/*

  * Copyright (c) 1996, 2011, 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;

 import java.util.Objects;

 import java.util.Formatter;

 import java.util.Locale;

 import java.nio.charset.Charset;

 import java.nio.charset.IllegalCharsetNameException;

 import java.nio.charset.UnsupportedCharsetException;

 /**

  * Prints formatted representations of objects to a text-output stream.  This

  * class implements all of the <tt>print</tt> methods found in {@link

  * PrintStream}.  It does not contain methods for writing raw bytes, for which

  * a program should use unencoded byte streams.

  *

  * <p> Unlike the {@link PrintStream} class, if automatic flushing is enabled

  * it will be done only when one of the <tt>println</tt>, <tt>printf</tt>, or

  * <tt>format</tt> methods is invoked, rather than whenever a newline character

  * happens to be output.  These methods use the platform's own notion of line

  * separator rather than the newline character.

  *

  * <p> Methods in this class never throw I/O exceptions, although some of its

  * constructors may.  The client may inquire as to whether any errors have

  * occurred by invoking {@link #checkError checkError()}.

  *

  * @author      Frank Yellin

  * @author      Mark Reinhold

  * @since       JDK1.1

  */

 public class PrintWriter extends Writer {

     /**

      * The underlying character-output stream of this

      * <code>PrintWriter</code>.

      *

      * @since 1.2

      */

     protected Writer out;

     private final boolean autoFlush;

     private boolean trouble = false;

     private Formatter formatter;

     private PrintStream psOut = null;

     /**

      * Line separator string.  This is the value of the line.separator

      * property at the moment that the stream was created.

      */

     private final String lineSeparator;

     /**

      * Returns a charset object for the given charset name.

      * @throws NullPointerException          is csn is null

      * @throws UnsupportedEncodingException  if the charset is not supported

      */

     private static Charset toCharset(String csn)

         throws UnsupportedEncodingException

     {

         Objects.requireNonNull(csn, "charsetName");

         try {

             return Charset.forName(csn);

         } catch (IllegalCharsetNameException|UnsupportedCharsetException unused) {

             // UnsupportedEncodingException should be thrown

             throw new UnsupportedEncodingException(csn);

         }

     }

     /**

      * Creates a new PrintWriter, without automatic line flushing.

      *

      * @param  out        A character-output stream

      */

     public PrintWriter (Writer out) {

         this(out, false);

     }

     /**

      * Creates a new PrintWriter.

      *

      * @param  out        A character-output stream

      * @param  autoFlush  A boolean; if true, the <tt>println</tt>,

      *                    <tt>printf</tt>, or <tt>format</tt> methods will

      *                    flush the output buffer

      */

     public PrintWriter(Writer out,

                        boolean autoFlush) {

         super(out);

         this.out = out;

         this.autoFlush = autoFlush;

         lineSeparator = java.security.AccessController.doPrivileged(

             new sun.security.action.GetPropertyAction("line.separator"));

     }

     /**

      * Creates a new PrintWriter, without automatic line flushing, from an

      * existing OutputStream.  This convenience constructor creates the

      * necessary intermediate OutputStreamWriter, which will convert characters

      * into bytes using the default character encoding.

      *

      * @param  out        An output stream

      *

      * @see java.io.OutputStreamWriter#OutputStreamWriter(java.io.OutputStream)

      */

     public PrintWriter(OutputStream out) {

         this(out, false);

     }

     /**

      * Creates a new PrintWriter from an existing OutputStream.  This

      * convenience constructor creates the necessary intermediate

      * OutputStreamWriter, which will convert characters into bytes using the

      * default character encoding.

      *

      * @param  out        An output stream

      * @param  autoFlush  A boolean; if true, the <tt>println</tt>,

      *                    <tt>printf</tt>, or <tt>format</tt> methods will

      *                    flush the output buffer

      *

      * @see java.io.OutputStreamWriter#OutputStreamWriter(java.io.OutputStream)

      */

     public PrintWriter(OutputStream out, boolean autoFlush) {

         this(new BufferedWriter(new OutputStreamWriter(out)), autoFlush);

         // save print stream for error propagation

         if (out instanceof java.io.PrintStream) {

             psOut = (PrintStream) out;

         }

     }

     /**

      * Creates a new PrintWriter, without automatic line flushing, with the

      * specified file name.  This convenience constructor creates the necessary

      * intermediate {@link java.io.OutputStreamWriter OutputStreamWriter},

      * which will encode characters using the {@linkplain

      * java.nio.charset.Charset#defaultCharset() default charset} for this

      * instance of the Java virtual machine.

