GeezerVison is showing docs.oracle.com — PrintStream (Java SE 24 & JDK 24)
Class PrintStream
- All Implemented Interfaces:
Closeable, Flushable, Appendable, AutoCloseable
- Direct Known Subclasses:
LogStream
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 of the underlying
output stream 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 given encoding or charset, or the default charset if not
specified.
The PrintWriter class should be used in situations that require
writing characters rather than bytes.
This class always replaces malformed and unmappable character sequences
with the charset's default replacement string.
The CharsetEncoder class should be used when more
control over the encoding process is required.
- Since:
- 1.0
- See Also:
-
-
-
Constructor Summary
Constructors
Constructor
Description
Creates a new print stream, without automatic line flushing, with the
specified file.
Creates a new print stream, without automatic line flushing, with the
specified file and charset.
Creates a new print stream, without automatic line flushing, with the
specified file and charset.
Creates a new print stream, without automatic line flushing, with the
specified OutputStream.
Creates a new print stream, with the specified OutputStream and line
flushing.
Creates a new print stream, with the specified OutputStream, line
flushing, and character encoding.
Creates a new print stream, with the specified OutputStream, line
flushing and charset.
Creates a new print stream, without automatic line flushing, with the
specified file name.
Creates a new print stream, without automatic line flushing, with the
specified file name and charset.
Creates a new print stream, without automatic line flushing, with the
specified file name and charset.
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Method Summary
Modifier and Type
Method
Description
Appends the specified character to this output stream.
Appends the specified character sequence to this output stream.
Appends a subsequence of the specified character sequence to this output
stream.
Returns the charset used in this PrintStream instance.
boolean
Flushes the stream if it's not closed and checks its error state.
protected void
Clears the error state of this stream.
void
void
Writes a formatted string to this output stream using the specified
format string and arguments.
Writes a formatted string to this output stream using the specified
format string and arguments.
void
void
void
Prints an array of characters.
void
Prints a double-precision floating-point number.
void
Prints a floating-point number.
void
void
void
void
A convenience method to write a formatted string to this output stream
using the specified format string and arguments.
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
Prints a boolean and then terminates the line.
void
Prints a character and then terminates the line.
void
Prints an array of characters and then terminates the line.
void
Prints a double and then terminates the line.
void
Prints a float and then terminates the line.
void
Prints an integer and then terminates the line.
void
Prints a long and then terminates the line.
void
Prints an Object and then terminates the line.
void
Prints a String and then terminates the line.
protected void
Sets the error state of the stream to true.
void
Writes all bytes from the specified byte array to this stream.
void
write(byte[] buf,
int off,
int len)
Writes len bytes from the specified byte array starting at
offset off to this stream.
void
Writes the specified byte to this stream.
void
Writes all bytes from the specified byte array to this stream.
Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
-
Constructor Details
-
PrintStream
Creates a new print stream, without automatic line flushing, with the
specified OutputStream. Characters written to the stream are converted
to bytes using the default charset, or where out is a
PrintStream, the charset used by the print stream.
- Parameters:
out - The output stream to which values and objects will be
printed
- See Also:
-
-
PrintStream
Creates a new print stream, with the specified OutputStream and line
flushing. Characters written to the stream are converted to bytes using
the default charset, or where out is a PrintStream,
the charset used by the print stream.
- Parameters:
out - The output stream to which values and objects will be
printed
autoFlush - Whether 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
Creates a new print stream, with the specified OutputStream, line
flushing, and character encoding.
- Parameters:
out - The output stream to which values and objects will be
printed
autoFlush - Whether 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
- Since:
- 1.4
-
PrintStream
Creates a new print stream, with the specified OutputStream, line
flushing and charset. This convenience constructor creates the necessary
intermediate OutputStreamWriter,
which will encode characters using the provided charset.
