/*
 * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

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 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 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 java.util.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 java.util.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 java.util.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 java.util.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;
 }

}