de.larssh.utils.io

Class PeekableReader

java.lang.Object

java.io.Reader

de.larssh.utils.io.PeekableReader

All Implemented Interfaces:

Closeable, AutoCloseable, Readable

public class PeekableReader
extends Reader

A Reader that allows peeking up to one character without removing it, from the logical I/O stream, supporting a one-element lookahead.

The methods hasNext() and next() are implemented similar to the methods of Iterator to simplify working with character based readers.

Field Summary

Fields inherited from class java.io.Reader

lock

Constructor Summary

Constructors

Constructor and Description
PeekableReader(Reader reader) Creates a new PeekableReader instance.

Method Summary

Modifier and Type	Method and Description
void	close()
boolean	hasNext() Returns true if the reader has more characters.
void	mark(int readAheadLimit)
boolean	markSupported()
char	next() Returns the next character of the reader.
char	peek() Returns the next character in the reader, returned by read(), without removing it from the I/O stream.
int	read()
int	read(char[] buffer, int offset, int length)
void	reset()

Methods inherited from class java.io.Reader

read, read, ready, skip

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PeekableReader

public PeekableReader(Reader reader)

Creates a new PeekableReader instance.

Parameters:

reader - The wrapped reader

Method Detail

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in class Reader

Throws:

IOException

hasNext

public final boolean hasNext()
                      throws IOException

Returns true if the reader has more characters. (In other words, returns true if next() would return a character rather than throwing an exception.)

Returns:

true if the reader has more characters, else false

Throws:

IOException - if an I/O error occurs

mark

public void mark(int readAheadLimit)
          throws IOException

Overrides:

mark in class Reader

Throws:

IOException

markSupported

public boolean markSupported()

Overrides:

markSupported in class Reader

next

public final char next()
                throws IOException

Returns the next character of the reader.

Returns:

the next character of the reader

Throws:

IOException - if an I/O error occurs

NoSuchElementException - if the reader has no more characters

peek

public char peek()
          throws IOException

Returns the next character in the reader, returned by read(), without removing it from the I/O stream.

Returns:

the next element in the iteration

Throws:

IOException - if an I/O error occurs

NoSuchElementException - if the iteration has no more elements

read

public int read()
         throws IOException

Overrides:

read in class Reader

Throws:

IOException

read

public int read(@Nullable
                char[] buffer,
                int offset,
                int length)
         throws IOException

Specified by:

read in class Reader

Throws:

IOException

reset

public void reset()
           throws IOException

Overrides:

reset in class Reader

Throws:

IOException