/* * * * Copyright 1990-2009 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version * 2 only, as published by the Free Software Foundation. * * This program 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 version 2 for more details (a copy is * included at /legal/license.txt). * * You should have received a copy of the GNU General Public License * version 2 along with this work; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa * Clara, CA 95054 or visit www.sun.com if you need additional * information or have any questions. */ package java.lang; //import com.sun.cldchi.jvm.JVM; /** * A string buffer implements a mutable sequence of characters. * A string buffer is like a {@link String}, but can be modified. At any * point in time it contains some particular sequence of characters, but * the length and content of the sequence can be changed through certain * method calls. * <p> * String buffers are safe for use by multiple threads. The methods * are synchronized where necessary so that all the operations on any * particular instance behave as if they occur in some serial order * that is consistent with the order of the method calls made by each of * the individual threads involved. * <p> * String buffers are used by the compiler to implement the binary * string concatenation operator <code>+</code>. For example, the code: * <p><blockquote><pre> * x = "a" + 4 + "c" * </pre></blockquote><p> * is compiled to the equivalent of: * <p><blockquote><pre> * x = new StringBuffer().append("a").append(4).append("c") * .toString() * </pre></blockquote> * which creates a new string buffer (initially empty), appends the string * representation of each operand to the string buffer in turn, and then * converts the contents of the string buffer to a string. Overall, this avoids * creating many temporary strings. * <p> * The principal operations on a <code>StringBuffer</code> are the * <code>append</code> and <code>insert</code> methods, which are * overloaded so as to accept data of any type. Each effectively * converts a given datum to a string and then appends or inserts the * characters of that string to the string buffer. The * <code>append</code> method always adds these characters at the end * of the buffer; the <code>insert</code> method adds the characters at * a specified point. * <p> * For example, if <code>z</code> refers to a string buffer object * whose current contents are "<code>start</code>", then * the method call <code>z.append("le")</code> would cause the string * buffer to contain "<code>startle</code>", whereas * <code>z.insert(4, "le")</code> would alter the string buffer to * contain "<code>starlet</code>". * <p> * In general, if sb refers to an instance of a <code>StringBuffer</code>, * then <code>sb.append(x)</code> has the same effect as * <code>sb.insert(sb.length(), x)</code>. * <p> * Every string buffer has a capacity. As long as the length of the * character sequence contained in the string buffer does not exceed * the capacity, it is not necessary to allocate a new internal * buffer array. If the internal buffer overflows, it is * automatically made larger. * * @version 12/17/01 (CLDC 1.1) * @see java.io.ByteArrayOutputStream * @see java.lang.String * @since JDK1.0, CLDC 1.0 */ public final class StringBuffer { /** * The value is used for character storage. */ // private char value[]; // Made visible for the String class char value[]; /** * The count is the number of characters in the buffer. */ // private int count; // Made visible for the String class int count; /** * A flag indicating whether the buffer is shared */ // private boolean shared; /** * Constructs a string buffer with no characters in it and an * initial capacity of 16 characters. */ public StringBuffer() { value = new char[16]; } /** * Constructs a string buffer with no characters in it and an * initial capacity specified by the <code>length</code> argument. * * @param length the initial capacity. * @exception NegativeArraySizeException if the <code>length</code> * argument is less than <code>0</code>. */ public StringBuffer(int length) { value = new char[length]; } /** * Constructs a string buffer so that it represents the same * sequence of characters as the string argument; in other * words, the initial contents of the string buffer is a copy of the * argument string. The initial capacity of the string buffer is * <code>16</code> plus the length of the string argument. * * @param str the initial contents of the buffer. */ public StringBuffer(String str) { this(str.length() + 16); append(str); } /** * Returns the length (character count) of this string buffer. * * @return the length of the sequence of characters currently * represented by this string buffer. */ public int length() { return count; } /** * Returns the current capacity of the String buffer. The capacity * is