File	Doc	Category	Size	Date	Package
PrintStream.java	API Doc	Java SE 6 API	36925	Tue Jun 10 00:25:34 BST 2008	java.io

PrintStream

• java.lang.Object
  • java.io.OutputStream
    • java.io.FilterOutputStream

Fields Summary
private boolean	autoFlush
private boolean	trouble
private Formatter	formatter
private BufferedWriter	textOut Track both the text- and character-output streams, so that their buffers can be flushed without flushing the entire stream.
private OutputStreamWriter	charOut
private boolean	closing

Constructors Summary
public PrintStream(OutputStream out) 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) this(out, false);
private PrintStream(boolean autoFlush, OutputStream out) super(out); if (out == null) throw new NullPointerException("Null output stream"); this.autoFlush = autoFlush;
public PrintStream(OutputStream out, boolean autoFlush) 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 println methods is invoked, or a newline character or byte ('\n') is written see java.io.PrintWriter#PrintWriter(java.io.OutputStream, boolean) this(autoFlush, out); init(new OutputStreamWriter(this));
public PrintStream(OutputStream out, boolean autoFlush, String encoding) 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 println methods is invoked, or a newline character or byte ('\n') is written param encoding The name of a supported character encoding throws UnsupportedEncodingException If the named encoding is not supported since 1.4 this(autoFlush, out); init(new OutputStreamWriter(this, encoding));
public PrintStream(String fileName) 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 this(false, new FileOutputStream(fileName)); init(new OutputStreamWriter(this));
public PrintStream(String fileName, String csn) 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 this(false, new FileOutputStream(fileName)); init(new OutputStreamWriter(this, csn));
public PrintStream(File file) 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 this(false, new FileOutputStream(file)); init(new OutputStreamWriter(this));
public PrintStream(File file, String csn) 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 this(false, new FileOutputStream(file)); init(new OutputStreamWriter(this, csn));

