Added in API level 1

Summary: Inherited Fields | Ctors | Methods | Inherited Methods

LineNumberReader

public class LineNumberReader
extends BufferedReader

java.lang.Object
↳	java.io.Reader
	↳	java.io.BufferedReader
		↳	java.io.LineNumberReader

A buffered character-input stream that keeps track of line numbers. This class defines methods setLineNumber(int) and getLineNumber() for setting and getting the current line number respectively.

By default, line numbering begins at 0. This number increments at every line terminator as the data is read, and can be changed with a call to setLineNumber(int). Note however, that setLineNumber(int) does not actually change the current position in the stream; it only changes the value that will be returned by getLineNumber().

A line is considered to be terminated by any one of a line feed ('\n'), a carriage return ('\r'), or a carriage return followed immediately by a linefeed.

Summary

Inherited fields

From class java.io.Reader


    protected
    
    
    Object

lock

The object used to synchronize operations on this stream.

Public constructors
`LineNumberReader(Reader in)` Create a new line-numbering reader, using the default input-buffer size.
`LineNumberReader(Reader in, int sz)` Create a new line-numbering reader, reading characters into a buffer of the given size.

Public methods
`int`	`getLineNumber()` Get the current line number.
`void`	`mark(int readAheadLimit)` Mark the present position in the stream.
`int`	`read()` Read a single character.
`int`	`read(char[] cbuf, int off, int len)` Read characters into a portion of an array.
`String`	`readLine()` Read a line of text.
`void`	`reset()` Reset the stream to the most recent mark.
`void`	`setLineNumber(int lineNumber)` Set the current line number.
`long`	`skip(long n)` Skip characters.

Inherited methods

From class


        
          java.io.BufferedReader

`void`	`close()` Closes the stream and releases any system resources associated with it.
`Stream<String>`	`lines()` Returns a `Stream`, the elements of which are lines read from this `BufferedReader`.
`void`	`mark(int readAheadLimit)` Marks the present position in the stream.
`boolean`	`markSupported()` Tells whether this stream supports the mark() operation, which it does.
`int`	`read()` Reads a single character.
`int`	`read(char[] cbuf, int off, int len)` Reads characters into a portion of an array.
`String`	`readLine()` Reads a line of text.
`boolean`	`ready()` Tells whether this stream is ready to be read.
`void`	`reset()` Resets the stream to the most recent mark.
`long`	`skip(long n)` Skips characters.

From class


        
          java.io.Reader

`abstract void`	`close()` Closes the stream and releases any system resources associated with it.
`void`	`mark(int readAheadLimit)` Marks the present position in the stream.
`boolean`	`markSupported()` Tells whether this stream supports the mark() operation.
`static Reader`	`nullReader()` Returns a new `Reader` that reads no characters.
`int`	`read()` Reads a single character.
`abstract int`	`read(char[] cbuf, int off, int len)` Reads characters into a portion of an array.
`int`	`read(char[] cbuf)` Reads characters into an array.
`int`	`read(CharBuffer target)` Attempts to read characters into the specified character buffer.
`boolean`	`ready()` Tells whether this stream is ready to be read.
`void`	`reset()` Resets the stream.
`long`	`skip(long n)` Skips characters.
`long`	`transferTo(Writer out)` Reads all characters from this reader and writes the characters to the given writer 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.Readable


      read(CharBuffer cb)

Attempts to read characters into the specified character buffer.

From interface


        
          java.lang.AutoCloseable


      close()

Closes this resource, relinquishing any underlying resources.

Public constructors

LineNumberReader

Added in API level 1

public LineNumberReader (Reader in)

Create a new line-numbering reader, using the default input-buffer size.

Parameters
`in`	`Reader`: A Reader object to provide the underlying stream

LineNumberReader

Added in API level 1

public LineNumberReader (Reader in, 
                int sz)

Create a new line-numbering reader, reading characters into a buffer of the given size.

Parameters
`in`	`Reader`: A Reader object to provide the underlying stream
`sz`	`int`: An int specifying the size of the buffer

Public methods

getLineNumber

Added in API level 1

public int getLineNumber ()

Get the current line number.

Returns
`int`	The current line number

See also:

setLineNumber(int)

mark

Added in API level 1

public void mark (int readAheadLimit)

Mark the present position in the stream. Subsequent calls to reset() will attempt to reposition the stream to this point, and will also reset the line number appropriately.

Parameters
`readAheadLimit`	`int`: Limit on the number of characters that may be read while still preserving the mark. After reading this many characters, attempting to reset the stream may fail.

Throws
`IOException`	If an I/O error occurs

read

Added in API level 1

public int read ()

Read a single character. Line terminators are compressed into single newline ('\n') characters. Whenever a line terminator is read the current line number is incremented.

Returns
`int`	The character read, or -1 if the end of the stream has been reached

Throws
`IOException`	If an I/O error occurs

read

Added in API level 1

public int read (char[] cbuf, 
                int off, 
                int len)

Read characters into a portion of an array. Whenever a line terminator is read the current line number is incremented.

Parameters
`cbuf`	`char`: Destination buffer
`off`	`int`: Offset at which to start storing characters
`len`	`int`: Maximum number of characters to read

Returns
`int`	The number of bytes read, or -1 if the end of the stream has already been reached

Throws
`IOException`	If an I/O error occurs
`IndexOutOfBoundsException`

readLine

Added in API level 1

public String readLine ()

Read a line of text. Whenever a line terminator is read the current line number is incremented.

Returns
`String`	A String containing the contents of the line, not including any line termination characters, or `null` if the end of the stream has been reached

Throws
`IOException`	If an I/O error occurs

reset

Added in API level 1

public void reset ()

Reset the stream to the most recent mark.

Throws
`IOException`	If the stream has not been marked, or if the mark has been invalidated

setLineNumber

Added in API level 1

public void setLineNumber (int lineNumber)

Set the current line number.

Parameters
`lineNumber`	`int`: An int specifying the line number

See also:

getLineNumber()

skip

Added in API level 1

public long skip (long n)

Skip characters.

Parameters
`n`	`long`: The number of characters to skip

Returns
`long`	The number of characters actually skipped

Throws
`IOException`	If an I/O error occurs
`IllegalArgumentException`	If `n` is negative