the amount of storage available for newly inserted * characters; beyond which an allocation will occur. * * @return the current capacity of this string buffer. */ public int capacity() { return value.length; } /** * Copies the buffer value. This is normally only called when shared * is true. It should only be called from a synchronized method. */ // private final void copy() { // char newValue[] = new char[value.length]; // JVM.unchecked_char_arraycopy(value, 0, newValue, 0, count); // value = newValue; // shared = false; // } /** * Ensures that the capacity of the buffer is at least equal to the * specified minimum. * If the current capacity of this string buffer is less than the * argument, then a new internal buffer is allocated with greater * capacity. The new capacity is the larger of: * <ul> * <li>The <code>minimumCapacity</code> argument. * <li>Twice the old capacity, plus <code>2</code>. * </ul> * If the <code>minimumCapacity</code> argument is nonpositive, this * method takes no action and simply returns. * * @param minimumCapacity the minimum desired capacity. */ public synchronized void ensureCapacity(int minimumCapacity) { if (minimumCapacity > value.length) { expandCapacity(minimumCapacity); } } /** * This implements the expansion semantics of ensureCapacity but is * unsynchronized for use internally by methods which are already * synchronized. * * @see java.lang.StringBuffer#ensureCapacity(int) */ private void expandCapacity(int minimumCapacity) { int newCapacity = (value.length + 1) * 2; if (newCapacity < 0) { newCapacity = Integer.MAX_VALUE; } else if (minimumCapacity > newCapacity) { newCapacity = minimumCapacity; } char newValue[] = new char[newCapacity]; // JVM.unchecked_char_arraycopy(value, 0, newValue, 0, count); System.arraycopy(value, 0, newValue, 0, count); value = newValue; // shared = false; } /** * Sets the length of this string buffer. * This string buffer is altered to represent a new character sequence * whose length is specified by the argument. For every nonnegative * index <i>k</i> less than <code>newLength</code>, the character at * index <i>k</i> in the new character sequence is the same as the * character at index <i>k</i> in the old sequence if <i>k</i> is less * than the length of the old character sequence; otherwise, it is the * null character <code>'\u0000'</code>. * * In other words, if the <code>newLength</code> argument is less than * the current length of the string buffer, the string buffer is * truncated to contain exactly the number of characters given by the * <code>newLength</code> argument. * <p> * If the <code>newLength</code> argument is greater than or equal * to the current length, sufficient null characters * (<code>'\u0000'</code>) are appended to the string buffer so that * length becomes the <code>newLength</code> argument. * <p> * The <code>newLength</code> argument must be greater than or equal * to <code>0</code>. * * @param newLength the new length of the buffer. * @exception IndexOutOfBoundsException if the * <code>newLength</code> argument is negative. * @see java.lang.StringBuffer#length() */ public synchronized void setLength(int newLength) { if (newLength < 0) { throw new StringIndexOutOfBoundsException( /* #ifdef VERBOSE_EXCEPTIONS */ /// skipped newLength /* #endif */ ); } if (newLength > value.length) { expandCapacity(newLength); } if (count < newLength) { // if (shared) copy(); for (; count < newLength; count++) { value[count] = '\0'; } } else { count = newLength; // This truncates the buffer to the specified size char[] newValue = new char[count]; for(int i = 0; i < count; i++) { newValue[i] = value[i]; } value = newValue; // if (shared) { // if (newLength > 0) { // copy(); // } else { // // If newLength is zero, assume the StringBuffer is being // // stripped for reuse; Make new buffer of default size // value = new char[16]; // shared = false; // } // } } } /** * The specified character of the sequence currently represented by * the string buffer, as indicated by the <code>index</code> argument, * is returned. The first character of a string buffer is at index * <code>0</code>, the next at index <code>1</code>, and so on, for * array indexing. * <p> * The index argument must be greater than or equal to * <code>0</code>, and less than the length of this string buffer. * * @param index the index of the desired character. * @return the character at the specified index of this string buffer. * @exception IndexOutOfBoundsException if <code>index</code> is * negative or greater than or equal to <code>length()</code>. * @see java.lang.StringBuffer#length() */ public synchronized char charAt(int index) { if ((index < 0) || (index >= count)) { throw new StringIndexOutOfBoundsException( /* #ifdef VERBOSE_EXCEPTIONS */ /// skipped index /* #endif */ ); } return value[index]; } /** * Characters are