/*

  * 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.Formatter;

 import java.util.Locale;

 import java.nio.charset.Charset;

 import java.nio.charset.IllegalCharsetNameException;

 import java.nio.charset.UnsupportedCharsetException;

 /**

  * A <code>PrintStream</code> adds functionality to another output stream,

  * namely the ability to print representations of various data values

  * conveniently.  Two other features are provided as well.  Unlike other output

  * streams, a <code>PrintStream</code> never throws an

  * <code>IOException</code>; instead, exceptional situations merely set an

  * internal flag that can be tested via the <code>checkError</code> method.

  * Optionally, a <code>PrintStream</code> can be created so as to flush

  * automatically; this means that the <code>flush</code> method is

  * automatically invoked after a byte array is written, one of the

  * <code>println</code> methods is invoked, or a newline character or byte

  * (<code>'\n'</code>) is written.

  *

  * <p> All characters printed by a <code>PrintStream</code> are converted into

  * bytes using the platform's default character encoding.  The <code>{@link

  * PrintWriter}</code> class should be used in situations that require writing

  * characters rather than bytes.

  *

  * @author     Frank Yellin

  * @author     Mark Reinhold

  * @since      JDK1.0

  */

 public class PrintStream extends FilterOutputStream

     implements Appendable, Closeable

 {

     private final boolean autoFlush;

     private boolean trouble = false;

     private Formatter formatter;

     /**

      * Track both the text- and character-output streams, so that their buffers

      * can be flushed without flushing the entire stream.

      */

     private BufferedWriter textOut;

     private OutputStreamWriter charOut;

     /**

      * requireNonNull is explicitly declared here so as not to create an extra

      * dependency on java.util.Objects.requireNonNull. PrintStream is loaded

      * early during system initialization.

      */

     private static <T> T requireNonNull(T obj, String message) {

         if (obj == null)

             throw new NullPointerException(message);

         return obj;

     }

     /**

      * 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

     {

         requireNonNull(csn, "charsetName");

         try {

             return Charset.forName(csn);

         } catch (IllegalCharsetNameException|UnsupportedCharsetException unused) {

             // UnsupportedEncodingException should be thrown

             throw new UnsupportedEncodingException(csn);

         }

     }

     /* Private constructors */

     private PrintStream(boolean autoFlush, OutputStream out) {

         super(out);

         this.autoFlush = autoFlush;

         this.charOut = new OutputStreamWriter(this);

         this.textOut = new BufferedWriter(charOut);

     }

     private PrintStream(boolean autoFlush, OutputStream out, Charset charset) {

         super(out);

         this.autoFlush = autoFlush;

         this.charOut = new OutputStreamWriter(this, charset);

         this.textOut = new BufferedWriter(charOut);

     }

     /* Variant of the private constructor so that the given charset name

      * can be verified before evaluating the OutputStream argument. Used

      * by constructors creating a FileOutputStream that also take a

      * charset name.

      */

     private PrintStream(boolean autoFlush, Charset charset, OutputStream out)

         throws UnsupportedEncodingException

     {

         this(autoFlush, out, charset);

     }

     /**

      * Creates a new print stream.  This stream will not flush automatically.

      *

      * @param  out        The output stream to which values and objects will be

      *                    printed

      *

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

      */

     public PrintStream(OutputStream out) {

         this(out, false);

     }

     /**

      * Creates a new print stream.

      *

      * @param  out        The output stream to which values and objects will be

      *                    printed

      * @param  autoFlush  A boolean; if true, the output buffer will be flushed

      *                    whenever a byte array is written, one of the

      *                    <code>println</code> methods is invoked, or a newline

      *                    character or byte (<code>'\n'</code>) is written

      *

      * @see java.io.PrintWriter#PrintWriter(java.io.OutputStream, boolean)

      */

     public PrintStream(OutputStream out, boolean autoFlush) {

         this(autoFlush, requireNonNull(out, "Null output stream"));

     }

     /**

      * Creates a new print stream.

      *

      * @param  out        The output stream to which values and objects will be

      *                    printed

      * @param  autoFlush  A boolean; if true, the output buffer will be flushed

      *                    whenever a byte array is written, one of the

      *                    <code>println</code> methods is invoked, or a newline

      *                    character or byte (<code>'\n'</code>) is written

      * @param  encoding   The name of a supported

      *                    <a href="../lang/package-summary.html#charenc">

      *                    character encoding</a>

      *

      * @throws  UnsupportedEncodingException

      *          If the named encoding is not supported

      *

      * @since  1.4

      */

     public PrintStream(OutputStream out, boolean autoFlush, String encoding)

         throws UnsupportedEncodingException

     {

         this(autoFlush,

              requireNonNull(out, "Null output stream"),

              toCharset(encoding));

     }

     /**

      * Creates a new print stream, 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 print

      *         stream.  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(fileName)} denies write

