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PrintStream

public class PrintStream
extends FilterOutputStream implements Appendable, Closeable

java.lang.Object
   ↳ java.io.OutputStream
     ↳ java.io.FilterOutputStream
       ↳ java.io.PrintStream


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 PrintWriter class should be used in situations that require writing characters rather than bytes.

Summary

Inherited fields

From class java.io.FilterOutputStream

Public constructors

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.

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.

Public methods

PrintStream append(char c)

Appends the specified character to this output stream.

PrintStream append(CharSequence csq, int start, int end)

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

PrintStream append(CharSequence csq)

Appends the specified character sequence to this output stream.

boolean checkError()

Flushes the stream and checks its error state.

void close()

Closes the stream.

void flush()

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(int i)

Prints an integer.

void print(double d)

Prints a double-precision floating-point number.

void print(boolean b)

Prints a boolean value.

void print(char c)

Prints a character.

void print(long l)

Prints a long integer.

void print(float f)

Prints a floating-point number.

void print(String s)

Prints a string.

void print(Object obj)

Prints an object.

void print(char[] s)

Prints an array of characters.

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.

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.

void println(Object x)

Prints an Object and then terminate the line.

void println(char x)

Prints a character and then terminate the line.

void println(boolean x)

Prints a boolean and then terminate the line.

void println(long x)

Prints a long and then terminate the line.

void println()

Terminates the current line by writing the line separator string.

void println(int x)

Prints an integer and then terminate the line.

void println(String x)

Prints a String and then terminate the line.

void println(char[] x)

Prints an array of characters and then terminate the line.

void println(float x)

Prints a float and then terminate the line.

void println(double x)

Prints a double and then terminate the line.

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.

Protected methods

void clearError()

Clears the internal error state of this stream.

void setError()

Sets the error state of the stream to true.

Inherited methods

From class java.io.FilterOutputStream
From class java.io.OutputStream
From class java.lang.Object
From interface java.io.Closeable
From interface java.io.Flushable
From interface java.lang.Appendable
From interface java.lang.AutoCloseable

Public constructors

PrintStream

Added in API level 1
PrintStream (OutputStream out)

Creates a new print stream. This stream will not flush automatically.

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

See also:

PrintStream

Added in API level 1
PrintStream (OutputStream out, 
                boolean autoFlush)

Creates a new print stream.

Parameters
out OutputStream: The output stream to which values and objects will be printed
autoFlush boolean: 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

See also:

PrintStream

Added in API level 1
PrintStream (OutputStream out, 
                boolean autoFlush, 
                String encoding)

Creates a new print stream.

Parameters
out OutputStream: The output stream to which values and objects will be printed
autoFlush boolean: 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 String: The name of a supported character encoding
Throws
UnsupportedEncodingException If the named encoding is not supported

PrintStream

Added in API level 1
PrintStream (String fileName)

Creates a new print stream, without automatic line flushing, with the specified file name. This convenience constructor creates the necessary intermediate OutputStreamWriter, which will encode characters using the default charset for this instance of the Java virtual machine.

Parameters
fileName String: 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
SecurityException If a security manager is present and checkWrite(fileName) denies write access to the file

PrintStream

Added in API level 1
PrintStream (String fileName, 
                String csn)

Creates a new print stream, without automatic line flushing, with the specified file name and charset. This convenience constructor creates the necessary intermediate OutputStreamWriter, which will encode characters using the provided charset.

Parameters
fileName String: 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 String: The name of a supported 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
SecurityException If a security manager is present and checkWrite(fileName) denies write access to the file
UnsupportedEncodingException If the named charset is not supported

PrintStream

Added in API level 1
PrintStream (File file)

Creates a new print stream, without automatic line flushing, with the specified file. This convenience constructor creates the necessary intermediate OutputStreamWriter, which will encode characters using the default charset for this instance of the Java virtual machine.

Parameters
file 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
SecurityException If a security manager is present and checkWrite(file.getPath()) denies write access to the file

PrintStream

Added in API level 1
PrintStream (File file, 
                String csn)

Creates a new print stream, without automatic line flushing, with the specified file and charset. This convenience constructor creates the necessary intermediate OutputStreamWriter, which will encode characters using the provided charset.

Parameters
file 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 String: The name of a supported 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
SecurityException If a security manager is presentand checkWrite(file.getPath()) denies write access to the file
UnsupportedEncodingException If the named charset is not supported

Public methods

append

Added in API level 1
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 char: The 16-bit character to append
Returns
PrintStream This output stream

append

Added in API level 1
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 CharSequence: 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 int: The index of the first character in the subsequence
end int: The index of the character following the last character in the subsequence
Returns
PrintStream This output stream
Throws
IndexOutOfBoundsException If start or end are negative, start is greater than end, or end is greater than csq.length()

append

Added in API level 1
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 CharSequence: The character sequence to append. If csq is null, then the four characters "null" are appended to this output stream.
Returns
PrintStream This output stream

checkError

Added in API level 1
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
boolean true if and only if this stream has encountered an IOException other than InterruptedIOException, or the setError method has been invoked

close

Added in API level 1
void close ()

Closes the stream. This is done by flushing the stream and then closing the underlying output stream.

