Unlike the {@link PrintStream} class, if automatic flushing is enabled + * it will be done only when one of the println, printf, or + * format 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. + * + *
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
+ * PrintWriter.
+ *
+ * @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 println,
+ * printf, or format 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 println,
+ * printf, or format 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 true 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.
+ *
+ *
This method will cause subsequent invocations of {@link + * #checkError()} to return true until {@link + * #clearError()} is invoked. + */ + protected void setError() { + trouble = true; + } + + /** + * Clears the error state of this stream. + * + *
This method will cause subsequent invocations of {@link
+ * #checkError()} to return false 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 {@link
+ * java.lang.String#valueOf(boolean)} is translated into bytes
+ * according to the platform's default character encoding, and these bytes
+ * are written in exactly the manner of the {@link
+ * #write(int)} method.
+ *
+ * @param b The boolean 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 {@link
+ * #write(int)} method.
+ *
+ * @param c The char to be printed
+ */
+ public void print(char c) {
+ write(c);
+ }
+
+ /**
+ * Prints an integer. The string produced by {@link
+ * java.lang.String#valueOf(int)} is translated into bytes according
+ * to the platform's default character encoding, and these bytes are
+ * written in exactly the manner of the {@link #write(int)}
+ * method.
+ *
+ * @param i The int 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 {@link
+ * java.lang.String#valueOf(long)} is translated into bytes
+ * according to the platform's default character encoding, and these bytes
+ * are written in exactly the manner of the {@link #write(int)}
+ * method.
+ *
+ * @param l The long 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 {@link
+ * java.lang.String#valueOf(float)} is translated into bytes
+ * according to the platform's default character encoding, and these bytes
+ * are written in exactly the manner of the {@link #write(int)}
+ * method.
+ *
+ * @param f The float 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
+ * {@link java.lang.String#valueOf(double)} is translated into
+ * bytes according to the platform's default character encoding, and these
+ * bytes are written in exactly the manner of the {@link
+ * #write(int)} method.
+ *
+ * @param d The double 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 {@link #write(int)}
+ * method.
+ *
+ * @param s The array of chars to be printed
+ *
+ * @throws NullPointerException If s is null
+ */
+ public void print(char s[]) {
+ write(s);
+ }
+
+ /**
+ * Prints a string. If the argument is null then the string
+ * "null" 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
+ * {@link #write(int)} method.
+ *
+ * @param s The String to be printed
+ */
+ public void print(String s) {
+ if (s == null) {
+ s = "null";
+ }
+ write(s);
+ }
+
+ /**
+ * Prints an object. The string produced by the {@link
+ * java.lang.String#valueOf(Object)} method is translated into bytes
+ * according to the platform's default character encoding, and these bytes
+ * are written in exactly the manner of the {@link #write(int)}
+ * method.
+ *
+ * @param obj The Object 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
+ * line.separator, and is not necessarily a single newline
+ * character ('\n').
+ */
+ public void println() {
+ newLine();
+ }
+
+ /**
+ * Prints a boolean value and then terminates the line. This method behaves
+ * as though it invokes {@link #print(boolean)} and then
+ * {@link #println()}.
+ *
+ * @param x the boolean 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 {@link #print(char)} and then {@link
+ * #println()}.
+ *
+ * @param x the char 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 {@link #print(int)} and then {@link
+ * #println()}.
+ *
+ * @param x the int 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 {@link #print(long)} and then
+ * {@link #println()}.
+ *
+ * @param x the long 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 {@link #print(float)} and then
+ * {@link #println()}.
+ *
+ * @param x the float 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 {@link
+ * #print(double)} and then {@link #println()}.
+ *
+ * @param x the double 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 {@link #print(char[])} and then
+ * {@link #println()}.
+ *
+ * @param x the array of char 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 {@link #print(String)} and then
+ * {@link #println()}.
+ *
+ * @param x the String 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 {@link #print(String)} and then
+ * {@link #println()}.
+ *
+ * @param x The Object 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.
+ *
+ *
An invocation of this method of the form out.printf(format, + * args) behaves in exactly the same way as the invocation + * + *
+ * out.format(format, args)+ * + * @param format + * A format string as described in Format string syntax. + * + * @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 + * The Java™ Virtual Machine Specification. + * The behaviour on a + * null argument depends on the conversion. + * + * @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 Details section of the + * formatter class specification. + * + * @throws NullPointerException + * If the format is null + * + * @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. + * + *
An invocation of this method of the form out.printf(l, format, + * args) behaves in exactly the same way as the invocation + * + *
+ * out.format(l, format, args)+ * + * @param l + * The {@linkplain java.util.Locale locale} to apply during + * formatting. If l is null then no localization + * is applied. + * + * @param format + * A format string as described in Format string syntax. + * + * @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 + * The Java™ Virtual Machine Specification. + * The behaviour on a + * null argument depends on the conversion. + * + * @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 Details section of the + * formatter class specification. + * + * @throws NullPointerException + * If the format is null + * + * @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. + * + *
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 Format string syntax. + * + * @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 + * The Java™ Virtual Machine Specification. + * The behaviour on a + * null argument depends on the conversion. + * + * @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 Details section of the + * Formatter class specification. + * + * @throws NullPointerException + * If the format is null + * + * @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 l is null then no localization + * is applied. + * + * @param format + * A format string as described in Format string syntax. + * + * @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 + * The Java™ Virtual Machine Specification. + * The behaviour on a + * null argument depends on the conversion. + * + * @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 Details section of the + * formatter class specification. + * + * @throws NullPointerException + * If the format is null + * + * @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. + * + *
An invocation of this method of the form out.append(csq) + * behaves in exactly the same way as the invocation + * + *
+ * out.write(csq.toString())+ * + *
Depending on the specification of toString for the + * character sequence csq, the entire sequence may not be + * appended. For instance, invoking the toString method of a + * character buffer will return a subsequence whose content depends upon + * the buffer's position and limit. + * + * @param csq + * The character sequence to append. If csq is + * null, then the four characters "null" 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. + * + *
An invocation of this method of the form out.append(csq, start, + * end) when csq is not null, behaves in + * exactly the same way as the invocation + * + *
+ * out.write(csq.subSequence(start, end).toString())+ * + * @param csq + * The character sequence from which a subsequence will be + * appended. If csq is null, then characters + * will be appended as if csq contained the four + * characters "null". + * + * @param start + * The index of the first character in the subsequence + * + * @param end + * The index of the character following the last character in the + * subsequence + * + * @return This writer + * + * @throws IndexOutOfBoundsException + * If start or end are negative, start + * is greater than end, or end is greater than + * csq.length() + * + * @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. + * + *
An invocation of this method of the form out.append(c) + * behaves in exactly the same way as the invocation + * + *
+ * out.write(c)+ * + * @param c + * The 16-bit character to append + * + * @return This writer + * + * @since 1.5 + */ + public PrintWriter append(char c) { + write(c); + return this; + } +}