      *          access to the file

      *

      * @since  1.5

      */

     public PrintStream(String fileName) throws FileNotFoundException {

         this(false, new FileOutputStream(fileName));

     }

     /**

      * Creates a new print stream, 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 print

      *         stream.  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(fileName)} denies write

      *          access to the file

      *

      * @throws  UnsupportedEncodingException

      *          If the named charset is not supported

      *

      * @since  1.5

      */

     public PrintStream(String fileName, String csn)

         throws FileNotFoundException, UnsupportedEncodingException

     {

         // ensure charset is checked before the file is opened

         this(false, toCharset(csn), new FileOutputStream(fileName));

     }

     /**

      * Creates a new print stream, 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 print stream.  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 PrintStream(File file) throws FileNotFoundException {

         this(false, new FileOutputStream(file));

     }

     /**

      * Creates a new print stream, 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 print stream.  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 presentand {@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 PrintStream(File file, String csn)

         throws FileNotFoundException, UnsupportedEncodingException

     {

         // ensure charset is checked before the file is opened

         this(false, toCharset(csn), new FileOutputStream(file));

     }

     /** Check 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.  This is done by writing any buffered output bytes to

      * the underlying output stream and then flushing that stream.

      *

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

      */

     public void flush() {

         synchronized (this) {

             try {

                 ensureOpen();

                 out.flush();

             }

             catch (IOException x) {

                 trouble = true;

             }

         }

     }

     private boolean closing = false; /* To avoid recursive closing */

     /**

      * Closes the stream.  This is done by flushing the stream and then closing

      * the underlying output stream.

      *

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

      */

     public void close() {

         synchronized (this) {

             if (! closing) {

                 closing = true;

                 try {

                     textOut.close();

                     out.close();

                 }

                 catch (IOException x) {

                     trouble = true;

                 }

                 textOut = null;

                 charOut = null;

                 out = null;

             }

         }

     }

     /**

      * Flushes the stream and checks its error state. The internal error state

      * is set to <code>true</code> when the underlying output stream throws an

      * <code>IOException</code> other than <code>InterruptedIOException</code>,

      * and when the <code>setError</code> method is invoked.  If an operation

      * on the underlying output stream throws an

      * <code>InterruptedIOException</code>, then the <code>PrintStream</code>

      * converts the exception back into an interrupt by doing:

      * <pre>

      *     Thread.currentThread().interrupt();

      * </pre>

      * or the equivalent.

      *

      * @return <code>true</code> if and only if this stream has encountered an

      *         <code>IOException</code> other than

      *         <code>InterruptedIOException</code>, or the

      *         <code>setError</code> method has been invoked

      */

     public boolean checkError() {

         if (out != null)

             flush();

         if (out instanceof java.io.PrintStream) {

             PrintStream ps = (PrintStream) out;

             return ps.checkError();

         }

         return trouble;

     }

     /**

      * Sets the error state of the stream to <code>true</code>.

      *

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

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

      * #clearError()} is invoked.

      *

      * @since JDK1.1

      */

     protected void setError() {

         trouble = true;

     }

     /**

      * Clears the internal 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 OutputStream

      */

     /**

      * Writes the specified byte to this stream.  If the byte is a newline and

      * automatic flushing is enabled then the <code>flush</code> method will be

      * invoked.

      *

      * <p> Note that the byte is written as given; to write a character that

      * will be translated according to the platform's default character

      * encoding, use the <code>print(char)</code> or <code>println(char)</code>

      * methods.

      *

      * @param  b  The byte to be written

      * @see #print(char)

      * @see #println(char)

      */

     public void write(int b) {

         try {

             synchronized (this) {

                 ensureOpen();

                 out.write(b);

                 if ((b == '\n') && autoFlush)

                     out.flush();

             }

         }

         catch (InterruptedIOException x) {

             Thread.currentThread().interrupt();

         }

         catch (IOException x) {

             trouble = true;

         }

     }

     /**

      * Writes <code>len</code> bytes from the specified byte array starting at

      * offset <code>off</code> to this stream.  If automatic flushing is

      * enabled then the <code>flush</code> method will be invoked.

      *

      * <p> Note that the bytes will be written as given; to write characters

      * that will be translated according to the platform's default character

      * encoding, use the <code>print(char)</code> or <code>println(char)</code>

      * methods.

      *

      * @param  buf   A byte array

      * @param  off   Offset from which to start taking bytes

      * @param  len   Number of bytes to write

      */

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

         try {

             synchronized (this) {

                 ensureOpen();

                 out.write(buf, off, len);

                 if (autoFlush)

                     out.flush();

             }

         }

         catch (InterruptedIOException x) {

             Thread.currentThread().interrupt();

         }

         catch (IOException x) {

             trouble = true;

         }

     }

     /*

      * The following private methods on the text- and character-output streams

      * always flush the stream buffers, so that writes to the underlying byte

      * stream occur as promptly as with the original PrintStream.