copied from this string buffer into the * destination character array <code>dst</code>. The first character to * be copied is at index <code>srcBegin</code>; the last character to * be copied is at index <code>srcEnd-1</code>. The total number of * characters to be copied is <code>srcEnd-srcBegin</code>. The * characters are copied into the subarray of <code>dst</code> starting * at index <code>dstBegin</code> and ending at index: * <p><blockquote><pre> * dstbegin + (srcEnd-srcBegin) - 1 * </pre></blockquote> * * @param srcBegin start copying at this offset in the string buffer. * @param srcEnd stop copying at this offset in the string buffer. * @param dst the array to copy the data into. * @param dstBegin offset into <code>dst</code>. * @exception NullPointerException if <code>dst</code> is * <code>null</code>. * @exception IndexOutOfBoundsException if any of the following is true: * <ul> * <li><code>srcBegin</code> is negative * <li><code>dstBegin</code> is negative * <li>the <code>srcBegin</code> argument is greater than * the <code>srcEnd</code> argument. * <li><code>srcEnd</code> is greater than * <code>this.length()</code>, the current length of this * string buffer. * <li><code>dstBegin+srcEnd-srcBegin</code> is greater than * <code>dst.length</code> * </ul> */ public synchronized void getChars(int srcBegin, int srcEnd, char dst[], int dstBegin) { if (srcBegin < 0) { throw new StringIndexOutOfBoundsException( /* #ifdef VERBOSE_EXCEPTIONS */ /// skipped srcBegin /* #endif */ ); } if ((srcEnd < 0) || (srcEnd > count)) { throw new StringIndexOutOfBoundsException( /* #ifdef VERBOSE_EXCEPTIONS */ /// skipped srcEnd /* #endif */ ); } if (srcBegin > srcEnd) { throw new StringIndexOutOfBoundsException( /* #ifdef VERBOSE_EXCEPTIONS */ /// skipped "srcBegin > srcEnd" /* #endif */ ); } // NOTE: dst not checked, cannot use unchecked arraycopy System.arraycopy(value, srcBegin, dst, dstBegin, srcEnd - srcBegin); } /** * The character at the specified index of this string buffer is set * to <code>ch</code>. The string buffer is altered to represent a new * character sequence that is identical to the old character sequence, * except that it contains the character <code>ch</code> at position * <code>index</code>. * <p> * The offset argument must be greater than or equal to * <code>0</code>, and less than the length of this string buffer. * * @param index the index of the character to modify. * @param ch the new character. * @exception IndexOutOfBoundsException if <code>index</code> is * negative or greater than or equal to <code>length()</code>. * @see java.lang.StringBuffer#length() */ public synchronized void setCharAt(int index, char ch) { if ((index < 0) || (index >= count)) { throw new StringIndexOutOfBoundsException( /* #ifdef VERBOSE_EXCEPTIONS */ /// skipped index /* #endif */ ); } // if (shared) copy(); value[index] = ch; } /** * Appends the string representation of the <code>Object</code> * argument to this string buffer. * <p> * The argument is converted to a string as if by the method * <code>String.valueOf</code>, and the characters of that * string are then appended to this string buffer. * * @param obj an <code>Object</code>. * @return a reference to this <code>StringBuffer</code> object. * @see java.lang.String#valueOf(java.lang.Object) * @see java.lang.StringBuffer#append(java.lang.String) */ public synchronized StringBuffer append(Object obj) { return append(String.valueOf(obj)); } /** * Appends the string to this string buffer. * <p> * The characters of the <code>String</code> argument are appended, in * order, to the contents of this string buffer, increasing the * length of this string buffer by the length of the argument. * If <code>str</code> is <code>null</code>, then the four characters * <code>"null"</code> are appended to this string buffer. * <p> * Let <i>n</i> be the length of the old character sequence, the one * contained in the string buffer just prior to execution of the * <code>append</code> method. Then the character at index <i>k</i> in * the new character sequence is equal to the character at index <i>k</i> * in the old character sequence, if <i>k</i> is less than <i>n</i>; * otherwise, it is equal to the character at index <i>k-n</i> in the * argument <code>str</code>. * * @param str a string. * @return a reference to this <code>StringBuffer</code>. */ public synchronized StringBuffer append(String str) { if (str == null) { str = String.valueOf(str); } int len = str.length(); int newcount = count + len; if (newcount > value.length) expandCapacity(newcount); str.getChars(0, len, value, count); count = newcount; return this; } /** * Appends the string representation of the <code>char</code> array * argument to this string buffer. * <p> * The characters of the array argument are appended, in order, to * the contents of this string buffer. The