This documentation differs from the official API. Jadeite adds extra features to the API including: variable font sizes, constructions examples, placeholders for classes and methods, and auto-generated “See Also” links. Additionally it is missing some items found in standard Javadoc documentation, including: generics type information, “Deprecated” tags and comments, “See Also” links, along with other minor differences. Please send any questions or feedback to bam@cs.cmu.edu.


java.io
class PrintStream

java.lang.Object extended by java.io.OutputStream extended by java.io.FilterOutputStream extended by java.io.PrintStream
All Implemented Interfaces:
Closeable, Flushable, Appendable
Direct Known Subclasses:
LogStream

Most common way to construct:

OutputStream out = …;

PrintStream p = new PrintStream(out);

Based on 36 examples


public class PrintStream
extends FilterOutputStream
implements Appendable, Closeable

A 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 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; this means that the flush method is automatically invoked after a byte array is written, one of the println methods is invoked, or a newline character or byte ('\n') is written.

All characters printed by a PrintStream are converted into bytes using the platform's default character encoding. The {@link PrintWriter} class should be used in situations that require writing characters rather than bytes.

See Also (auto-generated):

Throwable

PrintWriter

Class


Field Summary
 
Fields inherited from class java.io.FilterOutputStream
out
 
Constructor Summary

          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.

          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.
 
Method Summary
 PrintStream
append(char c)

          Appends the specified character to this output stream.
 PrintStream

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

          Appends a subsequence of the specified character sequence to this output stream.
 boolean

          Flushes the stream and checks its error state.
protected void

          Clears the internal error state of this stream.
 void

          Closes the stream.
 void

          Flushes the stream.
 PrintStream
format(Locale l, String format, Object[] args)

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

          Writes a formatted string to this output stream using the specified format string and arguments.
 void
print(boolean b)

          Prints a boolean value.
 void
print(char c)

          Prints a character.
 void
print(char[] s)

          Prints an array of characters.
 void
print(double d)

          Prints a double-precision floating-point number.
 void
print(float f)

          Prints a floating-point number.
 void
print(int i)

          Prints an integer.
 void
print(long l)

          Prints a long integer.
 void

          Prints an object.
 void

          Prints a string.
 PrintStream
printf(Locale l, String format, Object[] args)

          A convenience method to write a formatted string to this output stream using the specified format string and arguments.
 PrintStream
printf(String format, Object[] args)

          A convenience method to write a formatted string to this output stream using the specified format string and arguments.
 void

          Terminates the current line by writing the line separator string.
 void
println(boolean x)

          Prints a boolean and then terminate the line.
 void
println(char x)

          Prints a character and then terminate the line.
 void
println(char[] x)

          Prints an array of characters and then terminate the line.
 void
println(double x)

          Prints a double and then terminate the line.
 void
println(float x)

          Prints a float and then terminate the line.
 void
println(int x)

          Prints an integer and then terminate the line.
 void
println(long x)

          Prints a long and then terminate the line.
 void

          Prints an Object and then terminate the line.
 void

          Prints a String and then terminate the line.
protected void

          Sets the error state of the stream to true.
 void
write(byte[] buf, int off, int len)

          Writes len bytes from the specified byte array starting at offset off to this stream.
 void
write(int b)

          Writes the specified byte to this stream.
 
Methods inherited from class java.io.FilterOutputStream
close, flush, write, write, write
 
Methods inherited from class java.io.OutputStream
close, flush, write, write, write
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

PrintStream

public PrintStream(File file)
            throws FileNotFoundException
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.

Parameters:
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

PrintStream

public PrintStream(File file,
                   String csn)
            throws FileNotFoundException,
                   UnsupportedEncodingException
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.

Parameters:
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.
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
UnsupportedEncodingException - If the named charset is not supported

PrintStream

public PrintStream(OutputStream out)
Creates a new print stream. This stream will not flush automatically.

Parameters:
out - The output stream to which values and objects will be printed

PrintStream

public PrintStream(OutputStream out,
                   boolean autoFlush)
Creates a new print stream.

Parameters:
out - The output stream to which values and objects will be printed
autoFlush - A boolean; if true, the output buffer will be flushed whenever a byte array is written, one of the println methods is invoked, or a newline character or byte ('\n') is written

PrintStream

public PrintStream(OutputStream out,
                   boolean autoFlush,
                   String encoding)
            throws UnsupportedEncodingException
Creates a new print stream.

