified index. This is implemented
+ * the same as <code>substring(beginIndex, endIndex)</code>, to satisfy
+ * the CharSequence interface.
+ *
+ * @param beginIndex index to start at (inclusive, base 0)
+ * @param endIndex index to end at (exclusive)
+ * @return new String which is a substring of this StringBuffer
+ * @throws IndexOutOfBoundsException if beginIndex or endIndex is out of
+ * bounds
+ * @see #substring(int, int)
+ * @since 1.4
+ */
+ public CharSequence subSequence(int beginIndex, int endIndex)
+ {
+ return substring(beginIndex, endIndex);
+ }
+
+ /**
+ * Creates a substring of this StringBuffer, starting at a specified index
+ * and ending at one character before a specified index.
+ *
+ * @param beginIndex index to start at (inclusive, base 0)
+ * @param endIndex index to end at (exclusive)
+ * @return new String which is a substring of this StringBuffer
+ * @throws StringIndexOutOfBoundsException if beginIndex or endIndex is out
+ * of bounds
+ * @since 1.2
+ */
+ public synchronized String substring(int beginIndex, int endIndex)
+ {
+ int len = endIndex - beginIndex;
+ if (beginIndex < 0 || endIndex > count || endIndex < beginIndex)
+ throw new StringIndexOutOfBoundsException();
+ if (len == 0)
+ return "";
+ // Don't copy unless substring is smaller than 1/4 of the buffer.
+ boolean share_buffer = ((len << 2) >= value.length);
+ if (share_buffer)
+ this.shared = true;
+ // Package constructor avoids an array copy.
+ return new String(value, beginIndex, len, share_buffer);
+ }
+
+ /**
+ * Insert a subarray of the <code>char[]</code> argument into this
+ * <code>StringBuffer</code>.
+ *
+ * @param offset the place to insert in this buffer
+ * @param str the <code>char[]</code> to insert
+ * @param str_offset the index in <code>str</code> to start inserting from
+ * @param len the number of characters to insert
+ * @return this <code>StringBuffer</code>
+ * @throws NullPointerException if <code>str</code> is <code>null</code>
+ * @throws StringIndexOutOfBoundsException if any index is out of bounds
+ * @since 1.2
+ */
+ public synchronized StringBuffer insert(int offset,
+ char[] str, int str_offset, int len)
+ {
+ if (offset < 0 || offset > count || len < 0
+ || str_offset < 0 || str_offset > str.length - len)
+ throw new StringIndexOutOfBoundsException();
+ ensureCapacity_unsynchronized(count + len);
+ System.arraycopy(value, offset, value, offset + len, count - offset);
+ System.arraycopy(str, str_offset, value, offset, len);
+ count += len;
+ return this;
+ }
+
+ /**
+ * Insert the <code>String</code> value of the argument into this
+ * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+ * to <code>String</code>.
+ *
+ * @param offset the place to insert in this buffer
+ * @param obj the <code>Object</code> to convert and insert
+ * @return this <code>StringBuffer</code>
+ * @exception StringIndexOutOfBoundsException if offset is out of bounds
+ * @see String#valueOf(Object)
+ */
+ public StringBuffer insert(int offset, Object obj)
+ {
+ return insert(offset, obj == null ? "null" : obj.toString());
+ }
+
+ /**
+ * Insert the <code>String</code> argument into this
+ * <code>StringBuffer</code>. If str is null, the String "null" is used
+ * instead.
+ *
+ * @param offset the place to insert in this buffer
+ * @param str the <code>String</code> to insert
+ * @return this <code>StringBuffer</code>
+ * @throws StringIndexOutOfBoundsException if offset is out of bounds
+ */
+ public synchronized StringBuffer insert(int offset, String str)
+ {
+ if (offset < 0 || offset > count)
+ throw new StringIndexOutOfBoundsException(offset);
+ if (str == null)
+ str = "null";
+ int len = str.count;
+ ensureCapacity_unsynchronized(count + len);
+ System.arraycopy(value, offset, value, offset + len, count - offset);
+ str.getChars(0, len, value, offset);
+ count += len;
+ return this;
+ }
+
+ /**
+ * Insert the <code>CharSequence</code> argument into this
+ * <code>StringBuffer</code>. If the sequence is null, the String
+ * "null" is used instead.
