Added in API level 1
Deprecated in API level 1

Summary: Inherited Fields | Ctors | Methods | Inherited Methods

LineNumberInputStream

public class LineNumberInputStream
extends FilterInputStream

java.lang.Object
↳	java.io.InputStream
	↳	java.io.FilterInputStream
		↳	java.io.LineNumberInputStream

This class was deprecated in API level 1.
This class incorrectly assumes that bytes adequately represent characters. As of JDK 1.1, the preferred way to operate on character streams is via the new character-stream classes, which include a class for counting line numbers.

This class is an input stream filter that provides the added functionality of keeping track of the current line number.

A line is a sequence of bytes ending with a carriage return character ('\r'), a newline character ('\n'), or a carriage return character followed immediately by a linefeed character. In all three cases, the line terminating character(s) are returned as a single newline character.

The line number begins at 0, and is incremented by 1 when a read returns a newline character.

See also:

LineNumberReader

Summary

Inherited fields

From class java.io.FilterInputStream


    protected
    
    
    InputStream

in

The input stream to be filtered.

Public constructors
`LineNumberInputStream(InputStream in)` Constructs a newline number input stream that reads its input from the specified input stream.

Public methods
`int`	`available()` Returns the number of bytes that can be read from this input stream without blocking.
`int`	`getLineNumber()` Returns the current line number.
`void`	`mark(int readlimit)` Marks the current position in this input stream.
`int`	`read()` Reads the next byte of data from this input stream.
`int`	`read(byte[] b, int off, int len)` Reads up to `len` bytes of data from this input stream into an array of bytes.
`void`	`reset()` Repositions this stream to the position at the time the `mark` method was last called on this input stream.
`void`	`setLineNumber(int lineNumber)` Sets the line number to the specified argument.
`long`	`skip(long n)` Skips over and discards `n` bytes of data from this input stream.

Inherited methods

From class


        
          java.io.FilterInputStream

`int`	`available()` Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next caller of a method for this input stream.
`void`	`close()` Closes this input stream and releases any system resources associated with the stream.
`void`	`mark(int readlimit)` Marks the current position in this input stream.
`boolean`	`markSupported()` Tests if this input stream supports the `mark` and `reset` methods.
`int`	`read()` Reads the next byte of data from this input stream.
`int`	`read(byte[] b, int off, int len)` Reads up to `len` bytes of data from this input stream into an array of bytes.
`int`	`read(byte[] b)` Reads up to `b.length` bytes of data from this input stream into an array of bytes.
`void`	`reset()` Repositions this stream to the position at the time the `mark` method was last called on this input stream.
`long`	`skip(long n)` Skips over and discards `n` bytes of data from the input stream.

From class


        
          java.io.InputStream

`int`	`available()` Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking, which may be 0, or 0 when end of stream is detected.
`void`	`close()` Closes this input stream and releases any system resources associated with the stream.
`void`	`mark(int readlimit)` Marks the current position in this input stream.
`boolean`	`markSupported()` Tests if this input stream supports the `mark` and `reset` methods.
`static InputStream`	`nullInputStream()` Returns a new `InputStream` that reads no bytes.
`int`	`read(byte[] b)` Reads some number of bytes from the input stream and stores them into the buffer array `b`.
`abstract int`	`read()` Reads the next byte of data from the input stream.
`int`	`read(byte[] b, int off, int len)` Reads up to `len` bytes of data from the input stream into an array of bytes.
`byte[]`	`readAllBytes()` Reads all remaining bytes from the input stream.
`int`	`readNBytes(byte[] b, int off, int len)` Reads the requested number of bytes from the input stream into the given byte array.
`byte[]`	`readNBytes(int len)` Reads up to a specified number of bytes from the input stream.
`void`	`reset()` Repositions this stream to the position at the time the `mark` method was last called on this input stream.
`long`	`skip(long n)` Skips over and discards `n` bytes of data from this input stream.
`void`	`skipNBytes(long n)` Skips over and discards exactly `n` bytes of data from this input stream.
`long`	`transferTo(OutputStream out)` Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read.

