Package java.io

Class CharArrayReader

java.lang.Object
java.io.Reader
java.io.CharArrayReader
All Implemented Interfaces:
Closeable, AutoCloseable, Readable
public class CharArrayReader
extends Reader
A specialized Reader for reading the contents of a char array.
See Also:
CharArrayWriter

  • Field Summary

    Fields
    Modifier and Type Field Description
    protected char[] buf
    The buffer for characters.
    protected int count
    The ending index of the buffer.
    protected int markedPos
    The current mark position.
    protected int pos
    The current buffer position.

    Fields inherited from class java.io.Reader

    lock

  • Constructor Summary

    Constructors
    Constructor Description
    CharArrayReader​(char[] buf)
    Constructs a CharArrayReader on the char array buf.
    CharArrayReader​(char[] buf, int offset, int length)
    Constructs a CharArrayReader on the char array buf.

  • Method Summary

    Modifier and Type Method Description
    void close()
    This method closes this CharArrayReader.
    void mark​(int readLimit)
    Sets a mark position in this reader.
    boolean markSupported()
    Indicates whether this reader supports the mark() and reset() methods.
    int read()
    Reads a single character from this reader and returns it as an integer with the two higher-order bytes set to 0.
    int read​(char[] buffer, int offset, int count)
    Reads up to count characters from this CharArrayReader and stores them at offset in the character array buffer.
    boolean ready()
    Indicates whether this reader is ready to be read without blocking.
    void reset()
    Resets this reader's position to the last mark() location.
    long skip​(long charCount)
    Skips charCount characters in this reader.

    Methods inherited from class java.io.Reader

    read, read

    Methods inherited from class java.lang.Object

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

  • Field Details

    • buf

      protected char[] buf
      The buffer for characters.

    • pos

      protected int pos
      The current buffer position.

    • markedPos

      protected int markedPos
      The current mark position.

    • count

      protected int count
      The ending index of the buffer.

  • Constructor Details

    • CharArrayReader

      public CharArrayReader​(char[] buf)
      Constructs a CharArrayReader on the char array buf. The size of the reader is set to the length of the buffer and the object to to read from is set to buf.
      Parameters:
      buf - the char array from which to read.

    • CharArrayReader

      public CharArrayReader​(char[] buf, int offset, int length)
      Constructs a CharArrayReader on the char array buf. The size of the reader is set to length and the start position from which to read the buffer is set to offset.
      Parameters:
      buf - the char array from which to read.
      offset - the index of the first character in buf to read.
      length - the number of characters that can be read from buf.
      Throws:
      IllegalArgumentException - if offset < 0 or length < 0, or if offset is greater than the size of buf .

  • Method Details

    • close

      public void close()
      This method closes this CharArrayReader. Once it is closed, you can no longer read from it. Only the first invocation of this method has any effect.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Specified by:
      close in class Reader

    • mark

      public void mark​(int readLimit) throws IOException
      Sets a mark position in this reader. The parameter readLimit is ignored for CharArrayReaders. Calling reset() will reposition the reader back to the marked position provided the mark has not been invalidated.
      Overrides:
      mark in class Reader
      Parameters:
      readLimit - ignored for CharArrayReaders.
      Throws:
      IOException - if this reader is closed.
      See Also:
      Reader.markSupported(), Reader.reset()

    • markSupported

      public boolean markSupported()
      Indicates whether this reader supports the mark() and reset() methods.
      Overrides:
      markSupported in class Reader
      Returns:
      true for CharArrayReader.
      See Also:
      mark(int), reset()

    • read

      public int read() throws IOException
      Reads a single character from this reader and returns it as an integer with the two higher-order bytes set to 0. Returns -1 if no more characters are available from this reader.
      Overrides:
      read in class Reader
      Returns:
      the character read as an int or -1 if the end of the reader has been reached.
      Throws:
      IOException - if this reader is closed.

    • read

      public int read​(char[] buffer, int offset, int count) throws IOException
      Reads up to count characters from this CharArrayReader and stores them at offset in the character array buffer. Returns the number of characters actually read or -1 if the end of reader was encountered.
      Specified by:
      read in class Reader
      Throws:
      IndexOutOfBoundsException - if offset < 0 || count < 0 || offset + count > buffer.length.
      IOException - if this reader is closed.

    • ready

      public boolean ready() throws IOException
      Indicates whether this reader is ready to be read without blocking. Returns true if the next read will not block. Returns false if this reader may or may not block when read is called. The implementation in CharArrayReader always returns true even when it has been closed.
      Overrides:
      ready in class Reader
      Returns:
      true if this reader will not block when read is called, false if unknown or blocking will occur.
      Throws:
      IOException - if this reader is closed.
      See Also:
      Reader.read(), Reader.read(char[]), Reader.read(char[], int, int)

    • reset

      public void reset() throws IOException
      Resets this reader's position to the last mark() location. Invocations of read() and skip() will occur from this new location. If this reader has not been marked, it is reset to the beginning of the string.
      Overrides:
      reset in class Reader
      Throws:
      IOException - if this reader is closed.
      See Also:
      Reader.mark(int), Reader.markSupported()

    • skip

      public long skip​(long charCount) throws IOException
      Skips charCount characters in this reader. Subsequent calls to read will not return these characters unless reset is used. This method does nothing and returns 0 if charCount <= 0.
      Overrides:
      skip in class Reader
      Returns:
      the number of characters actually skipped.
      Throws:
      IOException - if this reader is closed.
      See Also:
      Reader.mark(int), Reader.markSupported(), Reader.reset()