length of this string * buffer increases by the length of the argument. * <p> * The overall effect is exactly as if the argument were converted to * a string by the method {@link String#valueOf(char[])} and the * characters of that string were then {@link #append(String) appended} * to this <code>StringBuffer</code> object. * * @param str the characters to be appended. * @return a reference to this <code>StringBuffer</code> object. */ public synchronized StringBuffer append(char str[]) { int len = str.length; int newcount = count + len; if (newcount > value.length) expandCapacity(newcount); // JVM.unchecked_char_arraycopy(str, 0, value, count, len); System.arraycopy(str, 0, value, count, len); count = newcount; return this; } /** * Appends the string representation of a subarray of the * <code>char</code> array argument to this string buffer. * <p> * Characters of the character array <code>str</code>, starting at * index <code>offset</code>, are appended, in order, to the contents * of this string buffer. The length of this string buffer increases * by the value of <code>len</code>. * <p> * The overall effect is exactly as if the arguments were converted to * a string by the method {@link String#valueOf(char[],int,int)} and the * characters of that string were then {@link #append(String) appended} * to this <code>StringBuffer</code> object. * * @param str the characters to be appended. * @param offset the index of the first character to append. * @param len the number of characters to append. * @return a reference to this <code>StringBuffer</code> object. */ public synchronized StringBuffer append(char str[], int offset, int len) { int newcount = count + len; if (newcount > value.length) expandCapacity(newcount); // NOTE: str and offset not checked, cannot use unchecked arraycopy System.arraycopy(str, offset, value, count, len); count = newcount; return this; } /** * Appends the string representation of the <code>boolean</code> * argument to the string buffer. * <p> * The argument is converted to a string as if by the method * <code>String.valueOf</code>, and the characters of that * string are then appended to this string buffer. * * @param b a <code>boolean</code>. * @return a reference to this <code>StringBuffer</code>. * @see java.lang.String#valueOf(boolean) * @see java.lang.StringBuffer#append(java.lang.String) */ public StringBuffer append(boolean b) { return append(String.valueOf(b)); } /** * Appends the string representation of the <code>char</code> * argument to this string buffer. * <p> * The argument is appended to the contents of this string buffer. * The length of this string buffer increases by <code>1</code>. * <p> * The overall effect is exactly as if the argument were converted to * a string by the method {@link String#valueOf(char)} and the character * in that string were then {@link #append(String) appended} to this * <code>StringBuffer</code> object. * * @param c a <code>char</code>. * @return a reference to this <code>StringBuffer</code> object. */ public synchronized StringBuffer append(char c) { int newcount = count + 1; if (newcount > value.length) expandCapacity(newcount); value[count++] = c; return this; } /** * Appends the string representation of the <code>int</code> * argument to this string buffer. * <p> * The argument is converted to a string as if by the method * <code>String.valueOf</code>, and the characters of that * string are then appended to this string buffer. * * @param i an <code>int</code>. * @return a reference to this <code>StringBuffer</code> object. * @see java.lang.String#valueOf(int) * @see java.lang.StringBuffer#append(java.lang.String) */ public StringBuffer append(int i) { return append(String.valueOf(i)); } /** * Appends the string representation of the <code>long</code> * argument to this string buffer. * <p> * The argument is converted to a string as if by the method * <code>String.valueOf</code>, and the characters of that * string are then appended to this string buffer. * * @param l a <code>long</code>. * @return a reference to this <code>StringBuffer</code> object. * @see java.lang.String#valueOf(long) * @see java.lang.StringBuffer#append(java.lang.String) */ public StringBuffer append(long l) { return append(String.valueOf(l)); } /** * Appends the string representation of the <code>float</code> * argument to this string buffer. * <p> * The argument is converted to a string as if by the method * <code>String.valueOf</code>, and the characters of that * string are then appended to this string buffer. * * @param f a <code>float</code>. * @return a reference to this <code>StringBuffer</code> object. * @see java.lang.String#valueOf(float) * @see java.lang.StringBuffer#append(java.lang.String) * @since CLDC 1.1 */ public StringBuffer append(float f) { return append(String.valueOf(f)); } /** * Appends the string