Closeable
, Flushable
, Appendable
, AutoCloseable
LogStream
public class PrintStream extends FilterOutputStream implements Appendable, Closeable
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.
out
Constructor | Description |
---|---|
PrintStream |
Creates a new print stream, without automatic line flushing, with the specified file. |
PrintStream |
Creates a new print stream, without automatic line flushing, with the specified file and charset. |
PrintStream |
Creates a new print stream, without automatic line flushing, with the specified file and charset. |
PrintStream |
Creates a new print stream, without automatic line flushing, with the specified OutputStream. |
PrintStream |
Creates a new print stream, with the specified OutputStream and line flushing. |
PrintStream |
Creates a new print stream, with the specified OutputStream, line flushing, and character encoding. |
PrintStream |
Creates a new print stream, with the specified OutputStream, line flushing and charset. |
PrintStream |
Creates a new print stream, without automatic line flushing, with the specified file name. |
PrintStream |
Creates a new print stream, without automatic line flushing, with the specified file name and charset. |
PrintStream |
Creates a new print stream, without automatic line flushing, with the specified file name and charset. |
Modifier and Type | Method | Description |
---|---|---|
PrintStream |
append |
Appends the specified character to this output stream. |
PrintStream |
append |
Appends the specified character sequence to this output stream. |
PrintStream |
append |
Appends a subsequence of the specified character sequence to this output stream. |
Charset |
charset() |
Returns the charset used in this PrintStream instance. |
boolean |
checkError() |
Flushes the stream if it's not closed and checks its error state. |
protected void |
clearError() |
Clears the error state of this stream. |
void |
close() |
Closes the stream. |
void |
flush() |
Flushes the stream. |
PrintStream |
format |
Writes a formatted string to this output stream using the specified format string and arguments. |
PrintStream |
format |
Writes a formatted string to this output stream using the specified format string and arguments. |
void |
print |
Prints a boolean value. |
void |
print |
Prints a character. |
void |
print |
Prints an array of characters. |
void |
print |
Prints a double-precision floating-point number. |
void |
print |
Prints a floating-point number. |
void |
print |
Prints an integer. |
void |
print |
Prints a long integer. |
void |
print |
Prints an object. |
void |
print |
Prints a string. |
PrintStream |
printf |
A convenience method to write a formatted string to this output stream using the specified format string and arguments. |
PrintStream |
printf |
A convenience method to write a formatted string to this output stream using the specified format string and arguments. |
void |
println() |
Terminates the current line by writing the line separator string. |
void |
println |
Prints a boolean and then terminates the line. |
void |
println |
Prints a character and then terminates the line. |
void |
println |
Prints an array of characters and then terminates the line. |
void |
println |
Prints a double and then terminates the line. |
void |
println |
Prints a float and then terminates the line. |
void |
println |
Prints an integer and then terminates the line. |
void |
println |
Prints a long and then terminates the line. |
void |
println |
Prints an Object and then terminates the line. |
void |
println |
Prints a String and then terminates the line. |
protected void |
setError() |
Sets the error state of the stream to true . |
void |
write |
Writes all bytes from the specified byte array to this stream. |
void |
write |
Writes len bytes from the specified byte array starting at offset off to this stream. |
void |
write |
Writes the specified byte to this stream. |
void |
writeBytes |
Writes all bytes from the specified byte array to this stream. |
nullOutputStream
public PrintStream(OutputStream out)
out
is a PrintStream
, the charset used by the print stream.out
- The output stream to which values and objects will be printedpublic PrintStream(OutputStream out, boolean autoFlush)
out
is a PrintStream
, the charset used by the print stream.out
- The output stream to which values and objects will be printedautoFlush
- 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 writtenpublic PrintStream(OutputStream out, boolean autoFlush, String encoding) throws UnsupportedEncodingException
out
- The output stream to which values and objects will be printedautoFlush
- 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 writtenencoding
- The name of a supported character encoding
UnsupportedEncodingException
- If the named encoding is not supportedpublic PrintStream(OutputStream out, boolean autoFlush, Charset charset)
OutputStreamWriter
, which will encode characters using the provided charset.out
- The output stream to which values and objects will be printedautoFlush
- 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 writtencharset
- A charset
public PrintStream(String fileName) throws FileNotFoundException
OutputStreamWriter
, which will encode characters using the default charset for this instance of the Java virtual machine.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.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 fileSecurityException
- If a security manager is present and checkWrite(fileName)
denies write access to the filepublic PrintStream(String fileName, String csn) throws FileNotFoundException, UnsupportedEncodingException
OutputStreamWriter
, which will encode characters using the provided charset.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
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 fileSecurityException
- If a security manager is present and checkWrite(fileName)
denies write access to the fileUnsupportedEncodingException
- If the named charset is not supportedpublic PrintStream(String fileName, Charset charset) throws IOException
OutputStreamWriter
, which will encode characters using the provided charset.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
IOException
- if an I/O error occurs while opening or creating the fileSecurityException
- If a security manager is present and checkWrite(fileName)
denies write access to the filepublic PrintStream(File file) throws FileNotFoundException
OutputStreamWriter