      *

      * @param  fileName

      *         The name of the file to use as the destination of this writer.

      *         If the file exists then it will be truncated to zero size;

      *         otherwise, a new file will be created.  The output will be

      *         written to the file and is buffered.

      *

      * @throws  FileNotFoundException

      *          If the given string does not denote an existing, writable

      *          regular file and a new regular file of that name cannot be

      *          created, or if some other error occurs while opening or

      *          creating the file

      *

      * @throws  SecurityException

      *          If a security manager is present and {@link

      *          SecurityManager#checkWrite checkWrite(fileName)} denies write

      *          access to the file

      *

      * @since  1.5

      */

     public PrintWriter(String fileName) throws FileNotFoundException {

         this(new BufferedWriter(new OutputStreamWriter(new FileOutputStream(fileName))),

              false);

     }

     /* Private constructor */

     private PrintWriter(Charset charset, File file)

         throws FileNotFoundException

     {

         this(new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file), charset)),

              false);

     }

     /**

      * Creates a new PrintWriter, without automatic line flushing, with the

      * specified file name and charset.  This convenience constructor creates

      * the necessary intermediate {@link java.io.OutputStreamWriter

      * OutputStreamWriter}, which will encode characters using the provided

      * charset.

      *

      * @param  fileName

      *         The name of the file to use as the destination of this writer.

      *         If the file exists then it will be truncated to zero size;

      *         otherwise, a new file will be created.  The output will be

      *         written to the file and is buffered.

      *

      * @param  csn

      *         The name of a supported {@linkplain java.nio.charset.Charset

      *         charset}

      *

      * @throws  FileNotFoundException

      *          If the given string does not denote an existing, writable

      *          regular file and a new regular file of that name cannot be

      *          created, or if some other error occurs while opening or

      *          creating the file

      *

      * @throws  SecurityException

      *          If a security manager is present and {@link

      *          SecurityManager#checkWrite checkWrite(fileName)} denies write

      *          access to the file

      *

      * @throws  UnsupportedEncodingException

      *          If the named charset is not supported

      *

      * @since  1.5

      */

     public PrintWriter(String fileName, String csn)

         throws FileNotFoundException, UnsupportedEncodingException

     {

         this(toCharset(csn), new File(fileName));

     }

     /**

      * Creates a new PrintWriter, without automatic line flushing, with the

      * specified file.  This convenience constructor creates the necessary

      * intermediate {@link java.io.OutputStreamWriter OutputStreamWriter},

      * which will encode characters using the {@linkplain

      * java.nio.charset.Charset#defaultCharset() default charset} for this

      * instance of the Java virtual machine.

      *

      * @param  file

      *         The file to use as the destination of this writer.  If the file

      *         exists then it will be truncated to zero size; otherwise, a new

      *         file will be created.  The output will be written to the file

      *         and is buffered.

      *

      * @throws  FileNotFoundException

      *          If the given file object does not denote an existing, writable

      *          regular file and a new regular file of that name cannot be

      *          created, or if some other error occurs while opening or

      *          creating the file

      *

      * @throws  SecurityException

      *          If a security manager is present and {@link

      *          SecurityManager#checkWrite checkWrite(file.getPath())}

      *          denies write access to the file

      *

      * @since  1.5

      */

     public PrintWriter(File file) throws FileNotFoundException {

         this(new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file))),

              false);

     }

     /**

      * Creates a new PrintWriter, without automatic line flushing, with the

      * specified file and charset.  This convenience constructor creates the

      * necessary intermediate {@link java.io.OutputStreamWriter

      * OutputStreamWriter}, which will encode characters using the provided

      * charset.

      *

      * @param  file

      *         The file to use as the destination of this writer.  If the file

      *         exists then it will be truncated to zero size; otherwise, a new

      *         file will be created.  The output will be written to the file

      *         and is buffered.

