/*
*
*
* Copyright 1990-2007 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program 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.
*
* This program 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 at /legal/license.txt).
*
* 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 Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*/
package java.io;
/**
* 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.
*
* @version 1.20, 99/12/04 (CLDC 1.0, Spring 2000)
* @since JDK1.0
*/
public class PrintStream extends OutputStream {
private boolean trouble = false;
/**
* Track both the text- and character-output streams, so that their buffers
* can be flushed without flushing the entire stream.
*/
private OutputStreamWriter charOut;
private OutputStream byteOut;
/**
* Create a new print stream. This stream will not flush automatically.
*
* @param out The output stream to which values and objects will be
* printed
*/
public PrintStream(OutputStream out) {
if (out == null) {
throw new NullPointerException(
/* #ifdef VERBOSE_EXCEPTIONS */
/// skipped "Null output stream"
/* #endif */
);
}
byteOut = out;
this.charOut = new OutputStreamWriter(out);
}
/**
* Check to make sure that the stream has not been closed
*/
private void ensureOpen() throws IOException {
if (charOut == null)
throw new IOException(
/* #ifdef VERBOSE_EXCEPTIONS */
/// skipped "Stream closed"
/* #endif */
);
}
/**
* Flush 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();
charOut.flush();
}
catch (IOException x) {
trouble = true;
}
}
}
private boolean closing = false; /* To avoid recursive closing */
/**
* Close 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 {
charOut.close();
}
catch (IOException x) {
trouble = true;
}
charOut = null;
byteOut = null;
}
}
}
/**
* Flush the stream and check its error state. The internal error state
* is set to <code>true</code> when the underlying output stream throws an
* <code>IOException</code>,
* and when the <code>setError</code> method is invoked.
*
* @return True if and only if this stream has encountered an
* <code>IOException</code>, or the
* <code>setError</code> method has been invoked
*/
public boolean checkError() {
if (charOut != null)
flush();
return trouble;
}
/**
* Set the error state of the stream to <code>true</code>.
*
* @since JDK1.1
*/
protected void setError() {
trouble = true;
}
/*
* Exception-catching, synchronized output operations,
* which also implement the write() methods of OutputStream
*/
/**
* Write 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();
byteOut.write(b);
}
} catch (IOException x) {
trouble = true;
}
}
/**
* Write <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();
byteOut.write(buf, off, len);
}
} 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();
charOut.write(buf);
}
} catch (IOException x) {
trouble = true;
}
}
private void write(String s) {
try {
synchronized (this) {
ensureOpen();
charOut.write(s);
}
} catch (IOException x) {
trouble = true;
}
}
private void newLine() {
try {
synchronized (this) {
ensureOpen();
charOut.write('\n');
}
} catch (IOException x) {
trouble = true;
}
}
/* Methods that do not terminate lines */
/**
* Print 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");
}
/**
* Print 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));
}
/**
* Print 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));
}
/**
* Print 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));
}
/**
* Print 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);
}
/**
* Print 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);
}
/**
* Print 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 */
/**
* Terminate 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();
}
/**
* Print 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();
}
}
/**
* Print 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();
}
}
/**
* Print 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();
}
}
/**
* Print 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();
}
}
/**
* Print 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();
}
}
/**
* Print 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();
}
}
/**
* Print an Object and then terminate the line. This method behaves as
* though it invokes <code>{@link #print(Object)}</code> and then
* <code>{@link #println()}</code>.
*
* @param x The <code>Object</code> to be printed.
*/
public void println(Object x) {
synchronized (this) {
print(x);
newLine();
}
}
}
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