StringBuffer, but with no guarantee of synchronization.
- * This class is designed for use as a drop-in replacement for
- * StringBuffer in places where the string buffer was being
- * used by a single thread (as is generally the case). Where possible,
- * it is recommended that this class be used in preference to
- * StringBuffer as it will be faster under most implementations.
- *
- * The principal operations on a StringBuilder are the
- * append and insert 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 builder. The
- * append method always adds these characters at the end
- * of the builder; the insert method adds the characters at
- * a specified point.
- *
- * For example, if z refers to a string builder object
- * whose current contents are "start", then
- * the method call z.append("le") would cause the string
- * builder to contain "startle", whereas
- * z.insert(4, "le") would alter the string builder to
- * contain "starlet".
- *
- * In general, if sb refers to an instance of a StringBuilder,
- * then sb.append(x) has the same effect as
- * sb.insert(sb.length(), x).
- *
- * Every string builder has a capacity. As long as the length of the
- * character sequence contained in the string builder does not exceed
- * the capacity, it is not necessary to allocate a new internal
- * buffer. If the internal buffer overflows, it is automatically made larger.
- *
- *
Instances of StringBuilder are not safe for
- * use by multiple threads. If such synchronization is required then it is
- * recommended that {@link java.lang.StringBuffer} be used.
- *
- * @author Michael McCloskey
- * @see java.lang.StringBuffer
- * @see java.lang.String
- * @since 1.5
- */
-public final class StringBuilder
- extends AbstractStringBuilder
- implements java.io.Serializable, CharSequence
-{
-
- /** use serialVersionUID for interoperability */
- static final long serialVersionUID = 4383685877147921099L;
-
- /**
- * Constructs a string builder with no characters in it and an
- * initial capacity of 16 characters.
- */
- public StringBuilder() {
- super(16);
- }
-
- /**
- * Constructs a string builder with no characters in it and an
- * initial capacity specified by the capacity argument.
- *
- * @param capacity the initial capacity.
- * @throws NegativeArraySizeException if the capacity
- * argument is less than 0.
- */
- public StringBuilder(int capacity) {
- super(capacity);
- }
-
- /**
- * Constructs a string builder initialized to the contents of the
- * specified string. The initial capacity of the string builder is
- * 16 plus the length of the string argument.
- *
- * @param str the initial contents of the buffer.
- * @throws NullPointerException if str is null
- */
- public StringBuilder(String str) {
- super(str.length() + 16);
- append(str);
- }
-
- /**
- * Constructs a string builder that contains the same characters
- * as the specified CharSequence. The initial capacity of
- * the string builder is 16 plus the length of the
- * CharSequence argument.
- *
- * @param seq the sequence to copy.
- * @throws NullPointerException if seq is null
- */
- public StringBuilder(CharSequence seq) {
- this(seq.length() + 16);
- append(seq);
- }
-
- public StringBuilder append(Object obj) {
- return append(String.valueOf(obj));
- }
-
- public StringBuilder append(String str) {
- super.append(str);
- return this;
- }
-
- // Appends the specified string builder to this sequence.
- private StringBuilder append(StringBuilder sb) {
- if (sb == null)
- return append("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;
- }
-
- /**
- * Appends the specified StringBuffer to this sequence.
- *
- * The characters of the StringBuffer argument are appended, - * in order, to this sequence, increasing the - * length of this sequence by the length of the argument. - * If sb is null, then the four characters - * "null" are appended to this sequence. - *
- * Let n be the length of this character sequence just prior to
- * execution of the append method. Then the character at index
- * k in the new character sequence is equal to the character at
- * index k in the old character sequence, if k is less than
- * n; otherwise, it is equal to the character at index k-n
- * in the argument sb.
- *
- * @param sb the StringBuffer to append.
- * @return a reference to this object.
