/*
* Copyright (c) 1994, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 in the LICENSE file that
* accompanied this code).
*
* 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package java.lang;
/**
* A thread-safe, 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>
* The principal operations on a {@code StringBuffer} are the
* {@code append} and {@code 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 buffer. The
* {@code append} method always adds these characters at the end
* of the buffer; the {@code insert} method adds the characters at
* a specified point.
* <p>
* For example, if {@code z} refers to a string buffer object
* whose current contents are {@code "start"}, then
* the method call {@code z.append("le")} would cause the string
* buffer to contain {@code "startle"}, whereas
* {@code z.insert(4, "le")} would alter the string buffer to
* contain {@code "starlet"}.
* <p>
* In general, if sb refers to an instance of a {@code StringBuffer},
* then {@code sb.append(x)} has the same effect as
* {@code sb.insert(sb.length(), x)}.
* <p>
* Whenever an operation occurs involving a source sequence (such as
* appending or inserting from a source sequence), this class synchronizes
* only on the string buffer performing the operation, not on the source.
* Note that while {@code StringBuffer} is designed to be safe to use
* concurrently from multiple threads, if the constructor or the
* {@code append} or {@code insert} operation is passed a source sequence
* that is shared across threads, the calling code must ensure
* that the operation has a consistent and unchanging view of the source
* sequence for the duration of the operation.
* This could be satisfied by the caller holding a lock during the
* operation's call, by using an immutable source sequence, or by not
* sharing the source sequence across threads.
* <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.
* <p>
* Unless otherwise noted, passing a {@code null} argument to a constructor
* or method in this class will cause a {@link NullPointerException} to be
* thrown.
* <p>
* As of release JDK 5, this class has been supplemented with an equivalent
* class designed for use by a single thread, {@link StringBuilder}. The
* {@code StringBuilder} class should generally be used in preference to
* this one, as it supports all of the same operations but it is faster, as
* it performs no synchronization.
*
* @author Arthur van Hoff
* @see java.lang.StringBuilder
* @see java.lang.String
* @since JDK1.0
*/
public final class StringBuffer
extends AbstractStringBuilder
implements java.io.Serializable, CharSequence
{
/** 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() {
super(16);
}
/**
* Constructs a string buffer with no characters in it and
* the specified initial capacity.
*
* @param capacity the initial capacity.
* @exception NegativeArraySizeException if the {@code capacity}
* argument is less than {@code 0}.
*/
public StringBuffer(int capacity) {
super(capacity);
}
/**
* Constructs a string buffer initialized to the contents of the
* specified string. The initial capacity of the string buffer is
* {@code 16} plus the length of the string argument.
*
* @param str the initial contents of the buffer.
*/
public StringBuffer(String str) {
super(str.length() + 16);
append(str);
}
/**
* Constructs a string buffer that contains the same characters
* as the specified {@code CharSequence}. The initial capacity of
* the string buffer is {@code 16} plus the length of the
* {@code CharSequence} argument.
* <p>
* If the length of the specified {@code CharSequence} is
* less than or equal to zero, then an empty buffer of capacity
* {@code 16} is returned.
*
* @param seq the sequence to copy.
* @since 1.5
*/
public StringBuffer(CharSequence seq) {
this(seq.length() + 16);
append(seq);
}
@Override
public synchronized native int length() /*-[
return self->delegate_.count_;
]-*/;
@Override
public synchronized native int capacity() /*-[
return self->delegate_.bufferSize_;
]-*/;
@Override
public synchronized void ensureCapacity(int minimumCapacity) {
super.ensureCapacity(minimumCapacity);
}
/**
* @since 1.5
*/
@Override
public synchronized void trimToSize() {
super.trimToSize();
}
/**
* @throws IndexOutOfBoundsException {@inheritDoc}
* @see #length()
*/
@Override
public synchronized void setLength(int newLength) {
super.setLength(newLength);
}
/**
* @throws IndexOutOfBoundsException {@inheritDoc}
* @see #length()
*/
@Override
public synchronized char charAt(int index) {
return super.charAt(index);
}
/**
* @since 1.5
*/
@Override
public synchronized int codePointAt(int index) {
return super.codePointAt(index);
}
/**
* @since 1.5
*/
@Override
public synchronized int codePointBefore(int index) {
return super.codePointBefore(index);
}
/**
* @since 1.5
*/
@Override
public synchronized int codePointCount(int beginIndex, int endIndex) {
return super.codePointCount(beginIndex, endIndex);
}
/**
* @since 1.5
*/
@Override
public synchronized int offsetByCodePoints(int index, int codePointOffset) {
return super.offsetByCodePoints(index, codePointOffset);
}
/**
* @throws IndexOutOfBoundsException {@inheritDoc}
*/
@Override
public synchronized void getChars(int srcBegin, int srcEnd, char[] dst,
int dstBegin)
{
super.getChars(srcBegin, srcEnd, dst, dstBegin);
}
/**
* @throws IndexOutOfBoundsException {@inheritDoc}
* @see #length()
*/
@Override
public synchronized void setCharAt(int index, char ch) {
super.setCharAt(index, ch);
}
public StringBuffer append(Object obj) {
return append(String.valueOf(obj));
}
public synchronized native StringBuffer append(String str) /*-[
JreStringBuilder_appendString(&self->delegate_, str);
return self;
]-*/;
/**
* Appends the specified {@code StringBuffer} to this sequence.
