package tests; import cute.Cute; /* * @(#)StringBuffer.java 1.78 03/05/16 * * Copyright 2003 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */ /** * 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. * * @author Arthur van Hoff * @version 1.78, 05/16/03 * @see java.io.ByteArrayOutputStream * @see java.lang.String * @since JDK1.0 */ public final class StringBuffer implements java.io.Serializable, CharSequence { /** * The value is used for character storage. * * @serial */ private char value[]; /** * The count is the number of characters in the buffer. * * @serial */ private int count; /** * A flag indicating whether the buffer is shared * * @serial */ private boolean shared; /** use serialVersionUID from JDK 1.0.2 for interoperability */ static final long serialVersionUID = 3388685877147921107L; /** * Constructs a string buffer with no characters in it and an * initial capacity of 16 characters. */ public StringBuffer() { this(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]; shared = false; } /** * 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. * @exception NullPointerException if <code>str</code> is <code>null</code> */ 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 synchronized 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 synchronized 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]; System.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]; 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(newLength); } if (newLength > value.length) { expandCapacity(newLength); } if (count < newLength) { if (shared) copy(); for (; count < newLength; count++) { value[count] = '\0'; } } else { count = newLength; 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(index); } 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(srcBegin); } if ((srcEnd < 0) || (srcEnd > count)) { throw new StringIndexOutOfBoundsException(srcEnd); } if (srcBegin > srcEnd) { throw new StringIndexOutOfBoundsException("srcBegin > srcEnd"); } 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 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 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(index); } 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 specified <tt>StringBuffer</tt> to this * <tt>StringBuffer</tt>. * <p> * The characters of the <tt>StringBuffer</tt> argument are appended, * in order, to the contents of this <tt>StringBuffer</tt>, increasing the * length of this <tt>StringBuffer</tt> by the length of the argument. * If <tt>sb</tt> is <tt>null</tt>, then the four characters * <tt>"null"</tt> are appended to this <tt>StringBuffer</tt>. * <p> * Let <i>n</i> be the length of the old character sequence, the one * contained in the <tt>StringBuffer</tt> just prior to execution of the * <tt>append</tt> 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>sb</code>. * <p> * The method <tt>ensureCapacity</tt> is first called on this * <tt>StringBuffer</tt> with the new buffer length as its argument. * (This ensures that the storage of this <tt>StringBuffer</tt> is * adequate to contain the additional characters being appended.) * * @param sb the <tt>StringBuffer</tt> to append. * @return a reference to this <tt>StringBuffer</tt>. * @since 1.4 */ public synchronized StringBuffer append(StringBuffer sb) { if (sb == null) { sb = NULL; } int len = sb.length(); int newcount = count + len; if (newcount > value.length) expandCapacity(newcount); sb.getChars(0, len, value, count); count = newcount; return this; } private static final StringBuffer NULL = new StringBuffer("null"); /** * 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); 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); 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 synchronized StringBuffer append(boolean b) { if (b) { int newcount = count + 4; if (newcount > value.length) expandCapacity(newcount); value[count++] = 't'; value[count++] = 'r'; value[count++] = 'u'; value[count++] = 'e'; } else { int newcount = count + 5; if (newcount > value.length) expandCapacity(newcount); value[count++] = 'f'; value[count++] = 'a'; value[count++] = 'l'; value[count++] = 's'; value[count++] = 'e'; } return this; } /** * 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 synchronized StringBuffer append(int i) { // Integer.appendTo(i, this); // return this; // } // // /** // * 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 synchronized StringBuffer append(long l) { // Long.appendTo(l, this); // return this; // } // // /** // * 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) // */ // public synchronized StringBuffer append(float f) { // new FloatingDecimal(f).appendTo(this); // return this; // } // // /** // * 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) // */ // public synchronized StringBuffer append(double d) { // new FloatingDecimal(d).appendTo(this); // return this; // } /** * 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 1.2 */ public synchronized StringBuffer delete(int start, int end) { if (start < 0) throw new StringIndexOutOfBoundsException(start); if (end > count) end = count; if (start > end) throw new StringIndexOutOfBoundsException(); int len = end - start; if (len > 0) { if (shared) copy(); 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 1.2 */ public synchronized StringBuffer deleteCharAt(int index) { if ((index < 0) || (index >= count)) throw new StringIndexOutOfBoundsException(); if (shared) copy(); System.arraycopy(value, index+1, value, index, count-index-1); count--; return this; } /** * Replaces the characters in a substring of this <code>StringBuffer</code> * with characters in the specified <code>String</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. First the * characters in the substring are removed and then the specified * <code>String</code> is inserted at <code>start</code>. (The * <code>StringBuffer</code> will be lengthened to accommodate the * specified String if necessary.) * * @param start The beginning index, inclusive. * @param end The ending index, exclusive. * @param str String that will replace previous contents. * @return This string buffer. * @exception StringIndexOutOfBoundsException if <code>start</code> * is negative, greater than <code>length()</code>, or * greater than <code>end</code>. * @since 1.2 */ public synchronized StringBuffer replace(int start, int end, String str) { if (start < 0) throw new StringIndexOutOfBoundsException(start); if (end > count) end = count; if (start > end) throw new StringIndexOutOfBoundsException(); int len = str.length(); int newCount = count + len - (end - start); if (newCount > value.length) expandCapacity(newCount); else if (shared) copy(); System.arraycopy(value, end, value, start + len, count - end); str.getChars(0, len, value, start); count = newCount; return this; } /** * Returns a new <code>String</code> that contains a subsequence of * characters currently contained in this <code>StringBuffer</code>.The * substring begins at the specified index and extends to the end of the * <code>StringBuffer</code>. * * @param start The beginning index, inclusive. * @return The new string. * @exception StringIndexOutOfBoundsException if <code>start</code> is * less than zero, or greater than the length of this * <code>StringBuffer</code>. * @since 1.2 */ public synchronized String substring(int start) { return substring(start, count); } /** * Returns a new character sequence that is a subsequence of this sequence. * * <p> An invocation of this method of the form * * <blockquote><pre> * sb.subSequence(begin, end)</pre></blockquote> * * behaves in exactly the same way as the invocation * * <blockquote><pre> * sb.substring(begin, end)</pre></blockquote> * * This method is provided so that the <tt>StringBuffer</tt> class can * implement the {@link CharSequence} interface. </p> * * @param start the start index, inclusive. * @param end the end index, exclusive. * @return the specified subsequence. * * @throws IndexOutOfBoundsException * if <tt>start</tt> or <tt>end</tt> are negative, * if <tt>end</tt> is greater than <tt>length()</tt>, * or if <tt>start</tt> is greater than <tt>end</tt> * * @since 1.4 */ public CharSequence subSequence(int start, int end) { return this.substring(start, end); } /** * Returns a new <code>String</code> that contains a subsequence of * characters currently contained in this <code>StringBuffer</code>. The * substring begins at the specified <code>start</code> and * extends to the character at index <code>end - 1</code>. An * exception is thrown if * * @param start The beginning index, inclusive. * @param end The ending index, exclusive. * @return The new string. * @exception StringIndexOutOfBoundsException if <code>start</code> * or <code>end</code> are negative or greater than * <code>length()</code>, or <code>start</code> is * greater than <code>end</code>. * @since 1.2 */ public synchronized String substring(int start, int end) { if (start < 0) throw new StringIndexOutOfBoundsException(start); if (end > count) throw new StringIndexOutOfBoundsException(end); if (start > end) throw new StringIndexOutOfBoundsException(end - start); return new String(value, start, end - start); } /** * Inserts the string representation of a subarray of the <code>str</code> * array argument into this string buffer. The subarray begins at the * specified <code>offset</code> and extends <code>len</code> characters. * The characters of the subarray are inserted into this string buffer at * the position indicated by <code>index</code>. The length of this * <code>StringBuffer</code> increases by <code>len</code> characters. * * @param index position at which to insert subarray. * @param str A character array. * @param offset the index of the first character in subarray to * to be inserted. * @param len the number of characters in the subarray to * to be inserted. * @return This string buffer. * @exception StringIndexOutOfBoundsException if <code>index</code> * is negative or greater than <code>length()</code>, or * <code>offset</code> or <code>len</code> are negative, or * <code>(offset+len)</code> is greater than * <code>str.length</code>. * @since 1.2 */ public synchronized StringBuffer insert(int index, char str[], int offset, int len) { if ((index < 0) || (index > count)) throw new StringIndexOutOfBoundsException(); if ((offset < 0) || (offset + len < 0) || (offset + len > str.length)) throw new StringIndexOutOfBoundsException(offset); if (len < 0) throw new StringIndexOutOfBoundsException(len); int newCount = count + len; if (newCount > value.length) expandCapacity(newCount); else if (shared) copy(); System.arraycopy(value, index, value, index + len, count - index); System.arraycopy(str, offset, value, index, len); count = newCount; 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(); 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(); System.arraycopy(value, offset, value, offset + len, count - offset); 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(); 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() */ 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() */ public StringBuffer insert(int offset, double d) { return