libcore/luni/src/main/java/java/io/BufferedWriter.java - platform/dalvik - Git at Google

 /*
  *  Licensed to the Apache Software Foundation (ASF) under one or more
  *  contributor license agreements.  See the NOTICE file distributed with
  *  this work for additional information regarding copyright ownership.
  *  The ASF licenses this file to You under the Apache License, Version 2.0
  *  (the "License"); you may not use this file except in compliance with
  *  the License.  You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  *  Unless required by applicable law or agreed to in writing, software
  *  distributed under the License is distributed on an "AS IS" BASIS,
  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  *  See the License for the specific language governing permissions and
  *  limitations under the License.
  */

 package java.io;

 import java.security.AccessController;

 import org.apache.harmony.luni.util.Msg;
 import org.apache.harmony.luni.util.PriviAction;
 import org.apache.harmony.luni.util.SneakyThrow;

 // BEGIN android-added
 import java.util.logging.Logger;
 // END android-added

 /**
  * Wraps an existing {@link Writer} and <em>buffers</em> the output. Expensive
  * interaction with the underlying reader is minimized, since most (smaller)
  * requests can be satisfied by accessing the buffer alone. The drawback is that
  * some extra space is required to hold the buffer and that copying takes place
  * when filling that buffer, but this is usually outweighed by the performance
  * benefits.
  *
  * <p/>A typical application pattern for the class looks like this:<p/>
  *
  * <pre>
  * BufferedWriter buf = new BufferedWriter(new FileWriter(&quot;file.java&quot;));
  * </pre>
  *
  * @see BufferedReader
  */
 public class BufferedWriter extends Writer {

     private Writer out;

     private char buf[];

     private int pos;

     private final String lineSeparator = AccessController
             .doPrivileged(new PriviAction<String>("line.separator")); //$NON-NLS-1$

     /**
      * Constructs a new {@code BufferedWriter} with {@code out} as the writer
      * for which to buffer write operations. The buffer size is set to the
      * default value of 8 KB.
      *
      * @param out
      *            the writer for which character writing is buffered.
      */
     public BufferedWriter(Writer out) {
         super(out);
         this.out = out;
         buf = new char[8192];

         // BEGIN android-added
         /*
          * For Android, we want to discourage the use of this constructor (with
          * its arguably too-large default), so we note its use in the log. We
          * don't disable it, nor do we alter the default, however, because we
          * still aim to behave compatibly, and the default value, though not
          * documented, is established by convention.
          */
         Logger.global.info(
                 "Default buffer size used in BufferedWriter " +
                 "constructor. It would be " +
                 "better to be explicit if an 8k-char buffer is required.");
         // END android-added
     }

     /**
      * Constructs a new {@code BufferedWriter} with {@code out} as the writer
      * for which to buffer write operations. The buffer size is set to {@code
      * size}.
      *
      * @param out
      *            the writer for which character writing is buffered.
      * @param size
      *            the size of the buffer in bytes.
      * @throws IllegalArgumentException
      *             if {@code size <= 0}.
      */
     public BufferedWriter(Writer out, int size) {
         super(out);
         if (size <= 0) {
             throw new IllegalArgumentException(Msg.getString("K0058")); //$NON-NLS-1$
         }
         this.out = out;
         this.buf = new char[size];
     }

     /**
      * Closes this writer. The contents of the buffer are flushed, the target
      * writer is closed, and the buffer is released. Only the first invocation
      * of close has any effect.
      *
      * @throws IOException
      *             if an error occurs while closing this writer.
      */
     @Override
     public void close() throws IOException {
         synchronized (lock) {
             if (isClosed()) {
                 return;
             }

             Throwable thrown = null;
             try {
                 flushInternal();
             } catch (Throwable e) {
                 thrown = e;
             }
             buf = null;

             try {
                 out.close();
             } catch (Throwable e) {
                 if (thrown == null) {
                     thrown = e;
                 }
             }
             out = null;

             if (thrown != null) {
                 SneakyThrow.sneakyThrow(thrown);
             }
         }
     }