+ *
+ * @param offset the place to insert in this buffer
+ * @param sequence the <code>CharSequence</code> to insert
+ * @return this <code>StringBuffer</code>
+ * @throws IndexOutOfBoundsException if offset is out of bounds
+ * @since 1.5
+ */
+ public synchronized StringBuffer insert(int offset, CharSequence sequence)
+ {
+ if (sequence == null)
+ sequence = "null";
+ return insert(offset, sequence, 0, sequence.length());
+ }
+
+ /**
+ * Insert a subsequence of the <code>CharSequence</code> argument into this
+ * <code>StringBuffer</code>. If the sequence is null, the String
+ * "null" is used instead.
+ *
+ * @param offset the place to insert in this buffer
+ * @param sequence the <code>CharSequence</code> to insert
+ * @param start the starting index of the subsequence
+ * @param end one past the ending index of the subsequence
+ * @return this <code>StringBuffer</code>
+ * @throws IndexOutOfBoundsException if offset, start,
+ * or end are out of bounds
+ * @since 1.5
+ */
+ public synchronized StringBuffer insert(int offset, CharSequence sequence,
+ int start, int end)
+ {
+ if (sequence == null)
+ sequence = "null";
+ if (start < 0 || end < 0 || start > end || end > sequence.length())
+ throw new IndexOutOfBoundsException();
+ int len = end - start;
+ ensureCapacity_unsynchronized(count + len);
+ System.arraycopy(value, offset, value, offset + len, count - offset);
+ for (int i = start; i < end; ++i)
+ value[offset++] = sequence.charAt(i);
+ count += len;
+ return this;
+ }
+
+ /**
+ * Insert the <code>char[]</code> argument into this
+ * <code>StringBuffer</code>.
+ *
+ * @param offset the place to insert in this buffer
+ * @param data the <code>char[]</code> to insert
+ * @return this <code>StringBuffer</code>
+ * @throws NullPointerException if <code>data</code> is <code>null</code>
+ * @throws StringIndexOutOfBoundsException if offset is out of bounds
+ * @see #insert(int, char[], int, int)
+ */
+ public StringBuffer insert(int offset, char[] data)
+ {
+ return insert(offset, data, 0, data.length);
+ }
+
+ /**
+ * Insert the <code>String</code> value of the argument into this
+ * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+ * to <code>String</code>.
+ *
+ * @param offset the place to insert in this buffer
+ * @param bool the <code>boolean</code> to convert and insert
+ * @return this <code>StringBuffer</code>
+ * @throws StringIndexOutOfBoundsException if offset is out of bounds
+ * @see String#valueOf(boolean)
+ */
+ public StringBuffer insert(int offset, boolean bool)
+ {
+ return insert(offset, bool ? "true" : "false");
+ }
+
+ /**
+ * Insert the <code>char</code> argument into this <code>StringBuffer</code>.
+ *
+ * @param offset the place to insert in this buffer
+ * @param ch the <code>char</code> to insert
+ * @return this <code>StringBuffer</code>
+ * @throws StringIndexOutOfBoundsException if offset is out of bounds
+ */
+ public synchronized StringBuffer insert(int offset, char ch)
+ {
+ if (offset < 0 || offset > count)
+ throw new StringIndexOutOfBoundsException(offset);
+ ensureCapacity_unsynchronized(count + 1);
+ System.arraycopy(value, offset, value, offset + 1, count - offset);
+ value[offset] = ch;
+ count++;
+ return this;
+ }
+
+ /**
+ * Insert the <code>String</code> value of the argument into this
+ * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+ * to <code>String</code>.
+ *
+ * @param offset the place to insert in this buffer
+ * @param inum the <code>int</code> to convert and insert
+ * @return this <code>StringBuffer</code>
+ * @throws StringIndexOutOfBoundsException if offset is out of bounds
+ * @see String#valueOf(int)
+ */
+ public StringBuffer insert(int offset, int inum)
+ {
+ return insert(offset, String.valueOf(inum));
+ }
+
+ /**
+ * Insert the <code>String</code> value of the argument into this
+ * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+ * to <code>String</code>.
+ *
+ * @param offset the place to insert in this buffer
+ * @param lnum the <code>long</code> to convert and insert
+ * @return this <code>StringBuffer</code>
+ * @throws StringIndexOutOfBoundsException if offset is out of bounds
+ * @see String#valueOf(long)
+ */
+ public StringBuffer insert(int offset, long lnum)
+ {
+ return insert(offset, Long.toString(lnum, 10));
+ }
+
+ /**
+ * Insert the <code>String</code> value of the argument into this
+ * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+ * to <code>String</code>.
