Package org.eclipse.nebula.widgets.picture.internal

Class LineIterator

java.lang.Object
org.eclipse.nebula.widgets.picture.internal.LineIterator
All Implemented Interfaces:
java.util.Iterator<java.lang.String>
public class LineIterator
extends java.lang.Object
implements java.util.Iterator<java.lang.String>
An Iterator over the lines in a Reader.

LineIterator holds a reference to an open Reader. When you have finished with the iterator you should close the reader to free internal resources. This can be done by closing the reader directly, or by calling the close() or closeQuietly(LineIterator) method on the iterator.

The recommended usage pattern is: 

 LineIterator it = FileUtils.lineIterator(file, "UTF-8");
 try {
   while (it.hasNext()) {
     String line = it.nextLine();
     // do something with line
   }
 } finally {
   it.close();
 }
Since:
Commons IO 1.2
Version:
$Id: LineIterator.java 1022322 2010-10-13 23:20:42Z ggregory $

  • Constructor Summary

    Constructors 
    Constructor Description
    LineIterator​(java.io.Reader reader)
    Constructs an iterator of the lines for a Reader.

  • Method Summary

    Modifier and Type Method Description
    void close()
    Closes the underlying Reader quietly.
    static void closeQuietly​(LineIterator iterator)
    Closes the iterator, handling null and ignoring exceptions.
    boolean hasNext()
    Indicates whether the Reader has more lines.
    protected boolean isValidLine​(java.lang.String line)
    Overridable method to validate each line that is returned.
    java.lang.String next()
    Returns the next line in the wrapped Reader.
    java.lang.String nextLine()
    Returns the next line in the wrapped Reader.
    void remove()
    Unsupported.

    Methods inherited from class java.lang.Object

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

    Methods inherited from interface java.util.Iterator

    forEachRemaining

  • Constructor Details

    • LineIterator

      public LineIterator​(java.io.Reader reader) throws java.lang.IllegalArgumentException
      Constructs an iterator of the lines for a Reader.
      Parameters:
      reader - the Reader to read from, not null
      Throws:
      java.lang.IllegalArgumentException - if the reader is null

  • Method Details

    • hasNext

      public boolean hasNext()
      Indicates whether the Reader has more lines. If there is an IOException then close() will be called on this instance.
      Specified by:
      hasNext in interface java.util.Iterator<java.lang.String>
      Returns:
      true if the Reader has more lines
      Throws:
      java.lang.IllegalStateException - if an IO exception occurs

    • isValidLine

      protected boolean isValidLine​(java.lang.String line)
      Overridable method to validate each line that is returned.
      Parameters:
      line - the line that is to be validated
      Returns:
      true if valid, false to remove from the iterator

    • next

      public java.lang.String next()
      Returns the next line in the wrapped Reader.
      Specified by:
      next in interface java.util.Iterator<java.lang.String>
      Returns:
      the next line from the input
      Throws:
      java.util.NoSuchElementException - if there is no line to return

    • nextLine

      public java.lang.String nextLine()
      Returns the next line in the wrapped Reader.
      Returns:
      the next line from the input
      Throws:
      java.util.NoSuchElementException - if there is no line to return

    • close

      public void close()
      Closes the underlying Reader quietly. This method is useful if you only want to process the first few lines of a larger file. If you do not close the iterator then the Reader remains open. This method can safely be called multiple times.

    • remove

      public void remove()
      Unsupported.
      Specified by:
      remove in interface java.util.Iterator<java.lang.String>
      Throws:
      java.lang.UnsupportedOperationException - always

    • closeQuietly

      public static void closeQuietly​(LineIterator iterator)
      Closes the iterator, handling null and ignoring exceptions.
      Parameters:
      iterator - the iterator to close