Inside java

Question

can anyone tell me the sequence of method call in java? i.e when i write system.out.println(), JVM invokes native calls. I want to know what are the libs and dlls involved for such a native call.

Answer 1

look at this method first :
    public void println(String x) {
     synchronized (this) {
         print(x);
         newLine();
* @(#)PrintStream.java     1.32 04/07/16
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
package java.io;
import java.util.Formatter;
import java.util.Locale;
* 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.  The <code>{@link
* PrintWriter}</code> class should be used in situations that require writing
* characters rather than bytes.
* @version    1.32, 04/07/16
* @author     Frank Yellin
* @author     Mark Reinhold
* @since      JDK1.0
public class PrintStream extends FilterOutputStream
    implements Appendable, Closeable
    private boolean autoFlush = false;
    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;
     * Create 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)
    public PrintStream(OutputStream out) {
     this(out, false);
    /* Initialization is factored into a private constructor (note the swapped
     * parameters so that this one isn't confused with the public one) and a
     * separate init method so that the following two public constructors can
     * share code.  We use a separate init method so that the constructor that
     * takes an encoding will throw an NPE for a null stream before it throws
     * an UnsupportedEncodingException for an unsupported encoding.
    private PrintStream(boolean autoFlush, OutputStream out)
     super(out);
     if (out == null)
         throw new NullPointerException("Null output stream");
     this.autoFlush = autoFlush;
    private void init(OutputStreamWriter osw) {
     this.charOut = osw;
     this.textOut = new BufferedWriter(osw);
     * Create 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
     *                    <code>println</code> methods is invoked, or a newline
     *                    character or byte (<code>'\n'</code>) is written
     * @see java.io.PrintWriter#PrintWriter(java.io.OutputStream, boolean)
    public PrintStream(OutputStream out, boolean autoFlush) {
     this(autoFlush, out);
     init(new OutputStreamWriter(this));
     * Create 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
     *                    <code>println</code> methods is invoked, or a newline
     *                    character or byte (<code>'\n'</code>) is written
     * @param  encoding   The name of a supported
     *                    <a href="../lang/package-summary.html#charenc">
     *                    character encoding</a>
     * @exception  UnsupportedEncodingException
     *             If the named encoding is not supported
    public PrintStream(OutputStream out, boolean autoFlush, String encoding)
        throws UnsupportedEncodingException
     this(autoFlush, out);
     init(new OutputStreamWriter(this, encoding));
     * 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));
     init(new OutputStreamWriter(this));
     * 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
     this(false, new FileOutputStream(fileName));
     init(new OutputStreamWriter(this, csn));
     * 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));
     init(new OutputStreamWriter(this));
     * 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
    public PrintStream(File file, String csn)
     throws FileNotFoundException, UnsupportedEncodingException
     this(false, new FileOutputStream(file));
     init(new OutputStreamWriter(this, csn));
    /** 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.  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();
          out.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 {
              textOut.close();
              out.close();
          catch (IOException x) {
              trouble = true;
          textOut = null;
          charOut = null;
          out = 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> other than <code>InterruptedIOException</code>,
     * and when the <code>setError</code> method is invoked.  If an operation
     * on the underlying output stream throws an
     * <code>InterruptedIOException</code>, then the <code>PrintStream</code>
     * converts the exception back into an interrupt by doing:
     * <pre>
     *     Thread.currentThread().interrupt();
     * </pre>
     * or the equivalent.
     * @return True if and only if this stream has encountered an
     *         <code>IOException</code> other than
     *         <code>InterruptedIOException</code>, or the
     *         <code>setError</code> method has been invoked
    public boolean checkError() {
     if (out != null)
         flush();
     return trouble;
     * Set the error state of the stream to <code>true</code>.
     * @since JDK1.1
    protected void setError() {
     trouble = true;
     try {
         throw new IOException();
     } catch (IOException x) {
     * 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();
          out.write(b);
          if ((b == '\n') && autoFlush)
              out.flush();
     catch (InterruptedIOException x) {
         Thread.currentThread().interrupt();
     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();
          out.write(buf, off, len);
          if (autoFlush)
              out.flush();
     catch (InterruptedIOException x) {
         Thread.currentThread().interrupt();
     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();
          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(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;
    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;
    /* 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 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 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 a float 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> to be printed.
    public void println(float x) {
     synchronized (this) {
         print(x);
         newLine();
     * Print a double 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> to be printed.
    public void println(double 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();
     * A convenience method to write a formatted string to this output stream
     * using the specified format string and arguments.
     * <p> An invocation of this method of the form <tt>out.printf(format,
     * args)</tt> behaves in exactly the same way as the invocation
     * <pre>
     *     out.format(format, args) </pre>
     * @param  format
     *         A format string as described in <a
     *         href="../util//Formatter.html#syntax">Format string syntax</a>
     * @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 <a href="http://java.sun.com/docs/books/vmspec/">Java
     *         Virtual Machine Specification</a>.  The behaviour on a
     *         <tt>null</tt> argument depends on the <a
     *         href="../util/Formatter.html#syntax">conversion</a>.
     * @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 <a
     *          href="../util/Formatter.html#detail">Details</a> section of the
     *          formatter class specification.
     * @throws  NullPointerException
     *          If the <tt>format</tt> is <tt>null</tt>
     * @return  This output stream
     * @since  1.5
    public PrintStream printf(String format, Object ... args) {
     return format(format, args);
     * A convenience method to write a formatted string to this output stream
     * using the specified format string and arguments.
     * <p> An invocation of this method of the form <tt>out.printf(l, format,
     * args)</tt> behaves in exactly the same way as the invocation
     * <pre>
     *     out.format(l, format, args) </pre>
     * @param  l
     *         The {@linkplain java.util.Locale locale} to apply during
     *         formatting.  If <tt>l</tt> is <tt>null</tt> then no localization
     *         is applied.
     * @param  format
     *         A format string as described in <a
     *         href="../util/Formatter.html#syntax">Format string syntax</a>
     * @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 <a href="http://java.sun.com/docs/books/vmspec/">Java
     *         Virtual Machine Specification</a>.  The behaviour on a
     *         <tt>null</tt> argument depends on the <a
     *         href="../util/Formatter.html#syntax">conversion</a>.
     * @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 <a
     *          href="../util/Formatter.html#detail">Details</a> section of the
     *          formatter class specification.
     * @throws  NullPointerException
     *          If the <tt>format</tt> is <tt>null</tt>
     * @return  This output stream
     * @since  1.5
    public PrintStream printf(Locale l, String format, Object ... args) {
     return format(l, format, args);
     * Writes a formatted string to this output stream using the specified
     * format string and arguments.
     * <p> 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 <a
     *         href="../util/Formatter.html#syntax">Format string syntax</a>
     * @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 <a href="http://java.sun.com/docs/books/vmspec/">Java
     *         Virtual Machine Specification</a>.  The behaviour on a
     *         <tt>null</tt> argument depends on the <a
     *         href="../util/Formatter.html#syntax">conversion</a>.
     * @throws  IllegalFormatException
     *          If a format string contains an