+ *
+ * @param offset the place to insert in this buffer
+ * @param fnum the <code>float</code> to convert and insert
+ * @return this <code>StringBuffer</code>
+ * @throws StringIndexOutOfBoundsException if offset is out of bounds
+ * @see String#valueOf(float)
+ */
+ public StringBuffer insert(int offset, float fnum)
+ {
+ return insert(offset, Float.toString(fnum));
+ }
+
+ /**
+ * Insert the <code>String</code> value of the argument into this
+ * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+ * to <code>String</code>.
+ *
+ * @param offset the place to insert in this buffer
+ * @param dnum the <code>double</code> to convert and insert
+ * @return this <code>StringBuffer</code>
+ * @throws StringIndexOutOfBoundsException if offset is out of bounds
+ * @see String#valueOf(double)
+ */
+ public StringBuffer insert(int offset, double dnum)
+ {
+ return insert(offset, Double.toString(dnum));
+ }
+
+ /**
+ * Finds the first instance of a substring in this StringBuffer.
+ *
+ * @param str String to find
+ * @return location (base 0) of the String, or -1 if not found
+ * @throws NullPointerException if str is null
+ * @see #indexOf(String, int)
+ * @since 1.4
+ */
+ public int indexOf(String str)
+ {
+ return indexOf(str, 0);
+ }
+
+ /**
+ * Finds the first instance of a String in this StringBuffer, starting at
+ * a given index. If starting index is less than 0, the search starts at
+ * the beginning of this String. If the starting index is greater than the
+ * length of this String, or the substring is not found, -1 is returned.
+ *
+ * @param str String to find
+ * @param fromIndex index to start the search
+ * @return location (base 0) of the String, or -1 if not found
+ * @throws NullPointerException if str is null
+ * @since 1.4
+ */
+ public synchronized int indexOf(String str, int fromIndex)
+ {
+ if (fromIndex < 0)
+ fromIndex = 0;
+ int limit = count - str.count;
+ for ( ; fromIndex <= limit; fromIndex++)
+ if (regionMatches(fromIndex, str))
+ return fromIndex;
+ return -1;
+ }
+
+ /**
+ * Finds the last instance of a substring in this StringBuffer.
+ *
+ * @param str String to find
+ * @return location (base 0) of the String, or -1 if not found
+ * @throws NullPointerException if str is null
+ * @see #lastIndexOf(String, int)
+ * @since 1.4
+ */
+ public int lastIndexOf(String str)
+ {
+ return lastIndexOf(str, count - str.count);
+ }
+
+ /**
+ * Finds the last instance of a String in this StringBuffer, starting at a
+ * given index. If starting index is greater than the maximum valid index,
+ * then the search begins at the end of this String. If the starting index
+ * is less than zero, or the substring is not found, -1 is returned.
+ *
+ * @param str String to find
+ * @param fromIndex index to start the search
+ * @return location (base 0) of the String, or -1 if not found
+ * @throws NullPointerException if str is null
+ * @since 1.4
+ */
+ public synchronized int lastIndexOf(String str, int fromIndex)
+ {
+ fromIndex = Math.min(fromIndex, count - str.count);
+ for ( ; fromIndex >= 0; fromIndex--)
+ if (regionMatches(fromIndex, str))
+ return fromIndex;
+ return -1;
+ }
+
+ /**
+ * Reverse the characters in this StringBuffer. The same sequence of
+ * characters exists, but in the reverse index ordering.
+ *
+ * @return this <code>StringBuffer</code>
+ */
+ public synchronized StringBuffer reverse()
+ {
+ // Call ensureCapacity to enforce copy-on-write.
+ ensureCapacity_unsynchronized(count);
+ for (int i = count >> 1, j = count - i; --i >= 0; ++j)
+ {
+ char c = value[i];
+ value[i] = value[j];
+ value[j] = c;
+ }
+ return this;
+ }
+
+ /**
+ * Convert this <code>StringBuffer</code> to a <code>String</code>. The
+ * String is composed of the characters currently in this StringBuffer. Note
+ * that the result is a copy, and that future modifications to this buffer
+ * do not affect the String.
+ *
+ * @return the characters in this StringBuffer
+ */
+ public String toString()
+ {
+ // The string will set this.shared = true.
+ return new String(this);
+ }
+
+ /**
+ * This may reduce the amount of memory used by the StringBuffer,
+ * by resizing the internal array to remove unused space. However,
+ * this method is not required to resize, so this behavior cannot
+ * be relied upon.