Methods Summary
public java.io.PrintStream	append(java.lang.CharSequence csq) Appends the specified character sequence to this output stream. An invocation of this method of the form out.append(csq) behaves in exactly the same way as the invocation out.print(csq.toString()) Depending on the specification of toString for the character sequence csq, the entire sequence may not be appended. For instance, invoking then 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 output stream. return This output stream since 1.5 if (csq == null) print("null"); else print(csq.toString()); return this;
public java.io.PrintStream	append(java.lang.CharSequence csq, int start, int end) Appends a subsequence of the specified character sequence to this output stream. 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.print(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 output stream throws IndexOutOfBoundsException If start or end are negative, start is greater than end, or end is greater than csq.length() since 1.5 CharSequence cs = (csq == null ? "null" : csq); write(cs.subSequence(start, end).toString()); return this;
public java.io.PrintStream	append(char c) Appends the specified character to this output stream. An invocation of this method of the form out.append(c) behaves in exactly the same way as the invocation out.print(c) param c The 16-bit character to append return This output stream since 1.5 print(c); return this;
public boolean	checkError() Flushes the stream and checks its error state. The internal error state is set to true when the underlying output stream throws an IOException other than InterruptedIOException, and when the setError method is invoked. If an operation on the underlying output stream throws an InterruptedIOException, then the PrintStream converts the exception back into an interrupt by doing: Thread.currentThread().interrupt(); or the equivalent. return true if and only if this stream has encountered an IOException other than InterruptedIOException, or the setError method has been invoked if (out != null) flush(); if (out instanceof java.io.PrintStream) { PrintStream ps = (PrintStream) out; return ps.checkError(); } return trouble;
protected void	clearError() Clears the internal 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 trouble = false;
public void	close() Closes the stream. This is done by flushing the stream and then closing the underlying output stream. see java.io.OutputStream#close() /* To avoid recursive closing */ synchronized (this) { if (! closing) { closing = true; try { textOut.close(); out.close(); } catch (IOException x) { trouble = true; } textOut = null; charOut = null; out = null; } }
private void	ensureOpen() Check to make sure that the stream has not been closed if (out == null) throw new IOException("Stream closed");
public void	flush() 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() synchronized (this) { try { ensureOpen(); out.flush(); } catch (IOException x) { trouble = true; } }
public java.io.PrintStream	format(java.lang.String format, java.lang.Object args) Writes a formatted string to this output stream using the specified format string and arguments. 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 output stream since 1.5 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;
public java.io.PrintStream	format(java.util.Locale l, java.lang.String format, java.lang.Object args) 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 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 output stream since 1.5 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;
private void	init(java.io.OutputStreamWriter osw) this.charOut = osw; this.textOut = new BufferedWriter(osw);
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; }
public void	print(boolean b) 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 write(b ? "true" : "false");
public void	print(char c) 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 write(String.valueOf(c));
public void	print(int i) 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) write(String.valueOf(i));
public void	print(long l) 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) write(String.valueOf(l));
public void	print(float f) 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) write(String.valueOf(f));
public void	print(double d) 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) write(String.valueOf(d));
public void	print(char[] s) 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 write(s);
public void	print(java.lang.String 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 if (s == null) { s = "null"; } write(s);
public void	print(java.lang.Object obj) 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() write(String.valueOf(obj));
public java.io.PrintStream	printf(java.lang.String format, java.lang.Object args) A convenience method to write a formatted string to this output stream using the specified format string and arguments. 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 output stream since 1.5 return format(format, args);
public java.io.PrintStream	printf(java.util.Locale l, java.lang.String format, java.lang.Object args) A convenience method to write a formatted string to this output stream using the specified format string and arguments. 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 output stream since 1.5 return format(l, format, args);
public void	println() 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'). newLine();
public void	println(boolean x) Prints a boolean and then terminate the line. This method behaves as though it invokes {@link #print(boolean)} and then {@link #println()}. param x The boolean to be printed synchronized (this) { print(x); newLine(); }
public void	println(char x) Prints a character and then terminate the line. This method behaves as though it invokes {@link #print(char)} and then {@link #println()}. param x The char to be printed. synchronized (this) { print(x); newLine(); }
public void	println(int x) Prints an integer and then terminate the line. This method behaves as though it invokes {@link #print(int)} and then {@link #println()}. param x The int to be printed. synchronized (this) { print(x); newLine(); }
public void	println(long x) Prints a long and then terminate the line. This method behaves as though it invokes {@link #print(long)} and then {@link #println()}. param x a The long to be printed. synchronized (this) { print(x); newLine(); }
public void	println(float x) Prints a float and then terminate the line. This method behaves as though it invokes {@link #print(float)} and then {@link #println()}. param x The float to be printed. synchronized (this) { print(x); newLine(); }
public void	println(double x) Prints a double and then terminate the line. This method behaves as though it invokes {@link #print(double)} and then {@link #println()}. param x The double to be printed. synchronized (this) { print(x); newLine(); }
public void	println(char[] x) Prints an array of characters and then terminate the line. This method behaves as though it invokes {@link #print(char[])} and then {@link #println()}. param x an array of chars to print. synchronized (this) { print(x); newLine(); }
public void	println(java.lang.String x) Prints a String and then terminate the line. This method behaves as though it invokes {@link #print(String)} and then {@link #println()}. param x The String to be printed. synchronized (this) { print(x); newLine(); }
public void	println(java.lang.Object x) 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 {@link #print(String)} and then {@link #println()}. param x The Object to be printed. String s = String.valueOf(x); synchronized (this) { print(s); newLine(); }
protected void	setError() Sets the error state of the stream to true. This method will cause subsequent invocations of {@link #checkError()} to return true until {@link #clearError()} is invoked. since JDK1.1 trouble = true;
public void	write(int b) Writes the specified byte to this stream. If the byte is a newline and automatic flushing is enabled then the flush method will be invoked. 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 print(char) or println(char) methods. param b The byte to be written see #print(char) see #println(char) try { synchronized (this) { ensureOpen(); out.write(b); if ((b == '\n") && autoFlush) out.flush(); } } catch (InterruptedIOException x) { Thread.currentThread().interrupt(); } catch (IOException x) { trouble = true; }
public void	write(byte[] buf, int off, int len) Writes len bytes from the specified byte array starting at offset off to this stream. If automatic flushing is enabled then the flush method will be invoked. 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 print(char) or println(char) methods. param buf A byte array param off Offset from which to start taking bytes param len Number of bytes to write try { synchronized (this) { ensureOpen(); out.write(buf, off, len); if (autoFlush) out.flush(); } } catch (InterruptedIOException x) { Thread.currentThread().interrupt(); } catch (IOException x) { trouble = true; }
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(java.lang.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; }