representation of the <code>double</code> * argument to this string buffer. * <p> * The argument is converted to a string as if by the method * <code>String.valueOf</code>, and the characters of that * string are then appended to this string buffer. * * @param d a <code>double</code>. * @return a reference to this <code>StringBuffer</code> object. * @see java.lang.String#valueOf(double) * @see java.lang.StringBuffer#append(java.lang.String) * @since CLDC 1.1 */ public StringBuffer append(double d) { return append(String.valueOf(d)); } /** * Removes the characters in a substring of this <code>StringBuffer</code>. * The substring begins at the specified <code>start</code> and extends to * the character at index <code>end - 1</code> or to the end of the * <code>StringBuffer</code> if no such character exists. If * <code>start</code> is equal to <code>end</code>, no changes are made. * * @param start The beginning index, inclusive. * @param end The ending index, exclusive. * @return This string buffer. * @exception StringIndexOutOfBoundsException if <code>start</code> * is negative, greater than <code>length()</code>, or * greater than <code>end</code>. * @since JDK1.2 */ public synchronized StringBuffer delete(int start, int end) { if (start < 0) throw new StringIndexOutOfBoundsException( /* #ifdef VERBOSE_EXCEPTIONS */ /// skipped start /* #endif */ ); if (end > count) end = count; if (start > end) throw new StringIndexOutOfBoundsException(); int len = end - start; if (len > 0) { // if (shared) // copy(); // JVM.unchecked_char_arraycopy(value, start+len, // value, start, count-end); System.arraycopy(value, start+len, value, start, count-end); count -= len; } return this; } /** * Removes the character at the specified position in this * <code>StringBuffer</code> (shortening the <code>StringBuffer</code> * by one character). * * @param index Index of character to remove * @return This string buffer. * @exception StringIndexOutOfBoundsException if the <code>index</code> * is negative or greater than or equal to * <code>length()</code>. * @since JDK1.2 */ public synchronized StringBuffer deleteCharAt(int index) { if ((index < 0) || (index >= count)) throw new StringIndexOutOfBoundsException(); // if (shared) // copy(); // JVM.unchecked_char_arraycopy(value, index+1, // value, index, count-index-1); System.arraycopy(value, index+1, value, index, count-index-1); count--; return this; } /** * Inserts the string representation of the <code>Object</code> * argument into this string buffer. * <p> * The second argument is converted to a string as if by the method * <code>String.valueOf</code>, and the characters of that * string are then inserted into this string buffer at the indicated * offset. * <p> * The offset argument must be greater than or equal to * <code>0</code>, and less than or equal to the length of this * string buffer. * * @param offset the offset. * @param obj an <code>Object</code>. * @return a reference to this <code>StringBuffer</code> object. * @exception StringIndexOutOfBoundsException if the offset is invalid. * @see java.lang.String#valueOf(java.lang.Object) * @see java.lang.StringBuffer#insert(int, java.lang.String) * @see java.lang.StringBuffer#length() */ public synchronized StringBuffer insert(int offset, Object obj) { return insert(offset, String.valueOf(obj)); } /** * Inserts the string into this string buffer. * <p> * The characters of the <code>String</code> argument are inserted, in * order, into this string buffer at the indicated offset, moving up any * characters originally above that position and increasing the length * of this string buffer by the length of the argument. If * <code>str</code> is <code>null</code>, then the four characters * <code>"null"</code> are inserted into this string buffer. * <p> * The character at index <i>k</i> in the new character sequence is * equal to: * <ul> * <li>the character at index <i>k</i> in the old character sequence, if * <i>k</i> is less than <code>offset</code> * <li>the character at index <i>k</i><code>-offset</code> in the * argument <code>str</code>, if <i>k</i> is not less than * <code>offset</code> but is less than <code>offset+str.length()</code> * <li>the character at index <i>k</i><code>-str.length()</code> in the * old character sequence, if <i>k</i> is not less than * <code>offset+str.length()</code> * </ul><p> * The offset argument must be greater than or equal to * <code>0</code>, and less than or equal to the length of this * string buffer. * * @param offset the offset. * @param str a string. * @return a reference to this <code>StringBuffer</code> object. * @exception StringIndexOutOfBoundsException if the offset is invalid. * @see java.lang.StringBuffer#length() */ public synchronized StringBuffer insert(int offset, String str) { if ((offset < 0) || (offset > count)) { throw new