, which will encode characters using the default charset for this instance of the Java virtual machine.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.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 fileSecurityException
- If a security manager is present and checkWrite(file.getPath())
denies write access to the filepublic PrintStream(File file, String csn) throws FileNotFoundException, UnsupportedEncodingException
OutputStreamWriter
, which will encode characters using the provided charset.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
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 fileSecurityException
- If a security manager is present and checkWrite(file.getPath())
denies write access to the fileUnsupportedEncodingException
- If the named charset is not supportedpublic PrintStream(File file, Charset charset) throws IOException
OutputStreamWriter
, which will encode characters using the provided charset.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
IOException
- if an I/O error occurs while opening or creating the fileSecurityException
- If a security manager is present and checkWrite(file.getPath())
denies write access to the filepublic void flush()
flush
in interface Flushable
flush
in class FilterOutputStream
public void close()
close
in interface AutoCloseable
close
in interface Closeable
close
in class FilterOutputStream
public boolean checkError()
true
if and only if this stream has encountered an IOException
, or the setError
method has been invokedprotected void setError()
true
. This method will cause subsequent invocations of checkError()
to return true
until clearError()
is invoked.
protected void clearError()
This method will cause subsequent invocations of checkError()
to return false
until another write operation fails and invokes setError()
.
public void write(int b)
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.
write
in class FilterOutputStream
b
- The byte to be writtenpublic void write(byte[] buf, int off, int len)
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.
write
in class FilterOutputStream
buf
- A byte arrayoff
- Offset from which to start taking byteslen
- Number of bytes to writeIndexOutOfBoundsException
- If off
is negative, len
is negative, or len
is greater than b.length - off
public void write(byte[] buf) throws IOException
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.
write
in class FilterOutputStream
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)
.this.write(buf, 0, buf.length)
.buf
- A byte arrayIOException
- If an I/O error occurs.public void writeBytes(byte[] buf)
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.
this.write(buf, 0, buf.length)
.buf
- A byte arraypublic void print(boolean b)
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.b
- The boolean
to be printedpublic void print(char c)
write(int)
method.c
- The char
to be printedpublic void print(int i)
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.i
- The int
to be printedpublic void print(long l)
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.l
- The long
to be printedpublic void print(float f)
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.f
- The float
to be printedpublic void print(double d)
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.d
- The double
to be printedpublic void print(char[] s)
write(int)
method.s
- The array of chars to be printedNullPointerException
- If s
is null
public void print(String s)
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.s
- The String
to be printedpublic void print(Object obj)
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.obj
- The Object
to be printedpublic void println()
line.separator
, and is not necessarily a single newline character ('\n'
).public void println(boolean x)
print(boolean)
and then println()
.x
- The boolean
to be printedpublic void println(char x)
print(char)
and then println()
.x
- The char
to be printed.public void println(int x)
print(int)
and then println()
.x
- The int
to be printed.public void println(long x)
print(long)
and then println()
.x
- a The long
to be printed.public void println(float x)
print(float)
and then println()
.x
- The float
to be printed.public void println(double x)
print(double)
and then println()
.x
- The double
to be printed.public void println(char[] x)
print(char[])
and then println()
.x
- an array of chars to print.public void println(String x)
print(String)
and then println()
.x
- The String
to be printed.public void println(Object x)
print(String)
and then println()
.x
- The Object
to be printed.public PrintStream printf(String format, Object... args)
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)
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.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
public PrintStream printf(Locale l, String format, Object... args)
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)
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.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
public PrintStream format(String format, Object... args)
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.
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.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
public PrintStream format(Locale l, String format, Object... args)
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.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
public PrintStream append(CharSequence csq)
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.
append
in interface Appendable
csq
- The character sequence to append. If csq
is null
, then the four characters "null"
are appended to this output stream.public PrintStream append(CharSequence csq, int start, int end)
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())
append
in interface Appendable
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 subsequenceend
- The index of the character following the last character in the subsequenceIndexOutOfBoundsException
- If start
or end
are negative, start
is greater than end
, or end
is greater than csq.length()
public PrintStream append(char c)
An invocation of this method of the form out.append(c)
behaves in exactly the same way as the invocation
out.print(c)
append
in interface Appendable
c
- The 16-bit character to appendpublic Charset charset()
PrintStream
instance.PrintStream
instance
© 1993, 2023, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/io/PrintStream.html