Class ServletOutputStream

java.lang.Object

java.io.OutputStream

jakarta.servlet.ServletOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

public abstract class ServletOutputStream
extends OutputStream

Provides an output stream for sending binary data to the client. A ServletOutputStream object is normally retrieved via the ServletResponse.getOutputStream() method.

This is an abstract class that the servlet container implements. Subclasses of this class must implement the java.io.OutputStream.write(int) method.

See Also:

• ServletResponse

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	ServletOutputStream()	Does nothing, because this is an abstract class.

Method Summary

Modifier and Type	Method	Description
abstract boolean	isReady()	Checks if a non-blocking write will succeed.
void	print(boolean b)	Writes a boolean value to the client, with no carriage return-line feed (CRLF) character at the end.
void	print(char c)	Writes a character to the client, with no carriage return-line feed (CRLF) at the end.
void	print(double d)	Writes a double value to the client, with no carriage return-line feed (CRLF) at the end.
void	print(float f)	Writes a float value to the client, with no carriage return-line feed (CRLF) at the end.
void	print(int i)	Writes an int to the client, with no carriage return-line feed (CRLF) at the end.
void	print(long l)	Writes a long value to the client, with no carriage return-line feed (CRLF) at the end.
void	print(String s)	Writes a String to the client, without a carriage return-line feed (CRLF) character at the end.
void	println()	Writes a carriage return-line feed (CRLF) to the client.
void	println(boolean b)	Writes a boolean value to the client, followed by a carriage return-line feed (CRLF).
void	println(char c)	Writes a character to the client, followed by a carriage return-line feed (CRLF).
void	println(double d)	Writes a double value to the client, followed by a carriage return-line feed (CRLF).
void	println(float f)	Writes a float value to the client, followed by a carriage return-line feed (CRLF).
void	println(int i)	Writes an int to the client, followed by a carriage return-line feed (CRLF) character.
void	println(long l)	Writes a long value to the client, followed by a carriage return-line feed (CRLF).
void	println(String s)	Writes a String to the client, followed by a carriage return-line feed (CRLF).
abstract void	setWriteListener(WriteListener listener)	Sets the WriteListener for this ServletOutputStream and thereby switches to non-blocking IO.

Methods inherited from class java.io.OutputStream

close, flush, nullOutputStream, write, write, write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ServletOutputStream

protected ServletOutputStream()

Does nothing, because this is an abstract class.

Method Details

print

public void print(String s)
           throws IOException

Writes a String to the client, without a carriage return-line feed (CRLF) character at the end.

Parameters:

s - the String to send to the client

Throws:

IOException - if an input or output exception occurred

print

public void print(boolean b)
           throws IOException

Writes a boolean value to the client, with no carriage return-line feed (CRLF) character at the end.

Parameters:

b - the boolean value to send to the client

Throws:

IOException - if an input or output exception occurred

print

public void print(char c)
           throws IOException

Writes a character to the client, with no carriage return-line feed (CRLF) at the end.

Parameters:

c - the character to send to the client

Throws:

IOException - if an input or output exception occurred

print

public void print(int i)
           throws IOException

Writes an int to the client, with no carriage return-line feed (CRLF) at the end.

Parameters:

i - the int to send to the client

Throws:

IOException - if an input or output exception occurred

print

public void print(long l)
           throws IOException

Writes a long value to the client, with no carriage return-line feed (CRLF) at the end.

Parameters:

l - the long value to send to the client

Throws:

IOException - if an input or output exception occurred

print

public void print(float f)
           throws IOException

Writes a float value to the client, with no carriage return-line feed (CRLF) at the end.

Parameters:

f - the float value to send to the client

Throws:

IOException - if an input or output exception occurred

print

public void print(double d)
           throws IOException

Writes a double value to the client, with no carriage return-line feed (CRLF) at the end.

Parameters:

d - the double value to send to the client

Throws:

IOException - if an input or output exception occurred

println

public void println()
             throws IOException

Writes a carriage return-line feed (CRLF) to the client.

Throws:

IOException - if an input or output exception occurred

println

public void println(String s)
             throws IOException

Writes a String to the client, followed by a carriage return-line feed (CRLF).

Parameters:

s - the String to write to the client

Throws:

IOException - if an input or output exception occurred

println

public void println(boolean b)
             throws IOException

Writes a boolean value to the client, followed by a carriage return-line feed (CRLF).

Parameters:

b - the boolean value to write to the client

Throws:

IOException - if an input or output exception occurred

println

public void println(char c)
             throws IOException

Writes a character to the client, followed by a carriage return-line feed (CRLF).

Parameters:

c - the character to write to the client

Throws:

IOException - if an input or output exception occurred

println

public void println(int i)
             throws IOException

Writes an int to the client, followed by a carriage return-line feed (CRLF) character.

Parameters:

i - the int to write to the client

Throws:

IOException - if an input or output exception occurred

println

public void println(long l)
             throws IOException

Writes a long value to the client, followed by a carriage return-line feed (CRLF).

Parameters:

l - the long value to write to the client

Throws:

IOException - if an input or output exception occurred

println

public void println(float f)
             throws IOException

Writes a float value to the client, followed by a carriage return-line feed (CRLF).

Parameters:

f - the float value to write to the client

Throws:

IOException - if an input or output exception occurred

println

public void println(double d)
             throws IOException

Writes a double value to the client, followed by a carriage return-line feed (CRLF).

Parameters:

d - the double value to write to the client

Throws:

IOException - if an input or output exception occurred

isReady

public abstract boolean isReady()

Checks if a non-blocking write will succeed. If this returns false, it will cause a callback to WriteListener.onWritePossible() when the buffer has emptied. If this method returns false no further data must be written until the container calls WriteListener.onWritePossible().

Returns:

true if data can be written, else false

Since:

Servlet 3.1

setWriteListener

public abstract void setWriteListener(WriteListener listener)

Sets the WriteListener for this ServletOutputStream and thereby switches to non-blocking IO. It is only valid to switch to non-blocking IO within async processing or HTTP upgrade processing.

Parameters:

listener - The non-blocking IO write listener

Throws:

IllegalStateException - If this method is called if neither async nor HTTP upgrade is in progress or if the WriteListener has already been set

NullPointerException - If listener is null

Since:

Servlet 3.1