/*

 * Copyright (c) 1996, 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 in the LICENSE file that

 * accompanied this code).

 *

 * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

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} 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} never throws an

 * {@code IOException}; instead, exceptional situations merely set an

 * internal flag that can be tested via the {@code checkError} method.

 * Optionally, a {@code PrintStream} can be created so as to flush

 * automatically; this means that the {@code flush} method is

 * automatically invoked after a byte array is written, one of the

 * {@code println} methods is invoked, or a newline character or byte

 * ({@code '\n'}) is written.

 *

 * <p> All characters printed by a {@code PrintStream} are converted into

 * bytes using the given encoding or charset, or the platform's default

 * character encoding if not specified.

 * The {@link PrintWriter} class should be used in situations that require

 * writing characters rather than bytes.

 *

 * <p> This class always replaces malformed and unmappable character sequences with

 * the charset's default replacement string.

 * The {@linkplain java.nio.charset.CharsetEncoder} class should be used when more

 * control over the encoding process is required.

 *

 * @author     Frank Yellin

 * @author     Mark Reinhold

 * @since      1.0

 */

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);

    }

    /* 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) {

        this(out, autoFlush, charset);

    }

    /**

     * Creates a new print stream, without automatic line flushing, with the

     * specified OutputStream. Characters written to the stream are converted

     * to bytes using the platform's default character encoding.

     *

     * @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, with the specified OutputStream and line

     * flushing. Characters written to the stream are converted to bytes using

     * the platform's default character encoding.

     *

     * @param  out        The output stream to which values and objects will be

     *                    printed

     * @param  autoFlush  Whether the output buffer will be flushed

     *                    whenever a byte array is written, one of the

     *                    {@code println} methods is invoked, or a newline

     *                    character or byte ({@code '\n'}) 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, with the specified OutputStream, line

     * flushing, and character encoding.

     *

     * @param  out        The output stream to which values and objects will be

     *                    printed

     * @param  autoFlush  Whether the output buffer will be flushed

     *                    whenever a byte array is written, one of the

     *                    {@code println} methods is invoked, or a newline

     *                    character or byte ({@code '\n'}) 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(requireNonNull(out, "Null output stream"), autoFlush, toCharset(encoding));

    }

    /**

     * Creates a new print stream, with the specified OutputStream, line

     * flushing and charset.  This convenience constructor creates the necessary

     * intermediate {@link java.io.OutputStreamWriter OutputStreamWriter},

     * which will encode characters using the provided charset.

     *

     * @param  out        The output stream to which values and objects will be

     *                    printed

     * @param  autoFlush  Whether the output buffer will be flushed

     *                    whenever a byte array is written, one of the

     *                    {@code println} methods is invoked, or a newline

     *                    character or byte ({@code '\n'}) is written

     * @param  charset    A {@linkplain java.nio.charset.Charset charset}

     *

     * @since  10

     */

    public PrintStream(OutputStream out, boolean autoFlush, Charset charset) {

        super(out);

        this.autoFlush = autoFlush;

        this.charOut = new OutputStreamWriter(this, charset);

        this.textOut = new BufferedWriter(charOut);

    }

    /**

     * 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 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  charset

     *         A {@linkplain java.nio.charset.Charset charset}

     *

     * @throws  IOException

     *          if an I/O 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  10

     */

    public PrintStream(String fileName, Charset charset) throws IOException {

        this(false, requireNonNull(charset, "charset"), 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));

    }

    /**

     * 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  charset

     *         A {@linkplain java.nio.charset.Charset charset}

     *

     * @throws  IOException

     *          if an I/O 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  10

     */

    public PrintStream(File file, Charset charset) throws IOException {

        this(false, requireNonNull(charset, "charset"), 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()

     */

    @Override

    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()

     */

    @Override

    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} when the underlying output stream throws an

     * {@code IOException} other than {@code InterruptedIOException},

     * and when the {@code setError} method is invoked.  If an operation

     * on the underlying output stream throws an

     * {@code InterruptedIOException}, then the {@code PrintStream}

     * converts the exception back into an interrupt by doing:

     * <pre>{@code

     *     Thread.currentThread().interrupt();

     * }</pre>

     * or the equivalent.

     *

     * @return {@code true} if and only if this stream has encountered an

     *         {@code IOException} other than

     *         {@code InterruptedIOException}, or the

     *         {@code setError} 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}.

     *

     * <p> This method will cause subsequent invocations of {@link

     * #checkError()} to return {@code true} until

     * {@link #clearError()} is invoked.

     *

     * @since 1.1

     */

    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 {@code false} until another write

     * operation fails and invokes {@link #setError()}.

     *

     * @since 1.6

     */

    protected void clearError() {

        trouble = false;