Parameters:
out - The output stream to which values and objects will be printed
autoFlush - A boolean; if true, the output buffer will be flushed whenever a byte array is written, one of the println methods is invoked, or a newline character or byte ('\n') is written
encoding - The name of a supported character encoding
Throws:
UnsupportedEncodingException - If the named encoding is not supported

PrintStream

public PrintStream(String fileName)
            throws FileNotFoundException
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.

Parameters:
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

PrintStream

public PrintStream(String fileName,
                   String csn)
            throws FileNotFoundException,
                   UnsupportedEncodingException
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.

Parameters:
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.
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
UnsupportedEncodingException - If the named charset is not supported
Method Detail

append

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

An invocation of this method of the form out.append(c) behaves in exactly the same way as the invocation

     out.print(c) 

Parameters:
c - The 16-bit character to append
Returns:
This output stream

append

public PrintStream append(CharSequence csq)
Appends the specified character sequence to this output stream.

An invocation of this method of the form out.append(csq) behaves in exactly the same way as the invocation

     out.print(csq.toString()) 

Depending on the specification of toString for the character sequence csq, the entire sequence may not be appended. For instance, invoking then toString method of a character buffer will return a subsequence whose content depends upon the buffer's position and limit.

Parameters:
csq - The character sequence to append. If csq is null, then the four characters "null" are appended to this output stream.
Returns:
This output stream

append

public PrintStream append(CharSequence csq,
                          int start,
                          int end)
Appends a subsequence of the specified character sequence to this output stream.

An invocation of this method of the form out.append(csq, start, end) when csq is not null, behaves in exactly the same way as the invocation

     out.print(csq.subSequence(start, end).toString()) 

Parameters:
csq - The character sequence from which a subsequence will be appended. If csq is null, then characters will be appended as if csq contained the four characters "null".
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

checkError

public boolean checkError()
Flushes the stream and checks its error state. The internal error state is set to true when the underlying output stream throws an IOException other than InterruptedIOException, and when the setError method is invoked. If an operation on the underlying output stream throws an InterruptedIOException, then the PrintStream converts the exception back into an interrupt by doing:
     Thread.currentThread().interrupt();
 
or the equivalent.

Returns:
true if and only if this stream has encountered an IOException other than InterruptedIOException, or the setError method has been invoked

clearError

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

This method will cause subsequent invocations of {@link #checkError()} to return false until another write operation fails and invokes {@link #setError()}.


close

public void close()
Closes the stream. This is done by flushing the stream and then closing the underlying output stream.

Overrides:
close in class FilterOutputStream

flush

public void flush()
Flushes the stream. This is done by writing any buffered output bytes to the underlying output stream and then flushing that stream.

Overrides:
flush in class FilterOutputStream

format

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

Parameters:
l - The {@linkplain java.util.Locale 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. 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 Java Virtual Machine Specification. The behaviour on a null argument depends on the conversion.
Returns:
This output stream

format

public PrintStream format(String format,
                          Object[] args)
Writes a formatted string to this output stream using the specified format string and arguments.

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.

Parameters:
format - A format string as described in Format string syntax
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 Java Virtual Machine Specification. The behaviour on a null argument depends on the conversion.
Returns:
This output stream

print

public void print(boolean b)
Prints a boolean value. The string produced by {@link java.lang.String#valueOf(boolean)} is translated into bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the {@link #write(int)} method.

Parameters:
b - The boolean to be printed

print

public void print(char c)
Prints 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 {@link #write(int)} method.

Parameters:
c - The char to be printed

print

public void print(char[] s)
Prints 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 {@link #write(int)} method.

Parameters:
s - The array of chars to be printed

print

public void print(double d)
Prints a double-precision floating-point number. The string produced by {@link java.lang.String#valueOf(double)} is translated into bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the {@link #write(int)} method.

Parameters:
d - The double to be printed

print

public void print(float f)
Prints a floating-point number. The string produced by {@link java.lang.String#valueOf(float)} is translated into bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the {@link #write(int)} method.

Parameters:
f - The float to be printed

print

public void print(int i)
Prints an integer. The string produced by {@link java.lang.String#valueOf(int)} is translated into bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the {@link #write(int)} method.

Parameters:
i - The int to be printed

print

public void print(long l)
Prints a long integer. The string produced by {@link java.lang.String#valueOf(long)} is translated into bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the {@link #write(int)} method.

