StringReader

AI-generated Key Takeaways

• StringReader is a class in Java that acts as a character stream, sourcing its input from a given string.

• It provides methods for reading characters, marking positions within the stream, resetting to marked positions, skipping characters, and closing the stream.

• StringReader inherits functionalities from Reader, Readable, Closeable, and AutoCloseable for stream manipulation and resource management.

• The class supports marking and resetting, unlike some other Reader implementations, because it reads from a fixed string.

• It handles skipping characters differently than the Reader superclass by allowing backward skipping within the bounds of the string.

public class StringReader extends Reader

A character stream whose source is a string.

Inherited Field Summary

From class java.io.Reader

protected Object

lock

The object used to synchronize operations on this stream.

Public Constructor Summary

StringReader(String s) Creates a new string reader.

Public Method Summary

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, 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.
boolean	ready() Tells whether this stream is ready to be read.
void	reset() Resets the stream to the most recent mark, or to the beginning of the string if it has never been marked.
long	skip(long ns) Skips the specified number of characters in the stream.

Inherited Method Summary

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.
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.

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

From interface java.lang.Readable

abstract int

read(CharBuffer cb) Attempts to read characters into the specified character buffer.

From interface java.io.Closeable

abstract void

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

From interface java.lang.AutoCloseable

abstract void

close() Closes this resource, relinquishing any underlying resources.

Public Constructors

public StringReader (String s)

Creates a new string reader.

Parameters

s	String providing the character stream.

Public Methods

public void close ()

Closes the stream and releases any system resources associated with it. Once the stream has been closed, further read(), ready(), mark(), or reset() invocations will throw an IOException. Closing a previously closed stream has no effect.

public void mark (int readAheadLimit)

Marks the present position in the stream. Subsequent calls to reset() will reposition the stream to this point.

Parameters

readAheadLimit	Limit on the number of characters that may be read while still preserving the mark. Because the stream's input comes from a string, there is no actual limit, so this argument must not be negative, but is otherwise ignored.

Throws

IllegalArgumentException	If readAheadLimit < 0
IOException	If an I/O error occurs

public boolean markSupported ()

Tells whether this stream supports the mark() operation, which it does.

Returns

• true if and only if this stream supports the mark operation.

public int read ()

Reads a single character.

Returns

• The character read, or -1 if the end of the stream has been reached

Throws

IOException	If an I/O error occurs

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

Reads characters into a portion of an array.

Parameters

cbuf	Destination buffer
off	Offset at which to start writing characters
len	Maximum number of characters to read

Returns

• The number of characters read, or -1 if the end of the stream has been reached

Throws

IOException	If an I/O error occurs

public boolean ready ()

Tells whether this stream is ready to be read.

Returns

• True if the next read() is guaranteed not to block for input

Throws

IOException	If the stream is closed

public void reset ()

Resets the stream to the most recent mark, or to the beginning of the string if it has never been marked.

Throws

IOException	If an I/O error occurs

public long skip (long ns)

Skips the specified number of characters in the stream. Returns the number of characters that were skipped.

The ns parameter may be negative, even though the skip method of the Reader superclass throws an exception in this case. Negative values of ns cause the stream to skip backwards. Negative return values indicate a skip backwards. It is not possible to skip backwards past the beginning of the string.

If the entire string has been read or skipped, then this method has no effect and always returns 0.

Parameters

ns	The number of characters to skip

Returns

• The number of characters actually skipped

Throws

IOException	If an I/O error occurs