     /**
      * Flushes this writer. The contents of the buffer are committed to the
      * target writer and it is then flushed.
      *
      * @throws IOException
      *             if an error occurs while flushing this writer.
      */
     @Override
     public void flush() throws IOException {
         synchronized (lock) {
             if (isClosed()) {
                 throw new IOException(Msg.getString("K005d")); //$NON-NLS-1$
             }
             flushInternal();
             out.flush();
         }
     }

     /**
      * Flushes the internal buffer.
      */
     private void flushInternal() throws IOException {
         if (pos > 0) {
             out.write(buf, 0, pos);
         }
         pos = 0;
     }

     /**
      * Indicates whether this writer is closed.
      *
      * @return {@code true} if this writer is closed, {@code false} otherwise.
      */
     private boolean isClosed() {
         return out == null;
     }

     /**
      * Writes a newline to this writer. A newline is determined by the System
      * property "line.separator". The target writer may or may not be flushed
      * when a newline is written.
      *
      * @throws IOException
      *             if an error occurs attempting to write to this writer.
      */
     public void newLine() throws IOException {
         write(lineSeparator, 0, lineSeparator.length());
     }

     /**
      * Writes {@code count} characters starting at {@code offset} in
      * {@code cbuf} to this writer. If {@code count} is greater than this
      * writer's buffer, then the buffer is flushed and the characters are
      * written directly to the target writer.
      *
      * @param cbuf
      *            the array containing characters to write.
      * @param offset
      *            the start position in {@code cbuf} for retrieving characters.
      * @param count
      *            the maximum number of characters to write.
      * @throws IndexOutOfBoundsException
      *             if {@code offset < 0} or {@code count < 0}, or if
      *             {@code offset + count} is greater than the size of
      *             {@code cbuf}.
      * @throws IOException
      *             if this writer is closed or another I/O error occurs.
      */
     @Override
     public void write(char[] cbuf, int offset, int count) throws IOException {
         synchronized (lock) {
             if (isClosed()) {
                 throw new IOException(Msg.getString("K005d")); //$NON-NLS-1$
             }
             // BEGIN android-changed
             // Exception priorities (in case of multiple errors) differ from
             // RI, but are spec-compliant.
             // made implicit null check explicit, used (offset | count) < 0
             // instead of (offset < 0) || (count < 0) to safe one operation
             if (cbuf == null) {
                 throw new NullPointerException(Msg.getString("K0047")); //$NON-NLS-1$
             }
             if ((offset | count) < 0 || offset > cbuf.length - count) {
                 throw new IndexOutOfBoundsException(Msg.getString("K002f")); //$NON-NLS-1$
             }
             // END android-changed
             if (pos == 0 && count >= this.buf.length) {
                 out.write(cbuf, offset, count);
                 return;
             }
             int available = this.buf.length - pos;
             if (count < available) {
                 available = count;
             }
             if (available > 0) {
                 System.arraycopy(cbuf, offset, this.buf, pos, available);
                 pos += available;
             }
             if (pos == this.buf.length) {
                 out.write(this.buf, 0, this.buf.length);
                 pos = 0;
                 if (count > available) {
                     offset += available;
                     available = count - available;
                     if (available >= this.buf.length) {
                         out.write(cbuf, offset, available);
                         return;
                     }

                     System.arraycopy(cbuf, offset, this.buf, pos, available);
                     pos += available;
                 }
             }
         }
     }

