Class NonBlockingPushbackReader

java.lang.Object
java.io.Reader
java.io.FilterReader
com.helger.commons.io.stream.NonBlockingPushbackReader
All Implemented Interfaces:
Closeable, AutoCloseable, Readable

public class NonBlockingPushbackReader extends FilterReader
A non-synchronized copy of the class PushbackReader.
Author:
Philip Helger
See Also:
  • Field Summary

    Fields inherited from class java.io.FilterReader

    in

    Fields inherited from class java.io.Reader

    lock
  • Constructor Summary

    Constructors
    Constructor
    Description
    Creates a new pushback reader with a one-character pushback buffer.
    NonBlockingPushbackReader(Reader aReader, int nSize)
    Creates a new pushback reader with a pushback buffer of the given size.
  • Method Summary

    Modifier and Type
    Method
    Description
    void
    Closes the stream and releases any system resources associated with it.
    int
     
    boolean
     
    void
    mark(int readAheadLimit)
    Marks the present position in the stream.
    boolean
    Tells whether this stream supports the mark() operation, which it does not.
    int
    Reads a single character.
    int
    read(char[] aBuf, int nOfs, int nLen)
    Reads characters into a portion of an array.
    boolean
    Tells whether this stream is ready to be read.
    void
    Resets the stream.
    long
    skip(long nSkip)
    Skips characters.
    void
    unread(char[] aBuf)
    Pushes back an array of characters by copying it to the front of the pushback buffer.
    void
    unread(char[] aBuf, int nOfs, int nLen)
    Pushes back a portion of an array of characters by copying it to the front of the pushback buffer.
    void
    unread(int c)
    Pushes back a single character by copying it to the front of the pushback buffer.

    Methods inherited from class java.io.Reader

    nullReader, read, read, transferTo

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Constructor Details

    • NonBlockingPushbackReader

      public NonBlockingPushbackReader(@Nonnull Reader aReader, @Nonnegative int nSize)
      Creates a new pushback reader with a pushback buffer of the given size.
      Parameters:
      aReader - The reader from which characters will be read
      nSize - The size of the pushback buffer
      Throws:
      IllegalArgumentException - if size is ≤ 0
    • NonBlockingPushbackReader

      public NonBlockingPushbackReader(@Nonnull Reader aReader)
      Creates a new pushback reader with a one-character pushback buffer.
      Parameters:
      aReader - The reader from which characters will be read
  • Method Details

    • getUnreadCount

      @Nonnegative public int getUnreadCount()
      Returns:
      The number of chars currently in the "unread" buffer.
    • hasUnreadChars

      public boolean hasUnreadChars()
      Returns:
      true if at least one "unread" char is present.
    • read

      public int read() throws IOException
      Reads a single character.
      Overrides:
      read in class FilterReader
      Returns:
      The character read, or -1 if the end of the stream has been reached
      Throws:
      IOException - If an I/O error occurs
    • read

      public int read(@Nonnull char[] aBuf, @Nonnegative int nOfs, @Nonnegative int nLen) throws IOException
      Reads characters into a portion of an array.
      Overrides:
      read in class FilterReader
      Parameters:
      aBuf - Destination buffer
      nOfs - Offset at which to start writing characters
      nLen - 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
    • unread

      public void unread(int c) throws IOException
      Pushes back a single character by copying it to the front of the pushback buffer. After this method returns, the next character to be read will have the value (char)c.
      Parameters:
      c - The int value representing a character to be pushed back
      Throws:
      IOException - If the pushback buffer is full, or if some other I/O error occurs
    • unread

      public void unread(@Nonnull char[] aBuf, @Nonnegative int nOfs, @Nonnegative int nLen) throws IOException
      Pushes back a portion of an array of characters by copying it to the front of the pushback buffer. After this method returns, the next character to be read will have the value cbuf[off], the character after that will have the value cbuf[off+1], and so forth.
      Parameters:
      aBuf - Character array
      nOfs - Offset of first character to push back
      nLen - Number of characters to push back
      Throws:
      IOException - If there is insufficient room in the pushback buffer, or if some other I/O error occurs
    • unread

      public void unread(@Nonnull char[] aBuf) throws IOException
      Pushes back an array of characters by copying it to the front of the pushback buffer. After this method returns, the next character to be read will have the value cbuf[0], the character after that will have the value cbuf[1], and so forth.
      Parameters:
      aBuf - Character array to push back
      Throws:
      IOException - If there is insufficient room in the pushback buffer, or if some other I/O error occurs
    • ready

      public boolean ready() throws IOException
      Tells whether this stream is ready to be read.
      Overrides:
      ready in class FilterReader
      Throws:
      IOException - If an I/O error occurs
    • mark

      public void mark(int readAheadLimit) throws IOException
      Marks the present position in the stream. The mark for class PushbackReader always throws an exception.
      Overrides:
      mark in class FilterReader
      Throws:
      IOException - Always, since mark is not supported
    • reset

      public void reset() throws IOException
      Resets the stream. The reset method of PushbackReader always throws an exception.
      Overrides:
      reset in class FilterReader
      Throws:
      IOException - Always, since reset is not supported
    • markSupported

      public boolean markSupported()
      Tells whether this stream supports the mark() operation, which it does not.
      Overrides:
      markSupported in class FilterReader
    • close

      public void close() throws IOException
      Closes the stream and releases any system resources associated with it. Once the stream has been closed, further read(), unread(), ready(), or skip() invocations will throw an IOException. Closing a previously closed stream has no effect.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Overrides:
      close in class FilterReader
      Throws:
      IOException - If an I/O error occurs
    • skip

      public long skip(long nSkip) throws IOException
      Skips characters. This method will block until some characters are available, an I/O error occurs, or the end of the stream is reached.
      Overrides:
      skip in class FilterReader
      Parameters:
      nSkip - The number of characters to skip. Must be ≥ 0.
      Returns:
      The number of characters actually skipped
      Throws:
      IllegalArgumentException - If n is negative.
      IOException - If an I/O error occurs