/*
* @(#)PrintWriter.java 1.32 06/10/13
*
* Copyright 1990-2008 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;
/**
* Print formatted representations of objects to a text-output stream. This
* class implements all of the print methods found in PrintStream. It does not
* contain methods for writing raw bytes, for which a program should use
* unencoded byte streams.
*
* <p> Unlike the PrintStream class, if automatic flushing is enabled it will
* be done only when one of the println() methods is invoked, rather than
* whenever a newline character happens to be output. The println() methods
* use the platform's own notion of line separator rather than the newline
* character.
*
* <p> Methods in this class never throw I/O exceptions. The client may
* inquire as to whether any errors have occurred by invoking checkError().
*
* @version 1.24, 02/02/00
* @author Mark Reinhold
* @since JDK1.1
*/
public class PrintWriter extends Writer {
/**
* The underlying character-output stream of this
* <code>PrintWriter</code>.
*
* @since 1.2
*/
protected Writer out;
private boolean autoFlush = false;
private boolean trouble = false;
/**
* Line separator string. This is the value of the line.separator
* property at the moment that the stream was created.
*/
private String lineSeparator;
/**
* Create a new PrintWriter, without automatic line flushing.
*
* @param out A character-output stream
*/
public PrintWriter (Writer out) {
this(out, false);
}
/**
* Create a new PrintWriter.
*
* @param out A character-output stream
* @param autoFlush A boolean; if true, the println() methods will flush
* the output buffer
*/
public PrintWriter(Writer out,
boolean autoFlush) {
super(out);
this.out = out;
this.autoFlush = autoFlush;
lineSeparator = (String) java.security.AccessController.doPrivileged(
new sun.security.action.GetPropertyAction("line.separator"));
}
/**
* Create 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);
}
/**
* Create 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() 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);
}
/** Check to make sure that the stream has not been closed */
private void ensureOpen() throws IOException {
if (out == null)
throw new IOException("Stream closed");
}
/**
* Flush the stream.
* @see #checkError()
*/
public void flush() {
try {
synchronized (lock) {
ensureOpen();
out.flush();
}
}
catch (IOException x) {
trouble = true;
}
}
/**
* Close the stream.
* @see #checkError()
*/
public void close() {
try {
synchronized (lock) {
if (out == null)
return;
out.close();
out = null;
}
}
catch (IOException x) {
trouble = true;
}
}
/**
* Flush the stream if it's not closed and check its error state.
* Errors are cumulative; once the stream encounters an error, this
* routine will return true on all successive calls.
*
* @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();
return trouble;
}
/** Indicate that an error has occurred. */
protected void setError() {
trouble = true;
}
/*
* Exception-catching, synchronized output operations,
* which also implement the write() methods of Writer
*/
/**
* Write 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;
}
}
/**
* Write 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;
}
}
/**
* Write 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);
}
/**
* Write 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;
}
}
/**
* Write 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 */
/**
* 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(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 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));
}
/**
* Print 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));
}
/**
* 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 value 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> value to be printed
*/
public void println(boolean x) {
synchronized (lock) {
print(x);
println();
}
}
/**
* 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> value to be printed
*/
public void println(char x) {
synchronized (lock) {
print(x);
println();
}
}
/**
* 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> value to be printed
*/
public void println(int x) {
synchronized (lock) {
print(x);
println();
}
}
/**
* Print a long integer 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 the <code>long</code> value to be printed
*/
public void println(long x) {
synchronized (lock) {
print(x);
println();
}
}
/**
* Print a floating-point number 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> value to be printed
*/
public void println(float x) {
synchronized (lock) {
print(x);
println();
}
}
/**
* Print a double-precision floating-point number 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> value to be printed
*/
public void println(double x) {
synchronized (lock) {
print(x);
println();
}
}
/**
* 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 the array of <code>char</code> values to be printed
*/
public void println(char x[]) {
synchronized (lock) {
print(x);
println();
}
}
/**
* 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> value to be printed
*/
public void println(String x) {
synchronized (lock) {
print(x);
println();
}
}
/**
* 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> value to be printed
*/
public void println(Object x) {
synchronized (lock) {
print(x);
println();
}
}
}