See also:

flush

Added in API level 1
void flush ()

Flushes the stream. This is done by writing any buffered output bytes to the underlying output stream and then flushing that stream.

See also:

format

Added in API level 1
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 Locale: The locale to apply during formatting. If l is null then no localization is applied.
format String: A format string as described in Format string syntax
args Object: 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
PrintStream This output stream
Throws
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 Details section of the formatter class specification.
NullPointerException If the format is null

format

Added in API level 1
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 Locale.getDefault(), regardless of any previous invocations of other formatting methods on this object.

Parameters
format String: A format string as described in Format string syntax
args Object: 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
PrintStream This output stream
Throws
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 Details section of the formatter class specification.
NullPointerException If the format is null

print

Added in API level 1
void print (int i)

Prints an integer. The string produced by 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 write(int) method.

Parameters
i int: The int to be printed

See also:

print

Added in API level 1
void print (double d)

Prints a double-precision floating-point number. The string produced by 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 write(int) method.

Parameters
d double: The double to be printed

See also:

print

Added in API level 1
void print (boolean b)

Prints a boolean value. The string produced by 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 write(int) method.

Parameters
b boolean: The boolean to be printed

print

Added in API level 1
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 write(int) method.

Parameters
c char: The char to be printed

print

Added in API level 1
void print (long l)

Prints a long integer. The string produced by 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 write(int) method.

Parameters
l long: The long to be printed

See also:

print

Added in API level 1
void print (float f)

Prints a floating-point number. The string produced by 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 write(int) method.

Parameters
f float: The float to be printed

See also:

print

Added in API level 1
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 write(int) method.

Parameters
s String: The String to be printed

print

Added in API level 1
void print (Object obj)

Prints an object. The string produced by the 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 write(int) method.

Parameters
obj Object: The Object to be printed

See also:

print

Added in API level 1
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 write(int) method.

Parameters
s char: The array of chars to be printed
Throws
NullPointerException If s is null

printf

Added in API level 1
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 String: A format string as described in Format string syntax
args Object: 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
PrintStream This output stream
Throws
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 Details section of the formatter class specification.
NullPointerException If the format is null

printf

Added in API level 1
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 Locale: The locale to apply during formatting. If l is null then no localization is applied.
format String: A format string as described in Format string syntax
args Object: 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
PrintStream This output stream
Throws
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 Details section of the formatter class specification.
NullPointerException If the format is null

println

Added in API level 1
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 print(String) and then println().

Parameters
x Object: The Object to be printed.

println

Added in API level 1
void println (char x)

Prints a character and then terminate the line. This method behaves as though it invokes print(char) and then println().

Parameters
x char: The char to be printed.

println

Added in API level 1
void println (boolean x)

Prints a boolean and then terminate the line. This method behaves as though it invokes print(boolean) and then println().

Parameters
x boolean: The boolean to be printed

println

Added in API level 1
void println (long x)

Prints a long and then terminate the line. This method behaves as though it invokes print(long) and then println().

Parameters
x long: a The long to be printed.

println

Added in API level 1
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

Added in API level 1
void println (int x)

Prints an integer and then terminate the line. This method behaves as though it invokes print(int) and then println().

Parameters
x int: The int to be printed.

println

Added in API level 1
void println (String x)

Prints a String and then terminate the line. This method behaves as though it invokes print(String) and then println().

Parameters
x String: The String to be printed.

println

Added in API level 1
void println (char[] x)

Prints an array of characters and then terminate the line. This method behaves as though it invokes print(char[]) and then println().

Parameters
x char: an array of chars to print.

println

Added in API level 1
void println (float x)

Prints a float and then terminate the line. This method behaves as though it invokes print(float) and then println().

Parameters
x float: The float to be printed.

println

Added in API level 1
void println (double x)

Prints a double and then terminate the line. This method behaves as though it invokes print(double) and then println().

Parameters
x double: The double to be printed.

write

Added in API level 1
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.

Parameters
buf byte: A byte array
off int: Offset from which to start taking bytes
len int: Number of bytes to write

write

Added in API level 1
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.

Parameters
b int: The byte to be written

See also:

Protected methods

clearError

Added in API level 9
void clearError ()

Clears the internal error state of this stream.

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

setError

Added in API level 1
void setError ()

Sets the error state of the stream to true.

This method will cause subsequent invocations of checkError() to return true until clearError() is invoked.

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