Parameters:
l - The long to be printed

print

public void print(Object obj)
Prints an object. The string produced by the {@link java.lang.String#valueOf(Object)} method is translated into bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the {@link #write(int)} method.

Parameters:
obj - The Object to be printed

print

public void print(String s)
Prints a string. If the argument is null then the string "null" 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 {@link #write(int)} method.

Parameters:
s - The String to be printed

printf

public PrintStream printf(Locale l,
                          String format,
                          Object[] args)
A convenience method to write a formatted string to this output stream using the specified format string and arguments.

An invocation of this method of the form out.printf(l, format, args) behaves in exactly the same way as the invocation

     out.format(l, format, args) 

Parameters:
l - The {@linkplain java.util.Locale 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. 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 Java Virtual Machine Specification. The behaviour on a null argument depends on the conversion.
Returns:
This output stream

printf

public PrintStream printf(String format,
                          Object[] args)
A convenience method to write a formatted string to this output stream using the specified format string and arguments.

An invocation of this method of the form out.printf(format, args) behaves in exactly the same way as the invocation

     out.format(format, args) 

Parameters:
format - A format string as described in Format string syntax
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 Java Virtual Machine Specification. The behaviour on a null argument depends on the conversion.
Returns:
This output stream

println

public void println()
Terminates the current line by writing the line separator string. The line separator string is defined by the system property line.separator, and is not necessarily a single newline character ('\n').


println

public void println(boolean x)
Prints a boolean and then terminate the line. This method behaves as though it invokes {@link #print(boolean)} and then {@link #println()}.

Parameters:
x - The boolean to be printed

println

public void println(char x)
Prints a character and then terminate the line. This method behaves as though it invokes {@link #print(char)} and then {@link #println()}.

Parameters:
x - The char to be printed.

println

public void println(char[] x)
Prints an array of characters and then terminate the line. This method behaves as though it invokes {@link #print(char[])} and then {@link #println()}.

Parameters:
x - an array of chars to print.

println

public void println(double x)
Prints a double and then terminate the line. This method behaves as though it invokes {@link #print(double)} and then {@link #println()}.

Parameters:
x - The double to be printed.

println

public void println(float x)
Prints a float and then terminate the line. This method behaves as though it invokes {@link #print(float)} and then {@link #println()}.

Parameters:
x - The float to be printed.

println

public void println(int x)
Prints an integer and then terminate the line. This method behaves as though it invokes {@link #print(int)} and then {@link #println()}.

Parameters:
x - The int to be printed.

println

public void println(long x)
Prints a long and then terminate the line. This method behaves as though it invokes {@link #print(long)} and then {@link #println()}.

Parameters:
x - a The long to be printed.

println

public void println(Object x)
Prints an Object and then terminate the line. This method calls at first String.valueOf(x) to get the printed object's string value, then behaves as though it invokes {@link #print(String)} and then {@link #println()}.

Parameters:
x - The Object to be printed.

println

public void println(String x)
Prints a String and then terminate the line. This method behaves as though it invokes {@link #print(String)} and then {@link #println()}.

Parameters:
x - The String to be printed.

setError

protected void setError()
Sets the error state of the stream to true.

This method will cause subsequent invocations of {@link #checkError()} to return true until {@link #clearError()} is invoked.


write

public void write(byte[] buf,
                  int off,
                  int len)
Writes len bytes from the specified byte array starting at offset off to this stream. If automatic flushing is enabled then the flush method will be invoked.

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 print(char) or println(char) methods.

Overrides:
write in class FilterOutputStream
Parameters:
buf - A byte array
off - Offset from which to start taking bytes
len - Number of bytes to write

write

public void write(int b)
Writes the specified byte to this stream. If the byte is a newline and automatic flushing is enabled then the flush method will be invoked.

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 print(char) or println(char) methods.

Overrides:
write in class FilterOutputStream
Parameters:
b - The byte to be written


This documentation differs from the official API. Jadeite adds extra features to the API including: variable font sizes, constructions examples, placeholders for classes and methods, and auto-generated “See Also” links. Additionally it is missing some items found in standard Javadoc documentation, including: generics type information, “Deprecated” tags and comments, “See Also” links, along with other minor differences. Please send any questions or feedback to bam@cs.cmu.edu.
This page displays the Jadeite version of the documention, which is derived from the offical documentation that contains this copyright notice:
Copyright 2008 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.
The official Sun™ documentation can be found here at http://java.sun.com/javase/6/docs/api/.