- Parameters:
out - The output stream to which values and objects will be
printed
autoFlush - Whether 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
charset - A charset
- Since:
- 10
-
PrintStream
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 - 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
- Since:
- 1.5
- See Also:
-
-
PrintStream
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 - 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 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
- Since:
- 1.5
-
PrintStream
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 - 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.
charset - A charset
- Throws:
IOException - if an I/O error occurs while opening or creating the file
- Since:
- 10
-
PrintStream
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 - 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
- Since:
- 1.5
- See Also:
-
-
PrintStream
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 - 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 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
- Since:
- 1.5
-
PrintStream
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 - 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.
charset - A charset
- Throws:
IOException - if an I/O error occurs while opening or creating the file
- Since:
- 10
-
Method Details
-
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.
- Specified by:
flush in interface Flushable
- Overrides:
flush in class FilterOutputStream
- See Also:
-
-
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checkError
public boolean checkError()
Flushes the stream if it's not closed and checks its error state.
- Returns:
true if and only if this stream has encountered an
IOException, or the setError method has been
invoked
-
setError
protected 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.
- Since:
- 1.1
-
clearError
protected void clearError()
Clears the error state of this stream.
This method will cause subsequent invocations of checkError() to return false until another write
operation fails and invokes setError().
- Since:
- 1.6
-
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 on the underlying output stream.
Note that the byte is written as given; to write a character that
will be translated according to the default charset, use the
print(char) or println(char) methods.
- Overrides:
write in class FilterOutputStream
- Parameters:
b - The byte to be written
- See Also:
-
-
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 on the underlying
output stream.
Note that the bytes will be written as given; to write characters
that will be translated according to the default charset, 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
- Throws:
IndexOutOfBoundsException - If off is negative,
len is negative, or len is greater than
b.length - off
- See Also:
-
-
write
Writes all bytes from the specified byte array to this stream. If
automatic flushing is enabled then the flush method will be
invoked on the underlying output stream.
Note that the bytes will be written as given; to write characters
that will be translated according to the default charset, use the
print(char[]) or println(char[]) methods.
- Overrides:
write in class FilterOutputStream
- API Note:
- Although declared to throw
IOException, this method never
actually does so. Instead, like other methods that this class
overrides, it sets an internal flag which may be tested via the
checkError() method. To write an array of bytes without having
to write a catch block for the IOException, use either
writeBytes(buf) or
write(buf, 0, buf.length).
- Implementation Requirements:
- This method is equivalent to
this.write(buf, 0, buf.length).
- Parameters:
buf - A byte array
- Throws:
IOException - If an I/O error occurs.
- See Also:
-
-
writeBytes
public void writeBytes(byte[] buf)
Writes all bytes from the specified byte array 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 default charset, use the
print(char[]) or println(char[]) methods.
- Implementation Requirements:
- This method is equivalent to
this.write(buf, 0, buf.length).
- Parameters:
buf - A byte array
- Since:
- 14
-
print
public void print(boolean b)
Prints a boolean value. The string produced by String.valueOf(boolean) is translated into bytes
according to the default charset, and these bytes
are written in exactly the manner of the
write(int) method.
- Parameters:
b - The boolean to be printed
- See Also:
-
-
print
public void print(char c)
Prints a character. The character is translated into one or more bytes
according to the character encoding given to the constructor, or the
default charset if none specified. These bytes
are written in exactly the manner of the write(int) method.
- Parameters:
c - The char to be printed
- See Also:
-
-
print
public void print(int i)
Prints an integer. The string produced by String.valueOf(int) is translated into bytes
according to the default charset, and these bytes
are written in exactly the manner of the
write(int) method.
- Parameters:
i - The int to be printed
- See Also:
-
-
print
public void print(long l)
Prints a long integer. The string produced by String.valueOf(long) is translated into bytes
according to the default charset, and these bytes
are written in exactly the manner of the
write(int) method.
- Parameters:
l - The long to be printed
- See Also:
-
-
print
public void print(float f)
Prints a floating-point number. The string produced by String.valueOf(float) is translated into bytes
according to the default charset, and these bytes
are written in exactly the manner of the
write(int) method.
