/*
* Copyright (c) 1996, 2016, 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
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.io;
/**
* A character stream that collects its output in a string buffer, which can
* then be used to construct a string.
* <p>
* Closing a {@code StringWriter} has no effect. The methods in this class
* can be called after the stream has been closed without generating an
* {@code IOException}.
*
* @author Mark Reinhold
* @since 1.1
*/
public class StringWriter extends Writer {
private StringBuffer buf;
/**
* Create a new string writer using the default initial string-buffer
* size.
*/
public StringWriter() {
buf = new StringBuffer();
lock = buf;
}
/**
* Create a new string writer using the specified initial string-buffer
* size.
*
* @param initialSize
* The number of {@code char} values that will fit into this buffer
* before it is automatically expanded
*
* @throws IllegalArgumentException
* If {@code initialSize} is negative
*/
public StringWriter(int initialSize) {
if (initialSize < 0) {
throw new IllegalArgumentException("Negative buffer size");
}
buf = new StringBuffer(initialSize);
lock = buf;
}
/**
* Write a single character.
*/
public void write(int c) {
buf.append((char) c);
}
/**
* Write a portion of an array of characters.
*
* @param cbuf Array of characters
* @param off Offset from which to start writing characters
* @param len Number of characters to write
*
* @throws IndexOutOfBoundsException
* If {@code off} is negative, or {@code len} is negative,
* or {@code off + len} is negative or greater than the length
* of the given array
*/
public void write(char cbuf[], int off, int len) {
if ((off < 0) || (off > cbuf.length) || (len < 0) ||
((off + len) > cbuf.length) || ((off + len) < 0)) {
throw new IndexOutOfBoundsException();
} else if (len == 0) {
return;
}
buf.append(cbuf, off, len);
}
/**
* Write a string.
*/
public void write(String str) {
buf.append(str);
}
/**
* Write a portion of a string.
*
* @param str String to be written
* @param off Offset from which to start writing characters
* @param len Number of characters to write
*
* @throws IndexOutOfBoundsException
* If {@code off} is negative, or {@code len} is negative,
* or {@code off + len} is negative or greater than the length
* of the given string
*/
public void write(String str, int off, int len) {
buf.append(str, off, off + len);
}
/**
* Appends the specified character sequence to this writer.
*
* <p> An invocation of this method of the form {@code out.append(csq)}
* behaves in exactly the same way as the invocation
*
* <pre>
* out.write(csq.toString()) </pre>
*
* <p> Depending on the specification of {@code toString} for the
* character sequence {@code csq}, the entire sequence may not be
* appended. For instance, invoking the {@code toString} method of a
* character buffer will return a subsequence whose content depends upon
* the buffer's position and limit.
*
* @param csq
* The character sequence to append. If {@code csq} is
* {@code null}, then the four characters {@code "null"} are
* appended to this writer.
*
* @return This writer
*
* @since 1.5
*/
public StringWriter append(CharSequence csq) {
write(String.valueOf(csq));
return this;
}
/**
* Appends a subsequence of the specified character sequence to this writer.
*
* <p> An invocation of this method of the form
* {@code out.append(csq, start, end)} when {@code csq}
* is not {@code null}, behaves in
* exactly the same way as the invocation
*
* <pre>{@code
* out.write(csq.subSequence(start, end).toString())
* }</pre>
*
* @param csq
* The character sequence from which a subsequence will be
* appended. If {@code csq} is {@code null}, then characters
* will be appended as if {@code csq} contained the four
* characters {@code "null"}.
*
* @param start
* The index of the first character in the subsequence
*
* @param end
* The index of the character following the last character in the
* subsequence
*
* @return This writer
*
* @throws IndexOutOfBoundsException
* If {@code start} or {@code end} are negative, {@code start}
* is greater than {@code end}, or {@code end} is greater than
* {@code csq.length()}
*
* @since 1.5
*/
public StringWriter append(CharSequence csq, int start, int end) {
if (csq == null) csq = "null";
return append(csq.subSequence(start, end));
}
/**
* Appends the specified character to this writer.
*
* <p> An invocation of this method of the form {@code out.append(c)}
* behaves in exactly the same way as the invocation
*
* <pre>
* out.write(c) </pre>
*
* @param c
* The 16-bit character to append
*
* @return This writer
*
* @since 1.5
*/
public StringWriter append(char c) {
write(c);
return this;
}
/**
* Return the buffer's current value as a string.
*/
public String toString() {
return buf.toString();
}
/**
* Return the string buffer itself.
*
* @return StringBuffer holding the current buffer value.
*/
public StringBuffer getBuffer() {
return buf;
}
/**
* Flush the stream.
*/
public void flush() {
}
/**
* Closing a {@code StringWriter} has no effect. The methods in this
* class can be called after the stream has been closed without generating
* an {@code IOException}.
*/
public void close() throws IOException {
}
}