      *

      * @param  csn

      *         The name of a supported {@linkplain java.nio.charset.Charset

      *         charset}

      *

      * @throws  FileNotFoundException

      *          If the given file object does not denote an existing, writable

      *          regular file and a new regular file of that name cannot be

      *          created, or if some other error occurs while opening or

      *          creating the file

      *

      * @throws  SecurityException

      *          If a security manager is present and {@link

      *          SecurityManager#checkWrite checkWrite(file.getPath())}

      *          denies write access to the file

      *

      * @throws  UnsupportedEncodingException

      *          If the named charset is not supported

      *

      * @since  1.5

      */

     public PrintWriter(File file, String csn)

         throws FileNotFoundException, UnsupportedEncodingException

     {

         this(toCharset(csn), file);

     }

     /** Checks to make sure that the stream has not been closed */

     private void ensureOpen() throws IOException {

         if (out == null)

             throw new IOException("Stream closed");

     }

     /**

      * Flushes the stream.

      * @see #checkError()

      */

     public void flush() {

         try {

             synchronized (lock) {

                 ensureOpen();

                 out.flush();

             }

         }

         catch (IOException x) {

             trouble = true;

         }

     }

     /**

      * Closes the stream and releases any system resources associated

      * with it. Closing a previously closed stream has no effect.

      *

      * @see #checkError()

      */

     public void close() {

         try {

             synchronized (lock) {

                 if (out == null)

                     return;

                 out.close();

                 out = null;

             }

         }

         catch (IOException x) {

             trouble = true;

         }

     }

     /**

      * Flushes the stream if it's not closed and checks its error state.

      *

      * @return <code>true</code> if the print stream has encountered an error,

      *          either on the underlying output stream or during a format

      *          conversion.

      */

     public boolean checkError() {

         if (out != null) {

             flush();

         }

         if (out instanceof java.io.PrintWriter) {

             PrintWriter pw = (PrintWriter) out;

             return pw.checkError();

         } else if (psOut != null) {

             return psOut.checkError();

         }

         return trouble;

     }

     /**

      * Indicates that an error has occurred.

      *

      * <p> This method will cause subsequent invocations of {@link

      * #checkError()} to return <tt>true</tt> until {@link

      * #clearError()} is invoked.

      */

     protected void setError() {

         trouble = true;

     }

     /**

      * Clears the error state of this stream.

      *

      * <p> This method will cause subsequent invocations of {@link

      * #checkError()} to return <tt>false</tt> until another write

      * operation fails and invokes {@link #setError()}.

      *

      * @since 1.6

      */

     protected void clearError() {

         trouble = false;

     }

     /*

      * Exception-catching, synchronized output operations,

      * which also implement the write() methods of Writer

      */

     /**

      * Writes a single character.

      * @param c int specifying a character to be written.

      */

     public void write(int c) {

         try {

             synchronized (lock) {

                 ensureOpen();

                 out.write(c);

             }

         }

         catch (InterruptedIOException x) {

             Thread.currentThread().interrupt();

         }

         catch (IOException x) {

             trouble = true;

         }

     }

     /**

      * Writes A Portion of an array of characters.

      * @param buf Array of characters

      * @param off Offset from which to start writing characters

      * @param len Number of characters to write

      */

     public void write(char buf[], int off, int len) {

         try {

             synchronized (lock) {

                 ensureOpen();

                 out.write(buf, off, len);

             }

         }

         catch (InterruptedIOException x) {

             Thread.currentThread().interrupt();

         }

         catch (IOException x) {

             trouble = true;

         }

     }

     /**

      * Writes an array of characters.  This method cannot be inherited from the

      * Writer class because it must suppress I/O exceptions.

      * @param buf Array of characters to be written

      */

     public void write(char buf[]) {

         write(buf, 0, buf.length);

     }

     /**

      * Writes a portion of a string.

      * @param s A String

      * @param off Offset from which to start writing characters

      * @param len Number of characters to write

      */

     public void write(String s, int off, int len) {

         try {

             synchronized (lock) {

                 ensureOpen();

                 out.write(s, off, len);

             }

         }

         catch (InterruptedIOException x) {

             Thread.currentThread().interrupt();

         }

         catch (IOException x) {

             trouble = true;

         }

     }

     /**

      * Writes a string.  This method cannot be inherited from the Writer class

      * because it must suppress I/O exceptions.