StringIndexOutOfBoundsException(); } if (str == null) { str = String.valueOf(str); } int len = str.length(); int newcount = count + len; if (newcount > value.length) expandCapacity(newcount); // else if (shared) // copy(); // JVM.unchecked_char_arraycopy(value, offset, // value, offset + len, count - offset); System.arraycopy(value, offset, value, offset + len, count - offset); str.getChars(0, len, value, offset); count = newcount; return this; } /** * Inserts the string representation of the <code>char</code> array * argument into this string buffer. * <p> * The characters of the array argument are inserted into the * contents of this string buffer at the position indicated by * <code>offset</code>. The length of this string buffer increases by * the length of the argument. * <p> * The overall effect is exactly as if the argument were converted to * a string by the method {@link String#valueOf(char[])} and the * characters of that string were then * {@link #insert(int,String) inserted} into this * <code>StringBuffer</code> object at the position indicated by * <code>offset</code>. * * @param offset the offset. * @param str a character array. * @return a reference to this <code>StringBuffer</code> object. * @exception StringIndexOutOfBoundsException if the offset is invalid. */ public synchronized StringBuffer insert(int offset, char str[]) { if ((offset < 0) || (offset > count)) { throw new StringIndexOutOfBoundsException(); } int len = str.length; int newcount = count + len; if (newcount > value.length) expandCapacity(newcount); // else if (shared) // copy(); // JVM.unchecked_char_arraycopy(value, offset, // value, offset + len, count - offset); System.arraycopy(value, offset, value, offset + len, count - offset); // JVM.unchecked_char_arraycopy(str, 0, value, offset, len); System.arraycopy(str, 0, value, offset, len); count = newcount; return this; } /** * Inserts the string representation of the <code>boolean</code> * argument into this string buffer. * <p> * The second argument is converted to a string as if by the method * <code>String.valueOf</code>, and the characters of that * string are then inserted into this string buffer at the indicated * offset. * <p> * The offset argument must be greater than or equal to * <code>0</code>, and less than or equal to the length of this * string buffer. * * @param offset the offset. * @param b a <code>boolean</code>. * @return a reference to this <code>StringBuffer</code> object. * @exception StringIndexOutOfBoundsException if the offset is invalid. * @see java.lang.String#valueOf(boolean) * @see java.lang.StringBuffer#insert(int, java.lang.String) * @see java.lang.StringBuffer#length() */ public StringBuffer insert(int offset, boolean b) { return insert(offset, String.valueOf(b)); } /** * Inserts the string representation of the <code>char</code> * argument into this string buffer. * <p> * The second argument is inserted into the contents of this string * buffer at the position indicated by <code>offset</code>. The length * of this string buffer increases by one. * <p> * The overall effect is exactly as if the argument were converted to * a string by the method {@link String#valueOf(char)} and the character * in that string were then {@link #insert(int, String) inserted} into * this <code>StringBuffer</code> object at the position indicated by * <code>offset</code>. * <p> * The offset argument must be greater than or equal to * <code>0</code>, and less than or equal to the length of this * string buffer. * * @param offset the offset. * @param c a <code>char</code>. * @return a reference to this <code>StringBuffer</code> object. * @exception IndexOutOfBoundsException if the offset is invalid. * @see java.lang.StringBuffer#length() */ public synchronized StringBuffer insert(int offset, char c) { int newcount = count + 1; if (newcount > value.length) expandCapacity(newcount); // else if (shared) // copy(); // NOTE: offset not checked, cannot use unchecked arraycopy System.arraycopy(value, offset, value, offset + 1, count - offset); value[offset] = c; count = newcount; return this; } /** * Inserts the string representation of the second <code>int</code> * argument into this string buffer. * <p> * The second argument is converted to a string as if by the method * <code>String.valueOf</code>, and the characters of that * string are then inserted into this string buffer at the indicated * offset. * <p> * The offset argument must be greater than or equal to * <code>0</code>, and less than or equal to the length of this * string buffer. * * @param offset the offset. * @param i an <code>int</code>. * @return a reference to this <code>StringBuffer</code> object. * @exception StringIndexOutOfBoundsException if the offset is invalid. * @see java.lang.String#valueOf(int) * @see java.lang.StringBuffer#insert(int, java.lang.String) * @see