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

From interface


        
          java.io.Closeable


      close()

Closes this stream and releases any system resources associated with it.

From interface


        
          java.lang.AutoCloseable


      close()

Closes this resource, relinquishing any underlying resources.

Public constructors

LineNumberInputStream

Added in API level 1

public LineNumberInputStream (InputStream in)

Constructs a newline number input stream that reads its input from the specified input stream.

Parameters
`in`	`InputStream`: the underlying input stream.

Public methods

available

Added in API level 1

public int available ()

Returns the number of bytes that can be read from this input stream without blocking.

Note that if the underlying input stream is able to supply k input characters without blocking, the LineNumberInputStream can guarantee only to provide k/2 characters without blocking, because the k characters from the underlying input stream might consist of k/2 pairs of '\r' and '\n', which are converted to just k/2 '\n' characters.

Returns
`int`	the number of bytes that can be read from this input stream without blocking.

Throws
`IOException`	if an I/O error occurs.

See also:

FilterInputStream.in

getLineNumber

Added in API level 1

public int getLineNumber ()

Returns the current line number.

Returns
`int`	the current line number.

See also:

setLineNumber(int)

mark

Added in API level 1

public void mark (int readlimit)

Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.

The mark method of LineNumberInputStream remembers the current line number in a private variable, and then calls the mark method of the underlying input stream.

Parameters
`readlimit`	`int`: the maximum limit of bytes that can be read before the mark position becomes invalid.

See also:

FilterInputStream.in
reset()

read

Added in API level 1

public int read ()

Reads the next byte of data from this input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

The read method of LineNumberInputStream calls the read method of the underlying input stream. It checks for carriage returns and newline characters in the input, and modifies the current line number as appropriate. A carriage-return character or a carriage return followed by a newline character are both converted into a single newline character.

Returns
`int`	the next byte of data, or `-1` if the end of this stream is reached.

Throws
`IOException`	if an I/O error occurs.

See also:

read

Added in API level 1

public int read (byte[] b, 
                int off, 
                int len)

Reads up to len bytes of data from this input stream into an array of bytes. This method blocks until some input is available.

The read method of LineNumberInputStream repeatedly calls the read method of zero arguments to fill in the byte array.

Parameters
`b`	`byte`: the buffer into which the data is read.
`off`	`int`: the start offset of the data.
`len`	`int`: the maximum number of bytes read.

Returns
`int`	the total number of bytes read into the buffer, or `-1` if there is no more data because the end of this stream has been reached.

Throws
`IOException`	if an I/O error occurs.

See also:

read()

reset

Added in API level 1

public void reset ()

Repositions this stream to the position at the time the mark method was last called on this input stream.

The reset method of LineNumberInputStream resets the line number to be the line number at the time the mark method was called, and then calls the reset method of the underlying input stream.

Stream marks are intended to be used in situations where you need to read ahead a little to see what's in the stream. Often this is most easily done by invoking some general parser. If the stream is of the type handled by the parser, it just chugs along happily. If the stream is not of that type, the parser should toss an exception when it fails, which, if it happens within readlimit bytes, allows the outer code to reset the stream and try another parser.

Throws
`IOException`	if an I/O error occurs.

See also:

setLineNumber

Added in API level 1

public void setLineNumber (int lineNumber)

Sets the line number to the specified argument.

Parameters
`lineNumber`	`int`: the new line number.

See also:

getLineNumber()

skip

Added in API level 1

public long skip (long n)

Skips over and discards n bytes of data from this input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. The actual number of bytes skipped is returned. If n is negative, no bytes are skipped.

The skip method of LineNumberInputStream creates a byte array and then repeatedly reads into it until n bytes have been read or the end of the stream has been reached.

Parameters
`n`	`long`: the number of bytes to be skipped.

Returns
`long`	the actual number of bytes skipped.

Throws
`IOException`	if an I/O error occurs.

See also:

FilterInputStream.in