      */

     private void write(char buf[]) {

         try {

             synchronized (this) {

                 ensureOpen();

                 textOut.write(buf);

                 textOut.flushBuffer();

                 charOut.flushBuffer();

                 if (autoFlush) {

                     for (int i = 0; i < buf.length; i++)

                         if (buf[i] == '\n')

                             out.flush();

                 }

             }

         }

         catch (InterruptedIOException x) {

             Thread.currentThread().interrupt();

         }

         catch (IOException x) {

             trouble = true;

         }

     }

     private void write(String s) {

         try {

             synchronized (this) {

                 ensureOpen();

                 textOut.write(s);

                 textOut.flushBuffer();

                 charOut.flushBuffer();

                 if (autoFlush && (s.indexOf('\n') >= 0))

                     out.flush();

             }

         }

         catch (InterruptedIOException x) {

             Thread.currentThread().interrupt();

         }

         catch (IOException x) {

             trouble = true;

         }

     }

     private void newLine() {

         try {

             synchronized (this) {

                 ensureOpen();

                 textOut.newLine();

                 textOut.flushBuffer();

                 charOut.flushBuffer();

                 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(String.valueOf(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 and then terminate 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> to be printed

      */

     public void println(boolean x) {

         synchronized (this) {

             print(x);

             newLine();

         }

     }

     /**

      * Prints a character and then terminate 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> to be printed.

      */

     public void println(char x) {

         synchronized (this) {

             print(x);

             newLine();

         }

     }

     /**

      * Prints an integer and then terminate 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> to be printed.

      */

     public void println(int x) {

         synchronized (this) {

             print(x);

             newLine();

         }

     }

     /**

      * Prints a long and then terminate the line.  This method behaves as

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

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

      *

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

      */

     public void println(long x) {

         synchronized (this) {

             print(x);

             newLine();

         }

     }

     /**

      * Prints a float and then terminate 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> to be printed.

      */

     public void println(float x) {

         synchronized (this) {

             print(x);

             newLine();

         }

     }

     /**

      * Prints a double and then terminate 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> to be printed.

      */

     public void println(double x) {

         synchronized (this) {

             print(x);

             newLine();

         }

     }

     /**

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

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

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

      *

      * @param x  an array of chars to print.

      */

     public void println(char x[]) {

         synchronized (this) {

             print(x);

             newLine();

         }

     }

     /**

      * Prints a String and then terminate 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> to be printed.

      */

     public void println(String x) {

         synchronized (this) {

             print(x);

             newLine();

         }

     }

     /**

      * Prints an Object and then terminate 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 (this) {

             print(s);

             newLine();

         }

     }

     /**

      * A convenience method to write a formatted string to this output stream

      * using the specified format string and arguments.

      *

      * <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 output stream

      *

      * @since  1.5

      */

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

         return format(format, args);

     }

     /**

      * A convenience method to write a formatted string to this output stream

      * using the specified format string and arguments.

      *

      * <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 output stream

      *

      * @since  1.5

      */

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

         return format(l, format, args);

     }

     /**

      * Writes a formatted string to this output stream using the specified

      * format string and arguments.

      *

      * <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 output stream

      *

      * @since  1.5

      */

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

         try {

             synchronized (this) {

                 ensureOpen();

                 if ((formatter == null)

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

                     formatter = new Formatter((Appendable) this);

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

             }

         } catch (InterruptedIOException x) {

             Thread.currentThread().interrupt();

         } catch (IOException x) {

             trouble = true;

         }

         return this;

     }

     /**

      * Writes a formatted string to this output stream using the specified

      * format string and arguments.

      *

      * @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 output stream

      *

      * @since  1.5

      */

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

         try {

             synchronized (this) {

                 ensureOpen();

                 if ((formatter == null)

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

                     formatter = new Formatter(this, l);

                 formatter.format(l, format, args);

             }

         } catch (InterruptedIOException x) {

             Thread.currentThread().interrupt();

         } catch (IOException x) {

             trouble = true;

         }

         return this;

     }

     /**

      * Appends the specified character sequence to this output stream.

      *

      * <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.print(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 then <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 output stream.

      *

      * @return  This output stream

      *

      * @since  1.5

      */

     public PrintStream append(CharSequence csq) {

         if (csq == null)

             print("null");

         else

             print(csq.toString());

         return this;

     }

     /**

      * Appends a subsequence of the specified character sequence to this output

      * stream.

      *

      * <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.print(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 output stream

      *

      * @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 PrintStream 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 output stream.

      *

      * <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.print(c) </pre>

      *

      * @param  c

      *         The 16-bit character to append

      *

      * @return  This output stream

      *

      * @since  1.5

      */

     public PrintStream append(char c) {

         print(c);

         return this;

     }

 }