Java.io.Printstream Class in Java | Set 1

A PrintStream adds functionality to another output stream, namely the ability to print representations of various data values conveniently. Unlike other output streams, a PrintStream never throws an IOException; instead, exceptional situations merely set an internal flag that can be tested via the checkError method. Optionally, a PrintStream can be created so as to flush automatically.
All characters printed by a PrintStream are converted into bytes using the platform’s default character encoding. The PrintWriter class should be used in situations that require writing characters rather than bytes.

Class declaration

public class PrintStream
  extends FilterOutputStream
    implements Appendable, Closeable

Field

 protected OutputStream out:This is the output stream to be filtered. 

Constructors and Description

• PrintStream(File file): Creates a new print stream, without automatic line flushing, with the specified file.
• PrintStream(File file, String csn) : Creates a new print stream, without automatic line flushing, with the specified file and charset.
• PrintStream(OutputStream out) : Creates a new print stream.
• PrintStream(OutputStream out, boolean autoFlush) : Creates a new print stream.
• PrintStream(OutputStream out, boolean autoFlush, String encoding) : Creates a new print stream.
• PrintStream(String fileName) : Creates a new print stream, without automatic line flushing, with the specified file name.
• PrintStream(String fileName, String csn) :Creates a new print stream, without automatic line flushing, with the specified file name and charset.

Methods:

• PrintStream append(char c) : Appends the specified character to this output stream.

  Syntax :public PrintStream append(char c)
  Parameters:
  c - The 16-bit character to append
  Returns:
  This output stream

• PrintStream append(CharSequence csq, int start, int end): Appends the specified character sequence to this output stream.

  Syntax :public PrintStream append(CharSequence csq,
                   int start,
                   int end)
  Parameters:
  csq - The character sequence from which a subsequence will be appended. 
  start - The index of the first character in the subsequence
  end - The index of the character following the last character in the subsequence
  Returns:
  This output stream
  Throws:
  IndexOutOfBoundsException

• PrintStream append(CharSequence csq) : Appends a subsequence of the specified character sequence to this output stream.

  Syntax :public PrintStream append(CharSequence csq)
  Parameters:
  csq - The character sequence to append. 
  Returns:
  This output stream
  

• boolean checkError(): Flushes the stream and checks its error state.

  Syntax :public boolean checkError()
  Returns:
  true if and only if this stream has encountered an IOException 
  other than InterruptedIOException, or the setError method has been invoked

• protected void clearError() : Clears the internal error state of this stream.

  Syntax :protected void clearError()
  

• void close() : Closes the stream.

  Syntax :public void close()
  Overrides:
  close in class FilterOutputStream

• void flush(): Flushes the stream.

  Syntax :public void flush()
  Overrides:
  flush in class FilterOutputStream

• PrintStream format(Locale l, String format, Object… args): Writes a formatted string to this output stream using the specified format string and arguments.

  Syntax :public PrintStream format(Locale l,
                   String format,
                   Object... args)
  Parameters:
  l - The locale to apply during formatting. 
  If l is null then no localization is applied.
  format - A format string as described in Format string syntax
  args - Arguments referenced by the format specifiers in the format string. 
  The number of arguments is variable and may be zero.
  Returns:
  This output stream
  Throws:
  IllegalFormatException 
  NullPointerException

• PrintStream format(String format, Object… args): Writes a formatted string to this output stream using the specified format string and arguments.

  Syntax :public PrintStream format(String format,
                   Object... args)
  Parameters:
  format - A format string as described in Format string syntax
  args - Arguments referenced by the format specifiers in the format string. 
  The number of arguments is variable and may be zero.
  Returns:
  This output stream
  Throws:
  IllegalFormatException 
  NullPointerException 

• void print(boolean b): Prints a boolean value.

  Syntax :public void print(boolean b)

• void print(char c): Prints a character.

  Syntax :public void print(char c)

• void print(char[] s): Prints an array of characters.

  Syntax :public void print(char[] s)
  

• void print(double d) :Prints a double-precision floating-point number.

  Syntax :public void print(double b)
  

• void print(float f): Prints a floating-point number.

  Syntax :public void print(float f)

• void print(int i): Prints an integer.

  Syntax :public void print(int i)

• void print(long l): Prints a long integer.

  Syntax :public void print(long l)

• void print(Object obj) :Prints an object.

  Syntax :public void print(Object obj)

• void print(String s): Prints a string.

  Syntax :public void print(String s)

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.PrintStream;
import java.util.Locale;
//Java program to demonstrate PrintStream methods
class Printstream
{
    public static void main(String args[]) throws FileNotFoundException
    {
        FileOutputStream fout=new FileOutputStream("file.txt");

        //creating Printstream obj
        PrintStream out=new PrintStream(fout);
        String s="First";

        //writing to file.txt
        char c[]={'G','E','E','K'};

        //illustrating print(boolean b) method
        out.print(true);

        //illustrating print(int i) method
        out.print(1);

        //illustrating print(float f) method
        out.print(4.533f);

        //illustrating print(String s) method
        out.print("GeeksforGeeks");
        out.println();

        //illustrating print(Object Obj) method
        out.print(fout);
        out.println();

        //illustrating append(CharSequence csq) method
        out.append("Geek");
        out.println();

        //illustrating checkError() method
        out.println(out.checkError());

        //illustrating format() method
        out.format(Locale.UK, "Welcome to my %s program", s);

        //illustrating flush method
        out.flush();

        //illustrating close method
        out.close();
    }
}

Note: The output might not be visible on online IDE as it is not able to read the file.
Output:

true14.533GeeksforGeeks
java.io.FileOutputStream@1540e19dGeek
false
Welcome to my First program

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