- Parameters:
f - The float to be printed
- See Also:
-
-
print
public void print(double d)
Prints a double-precision floating-point number. The string produced by
String.valueOf(double) is translated into
bytes according to the default charset, and these
bytes are written in exactly the manner of the write(int) method.
- Parameters:
d - The double to be printed
- See Also:
-
-
print
public void print(char[] s)
Prints an array of characters. The characters are converted into bytes
according to the character encoding given to the constructor, or the
default charset if none specified. These bytes
are written in exactly the manner of the write(int) method.
- Parameters:
s - The array of chars to be printed
- Throws:
NullPointerException - If s is null
- See Also:
-
-
print
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 character encoding given to the
constructor, or the default charset if none
specified. These bytes are written in exactly the manner of the
write(int) method.
- Parameters:
s - The String to be printed
- See Also:
-
-
print
Prints an object. The string produced by the String.valueOf(Object) method is translated into bytes
according to the default charset, and these bytes
are written in exactly the manner of the
write(int) method.
- Parameters:
obj - The Object to be printed
- See Also:
-
-
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 terminates the line. This method behaves as
though it invokes print(boolean) and then
println().
- Parameters:
x - The boolean to be printed
-
println
public void println(char x)
Prints a character and then terminates the line. This method behaves as
though it invokes print(char) and then
println().
- Parameters:
x - The char to be printed.
-
println
public void println(int x)
Prints an integer and then terminates the line. This method behaves as
though it invokes print(int) and then
println().
- Parameters:
x - The int to be printed.
-
println
public void println(long x)
Prints a long and then terminates the line. This method behaves as
though it invokes print(long) and then
println().
- Parameters:
x - a The long to be printed.
-
println
public void println(float x)
Prints a float and then terminates the line. This method behaves as
though it invokes print(float) and then
println().
- Parameters:
x - The float to be printed.
-
println
public void println(double x)
Prints a double and then terminates the line. This method behaves as
though it invokes print(double) and then
println().
- Parameters:
x - The double to be printed.
-
println
public void println(char[] x)
Prints an array of characters and then terminates the line. This method
behaves as though it invokes print(char[]) and
then println().
- Parameters:
x - an array of chars to print.
-
println
Prints a String and then terminates the line. This method behaves as
though it invokes print(String) and then
println().
- Parameters:
x - The String to be printed.
-
println
Prints an Object and then terminates 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 - The Object to be printed.
-
printf
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
- 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
- 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 Details section of the
formatter class specification.
NullPointerException - If the format is null
- Since:
- 1.5
-
printf
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 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
- 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 Details section of the
formatter class specification.
NullPointerException - If the format is null
- Since:
- 1.5
-
format
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(Locale.Category) with
FORMAT category specified,
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
- 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 Details section of the
formatter class specification.
NullPointerException - If the format is null
- Since:
- 1.5
-
format
Writes a formatted string to this output stream using the specified
format string and arguments.
- 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. 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
- 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 Details section of the
formatter class specification.
NullPointerException - If the format is null
- Since:
- 1.5
-
append
Appends the specified character sequence to this output stream.
An invocation of this method of the form out.append(csq)
when csq is not null, 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 the toString method of a
character buffer will return a subsequence whose content depends upon
the buffer's position and limit.
- Specified by:
append in interface Appendable
- 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
- Since:
- 1.5
-
append
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())
- Specified by:
append in interface Appendable
- 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
- Throws:
IndexOutOfBoundsException - If start or end are negative, start
is greater than end, or end is greater than
csq.length()
- Since:
- 1.5
-
append
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
- Specified by:
append in interface Appendable
- Parameters:
c - The 16-bit character to append
- Returns:
- This output stream
- Since:
- 1.5
-
charset
Returns the charset used in this PrintStream instance.
- Returns:
- the charset used in this
PrintStream instance
- Since:
- 18
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