     /**
      * Writes the character {@code oneChar} to this writer. If the buffer
      * gets full by writing this character, this writer is flushed. Only the
      * lower two bytes of the integer {@code oneChar} are written.
      *
      * @param oneChar
      *            the character to write.
      * @throws IOException
      *             if this writer is closed or another I/O error occurs.
      */
     @Override
     public void write(int oneChar) throws IOException {
         synchronized (lock) {
             if (isClosed()) {
                 throw new IOException(Msg.getString("K005d")); //$NON-NLS-1$
             }
             if (pos >= buf.length) {
                 out.write(buf, 0, buf.length);
                 pos = 0;
             }
             buf[pos++] = (char) oneChar;
         }
     }

     /**
      * Writes {@code count} characters starting at {@code offset} in {@code str}
      * to this writer. If {@code count} is greater than this writer's buffer,
      * then this writer is flushed and the remaining characters are written
      * directly to the target writer. If count is negative no characters are
      * written to the buffer. This differs from the behavior of the superclass.
      *
      * @param str
      *            the non-null String containing characters to write.
      * @param offset
      *            the start position in {@code str} for retrieving characters.
      * @param count
      *            maximum number of characters to write.
      * @throws IOException
      *             if this writer has already been closed or another I/O error
      *             occurs.
      * @throws IndexOutOfBoundsException
      *             if {@code offset < 0} or {@code offset + count} is greater
      *             than the length of {@code str}.
      */
     @Override
     public void write(String str, int offset, int count) throws IOException {
         synchronized (lock) {
             if (isClosed()) {
                 throw new IOException(Msg.getString("K005d")); //$NON-NLS-1$
             }
             if (count <= 0) {
                 return;
             }
             if (offset > str.length() - count || offset < 0) {
                 throw new StringIndexOutOfBoundsException();
             }
             if (pos == 0 && count >= buf.length) {
                 char[] chars = new char[count];
                 str.getChars(offset, offset + count, chars, 0);
                 out.write(chars, 0, count);
                 return;
             }
             int available = buf.length - pos;
             if (count < available) {
                 available = count;
             }
             if (available > 0) {
                 str.getChars(offset, offset + available, buf, pos);
                 pos += available;
             }
             if (pos == buf.length) {
                 out.write(this.buf, 0, this.buf.length);
                 pos = 0;
                 if (count > available) {
                     offset += available;
                     available = count - available;
                     if (available >= buf.length) {
                         char[] chars = new char[count];
                         str.getChars(offset, offset + available, chars, 0);
                         out.write(chars, 0, available);
                         return;
                     }
                     str.getChars(offset, offset + available, buf, pos);
                     pos += available;
                 }
             }
         }
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package java.io;

	import java.security.AccessController;

	import org.apache.harmony.luni.util.Msg;
	import org.apache.harmony.luni.util.PriviAction;
	import org.apache.harmony.luni.util.SneakyThrow;

	// BEGIN android-added
	import java.util.logging.Logger;
	// END android-added

	/**
	* Wraps an existing {@link Writer} and <em>buffers</em> the output. Expensive
	* interaction with the underlying reader is minimized, since most (smaller)
	* requests can be satisfied by accessing the buffer alone. The drawback is that
	* some extra space is required to hold the buffer and that copying takes place
	* when filling that buffer, but this is usually outweighed by the performance
	* benefits.
	*
	* <p/>A typical application pattern for the class looks like this:<p/>
	*
	* <pre>
	* BufferedWriter buf = new BufferedWriter(new FileWriter("file.java"));
	* </pre>
	*
	* @see BufferedReader
	*/
	public class BufferedWriter extends Writer {

	private Writer out;

	private char buf[];

	private int pos;

	private final String lineSeparator = AccessController
	.doPrivileged(new PriviAction<String>("line.separator")); //$NON-NLS-1$

	/**
	* Constructs a new {@code BufferedWriter} with {@code out} as the writer
	* for which to buffer write operations. The buffer size is set to the
	* default value of 8 KB.
	*
	* @param out
	* the writer for which character writing is buffered.
	*/
	public BufferedWriter(Writer out) {
	super(out);
	this.out = out;
	buf = new char[8192];

