PrintWriter (Java Platform SE 6)

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.

Overview

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java.io
class PrintWriter

java.lang.Object
  java.io.Writer
      java.io.PrintWriter

All Implemented Interfaces:: Closeable, Flushable, Appendable

Most common ways to construct:

OutputStream out = …;

PrintWriter p = new PrintWriter(out);

Based on 15 examples

OutputStream out = …;
boolean autoFlush = …;

PrintWriter p = new PrintWriter(out, autoFlush);

Based on 15 examples

StringWriter stringWriter = …;

PrintWriter printWriter = new PrintWriter(stringWriter);

Based on 14 examples

public class PrintWriter
extends Writer

Prints formatted representations of objects to a text-output stream. This class implements all of the print methods found in {@link PrintStream}. It does not contain methods for writing raw bytes, for which a program should use unencoded byte streams.

Unlike the {@link PrintStream} class, if automatic flushing is enabled it will be done only when one of the println, printf, or format methods is invoked, rather than whenever a newline character happens to be output. These methods use the platform's own notion of line separator rather than the newline character.

Methods in this class never throw I/O exceptions, although some of its constructors may. The client may inquire as to whether any errors have occurred by invoking {@link #checkError checkError()}.

See Also (auto-generated):

BufferedReader

File

Integer

Field Summary
`protected Writer`	`out` The underlying character-output stream of this `PrintWriter`.

Fields inherited from class java.io.Writer
`lock`

Constructor Summary
`PrintWriter(File file)` Creates a new PrintWriter, without automatic line flushing, with the specified file.
`PrintWriter(File file, String csn)` Creates a new PrintWriter, without automatic line flushing, with the specified file and charset.
`PrintWriter(OutputStream out)` Creates a new PrintWriter, without automatic line flushing, from an existing OutputStream.
`PrintWriter(OutputStream out, boolean autoFlush)` Creates a new PrintWriter from an existing OutputStream.
`PrintWriter(String fileName)` Creates a new PrintWriter, without automatic line flushing, with the specified file name.
`PrintWriter(String fileName, String csn)` Creates a new PrintWriter, without automatic line flushing, with the specified file name and charset.
`PrintWriter(Writer out)` Creates a new PrintWriter, without automatic line flushing.
`PrintWriter(Writer out, boolean autoFlush)` Creates a new PrintWriter.

Method Summary
`PrintWriter`	`append(char c)` Appends the specified character to this writer.
`PrintWriter`	`append(CharSequence csq)` Appends the specified character sequence to this writer.
`PrintWriter`	`append(CharSequence csq, int start, int end)` Appends a subsequence of the specified character sequence to this writer.
`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 and releases any system resources associated with it.
`void`	`flush()` Flushes the stream.
`PrintWriter`	`format(Locale l, String format, Object[] args)` Writes a formatted string to this writer using the specified format string and arguments.
`PrintWriter`	`format(String format, Object[] args)` Writes a formatted string to this writer 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`	`print(Object obj)` Prints an object.
`void`	`print(String s)` Prints a string.
`PrintWriter`	`printf(Locale l, String format, Object[] args)` A convenience method to write a formatted string to this writer using the specified format string and arguments.
`PrintWriter`	`printf(String format, Object[] args)` A convenience method to write a formatted string to this writer using the specified format string and arguments.
`void`	`println()` Terminates the current line by writing the line separator string.
`void`	`println(boolean x)` Prints a boolean value and then terminates the line.
`void`	`println(char x)` Prints a character and then terminates the line.
`void`	`println(char[] x)` Prints an array of characters and then terminates the line.
`void`	`println(double x)` Prints a double-precision floating-point number and then terminates the line.
`void`	`println(float x)` Prints a floating-point number and then terminates the line.
`void`	`println(int x)` Prints an integer and then terminates the line.
`void`	`println(long x)` Prints a long integer and then terminates the line.
`void`	`println(Object x)` Prints an Object and then terminates the line.
`void`	`println(String x)` Prints a String and then terminates the line.
`protected void`	`setError()` Indicates that an error has occurred.
`void`	`write(char[] buf)` Writes an array of characters.
`void`	`write(char[] buf, int off, int len)` Writes A Portion of an array of characters.
`void`	`write(int c)` Writes a single character.
`void`	`write(String s)` Writes a string.
`void`	`write(String s, int off, int len)` Writes a portion of a string.

Methods inherited from class java.io.Writer
`append, append, append, close, flush, write, write, write, write, write`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

out

protected Writer out

The underlying character-output stream of this PrintWriter.

Constructor Detail

PrintWriter

public PrintWriter(File file)
            throws FileNotFoundException

Creates a new PrintWriter, 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 writer. 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

PrintWriter

public PrintWriter(File file,
                   String csn)
            throws FileNotFoundException,
                   UnsupportedEncodingException

Creates a new PrintWriter, 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 writer. 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

PrintWriter

public PrintWriter(OutputStream out)

Creates a new PrintWriter, without automatic line flushing, from an existing OutputStream. This convenience constructor creates the necessary intermediate OutputStreamWriter, which will convert characters into bytes using the default character encoding.

Parameters:: out - An output stream

PrintWriter

public PrintWriter(OutputStream out,
                   boolean autoFlush)

Creates a new PrintWriter from an existing OutputStream. This convenience constructor creates the necessary intermediate OutputStreamWriter, which will convert characters into bytes using the default character encoding.

