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
; instead, exceptional situations merely set an
internal flag that can be tested via the
Constructor: |
public PrintStream(OutputStream out) {
this(out, false);
}
Creates a new print stream. This stream will not flush automatically. Parameters:
out - The output stream to which values and objects will be
printed
Also see:
- java.io.PrintWriter#PrintWriter(java.io.OutputStream)
|
public PrintStream(String fileName) throws FileNotFoundException {
this(false, new FileOutputStream(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
{@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
SecurityException -
If a security manager is present and checkWrite(fileName) denies write
access to the file
- since:
1.5 -
|
public PrintStream(File file) throws FileNotFoundException {
this(false, new FileOutputStream(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 {@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
SecurityException -
If a security manager is present and checkWrite(file.getPath())
denies write access to the file
- since:
1.5 -
|
public PrintStream(OutputStream out,
boolean autoFlush) {
this(autoFlush, requireNonNull(out, "Null output stream"));
}
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
Also see:
- java.io.PrintWriter#PrintWriter(java.io.OutputStream, boolean)
|
public PrintStream(String fileName,
String csn) throws FileNotFoundException, UnsupportedEncodingException {
// ensure charset is checked before the file is opened
this(false, toCharset(csn), new FileOutputStream(fileName));
}
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 {@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
SecurityException -
If a security manager is present and checkWrite(fileName) denies write
access to the file
UnsupportedEncodingException -
If the named charset is not supported
- since:
1.5 -
|
public PrintStream(File file,
String csn) throws FileNotFoundException, UnsupportedEncodingException {
// ensure charset is checked before the file is opened
this(false, toCharset(csn), new FileOutputStream(file));
}
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 {@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
SecurityException -
If a security manager is presentand checkWrite(file.getPath())
denies write access to the file
UnsupportedEncodingException -
If the named charset is not supported
- since:
1.5 -
|
public PrintStream(OutputStream out,
boolean autoFlush,
String encoding) throws UnsupportedEncodingException {
this(autoFlush,
requireNonNull(out, "Null output stream"),
toCharset(encoding));
}
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
- since:
1.4 -
|
Method from java.io.PrintStream Detail: |
public PrintStream append(CharSequence csq) {
if (csq == null)
print("null");
else
print(csq.toString());
return this;
}
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. |
public PrintStream append(char c) {
print(c);
return this;
}
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) |
public PrintStream append(CharSequence csq,
int start,
int end) {
CharSequence cs = (csq == null ? "null" : csq);
write(cs.subSequence(start, end).toString());
return this;
}
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()) |
public boolean checkError() {
if (out != null)
flush();
if (out instanceof java.io.PrintStream) {
PrintStream ps = (PrintStream) out;
return ps.checkError();
}
return trouble;
}
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. |
protected void clearError() {
trouble = false;
}
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() . |
public void close() {
synchronized (this) {
if (! closing) {
closing = true;
try {
textOut.close();
out.close();
}
catch (IOException x) {
trouble = true;
}
textOut = null;
charOut = null;
out = null;
}
}
}
Closes the stream. This is done by flushing the stream and then closing
the underlying output stream. |
public void flush() {
synchronized (this) {
try {
ensureOpen();
out.flush();
}
catch (IOException x) {
trouble = true;
}
}
}
Flushes the stream. This is done by writing any buffered output bytes to
the underlying output stream and then flushing that stream. |
public PrintStream format(String format,
Object args) {
try {
synchronized (this) {
ensureOpen();
if ((formatter == null)
|| (formatter.locale() != Locale.getDefault()))
formatter = new Formatter((Appendable) this);
formatter.format(Locale.getDefault(), format, args);
}
} catch (InterruptedIOException x) {
Thread.currentThread().interrupt();
} catch (IOException x) {
trouble = true;
}
return this;
}
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. |
public PrintStream format(Locale l,
String format,
Object args) {
try {
synchronized (this) {
ensureOpen();
if ((formatter == null)
|| (formatter.locale() != l))
formatter = new Formatter(this, l);
formatter.format(l, format, args);
}
} catch (InterruptedIOException x) {
Thread.currentThread().interrupt();
} catch (IOException x) {
trouble = true;
}
return this;
}
Writes a formatted string to this output stream using the specified
format string and arguments. |
public void print(boolean b) {
write(b ? "true" : "false");
}
Prints a boolean value. The string produced by 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
#write(int) method. |
public void print(char c) {
write(String.valueOf(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. |
public void print(int i) {
write(String.valueOf(i));
}
Prints an integer. The string produced by 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
#write(int) method. |
public void print(long l) {
write(String.valueOf(l));
}
Prints a long integer. The string produced by 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
#write(int) method. |
public void print(float f) {
write(String.valueOf(f));
}
Prints a floating-point number. The string produced by 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
#write(int) method. |
public void print(double d) {
write(String.valueOf(d));
}
Prints a double-precision floating-point number. The string produced by
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 #write(int) method. |
public void print(char[] s) {
write(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. |
public void print(String s) {
if (s == null) {
s = "null";
}
write(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. |
public void print(Object obj) {
write(String.valueOf(obj));
}
Prints an object. The string produced by the 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
#write(int) method. |
public PrintStream printf(String format,
Object args) {
return format(format, 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) |
public PrintStream printf(Locale l,
String format,
Object args) {
return format(l, format, 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) |
public void println() {
newLine();
}
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' ). |
public void println(boolean x) {
synchronized (this) {
print(x);
newLine();
}
}
|
public void println(char x) {
synchronized (this) {
print(x);
newLine();
}
}
Prints a character and then terminate the line. This method behaves as
though it invokes #print(char) and then
#println() . |
public void println(int x) {
synchronized (this) {
print(x);
newLine();
}
}
Prints an integer and then terminate the line. This method behaves as
though it invokes #print(int) and then
#println() . |
public void println(long x) {
synchronized (this) {
print(x);
newLine();
}
}
Prints a long and then terminate the line. This method behaves as
though it invokes #print(long) and then
#println() . |
public void println(float x) {
synchronized (this) {
print(x);
newLine();
}
}
Prints a float and then terminate the line. This method behaves as
though it invokes #print(float) and then
#println() . |
public void println(double x) {
synchronized (this) {
print(x);
newLine();
}
}
Prints a double and then terminate the line. This method behaves as
though it invokes #print(double) and then
#println() . |
public void println(char[] x) {
synchronized (this) {
print(x);
newLine();
}
}
Prints an array of characters and then terminate the line. This method
behaves as though it invokes #print(char[]) and
then #println() . |
public void println(String x) {
synchronized (this) {
print(x);
newLine();
}
}
Prints a String and then terminate the line. This method behaves as
though it invokes #print(String) and then
#println() . |
public void println(Object x) {
String s = String.valueOf(x);
synchronized (this) {
print(s);
newLine();
}
}
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() . |
protected void setError() {
trouble = true;
}
Sets the error state of the stream to true .
This method will cause subsequent invocations of #checkError() to return true until #clearError() is invoked. |
public void write(int b) {
try {
synchronized (this) {
ensureOpen();
out.write(b);
if ((b == '\n') && autoFlush)
out.flush();
}
}
catch (InterruptedIOException x) {
Thread.currentThread().interrupt();
}
catch (IOException x) {
trouble = true;
}
}
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. |
public void write(byte[] buf,
int off,
int len) {
try {
synchronized (this) {
ensureOpen();
out.write(buf, off, len);
if (autoFlush)
out.flush();
}
}
catch (InterruptedIOException x) {
Thread.currentThread().interrupt();
}
catch (IOException x) {
trouble = true;
}
}
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. |