* <p>
* The characters of the {@code StringBuffer} argument are appended,
* in order, to the contents of this {@code StringBuffer}, increasing the
* length of this {@code StringBuffer} by the length of the argument.
* If {@code sb} is {@code null}, then the four characters
* {@code "null"} are appended to this {@code StringBuffer}.
* <p>
* Let <i>n</i> be the length of the old character sequence, the one
* contained in the {@code StringBuffer} just prior to execution of the
* {@code append} 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}.
* <p>
* This method synchronizes on {@code this}, the destination
* object, but does not synchronize on the source ({@code sb}).
*
* @param sb the {@code StringBuffer} to append.
* @return a reference to this object.
* @since 1.4
*/
public synchronized native StringBuffer append(StringBuffer sb) /*-[
JreStringBuilder_appendStringBuffer(&self->delegate_, sb);
return self;
]-*/;
/**
* @since 1.8
* J2ObjC - Unused.
synchronized StringBuffer append(AbstractStringBuilder asb) {
super.append(asb);
return this;
}*/
/**
* Appends the specified {@code CharSequence} to this
* sequence.
* <p>
* The characters of the {@code CharSequence} argument are appended,
* in order, increasing the length of this sequence by the length of the
* argument.
*
* <p>The result of this method is exactly the same as if it were an
* invocation of this.append(s, 0, s.length());
*
* <p>This method synchronizes on {@code this}, the destination
* object, but does not synchronize on the source ({@code s}).
*
* <p>If {@code s} is {@code null}, then the four characters
* {@code "null"} are appended.
*
* @param s the {@code CharSequence} to append.
* @return a reference to this object.
* @since 1.5
*/
@Override
public synchronized native StringBuffer append(CharSequence s) /*-[
JreStringBuilder_appendCharSequence(&self->delegate_, s);
return self;
]-*/;
/**
* @throws IndexOutOfBoundsException {@inheritDoc}
* @since 1.5
*/
@Override
public synchronized native StringBuffer append(CharSequence s, int start, int end) /*-[
JreStringBuilder_appendCharSequenceSubset(&self->delegate_, s, start, end);
return self;
]-*/;
public synchronized native StringBuffer append(char[] str) /*-[
JreStringBuilder_appendCharArray(&self->delegate_, str);
return self;
]-*/;
/**
* @throws IndexOutOfBoundsException {@inheritDoc}
*/
public synchronized native StringBuffer append(char[] str, int offset, int len) /*-[
JreStringBuilder_appendCharArraySubset(&self->delegate_, str, offset, len);
return self;
]-*/;
public StringBuffer append(boolean b) {
return append(Boolean.toString(b));
}
@Override
public synchronized native StringBuffer append(char c) /*-[
JreStringBuilder_appendChar(&self->delegate_, c);
return self;
]-*/;
public synchronized native StringBuffer append(int i) /*-[
JreStringBuilder_appendInt(&self->delegate_, i);
return self;
]-*/;
/**
* @since 1.5
*/
public StringBuffer appendCodePoint(int codePoint) {
return append(Character.toChars(codePoint));
}
public synchronized native StringBuffer append(long lng) /*-[
JreStringBuilder_appendLong(&self->delegate_, lng);
return self;
]-*/;
public synchronized native StringBuffer append(float f) /*-[
JreStringBuilder_appendFloat(&self->delegate_, f);
return self;
]-*/;
public synchronized native StringBuffer append(double d) /*-[
JreStringBuilder_appendDouble(&self->delegate_, d);
return self;
]-*/;
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
* @since 1.2
*/
public synchronized native StringBuffer delete(int start, int end) /*-[
JreStringBuilder_delete(&self->delegate_, start, end);
return self;
]-*/;
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
* @since 1.2
*/
public synchronized native StringBuffer deleteCharAt(int index) /*-[
JreStringBuilder_deleteCharAt(&self->delegate_, index);
return self;
]-*/;
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
* @since 1.2
*/
public synchronized native StringBuffer replace(int start, int end, String str) /*-[
JreStringBuilder_replace(&self->delegate_, start, end, str);
return self;
]-*/;
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
* @since 1.2
*/
@Override
public synchronized String substring(int start) {
return super.substring(start);
}
/**
* @throws IndexOutOfBoundsException {@inheritDoc}
* @since 1.4
*/
@Override
public synchronized CharSequence subSequence(int start, int end) {
return super.substring(start, end);
}
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
* @since 1.2
*/
@Override