      * @param s String to be written

      */

     public void write(String s) {

         write(s, 0, s.length());

     }

     private void newLine() {

         try {

             synchronized (lock) {

                 ensureOpen();

                 out.write(lineSeparator);

                 if (autoFlush)

                     out.flush();

             }

         }

         catch (InterruptedIOException x) {

             Thread.currentThread().interrupt();

         }

         catch (IOException x) {

             trouble = true;

         }

     }

     /* Methods that do not terminate lines */

     /**

      * Prints a boolean value.  The string produced by <code>{@link

      * java.lang.String#valueOf(boolean)}</code> is translated into bytes

      * according to the platform's default character encoding, and these bytes

      * are written in exactly the manner of the <code>{@link

      * #write(int)}</code> method.

      *

      * @param      b   The <code>boolean</code> to be printed

      */

     public void print(boolean b) {

         write(b ? "true" : "false");

     }

     /**

      * Prints a character.  The character is translated into one or more bytes

      * according to the platform's default character encoding, and these bytes

      * are written in exactly the manner of the <code>{@link

      * #write(int)}</code> method.

      *

      * @param      c   The <code>char</code> to be printed

      */

     public void print(char c) {

         write(c);

     }

     /**

      * Prints an integer.  The string produced by <code>{@link

      * java.lang.String#valueOf(int)}</code> is translated into bytes according

      * to the platform's default character encoding, and these bytes are

      * written in exactly the manner of the <code>{@link #write(int)}</code>

      * method.

      *

      * @param      i   The <code>int</code> to be printed

      * @see        java.lang.Integer#toString(int)

      */

     public void print(int i) {

         write(String.valueOf(i));

     }

     /**

      * Prints a long integer.  The string produced by <code>{@link

      * java.lang.String#valueOf(long)}</code> is translated into bytes

      * according to the platform's default character encoding, and these bytes

      * are written in exactly the manner of the <code>{@link #write(int)}</code>

      * method.

      *

      * @param      l   The <code>long</code> to be printed

      * @see        java.lang.Long#toString(long)

      */

     public void print(long l) {

         write(String.valueOf(l));

     }

     /**

      * Prints a floating-point number.  The string produced by <code>{@link

      * java.lang.String#valueOf(float)}</code> is translated into bytes

      * according to the platform's default character encoding, and these bytes

      * are written in exactly the manner of the <code>{@link #write(int)}</code>

      * method.

      *

      * @param      f   The <code>float</code> to be printed

      * @see        java.lang.Float#toString(float)

      */

     public void print(float f) {

         write(String.valueOf(f));

     }

     /**

      * Prints a double-precision floating-point number.  The string produced by

      * <code>{@link java.lang.String#valueOf(double)}</code> is translated into

      * bytes according to the platform's default character encoding, and these

      * bytes are written in exactly the manner of the <code>{@link

      * #write(int)}</code> method.

      *

      * @param      d   The <code>double</code> to be printed

      * @see        java.lang.Double#toString(double)

      */

     public void print(double d) {

         write(String.valueOf(d));

     }

     /**

      * Prints an array of characters.  The characters are converted into bytes

      * according to the platform's default character encoding, and these bytes

      * are written in exactly the manner of the <code>{@link #write(int)}</code>

      * method.

      *

      * @param      s   The array of chars to be printed

      *

      * @throws  NullPointerException  If <code>s</code> is <code>null</code>

      */

     public void print(char s[]) {

         write(s);

     }

     /**

      * Prints a string.  If the argument is <code>null</code> then the string

      * <code>"null"</code> is printed.  Otherwise, the string's characters are

      * converted into bytes according to the platform's default character

      * encoding, and these bytes are written in exactly the manner of the

      * <code>{@link #write(int)}</code> method.

      *

      * @param      s   The <code>String</code> to be printed

      */

     public void print(String s) {

         if (s == null) {

             s = "null";

         }

         write(s);

     }

     /**

      * Prints an object.  The string produced by the <code>{@link

      * java.lang.String#valueOf(Object)}</code> method is translated into bytes

      * according to the platform's default character encoding, and these bytes

      * are written in exactly the manner of the <code>{@link #write(int)}</code>

      * method.

      *

      * @param      obj   The <code>Object</code> to be printed

      * @see        java.lang.Object#toString()

      */

     public void print(Object obj) {

         write(String.valueOf(obj));

     }

     /* Methods that do terminate lines */

     /**

      * Terminates the current line by writing the line separator string.  The

      * line separator string is defined by the system property

      * <code>line.separator</code>, and is not necessarily a single newline

      * character (<code>'\n'</code>).