	// BEGIN android-added
	/*
	* For Android, we want to discourage the use of this constructor (with
	* its arguably too-large default), so we note its use in the log. We
	* don't disable it, nor do we alter the default, however, because we
	* still aim to behave compatibly, and the default value, though not
	* documented, is established by convention.
	*/
	Logger.global.info(
	"Default buffer size used in BufferedWriter " +
	"constructor. It would be " +
	"better to be explicit if an 8k-char buffer is required.");
	// END android-added
	}

	/**
	* Constructs a new {@code BufferedWriter} with {@code out} as the writer
	* for which to buffer write operations. The buffer size is set to {@code
	* size}.
	*
	* @param out
	* the writer for which character writing is buffered.
	* @param size
	* the size of the buffer in bytes.
	* @throws IllegalArgumentException
	* if {@code size <= 0}.
	*/
	public BufferedWriter(Writer out, int size) {
	super(out);
	if (size <= 0) {
	throw new IllegalArgumentException(Msg.getString("K0058")); //$NON-NLS-1$
	}
	this.out = out;
	this.buf = new char[size];
	}

	/**
	* Closes this writer. The contents of the buffer are flushed, the target
	* writer is closed, and the buffer is released. Only the first invocation
	* of close has any effect.
	*
	* @throws IOException
	* if an error occurs while closing this writer.
	*/
	@Override
	public void close() throws IOException {
	synchronized (lock) {
	if (isClosed()) {
	return;
	}

	Throwable thrown = null;
	try {
	flushInternal();
	} catch (Throwable e) {
	thrown = e;
	}
	buf = null;

	try {
	out.close();
	} catch (Throwable e) {
	if (thrown == null) {
	thrown = e;
	}
	}
	out = null;

	if (thrown != null) {
	SneakyThrow.sneakyThrow(thrown);
	}
	}
	}

	/**
	* Flushes this writer. The contents of the buffer are committed to the
	* target writer and it is then flushed.
	*
	* @throws IOException
	* if an error occurs while flushing this writer.
	*/
	@Override
	public void flush() throws IOException {
	synchronized (lock) {
	if (isClosed()) {
	throw new IOException(Msg.getString("K005d")); //$NON-NLS-1$
	}
	flushInternal();
	out.flush();
	}
	}

	/**
	* Flushes the internal buffer.
	*/
	private void flushInternal() throws IOException {
	if (pos > 0) {
	out.write(buf, 0, pos);
	}
	pos = 0;
	}

	/**
	* Indicates whether this writer is closed.
	*
	* @return {@code true} if this writer is closed, {@code false} otherwise.
	*/
	private boolean isClosed() {
	return out == null;
	}

	/**
	* Writes a newline to this writer. A newline is determined by the System
	* property "line.separator". The target writer may or may not be flushed
	* when a newline is written.
	*
	* @throws IOException
	* if an error occurs attempting to write to this writer.
	*/
	public void newLine() throws IOException {
	write(lineSeparator, 0, lineSeparator.length());
	}