- */
- public StringBuilder append(StringBuffer sb) {
- super.append(sb);
- return this;
- }
-
- /**
- */
- public StringBuilder append(CharSequence s) {
- if (s == null)
- s = "null";
- if (s instanceof String)
- return this.append((String)s);
- if (s instanceof StringBuffer)
- return this.append((StringBuffer)s);
- if (s instanceof StringBuilder)
- return this.append((StringBuilder)s);
- return this.append(s, 0, s.length());
- }
-
- /**
- * @throws IndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder append(CharSequence s, int start, int end) {
- super.append(s, start, end);
- return this;
- }
-
- public StringBuilder append(char[] str) {
- super.append(str);
- return this;
- }
-
- /**
- * @throws IndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder append(char[] str, int offset, int len) {
- super.append(str, offset, len);
- return this;
- }
-
- public StringBuilder append(boolean b) {
- super.append(b);
- return this;
- }
-
- public StringBuilder append(char c) {
- super.append(c);
- return this;
- }
-
- public StringBuilder append(int i) {
- super.append(i);
- return this;
- }
-
- public StringBuilder append(long lng) {
- super.append(lng);
- return this;
- }
-
- public StringBuilder append(float f) {
- super.append(f);
- return this;
- }
-
- public StringBuilder append(double d) {
- super.append(d);
- return this;
- }
-
- /**
- * @since 1.5
- */
- public StringBuilder appendCodePoint(int codePoint) {
- super.appendCodePoint(codePoint);
- return this;
- }
-
- /**
- * @throws StringIndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder delete(int start, int end) {
- super.delete(start, end);
- return this;
- }
-
- /**
- * @throws StringIndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder deleteCharAt(int index) {
- super.deleteCharAt(index);
- return this;
- }
-
- /**
- * @throws StringIndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder replace(int start, int end, String str) {
- super.replace(start, end, str);
- return this;
- }
-
- /**
- * @throws StringIndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder insert(int index, char[] str, int offset,
- int len)
- {
- super.insert(index, str, offset, len);
- return this;
- }
-
- /**
- * @throws StringIndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder insert(int offset, Object obj) {
- return insert(offset, String.valueOf(obj));
- }
-
- /**
- * @throws StringIndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder insert(int offset, String str) {
- super.insert(offset, str);
- return this;
- }
-
- /**
- * @throws StringIndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder insert(int offset, char[] str) {
- super.insert(offset, str);
- return this;
- }
-
- /**
- * @throws IndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder insert(int dstOffset, CharSequence s) {
- if (s == null)
- s = "null";
- if (s instanceof String)
- return this.insert(dstOffset, (String)s);
- return this.insert(dstOffset, s, 0, s.length());
- }
-
- /**
- * @throws IndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder insert(int dstOffset, CharSequence s,
- int start, int end)
- {
- super.insert(dstOffset, s, start, end);
- return this;
- }
-
- /**
- * @throws StringIndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder insert(int offset, boolean b) {
- super.insert(offset, b);
- return this;
- }
-
- /**
- * @throws IndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder insert(int offset, char c) {
- super.insert(offset, c);
- return this;
- }
-
- /**
- * @throws StringIndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder insert(int offset, int i) {
- return insert(offset, String.valueOf(i));
- }
-
- /**
- * @throws StringIndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder insert(int offset, long l) {
- return insert(offset, String.valueOf(l));
- }
-
- /**
- * @throws StringIndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder insert(int offset, float f) {
- return insert(offset, String.valueOf(f));
- }
-
- /**
- * @throws StringIndexOutOfBoundsException {@inheritDoc}
- */
- public StringBuilder insert(int offset, double d) {
- return insert(offset, String.valueOf(d));
- }
-
- /**
- * @throws NullPointerException {@inheritDoc}
- */
- public int indexOf(String str) {
- return indexOf(str, 0);
- }
-
- /**
- * @throws NullPointerException {@inheritDoc}
- */
- public int indexOf(String str, int fromIndex) {
- return super.indexOf(str, fromIndex);
- }
-
- /**
- * @throws NullPointerException {@inheritDoc}
- */
- public int lastIndexOf(String str) {
- return lastIndexOf(str, count);
- }
-
- /**
- * @throws NullPointerException {@inheritDoc}
- */
- public int lastIndexOf(String str, int fromIndex) {
- return String.lastIndexOf(value, 0, count,
- str.toCharArray(), 0, str.length(), fromIndex);
- }
-
- public StringBuilder reverse() {
- super.reverse();
- return this;
- }
-
- public String toString() {
- // Create a copy, don't share the array
- return new String(value, 0, count);
- }
-
- /**
- * Save the state of the StringBuilder instance to a stream
- * (that is, serialize it).
- *
- * @serialData the number of characters currently stored in the string
- * builder (int), followed by the characters in the
- * string builder (char[]). The length of the
- * char array may be greater than the number of
- * characters currently stored in the string builder, in which
- * case extra characters are ignored.
- */
-// private void writeObject(java.io.ObjectOutputStream s)
-// throws java.io.IOException {
-// s.defaultWriteObject();
-// s.writeInt(count);
-// s.writeObject(value);
-// }
-
- /**
- * readObject is called to restore the state of the StringBuffer from
- * a stream.
- */
-// private void readObject(java.io.ObjectInputStream s)
-// throws java.io.IOException, ClassNotFoundException {
-// s.defaultReadObject();
-// count = s.readInt();
-// value = (char[]) s.readObject();
-// }
-
-}