      */

     public void println() {

         newLine();

     }

     /**

      * Prints a boolean value and then terminates the line.  This method behaves

      * as though it invokes <code>{@link #print(boolean)}</code> and then

      * <code>{@link #println()}</code>.

      *

      * @param x the <code>boolean</code> value to be printed

      */

     public void println(boolean x) {

         synchronized (lock) {

             print(x);

             println();

         }

     }

     /**

      * Prints a character and then terminates the line.  This method behaves as

      * though it invokes <code>{@link #print(char)}</code> and then <code>{@link

      * #println()}</code>.

      *

      * @param x the <code>char</code> value to be printed

      */

     public void println(char x) {

         synchronized (lock) {

             print(x);

             println();

         }

     }

     /**

      * Prints an integer and then terminates the line.  This method behaves as

      * though it invokes <code>{@link #print(int)}</code> and then <code>{@link

      * #println()}</code>.

      *

      * @param x the <code>int</code> value to be printed

      */

     public void println(int x) {

         synchronized (lock) {

             print(x);

             println();

         }

     }

     /**

      * Prints a long integer and then terminates the line.  This method behaves

      * as though it invokes <code>{@link #print(long)}</code> and then

      * <code>{@link #println()}</code>.

      *

      * @param x the <code>long</code> value to be printed

      */

     public void println(long x) {

         synchronized (lock) {

             print(x);

             println();

         }

     }

     /**

      * Prints a floating-point number and then terminates the line.  This method

      * behaves as though it invokes <code>{@link #print(float)}</code> and then

      * <code>{@link #println()}</code>.

      *

      * @param x the <code>float</code> value to be printed

      */

     public void println(float x) {

         synchronized (lock) {

             print(x);

             println();

         }

     }

     /**

      * Prints a double-precision floating-point number and then terminates the

      * line.  This method behaves as though it invokes <code>{@link

      * #print(double)}</code> and then <code>{@link #println()}</code>.

      *

      * @param x the <code>double</code> value to be printed

      */

     public void println(double x) {

         synchronized (lock) {

             print(x);

             println();

         }

     }

     /**

      * Prints an array of characters and then terminates the line.  This method

      * behaves as though it invokes <code>{@link #print(char[])}</code> and then

      * <code>{@link #println()}</code>.

      *

      * @param x the array of <code>char</code> values to be printed

      */

     public void println(char x[]) {

         synchronized (lock) {

             print(x);

             println();

         }

     }

     /**

      * Prints a String and then terminates the line.  This method behaves as

      * though it invokes <code>{@link #print(String)}</code> and then

      * <code>{@link #println()}</code>.

      *

      * @param x the <code>String</code> value to be printed

      */

     public void println(String x) {

         synchronized (lock) {

             print(x);

             println();

         }

     }

     /**

      * Prints an Object and then terminates the line.  This method calls

      * at first String.valueOf(x) to get the printed object's string value,

      * then behaves as

      * though it invokes <code>{@link #print(String)}</code> and then

      * <code>{@link #println()}</code>.

      *

      * @param x  The <code>Object</code> to be printed.

      */

     public void println(Object x) {

         String s = String.valueOf(x);

         synchronized (lock) {

             print(s);

             println();

         }

     }

     /**

      * A convenience method to write a formatted string to this writer using

      * the specified format string and arguments.  If automatic flushing is

      * enabled, calls to this method will flush the output buffer.

      *

      * <p> An invocation of this method of the form <tt>out.printf(format,

      * args)</tt> behaves in exactly the same way as the invocation

      *

      * <pre>

      *     out.format(format, args) </pre>

      *

      * @param  format

      *         A format string as described in <a

      *         href="../util/Formatter.html#syntax">Format string syntax</a>.

      *

      * @param  args

      *         Arguments referenced by the format specifiers in the format

      *         string.  If there are more arguments than format specifiers, the

      *         extra arguments are ignored.  The number of arguments is

      *         variable and may be zero.  The maximum number of arguments is

      *         limited by the maximum dimension of a Java array as defined by

      *         <cite>The Java&trade; Virtual Machine Specification</cite>.

      *         The behaviour on a

      *         <tt>null</tt> argument depends on the <a

      *         href="../util/Formatter.html#syntax">conversion</a>.