+ * @since 1.5
+ */
+ public synchronized void trimToSize()
+ {
+ int wouldSave = value.length - count;
+ // Some random heuristics: if we save less than 20 characters, who
+ // cares.
+ if (wouldSave < 20)
+ return;
+ // If we save more than 200 characters, shrink.
+ // If we save more than 1/4 of the buffer, shrink.
+ if (wouldSave > 200 || wouldSave * 4 > value.length)
+ {
+ char[] newValue = new char[count];
+ System.arraycopy(value, 0, newValue, 0, count);
+ value = newValue;
+ }
+ }
+
+ /**
+ * Return the number of code points between two indices in the
+ * <code>StringBuffer</code>. An unpaired surrogate counts as a
+ * code point for this purpose. Characters outside the indicated
+ * range are not examined, even if the range ends in the middle of a
+ * surrogate pair.
+ *
+ * @param start the starting index
+ * @param end one past the ending index
+ * @return the number of code points
+ * @since 1.5
+ */
+ public synchronized int codePointCount(int start, int end)
+ {
+ if (start < 0 || end >= count || start > end)
+ throw new StringIndexOutOfBoundsException();
+
+ int count = 0;
+ while (start < end)
+ {
+ char base = value[start];
+ if (base < Character.MIN_HIGH_SURROGATE
+ || base > Character.MAX_HIGH_SURROGATE
+ || start == end
+ || start == count
+ || value[start + 1] < Character.MIN_LOW_SURROGATE
+ || value[start + 1] > Character.MAX_LOW_SURROGATE)
+ {
+ // Nothing.
+ }
+ else
+ {
+ // Surrogate pair.
+ ++start;
+ }
+ ++start;
+ ++count;
+ }
+ return count;
+ }
+
+ /**
+ * Starting at the given index, this counts forward by the indicated
+ * number of code points, and then returns the resulting index. An
+ * unpaired surrogate counts as a single code point for this
+ * purpose.
+ *
+ * @param start the starting index
+ * @param codePoints the number of code points
+ * @return the resulting index
+ * @since 1.5
+ */
+ public synchronized int offsetByCodePoints(int start, int codePoints)
+ {
+ while (codePoints > 0)
+ {
+ char base = value[start];
+ if (base < Character.MIN_HIGH_SURROGATE
+ || base > Character.MAX_HIGH_SURROGATE
+ || start == count
+ || value[start + 1] < Character.MIN_LOW_SURROGATE
+ || value[start + 1] > Character.MAX_LOW_SURROGATE)
+ {
+ // Nothing.
+ }
+ else
+ {
+ // Surrogate pair.
+ ++start;
+ }
+ ++start;
+ --codePoints;
+ }
+ return start;
+ }
+
+ /**
+ * An unsynchronized version of ensureCapacity, used internally to avoid
+ * the cost of a second lock on the same object. This also has the side
+ * effect of duplicating the array, if it was shared (to form copy-on-write
+ * semantics).
+ *
+ * @param minimumCapacity the minimum capacity
+ * @see #ensureCapacity(int)
+ */
+ private void ensureCapacity_unsynchronized(int minimumCapacity)
+ {
+ if (shared || minimumCapacity > value.length)
+ {
+ // We don't want to make a larger vector when `shared' is
+ // set. If we do, then setLength becomes very inefficient
+ // when repeatedly reusing a StringBuffer in a loop.
+ int max = (minimumCapacity > value.length
+ ? value.length * 2 + 2
+ : value.length);
+ minimumCapacity = (minimumCapacity < max ? max : minimumCapacity);
+ char[] nb = new char[minimumCapacity];
+ System.arraycopy(value, 0, nb, 0, count);
+ value = nb;
+ shared = false;
+ }
+ }
- // True if we need to copy the buffer before writing to it again.
- // FIXME: JDK 1.2 doesn't specify this. The new buffer-growing
- // semantics make this less useful in that case, too.
- private boolean shared;
+ /**
+ * Predicate which determines if a substring of this matches another String
+ * starting at a specified offset for each String and continuing for a
+ * specified length. This is more efficient than creating a String to call
+ * indexOf on.
+ *
+ * @param toffset index to start comparison at for this String
+ * @param other non-null String to compare to region of this
+ * @return true if regions match, false otherwise
+ * @see #indexOf(String, int)
+ * @see #lastIndexOf(String, int)
+ * @see String#regionMatches(boolean, int, String, int, int)
+ */
+ // GCJ LOCAL: native for gcj.
+ private native boolean regionMatches(int toffset, String other);
}
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