public synchronized String substring(int start, int end) {
return super.substring(start, end);
}
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
* @since 1.2
*/
public synchronized native StringBuffer insert(int index, char[] str, int offset, int len) /*-[
JreStringBuilder_insertCharArraySubset(&self->delegate_, index, str, offset, len);
return self;
]-*/;
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
*/
public StringBuffer insert(int offset, Object obj) {
return insert(offset, String.valueOf(obj));
}
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
*/
public synchronized native StringBuffer insert(int offset, String str) /*-[
JreStringBuilder_insertString(&self->delegate_, offset, str);
return self;
]-*/;
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
*/
public synchronized native StringBuffer insert(int offset, char[] str) /*-[
JreStringBuilder_insertCharArray(&self->delegate_, offset, str);
return self;
]-*/;
/**
* @throws IndexOutOfBoundsException {@inheritDoc}
* @since 1.5
*/
public StringBuffer insert(int dstOffset, CharSequence s) {
return insert(dstOffset, String.valueOf(s));
}
/**
* @throws IndexOutOfBoundsException {@inheritDoc}
* @since 1.5
*/
public synchronized native StringBuffer insert(int dstOffset, CharSequence s,
int start, int end) /*-[
JreStringBuilder_insertCharSequence(&self->delegate_, dstOffset, s, start, end);
return self;
]-*/;
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
*/
public StringBuffer insert(int offset, boolean b) {
return insert(offset, Boolean.toString(b));
}
/**
* @throws IndexOutOfBoundsException {@inheritDoc}
*/
public synchronized native StringBuffer insert(int offset, char c) /*-[
JreStringBuilder_insertChar(&self->delegate_, offset, c);
return self;
]-*/;
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
*/
public StringBuffer insert(int offset, int i) {
return insert(offset, Integer.toString(i));
}
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
*/
public StringBuffer insert(int offset, long l) {
return insert(offset, Long.toString(l));
}
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
*/
public StringBuffer insert(int offset, float f) {
return insert(offset, Float.toString(f));
}
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
*/
public StringBuffer insert(int offset, double d) {
return insert(offset, Double.toString(d));
}
/**
* @since 1.4
*/
@Override
public int indexOf(String str) {
// Note, synchronization achieved via invocations of other StringBuffer methods
return super.indexOf(str);
}
/**
* @since 1.4
*/
@Override
public synchronized int indexOf(String str, int fromIndex) {
return super.indexOf(str, fromIndex);
}
/**
* @since 1.4
* J2ObjC - Provided by superclass. Synchronization achieved via call into
* lastIndexOf(String,int).
@Override
public int lastIndexOf(String str) {
// Note, synchronization achieved via invocations of other StringBuffer methods
return lastIndexOf(str, count);
}*/
/**
* @since 1.4
*/
@Override
public synchronized int lastIndexOf(String str, int fromIndex) {
return super.lastIndexOf(str, fromIndex);
}
/**
* @since JDK1.0.2
*/
public synchronized native StringBuffer reverse() /*-[
JreStringBuilder_reverse(&self->delegate_);
return self;
]-*/;
@Override
public synchronized native String toString() /*-[
return JreStringBuilder_toString(&self->delegate_);
]-*/;
/**
* Serializable fields for StringBuffer.
*
* @serialField value char[]
* The backing character array of this StringBuffer.
* @serialField count int
* The number of characters in this StringBuffer.
* @serialField shared boolean
* A flag indicating whether the backing array is shared.
* The value is ignored upon deserialization.
*/
private static final java.io.ObjectStreamField[] serialPersistentFields =
{
new java.io.ObjectStreamField("value", char[].class),
new java.io.ObjectStreamField("count", Integer.TYPE),
new java.io.ObjectStreamField("shared", Boolean.TYPE),
};
/**
* readObject is called to restore the state of the StringBuffer from
* a stream.
*/
private synchronized void writeObject(java.io.ObjectOutputStream s)
throws java.io.IOException {
java.io.ObjectOutputStream.PutField fields = s.putFields();
fields.put("value", getValue());
fields.put("count", length());
fields.put("shared", false);
s.writeFields();
}
/**
* 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 {
java.io.ObjectInputStream.GetField fields = s.readFields();
char[] value = (char[])fields.get("value", null);
int count = fields.get("count", 0);
append(value, 0, count);
}
}