Parameters:: out - An output stream; autoFlush - A boolean; if true, the println, printf, or format methods will flush the output buffer

PrintWriter

public PrintWriter(String fileName)
            throws FileNotFoundException

Creates a new PrintWriter, 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 writer. 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 string 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

PrintWriter

public PrintWriter(String fileName,
                   String csn)
            throws FileNotFoundException,
                   UnsupportedEncodingException

Creates a new PrintWriter, 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 writer. 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 string 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

PrintWriter

public PrintWriter(Writer out)

Creates a new PrintWriter, without automatic line flushing.

Parameters:: out - A character-output stream

PrintWriter

public PrintWriter(Writer out,
                   boolean autoFlush)

Creates a new PrintWriter.

Parameters:: out - A character-output stream; autoFlush - A boolean; if true, the println, printf, or format methods will flush the output buffer

Method Detail

append

public PrintWriter append(char c)

Appends the specified character to this writer.

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

     out.write(c)

Overrides:: append in class Writer
Parameters:: c - The 16-bit character to append
Returns:: This writer

append

public PrintWriter append(CharSequence csq)

Appends the specified character sequence to this writer.

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

     out.write(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.

Overrides:: append in class Writer
Parameters:: csq - The character sequence to append. If csq is null, then the four characters "null" are appended to this writer.
Returns:: This writer

append

public PrintWriter append(CharSequence csq,
                          int start,
                          int end)

Appends a subsequence of the specified character sequence to this writer.

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.write(csq.subSequence(start, end).toString())

Overrides:: append in class Writer
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 writer

checkError

public boolean checkError()

Flushes the stream if it's not closed and checks its error state.

Returns:: true if the print stream has encountered an error, either on the underlying output stream or during a format conversion.

clearError

protected void clearError()

Clears the 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 and releases any system resources associated with it. Closing a previously closed stream has no effect.

Overrides:: close in class Writer

flush

public void flush()

Flushes the stream.

Overrides:: flush in class Writer

format

public PrintWriter format(Locale l,
                          String format,
                          Object[] args)

Writes a formatted string to this writer using the specified format string and arguments. If automatic flushing is enabled, calls to this method will flush the output buffer.

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 writer

format

public PrintWriter format(String format,
                          Object[] args)

Writes a formatted string to this writer using the specified format string and arguments. If automatic flushing is enabled, calls to this method will flush the output buffer.

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 writer

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 PrintWriter printf(Locale l,
                          String format,
                          Object[] args)

A convenience method to write a formatted string to this writer using the specified format string and arguments. If automatic flushing is enabled, calls to this method will flush the output buffer.

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 writer

printf

public PrintWriter printf(String format,
                          Object[] args)

A convenience method to write a formatted string to this writer using the specified format string and arguments. If automatic flushing is enabled, calls to this method will flush the output buffer.

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 writer

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 value and then terminates the line. This method behaves as though it invokes {@link #print(boolean)} and then {@link #println()}.

Parameters:: x - the boolean value to be printed

println

public void println(char x)

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

{@link
 #println()}

Parameters:: x - the char value 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 {@link #print(char[])} and then {@link #println()}.

Parameters:: x - the array of char values to be printed

println

public void println(double x)

Prints a double-precision floating-point number and then terminates the line. This method behaves as though it invokes

{@link
 #print(double)}

and then {@link #println()}.

Parameters:: x - the double value to be printed

println

public void println(float x)

Prints a floating-point number and then terminates the line. This method behaves as though it invokes {@link #print(float)} and then {@link #println()}.

Parameters:: x - the float value to be printed

println

public void println(int x)

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

{@link
 #println()}

Parameters:: x - the int value to be printed

println

public void println(long x)

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

Parameters:: x - the long value to be printed

println

public void println(Object x)

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 {@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 terminates the line. This method behaves as though it invokes {@link #print(String)} and then {@link #println()}.

Parameters:: x - the String value to be printed

setError

protected void setError()

Indicates that an error has occurred.

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

write

public void write(char[] buf)

Writes an array of characters. This method cannot be inherited from the Writer class because it must suppress I/O exceptions.

Overrides:: write in class Writer
Parameters:: buf - Array of characters to be written

write

public void write(char[] buf,
                  int off,
                  int len)

Writes A Portion of an array of characters.

Overrides:: write in class Writer
Parameters:: buf - Array of characters; off - Offset from which to start writing characters; len - Number of characters to write

write

public void write(int c)

Writes a single character.

Overrides:: write in class Writer
Parameters:: c - int specifying a character to be written.

write

public void write(String s)

Writes a string. This method cannot be inherited from the Writer class because it must suppress I/O exceptions.

Overrides:: write in class Writer
Parameters:: s - String to be written

write

public void write(String s,
                  int off,
                  int len)

Writes a portion of a string.

Overrides:: write in class Writer
Parameters:: s - A String; off - Offset from which to start writing characters; len - Number of characters to write

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This page displays the Jadeite version of the documention, which is derived from the offical documentation that contains this copyright notice:

The official Sun™ documentation can be found here at http://java.sun.com/javase/6/docs/api/.

java.ioclass PrintWriter

out

PrintWriter

PrintWriter

PrintWriter

PrintWriter

PrintWriter

PrintWriter

PrintWriter

PrintWriter

append

append

append

checkError

clearError

close

flush

format

format

print

print

print

print

print

print

print

print

print

printf

printf

println

println

println

println

println

println

println

println

println

println

setError

write

write

write

write

write

java.io
class PrintWriter