Android
java.io
public abstract class

java.io.FilterReader

java.lang.Object
java.io.Reader Closeable Readable
java.io.FilterReader

FilterReader is a class which takes a Reader and filters the input in some way. The filtered view may be a buffered view or one which uncompresses data before returning characters read.

Known Direct Subclasses

See Also

Summary

Fields

protected      Reader  in  The target Reader which is being filtered. 
Fields inherited from class java.io.Reader

Protected Constructors

            FilterReader(Reader in)
Constructs a new FilterReader on the Reader in.

Public Methods

          void  close()
Close this FilterReader.
  synchronized        void  mark(int readlimit)
Set a Mark position in this FilterReader.
          boolean  markSupported()
Returns a boolean indicating whether or not this FilterReader supports mark() and reset().
          int  read(char[] buffer, int offset, int count)
Reads at most count chars from this FilterReader and stores them in char array buffer starting at offset offset.
          int  read()
Reads a single char from this FilterReader and returns the result as an int.
          boolean  ready()
Returns a boolean indicating whether or not this Reader is ready to be read without blocking.
          void  reset()
Reset this Readers position to the last mark() location.
          long  skip(long count)
Skips count number of characters in this Reader.
Methods inherited from class java.io.Reader
Methods inherited from class java.lang.Object
Methods inherited from interface java.io.Closeable
Methods inherited from interface java.lang.Readable

Details

Fields

protected Reader in

The target Reader which is being filtered.

Protected Constructors

protected FilterReader(Reader in)

Constructs a new FilterReader on the Reader in. All reads are now filtered through this Reader.

Parameters

in The non-null Reader to filter reads on.

Public Methods

public void close()

Close this FilterReader. This implementation closes the target Reader.

Throws

IOException If an error occurs attempting to close this Reader.

public synchronized void mark(int readlimit)

Set a Mark position in this FilterReader. The parameter readLimit indicates how many characters can be read before a mark is invalidated. Sending reset() will reposition the Reader back to the marked position provided readLimit has not been surpassed.

This implementation sets a mark in the target Reader.

Parameters

readlimit the number of characters to be able to read before invalidating the mark.

Throws

IOException If an error occurs attempting mark this Reader.

public boolean markSupported()

Returns a boolean indicating whether or not this FilterReader supports mark() and reset(). This implementation returns whether or not the target Reader supports marking.

Returns

  • indicates whether or not mark() and reset() are supported.

public int read(char[] buffer, int offset, int count)

Reads at most count chars from this FilterReader and stores them in char array buffer starting at offset offset. Answer the number of chars actually read or -1 if no chars were read and end of reader was encountered. This implementation reads chars from the target reader.

Parameters

buffer the char array in which to store the read chars.
offset the offset in buffer to store the read chars.
count the maximum number of chars to store in buffer.

Returns

  • the number of chars actually read or -1 if end of reader.

Throws

IOException If an error occurs attempting to read from this Reader.

public int read()

Reads a single char from this FilterReader and returns the result as an int. The 2 lowest order bytes are returned or -1 of the end of reader was encountered. This implementation returns a char from the target Reader.

Returns

  • The byte read or -1 if end of reader.

Throws

IOException If an error occurs attempting to read from this Reader.

public boolean ready()

Returns a boolean indicating whether or not this Reader is ready to be read without blocking. If the result is true, the next read() will not block. If the result is false this Reader may or may not block when read() is sent.

Returns

  • true if the receiver will not block when read() is called, false if unknown or blocking will occur.

Throws

IOException If the Reader is already closed or some other IO error occurs.

public void reset()

Reset this Readers position to the last mark() location. Invocations of read()/skip() will occur from this new location. If this Reader was not marked, the implementation of reset() is implementation specific. See the comment for the specific Reader subclass for implementation details. The default action is to throw IOException.

Throws

IOException if a problem occurred or the target Reader does not support mark()/reset().

public long skip(long count)

Skips count number of characters in this Reader. Subsequent read()'s will not return these characters unless reset() is used. The default implementation is to skip chars in the filtered Reader.

Parameters

count the maximum number of characters to skip.

Returns

  • the number of characters actually skipped.

Throws

IOException If the Reader is already closed or some other IO error occurs.
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