Class ServletOutputStream
- All Implemented Interfaces:
- Closeable,- Flushable,- AutoCloseable
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:
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Constructor SummaryConstructorsModifierConstructorDescriptionprotectedDoes nothing, because this is an abstract class.
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Method SummaryModifier and TypeMethodDescriptionvoidclose()abstract booleanisReady()Returnstrueif it is allowable to call any method that may write data (e.g.voidprint(boolean b) Writes abooleanvalue to the client, with no carriage return-line feed (CRLF) character at the end.voidprint(char c) Writes a character to the client, with no carriage return-line feed (CRLF) at the end.voidprint(double d) Writes adoublevalue to the client, with no carriage return-line feed (CRLF) at the end.voidprint(float f) Writes afloatvalue to the client, with no carriage return-line feed (CRLF) at the end.voidprint(int i) Writes an int to the client, with no carriage return-line feed (CRLF) at the end.voidprint(long l) Writes alongvalue to the client, with no carriage return-line feed (CRLF) at the end.voidWrites aStringto the client, without a carriage return-line feed (CRLF) character at the end.voidprintln()Writes a carriage return-line feed (CRLF) to the client.voidprintln(boolean b) Writes abooleanvalue to the client, followed by a carriage return-line feed (CRLF).voidprintln(char c) Writes a character to the client, followed by a carriage return-line feed (CRLF).voidprintln(double d) Writes adoublevalue to the client, followed by a carriage return-line feed (CRLF).voidprintln(float f) Writes afloatvalue to the client, followed by a carriage return-line feed (CRLF).voidprintln(int i) Writes an int to the client, followed by a carriage return-line feed (CRLF) character.voidprintln(long l) Writes alongvalue to the client, followed by a carriage return-line feed (CRLF).voidWrites aStringto the client, followed by a carriage return-line feed (CRLF).abstract voidsetWriteListener(WriteListener listener) Sets theWriteListenerfor thisServletOutputStreamand thereby switches to non-blocking IO.voidwrite(ByteBuffer buffer) Writes from the given buffer to the output stream.Methods inherited from class java.io.OutputStreamflush, nullOutputStream, write, write, write
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Constructor Details- 
ServletOutputStreamprotected ServletOutputStream()Does nothing, because this is an abstract class.
 
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Method Details- 
writeWrites from the given buffer to the output stream.If the output steam is in non-blocking mode, before each invocation of this method isReady()must be called and must returntrueor theWriteListener.onWritePossible()call back must indicate that data may be written else anIllegalStateExceptionmust be thrown.Otherwise, if this method is called when bufferhas no data remaining, the method returns immediately andbufferis unchanged.If the output stream is in non-blocking mode, neither the position, limit nor content of the buffer passed to this method may be modified until a subsequent call to isReady()returns true or theWriteListener.onWritePossible()call back indicates data may be written again. At this point the buffer's limit will be unchanged from the value when passed to this method and the position will be the same as the limit.If the output stream is in blocking mode and bufferhas space remaining, this method blocks until all the remaining data in the buffer has been written. When the method returns, and if data has been written, the buffer's limit will be unchanged from the value when passed to this method and the position will be the same as the limit.Subclasses are strongly encouraged to override this method and provide a more efficient implementation. - Parameters:
- buffer- The buffer from which the data is written.
- Throws:
- IllegalStateException- If the output stream is in non-blocking mode and this method is called without first calling- isReady()and that method has returned- trueor- WriteListener.onWritePossible()has not signalled that data may be written.
- IOException- If the output stream has been closed or if some other I/O error occurs.
- NullPointerException- If buffer is null.
- Since:
- Servlet 6.1
 
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printWrites aStringto the client, without a carriage return-line feed (CRLF) character at the end.- Parameters:
- s- the- Stringto send to the client
- Throws:
- IOException- if an input or output exception occurred
 
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printWrites abooleanvalue to the client, with no carriage return-line feed (CRLF) character at the end.- Parameters:
- b- the- booleanvalue to send to the client
- Throws:
- IOException- if an input or output exception occurred
 
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printWrites 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
 
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printWrites 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
 
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printWrites alongvalue to the client, with no carriage return-line feed (CRLF) at the end.- Parameters:
- l- the- longvalue to send to the client
- Throws:
- IOException- if an input or output exception occurred
 
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printWrites afloatvalue to the client, with no carriage return-line feed (CRLF) at the end.- Parameters:
- f- the- floatvalue to send to the client
- Throws:
- IOException- if an input or output exception occurred
 
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printWrites adoublevalue to the client, with no carriage return-line feed (CRLF) at the end.- Parameters:
- d- the- doublevalue to send to the client
- Throws:
- IOException- if an input or output exception occurred
 
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printlnWrites a carriage return-line feed (CRLF) to the client.- Throws:
- IOException- if an input or output exception occurred
 
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printlnWrites aStringto the client, followed by a carriage return-line feed (CRLF).- Parameters:
- s- the- Stringto write to the client
- Throws:
- IOException- if an input or output exception occurred
 
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printlnWrites abooleanvalue to the client, followed by a carriage return-line feed (CRLF).- Parameters:
- b- the- booleanvalue to write to the client
- Throws:
- IOException- if an input or output exception occurred
 
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printlnWrites 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
 
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printlnWrites 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
 
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printlnWrites alongvalue to the client, followed by a carriage return-line feed (CRLF).- Parameters:
- l- the- longvalue to write to the client
- Throws:
- IOException- if an input or output exception occurred
 
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printlnWrites afloatvalue to the client, followed by a carriage return-line feed (CRLF).- Parameters:
- f- the- floatvalue to write to the client
- Throws:
- IOException- if an input or output exception occurred
 
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printlnWrites adoublevalue to the client, followed by a carriage return-line feed (CRLF).- Parameters:
- d- the- doublevalue to write to the client
- Throws:
- IOException- if an input or output exception occurred
 
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isReadypublic abstract boolean isReady()Returnstrueif it is allowable to call any method that may write data (e.g.write(),print()orflush). In blocking mode, this method will always returntrue, but a subsequent call to a method that writes data may block. In non-blocking mode this method may returnfalse, in which case it is illegal to call a method that writes data and anIllegalStateExceptionMUST be thrown. WhenWriteListener.onWritePossible()is called, a call to this method that returnedtrueis implicit.If this method returns falseand aWriteListenerhas been set viasetWriteListener(WriteListener), then container will subsequently invokeWriteListener.onWritePossible()once a write operation becomes possible without blocking. Other than the initial call,WriteListener.onWritePossible()will only be called if and only if this method is called and returns false.- Returns:
- trueif data can be written without blocking, otherwise returns- false.
- Since:
- Servlet 3.1
 
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setWriteListenerSets theWriteListenerfor thisServletOutputStreamand 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- WriteListenerhas already been set
- NullPointerException- If listener is null
- Since:
- Servlet 3.1
 
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closeIf this method is called when the output stream is in non-blocking mode, it will immediately return with the stream effectively closed, even if the stream contains buffered data that is yet to be written to client. The container will write this data out in the background. If this process fails the WriteListener.onError(Throwable)method will be invoked as normal.- Specified by:
- closein interface- AutoCloseable
- Specified by:
- closein interface- Closeable
- Overrides:
- closein class- OutputStream
- Throws:
- IOException
 
 
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