      *

      * @throws  IllegalFormatException

      *          If a format string contains an illegal syntax, a format

      *          specifier that is incompatible with the given arguments,

      *          insufficient arguments given the format string, or other

      *          illegal conditions.  For specification of all possible

      *          formatting errors, see the <a

      *          href="../util/Formatter.html#detail">Details</a> section of the

      *          formatter class specification.

      *

      * @throws  NullPointerException

      *          If the <tt>format</tt> is <tt>null</tt>

      *

      * @return  This writer

      *

      * @since  1.5

      */

     public PrintWriter printf(String format, Object ... args) {

         return format(format, args);

     }

     /**

      * A convenience method to write a formatted string to this writer using

      * the specified format string and arguments.  If automatic flushing is

      * enabled, calls to this method will flush the output buffer.

      *

      * <p> An invocation of this method of the form <tt>out.printf(l, format,

      * args)</tt> behaves in exactly the same way as the invocation

      *

      * <pre>

      *     out.format(l, format, args) </pre>

      *

      * @param  l

      *         The {@linkplain java.util.Locale locale} to apply during

      *         formatting.  If <tt>l</tt> is <tt>null</tt> then no localization

      *         is applied.

      *

      * @param  format

      *         A format string as described in <a

      *         href="../util/Formatter.html#syntax">Format string syntax</a>.

      *

      * @param  args

      *         Arguments referenced by the format specifiers in the format

      *         string.  If there are more arguments than format specifiers, the

      *         extra arguments are ignored.  The number of arguments is

      *         variable and may be zero.  The maximum number of arguments is

      *         limited by the maximum dimension of a Java array as defined by

      *         <cite>The Java&trade; Virtual Machine Specification</cite>.

      *         The behaviour on a

      *         <tt>null</tt> argument depends on the <a

      *         href="../util/Formatter.html#syntax">conversion</a>.

      *

      * @throws  IllegalFormatException

      *          If a format string contains an illegal syntax, a format

      *          specifier that is incompatible with the given arguments,

      *          insufficient arguments given the format string, or other

      *          illegal conditions.  For specification of all possible

      *          formatting errors, see the <a

      *          href="../util/Formatter.html#detail">Details</a> section of the

      *          formatter class specification.

      *

      * @throws  NullPointerException

      *          If the <tt>format</tt> is <tt>null</tt>

      *

      * @return  This writer

      *

      * @since  1.5

      */

     public PrintWriter printf(Locale l, String format, Object ... args) {

         return format(l, format, args);

     }

     /**

      * Writes a formatted string to this writer using the specified format

      * string and arguments.  If automatic flushing is enabled, calls to this

      * method will flush the output buffer.

      *

      * <p> The locale always used is the one returned by {@link

      * java.util.Locale#getDefault() Locale.getDefault()}, regardless of any

      * previous invocations of other formatting methods on this object.

      *

      * @param  format

      *         A format string as described in <a

      *         href="../util/Formatter.html#syntax">Format string syntax</a>.

      *

      * @param  args

      *         Arguments referenced by the format specifiers in the format

      *         string.  If there are more arguments than format specifiers, the

      *         extra arguments are ignored.  The number of arguments is

      *         variable and may be zero.  The maximum number of arguments is

      *         limited by the maximum dimension of a Java array as defined by

      *         <cite>The Java&trade; Virtual Machine Specification</cite>.

      *         The behaviour on a

      *         <tt>null</tt> argument depends on the <a

      *         href="../util/Formatter.html#syntax">conversion</a>.

      *

      * @throws  IllegalFormatException

      *          If a format string contains an illegal syntax, a format

      *          specifier that is incompatible with the given arguments,

      *          insufficient arguments given the format string, or other

      *          illegal conditions.  For specification of all possible

      *          formatting errors, see the <a

      *          href="../util/Formatter.html#detail">Details</a> section of the

      *          Formatter class specification.

      *

      * @throws  NullPointerException

      *          If the <tt>format</tt> is <tt>null</tt>

      *

      * @return  This writer

      *

      * @since  1.5

      */

     public PrintWriter format(String format, Object ... args) {

         try {

             synchronized (lock) {

                 ensureOpen();

                 if ((formatter == null)

                     || (formatter.locale() != Locale.getDefault()))

                     formatter = new Formatter(this);

                 formatter.format(Locale.getDefault(), format, args);

                 if (autoFlush)

                     out.flush();

             }

         } catch (InterruptedIOException x) {

             Thread.currentThread().interrupt();

         } catch (IOException x) {

             trouble = true;

         }

         return this;

     }

     /**

      * Writes a formatted string to this writer using the specified format

      * string and arguments.  If automatic flushing is enabled, calls to this

      * method will flush the output buffer.

