- All Implemented Interfaces:
Closeable,Flushable,AutoCloseable
- Direct Known Subclasses:
ByteArrayOutputStream,FileOutputStream,FilterOutputStream,ObjectOutputStream,PipedOutputStream
Applications that need to define a subclass of
OutputStream must always provide at least a method
that writes one byte of output.
- Since:
- 1.0
- See Also:
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoidclose()Closes this output stream and releases any system resources associated with this stream.voidflush()Flushes this output stream and forces any buffered output bytes to be written out.static OutputStreamReturns a newOutputStreamwhich discards all bytes.voidwrite(byte[] b) Writesb.lengthbytes from the specified byte array to this output stream.voidwrite(byte[] b, int off, int len) Writeslenbytes from the specified byte array starting at offsetoffto this output stream.abstract voidwrite(int b) Writes the specified byte to this output stream.
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Constructor Details
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OutputStream
public OutputStream()Constructor for subclasses to call.
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Method Details
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nullOutputStream
Returns a newOutputStreamwhich discards all bytes. The returned stream is initially open. The stream is closed by calling theclose()method. Subsequent calls toclose()have no effect.While the stream is open, the
write(int),write(byte[]), andwrite(byte[], int, int)methods do nothing. After the stream has been closed, these methods all throwIOException.The
flush()method does nothing.- Returns:
- an
OutputStreamwhich discards all bytes - Since:
- 11
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write
Writes the specified byte to this output stream. The general contract forwriteis that one byte is written to the output stream. The byte to be written is the eight low-order bits of the argumentb. The 24 high-order bits ofbare ignored.- Parameters:
b- thebyte.- Throws:
IOException- if an I/O error occurs. In particular, anIOExceptionmay be thrown if the output stream has been closed.
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write
Writesb.lengthbytes from the specified byte array to this output stream. The general contract forwrite(b)is that it should have exactly the same effect as the callwrite(b, 0, b.length).- Parameters:
b- the data.- Throws:
IOException- if an I/O error occurs.- See Also:
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write
Writeslenbytes from the specified byte array starting at offsetoffto this output stream. The general contract forwrite(b, off, len)is that some of the bytes in the arraybare written to the output stream in order; elementb[off]is the first byte written andb[off+len-1]is the last byte written by this operation.If
bisnull, aNullPointerExceptionis thrown.If
offis negative, orlenis negative, oroff+lenis greater than the length of the arrayb, then anIndexOutOfBoundsExceptionis thrown.- API Note:
- Subclasses are encouraged to override this method and provide a more efficient implementation.
- Implementation Requirements:
- The
writemethod ofOutputStreamcalls the write method of one argument on each of the bytes to be written out. - Parameters:
b- the data.off- the start offset in the data.len- the number of bytes to write.- Throws:
IOException- if an I/O error occurs. In particular, anIOExceptionis thrown if the output stream is closed.IndexOutOfBoundsException- Ifoffis negative,lenis negative, orlenis greater thanb.length - off
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flush
Flushes this output stream and forces any buffered output bytes to be written out. The general contract offlushis that calling it is an indication that, if any bytes previously written have been buffered by the implementation of the output stream, such bytes should immediately be written to their intended destination.If the intended destination of this stream is an abstraction provided by the underlying operating system, for example a file, then flushing the stream guarantees only that bytes previously written to the stream are passed to the operating system for writing; it does not guarantee that they are actually written to a physical device such as a disk drive.
- Specified by:
flushin interfaceFlushable- Implementation Requirements:
- The
flushmethod ofOutputStreamdoes nothing. - Throws:
IOException- if an I/O error occurs.
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close
Closes this output stream and releases any system resources associated with this stream. The general contract ofcloseis that it closes the output stream. A closed stream cannot perform output operations and cannot be reopened.- Specified by:
closein interfaceAutoCloseable- Specified by:
closein interfaceCloseable- Implementation Requirements:
- The
closemethod ofOutputStreamdoes nothing. - Throws:
IOException- if an I/O error occurs.
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