java.lang.StringBuffer#length() */ public StringBuffer insert(int offset, int i) { return insert(offset, String.valueOf(i)); } /** * Inserts the string representation of the <code>long</code> * argument into this string buffer. * <p> * The second argument is converted to a string as if by the method * <code>String.valueOf</code>, and the characters of that * string are then inserted into this string buffer at the position * indicated by <code>offset</code>. * <p> * The offset argument must be greater than or equal to * <code>0</code>, and less than or equal to the length of this * string buffer. * * @param offset the offset. * @param l a <code>long</code>. * @return a reference to this <code>StringBuffer</code> object. * @exception StringIndexOutOfBoundsException if the offset is invalid. * @see java.lang.String#valueOf(long) * @see java.lang.StringBuffer#insert(int, java.lang.String) * @see java.lang.StringBuffer#length() */ public StringBuffer insert(int offset, long l) { return insert(offset, String.valueOf(l)); } /** * Inserts the string representation of the <code>float</code> * argument into this string buffer. * <p> * The second argument is converted to a string as if by the method * <code>String.valueOf</code>, and the characters of that * string are then inserted into this string buffer at the indicated * offset. * <p> * The offset argument must be greater than or equal to * <code>0</code>, and less than or equal to the length of this * string buffer. * * @param offset the offset. * @param f a <code>float</code>. * @return a reference to this <code>StringBuffer</code> object. * @exception StringIndexOutOfBoundsException if the offset is invalid. * @see java.lang.String#valueOf(float) * @see java.lang.StringBuffer#insert(int, java.lang.String) * @see java.lang.StringBuffer#length() * @since CLDC 1.1 */ public StringBuffer insert(int offset, float f) { return insert(offset, String.valueOf(f)); } /** * Inserts the string representation of the <code>double</code> * argument into this string buffer. * <p> * The second argument is converted to a string as if by the method * <code>String.valueOf</code>, and the characters of that * string are then inserted into this string buffer at the indicated * offset. * <p> * The offset argument must be greater than or equal to * <code>0</code>, and less than or equal to the length of this * string buffer. * * @param offset the offset. * @param d a <code>double</code>. * @return a reference to this <code>StringBuffer</code> object. * @exception StringIndexOutOfBoundsException if the offset is invalid. * @see java.lang.String#valueOf(double) * @see java.lang.StringBuffer#insert(int, java.lang.String) * @see java.lang.StringBuffer#length() * @since CLDC 1.1 */ public StringBuffer insert(int offset, double d) { return insert(offset, String.valueOf(d)); } /** * The character sequence contained in this string buffer is * replaced by the reverse of the sequence. * <p> * Let <i>n</i> be the length of the old character sequence, the one * contained in the string buffer just prior to execution of the * <code>reverse</code> method. Then the character at index <i>k</i> in * the new character sequence is equal to the character at index * <i>n-k-1</i> in the old character sequence. * * @return a reference to this <code>StringBuffer</code> object.. * @since JDK1.0.2 */ public synchronized StringBuffer reverse() { // if (shared) copy(); int n = count - 1; for (int j = (n-1) >> 1; j >= 0; --j) { char temp = value[j]; value[j] = value[n - j]; value[n - j] = temp; } return this; } /** * Converts to a string representing the data in this string buffer. * A new <code>String</code> object is allocated and initialized to * contain the character sequence currently represented by this * string buffer. This <code>String</code> is then returned. Subsequent * changes to the string buffer do not affect the contents of the * <code>String</code>. * <p> * Implementation advice: This method can be coded so as to create a new * <code>String</code> object without allocating new memory to hold a * copy of the character sequence. Instead, the string can share the * memory used by the string buffer. Any subsequent operation that alters * the content or capacity of the string buffer must then make a copy of * the internal buffer at that time. This strategy is effective for * reducing the amount of memory allocated by a string concatenation * operation when it is implemented using a string buffer. * * @return a string representation of the string buffer. */ public String toString() { return new String(this); } // The following two methods are needed by String to efficiently // convert a StringBuffer into a String. They are not public. // They shouldn't be called by anyone but String. // final void setShared() { shared = true; } // final char[] getValue() { return value; } }