	/**
	* Writes {@code count} characters starting at {@code offset} in
	* {@code cbuf} to this writer. If {@code count} is greater than this
	* writer's buffer, then the buffer is flushed and the characters are
	* written directly to the target writer.
	*
	* @param cbuf
	* the array containing characters to write.
	* @param offset
	* the start position in {@code cbuf} for retrieving characters.
	* @param count
	* the maximum number of characters to write.
	* @throws IndexOutOfBoundsException
	* if {@code offset < 0} or {@code count < 0}, or if
	* {@code offset + count} is greater than the size of
	* {@code cbuf}.
	* @throws IOException
	* if this writer is closed or another I/O error occurs.
	*/
	@Override
	public void write(char[] cbuf, int offset, int count) throws IOException {
	synchronized (lock) {
	if (isClosed()) {
	throw new IOException(Msg.getString("K005d")); //$NON-NLS-1$
	}
	// BEGIN android-changed
	// Exception priorities (in case of multiple errors) differ from
	// RI, but are spec-compliant.
	// made implicit null check explicit, used (offset \| count) < 0
	// instead of (offset < 0) \|\| (count < 0) to safe one operation
	if (cbuf == null) {
	throw new NullPointerException(Msg.getString("K0047")); //$NON-NLS-1$
	}
	if ((offset \| count) < 0 \|\| offset > cbuf.length - count) {
	throw new IndexOutOfBoundsException(Msg.getString("K002f")); //$NON-NLS-1$
	}
	// END android-changed
	if (pos == 0 && count >= this.buf.length) {
	out.write(cbuf, offset, count);
	return;
	}
	int available = this.buf.length - pos;
	if (count < available) {
	available = count;
	}
	if (available > 0) {
	System.arraycopy(cbuf, offset, this.buf, pos, available);
	pos += available;
	}
	if (pos == this.buf.length) {
	out.write(this.buf, 0, this.buf.length);
	pos = 0;
	if (count > available) {
	offset += available;
	available = count - available;
	if (available >= this.buf.length) {
	out.write(cbuf, offset, available);
	return;
	}

	System.arraycopy(cbuf, offset, this.buf, pos, available);
	pos += available;
	}
	}
	}
	}

	/**
	* Writes the character {@code oneChar} to this writer. If the buffer
	* gets full by writing this character, this writer is flushed. Only the
	* lower two bytes of the integer {@code oneChar} are written.
	*
	* @param oneChar
	* the character to write.
	* @throws IOException
	* if this writer is closed or another I/O error occurs.
	*/
	@Override
	public void write(int oneChar) throws IOException {
	synchronized (lock) {
	if (isClosed()) {
	throw new IOException(Msg.getString("K005d")); //$NON-NLS-1$
	}
	if (pos >= buf.length) {
	out.write(buf, 0, buf.length);
	pos = 0;
	}
	buf[pos++] = (char) oneChar;
	}
	}

	/**
	* Writes {@code count} characters starting at {@code offset} in {@code str}
	* to this writer. If {@code count} is greater than this writer's buffer,
	* then this writer is flushed and the remaining characters are written
	* directly to the target writer. If count is negative no characters are
	* written to the buffer. This differs from the behavior of the superclass.
	*
	* @param str
	* the non-null String containing characters to write.
	* @param offset
	* the start position in {@code str} for retrieving characters.
	* @param count
	* maximum number of characters to write.
	* @throws IOException
	* if this writer has already been closed or another I/O error
	* occurs.
	* @throws IndexOutOfBoundsException
	* if {@code offset < 0} or {@code offset + count} is greater
	* than the length of {@code str}.
	*/
	@Override
	public void write(String str, int offset, int count) throws IOException {
	synchronized (lock) {
	if (isClosed()) {
	throw new IOException(Msg.getString("K005d")); //$NON-NLS-1$
	}
	if (count <= 0) {
	return;
	}
	if (offset > str.length() - count \|\| offset < 0) {
	throw new StringIndexOutOfBoundsException();
	}
	if (pos == 0 && count >= buf.length) {
	char[] chars = new char[count];
	str.getChars(offset, offset + count, chars, 0);
	out.write(chars, 0, count);
	return;
	}
	int available = buf.length - pos;
	if (count < available) {
	available = count;
	}
	if (available > 0) {
	str.getChars(offset, offset + available, buf, pos);
	pos += available;
	}
	if (pos == buf.length) {
	out.write(this.buf, 0, this.buf.length);
	pos = 0;
	if (count > available) {
	offset += available;
	available = count - available;
	if (available >= buf.length) {
	char[] chars = new char[count];
	str.getChars(offset, offset + available, chars, 0);
	out.write(chars, 0, available);
	return;
	}
	str.getChars(offset, offset + available, buf, pos);
	pos += available;
	}
	}
	}
	}
	}