Package org.apache.commons.io.input

Class BoundedReader

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable, java.lang.Readable
    public class BoundedReader
extends java.io.Reader
    A reader that imposes a limit to the number of characters that can be read from an underlying reader, returning eof when this limit is reached -regardless of state of underlying reader.

    One use case is to avoid overrunning the readAheadLimit supplied to java.io.Reader#mark(int), since reading too many characters removes the ability to do a successful reset.

    Since:
    2.5

    • Field Summary

      • Fields inherited from class java.io.Reader

        lock

    • Constructor Summary

      Constructors 
      Constructor Description
      BoundedReader​(java.io.Reader target, int maxCharsFromTargetReader)
      Constructs a bounded reader

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void close()
      Closes the target
      void mark​(int readAheadLimit)
      marks the target stream
      int read()
      Reads a single character
      int read​(char[] cbuf, int off, int len)
      Reads into an array
      void reset()
      Resets the target to the latest mark,

      • Methods inherited from class java.io.Reader

        markSupported, nullReader, read, read, ready, skip, transferTo

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • BoundedReader

        public BoundedReader​(java.io.Reader target,
                     int maxCharsFromTargetReader)
              throws java.io.IOException
        Constructs a bounded reader
        Parameters:
        target - The target stream that will be used
        maxCharsFromTargetReader - The maximum number of characters that can be read from target
        Throws:
        java.io.IOException - if mark fails

    • Method Detail

      • close

        public void close()
           throws java.io.IOException
        Closes the target
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Specified by:
        close in class java.io.Reader
        Throws:
        java.io.IOException - If an I/O error occurs while calling the underlying reader's close method

      • reset

        public void reset()
           throws java.io.IOException
        Resets the target to the latest mark,
        Overrides:
        reset in class java.io.Reader
        Throws:
        java.io.IOException - If an I/O error occurs while calling the underlying reader's reset method
        See Also:
        Reader.reset()

      • mark

        public void mark​(int readAheadLimit)
          throws java.io.IOException
        marks the target stream
        Overrides:
        mark in class java.io.Reader
        Parameters:
        readAheadLimit - The number of characters that can be read while still retaining the ability to do #reset(). Note that this parameter is not validated with respect to maxCharsFromTargetReader. There is no way to pass past maxCharsFromTargetReader, even if this value is greater.
        Throws:
        java.io.IOException - If an I/O error occurs while calling the underlying reader's mark method
        See Also:
        Reader.mark(int)

      • read

        public int read()
         throws java.io.IOException
        Reads a single character
        Overrides:
        read in class java.io.Reader
        Returns:
        -1 on eof or the character read
        Throws:
        java.io.IOException - If an I/O error occurs while calling the underlying reader's read method
        See Also:
        Reader.read()

      • read

        public int read​(char[] cbuf,
                int off,
                int len)
         throws java.io.IOException
        Reads into an array
        Specified by:
        read in class java.io.Reader
        Parameters:
        cbuf - The buffer to fill
        off - The offset
        len - The number of chars to read
        Returns:
        the number of chars read
        Throws:
        java.io.IOException - If an I/O error occurs while calling the underlying reader's read method
        See Also:
        Reader.read(char[], int, int)