      *

      * @param  l

      *         The {@linkplain java.util.Locale locale} to apply during

      *         formatting.  If <tt>l</tt> is <tt>null</tt> then no localization

      *         is applied.

      *

      * @param  format

      *         A format string as described in <a

      *         href="../util/Formatter.html#syntax">Format string syntax</a>.

      *

      * @param  args

      *         Arguments referenced by the format specifiers in the format

      *         string.  If there are more arguments than format specifiers, the

      *         extra arguments are ignored.  The number of arguments is

      *         variable and may be zero.  The maximum number of arguments is

      *         limited by the maximum dimension of a Java array as defined by

      *         <cite>The Java&trade; Virtual Machine Specification</cite>.

      *         The behaviour on a

      *         <tt>null</tt> argument depends on the <a

      *         href="../util/Formatter.html#syntax">conversion</a>.

      *

      * @throws  IllegalFormatException

      *          If a format string contains an illegal syntax, a format

      *          specifier that is incompatible with the given arguments,

      *          insufficient arguments given the format string, or other

      *          illegal conditions.  For specification of all possible

      *          formatting errors, see the <a

      *          href="../util/Formatter.html#detail">Details</a> section of the

      *          formatter class specification.

      *

      * @throws  NullPointerException

      *          If the <tt>format</tt> is <tt>null</tt>

      *

      * @return  This writer

      *

      * @since  1.5

      */

     public PrintWriter format(Locale l, String format, Object ... args) {

         try {

             synchronized (lock) {

                 ensureOpen();

                 if ((formatter == null) || (formatter.locale() != l))

                     formatter = new Formatter(this, l);

                 formatter.format(l, format, args);

                 if (autoFlush)

                     out.flush();

             }

         } catch (InterruptedIOException x) {

             Thread.currentThread().interrupt();

         } catch (IOException x) {

             trouble = true;

         }

         return this;

     }

     /**

      * Appends the specified character sequence to this writer.

      *

      * <p> An invocation of this method of the form <tt>out.append(csq)</tt>

      * behaves in exactly the same way as the invocation

      *

      * <pre>

      *     out.write(csq.toString()) </pre>

      *

      * <p> Depending on the specification of <tt>toString</tt> for the

      * character sequence <tt>csq</tt>, the entire sequence may not be

      * appended. For instance, invoking the <tt>toString</tt> 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 <tt>csq</tt> is

      *         <tt>null</tt>, then the four characters <tt>"null"</tt> are

      *         appended to this writer.

      *

      * @return  This writer

      *

      * @since  1.5

      */

     public PrintWriter append(CharSequence csq) {

         if (csq == null)

             write("null");

         else

             write(csq.toString());

         return this;

     }

     /**

      * Appends a subsequence of the specified character sequence to this writer.

      *

      * <p> An invocation of this method of the form <tt>out.append(csq, start,

      * end)</tt> when <tt>csq</tt> is not <tt>null</tt>, behaves in

      * exactly the same way as the invocation

      *

      * <pre>

      *     out.write(csq.subSequence(start, end).toString()) </pre>

      *

      * @param  csq

      *         The character sequence from which a subsequence will be

      *         appended.  If <tt>csq</tt> is <tt>null</tt>, then characters

      *         will be appended as if <tt>csq</tt> contained the four

      *         characters <tt>"null"</tt>.

      *

      * @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 <tt>start</tt> or <tt>end</tt> are negative, <tt>start</tt>

      *          is greater than <tt>end</tt>, or <tt>end</tt> is greater than

      *          <tt>csq.length()</tt>

      *

      * @since  1.5

      */

     public PrintWriter append(CharSequence csq, int start, int end) {

         CharSequence cs = (csq == null ? "null" : csq);

         write(cs.subSequence(start, end).toString());

         return this;

     }

     /**

      * Appends the specified character to this writer.

      *

      * <p> An invocation of this method of the form <tt>out.append(c)</tt>

      * 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 PrintWriter append(char c) {

         write(c);

         return this;

     }

 }