insert(offset, String.valueOf(d)); } /** * Returns the index within this string of the first occurrence of the * specified substring. The integer returned is the smallest value * <i>k</i> such that: * <blockquote><pre> * this.toString().startsWith(str, <i>k</i>) * </pre></blockquote> * is <code>true</code>. * * @param str any string. * @return if the string argument occurs as a substring within this * object, then the index of the first character of the first * such substring is returned; if it does not occur as a * substring, <code>-1</code> is returned. * @exception java.lang.NullPointerException if <code>str</code> is * <code>null</code>. * @since 1.4 */ // public int indexOf(String str) { // return indexOf(str, 0); // } /** * Returns the index within this string of the first occurrence of the * specified substring, starting at the specified index. The integer * returned is the smallest value <tt>k</tt> for which: * <blockquote><pre> * k >= Math.min(fromIndex, str.length()) && * this.toString().startsWith(str, k) * </pre></blockquote> * If no such value of <i>k</i> exists, then -1 is returned. * * @param str the substring for which to search. * @param fromIndex the index from which to start the search. * @return the index within this string of the first occurrence of the * specified substring, starting at the specified index. * @exception java.lang.NullPointerException if <code>str</code> is * <code>null</code>. * @since 1.4 */ // public synchronized int indexOf(String str, int fromIndex) { // return String.indexOf(value, 0, count, // str.toCharArray(), 0, str.length(), fromIndex); // } // /** * Returns the index within this string of the rightmost occurrence * of the specified substring. The rightmost empty string "" is * considered to occur at the index value <code>this.length()</code>. * The returned index is the largest value <i>k</i> such that * <blockquote><pre> * this.toString().startsWith(str, k) * </pre></blockquote> * is true. * * @param str the substring to search for. * @return if the string argument occurs one or more times as a substring * within this object, then the index of the first character of * the last such substring is returned. If it does not occur as * a substring, <code>-1</code> is returned. * @exception java.lang.NullPointerException if <code>str</code> is * <code>null</code>. * @since 1.4 */ // public synchronized int lastIndexOf(String str) { // return lastIndexOf(str, count); // } /** * Returns the index within this string of the last occurrence of the * specified substring. The integer returned is the largest value <i>k</i> * such that: * <blockquote><pre> * k <= Math.min(fromIndex, str.length()) && * this.toString().startsWith(str, k) * </pre></blockquote> * If no such value of <i>k</i> exists, then -1 is returned. * * @param str the substring to search for. * @param fromIndex the index to start the search from. * @return the index within this string of the last occurrence of the * specified substring. * @exception java.lang.NullPointerException if <code>str</code> is * <code>null</code>. * @since 1.4 */ // public synchronized int lastIndexOf(String str, int fromIndex) { // return String.lastIndexOf(value, 0, count, // str.toCharArray(), 0, str.length(), fromIndex); // } /** * 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(value); } // // 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; } /** * readObject is called to restore the state of the StringBuffer from * a stream. */ private synchronized void readObject(java.io.ObjectInputStream s) throws java.io.IOException, ClassNotFoundException { s.defaultReadObject(); value = (char[]) value.clone(); shared = false; } public static void main(String[] args) { StringBuffer sb1 = new StringBuffer(); StringBuffer sb2 = new StringBuffer(); for(int i=0;i<1;i++){ (new MyThread1(sb1,sb2)).start(); } int bound = Cute.input.Integer(); Cute.Assume(bound<=3); for(int i=0;i<bound;i++){ (new MyThread2(sb1)).start(); } bound = Cute.input.Integer(); Cute.Assume(bound<=3); for(int i=0;i<bound;i++){ (new MyThread2(sb2)).start(); } } } class MyThread1 extends Thread{ StringBuffer sb1; StringBuffer sb2; public MyThread1(StringBuffer sb1, StringBuffer sb2) { this.sb1 = sb1; this.sb2 = sb2; } public void run() { //System.out.println("t1 sb1 = " + sb1); //System.out.println("t1 sb2 = " + sb2); //System.out.flush(); sb1.append(sb2); } } class MyThread2 extends Thread{ StringBuffer sb; public MyThread2(StringBuffer sb) { this.sb = sb; } public void run() { //System.out.println("t2 sb = " + sb); //System.out.flush(); int toss = Cute.input.Integer(); //System.out.println("toss = " + toss); if(toss==0){ char c = Cute.input.Character(); sb.append(c); } else if(toss==1){ sb.setLength(0); } else if(toss==2){ char c2 = Cute.input.Character(); int index = Cute.input.Integer(); synchronized(sb){ Cute.Assume(index>=0 && index <= sb.length()-1); sb.insert(index,c2); } } } } //@The following comments are auto-generated to save options for testing the current file //@jcute.optionPrintOutput=true //@jcute.optionLogPath=false //@jcute.optionLogTraceAndInput=false //@jcute.optionGenerateJUnit=false //@jcute.optionExtraOptions= //@jcute.optionJUnitOutputFolderName=D:\sync\work\cute\java //@jcute.optionJUnitPkgName= //@jcute.optionNumberOfPaths=380 //@jcute.optionLogLevel=2 //@jcute.optionDepthForDFS=0 //@jcute.optionSearchStrategy=0 //@jcute.optionSequential=false //@jcute.optionQuickSearchThreshold=100 //@jcute.optionLogRace=true //@jcute.optionLogDeadlock=true //@jcute.optionLogException=true //@jcute.optionLogAssertion=true //@jcute.optionUseRandomInputs=false