Class RegexFilter

java.lang.Object
org.htmlparser.filters.RegexFilter
All Implemented Interfaces:
Serializable, Cloneable, NodeFilter

public class RegexFilter extends Object implements NodeFilter
This filter accepts all string nodes matching a regular expression. Because this searches Text nodes. it is only useful for finding small fragments of text, where it is unlikely to be broken up by a tag. To find large fragments of text you should convert the page to plain text with something like the StringBean and then apply the regular expression.

For example, to look for dates use:

   (19|20)\d\d([- \\/.](0[1-9]|1[012])[- \\/.](0[1-9]|[12][0-9]|3[01]))?
 
as in:
 Parser parser = new Parser ("http://cbc.ca");
 RegexFilter filter = new RegexFilter ("(19|20)\\d\\d([- \\\\/.](0[1-9]|1[012])[- \\\\/.](0[1-9]|[12][0-9]|3[01]))?");
 NodeIterator iterator = parser.extractAllNodesThatMatch (filter).elements ();
 
which matches a date in yyyy-mm-dd format between 1900-01-01 and 2099-12-31, with a choice of five separators, either a dash, a space, either kind of slash or a period. The year is matched by (19|20)\d\d which uses alternation to allow the either 19 or 20 as the first two digits. The round brackets are mandatory. The month is matched by 0[1-9]|1[012], again enclosed by round brackets to keep the two options together. By using character classes, the first option matches a number between 01 and 09, and the second matches 10, 11 or 12. The last part of the regex consists of three options. The first matches the numbers 01 through 09, the second 10 through 29, and the third matches 30 or 31. The day and month are optional, but must occur together because of the ()? bracketing after the year.
See Also:
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    Use find() match strategy.
    static final int
    Use lookingAt() match strategy.
    static final int
    Use match() matching strategy.
    protected Pattern
    The compiled regular expression to search for.
    protected String
    The regular expression to search for.
    protected int
    The match strategy.
  • Constructor Summary

    Constructors
    Constructor
    Description
    Creates a new instance of RegexFilter that accepts string nodes matching the regular expression ".*" using the FIND strategy.
    Creates a new instance of RegexFilter that accepts string nodes matching a regular expression using the FIND strategy.
    RegexFilter(String pattern, int strategy)
    Creates a new instance of RegexFilter that accepts string nodes matching a regular expression.
  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    accept(Node node)
    Accept string nodes that match the regular expression.
    Get the search pattern.
    int
    Get the search strategy.
    void
    setPattern(String pattern)
    Set the search pattern.
    void
    setStrategy(int strategy)
    Set the search pattern.

    Methods inherited from class java.lang.Object

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

    • MATCH

      public static final int MATCH
      Use match() matching strategy.
      See Also:
    • LOOKINGAT

      public static final int LOOKINGAT
      Use lookingAt() match strategy.
      See Also:
    • FIND

      public static final int FIND
      Use find() match strategy.
      See Also:
    • mPatternString

      protected String mPatternString
      The regular expression to search for.
    • mPattern

      protected Pattern mPattern
      The compiled regular expression to search for.
    • mStrategy

      protected int mStrategy
      The match strategy.
      See Also:
  • Constructor Details

    • RegexFilter

      public RegexFilter()
      Creates a new instance of RegexFilter that accepts string nodes matching the regular expression ".*" using the FIND strategy.
    • RegexFilter

      public RegexFilter(String pattern)
      Creates a new instance of RegexFilter that accepts string nodes matching a regular expression using the FIND strategy.
      Parameters:
      pattern - The pattern to search for.
    • RegexFilter

      public RegexFilter(String pattern, int strategy)
      Creates a new instance of RegexFilter that accepts string nodes matching a regular expression.
      Parameters:
      pattern - The pattern to search for.
      strategy - The type of match:
      1. MATCH use matches() method: attempts to match the entire input sequence against the pattern
      2. LOOKINGAT use lookingAt() method: attempts to match the input sequence, starting at the beginning, against the pattern
      3. FIND use find() method: scans the input sequence looking for the next subsequence that matches the pattern
  • Method Details

    • getPattern

      public String getPattern()
      Get the search pattern.
      Returns:
      Returns the pattern.
    • setPattern

      public void setPattern(String pattern)
      Set the search pattern.
      Parameters:
      pattern - The pattern to set.
    • getStrategy

      public int getStrategy()
      Get the search strategy.
      Returns:
      Returns the strategy.
    • setStrategy

      public void setStrategy(int strategy)
      Set the search pattern.
      Parameters:
      strategy - The strategy to use. One of MATCH, LOOKINGAT or FIND.
    • accept

      public boolean accept(Node node)
      Accept string nodes that match the regular expression.
      Specified by:
      accept in interface NodeFilter
      Parameters:
      node - The node to check.
      Returns:
      true if the regular expression matches the text of the node, false otherwise.