Package org.htmlparser.beans

Class StringBean

java.lang.Object
org.htmlparser.visitors.NodeVisitor
org.htmlparser.beans.StringBean
All Implemented Interfaces:
Serializable
public class StringBean extends NodeVisitor implements Serializable
Extract strings from a URL.

Text within <SCRIPT></SCRIPT> tags is removed.

The text within <PRE></PRE> tags is not altered.

The property Strings, which is the output property is null until a URL is set. So a typical usage is:

     StringBean sb = new StringBean ();
     sb.setLinks (false);
     sb.setReplaceNonBreakingSpaces (true);
     sb.setCollapse (true);
     sb.setURL ("http://www.netbeans.org"); // the HTTP is performed here
     String s = sb.getStrings ();
You can also use the StringBean as a NodeVisitor on your own parser, in which case you have to refetch your page if you change one of the properties because it resets the Strings property:

     StringBean sb = new StringBean ();
     Parser parser = new Parser ("http://cbc.ca");
     parser.visitAllNodesWith (sb);
     String s = sb.getStrings ();
     sb.setLinks (true);
     parser.reset ();
     parser.visitAllNodesWith (sb);
     String sl = sb.getStrings ();
According to Nick Burch, who contributed the patch, this is handy if you don't want StringBean to wander off and get the content itself, either because you already have it, it's not on a website etc.
See Also:

  • Field Details

    • PROP_STRINGS_PROPERTY

      public static final String PROP_STRINGS_PROPERTY
      Property name in event where the URL contents changes.
      See Also:

    • PROP_URL_PROPERTY

      public static final String PROP_URL_PROPERTY
      Property name in event where the URL changes.
      See Also:

    • PROP_REPLACE_SPACE_PROPERTY

      public static final String PROP_REPLACE_SPACE_PROPERTY
      Property name in event where the 'replace non-breaking spaces' state changes.
      See Also:

    • PROP_COLLAPSE_PROPERTY

      public static final String PROP_COLLAPSE_PROPERTY
      Property name in event where the 'collapse whitespace' state changes.
      See Also:

    • PROP_CONNECTION_PROPERTY

      public static final String PROP_CONNECTION_PROPERTY
      Property name in event where the connection changes.
      See Also:

    • mPropertySupport

      protected PropertyChangeSupport mPropertySupport
      Bound property support.

    • mParser

      protected Parser mParser
      The parser used to extract strings.

    • mStrings

      protected String mStrings
      The strings extracted from the URL.

    • mReplaceSpace

      protected boolean mReplaceSpace
      If true regular space characters are substituted for non-breaking spaces in the text output.

    • mCollapse

      protected boolean mCollapse
      If true sequences of whitespace characters are replaced with a single space character.

    • mCollapseState

      protected int mCollapseState
      The state of the collapse processiung state machine.

    • mBuffer

      protected StringBuffer mBuffer
      The buffer text is stored in while traversing the HTML.

    • mIsScript

      protected boolean mIsScript
      Set true when traversing a SCRIPT tag.

    • mIsPre

      protected boolean mIsPre
      Set true when traversing a PRE tag.

    • mIsStyle

      protected boolean mIsStyle
      Set true when traversing a STYLE tag.

  • Constructor Details

    • StringBean

      public StringBean()
      Create a StringBean object. Default property values are set to 'do the right thing':

      Links is set false so text appears like a browser would display it, albeit without the colour or underline clues normally associated with a link.

      ReplaceNonBreakingSpaces is set true, so that printing the text works, but the extra information regarding these formatting marks is available if you set it false.

      Collapse is set true, so text appears compact like a browser would display it.

  • Method Details

    • carriageReturn

      protected void carriageReturn()
      Appends a newline to the buffer if there isn't one there already. Except if the buffer is empty.

    • collapse

      protected void collapse(StringBuffer buffer, String string)
      Add the given text collapsing whitespace. Use a little finite state machine: 
       state 0: whitepace was last emitted character
 state 1: in whitespace
 state 2: in word
 A whitespace character moves us to state 1 and any other character
 moves us to state 2, except that state 0 stays in state 0 until
 a non-whitespace and going from whitespace to word we emit a space
 before the character:
    input:     whitespace   other-character
 state\next
    0               0             2
    1               1        space then 2
    2               1             2
      Parameters:
      buffer - The buffer to append to.
      string - The string to append.

    • extractStrings

      protected String extractStrings() throws ParserException
      Extract the text from a page.
      Returns:
      The textual contents of the page.
      Throws:
      ParserException - If a parse error occurs.

    • updateStrings

      protected void updateStrings(String strings)
      Assign the Strings property, firing the property change.
      Parameters:
      strings - The new value of the Strings property.

    • setStrings

      protected void setStrings()
      Fetch the URL contents. Only do work if there is a valid parser with it's URL set.

    • addPropertyChangeListener

      public void addPropertyChangeListener(PropertyChangeListener listener)
      Add a PropertyChangeListener to the listener list. The listener is registered for all properties.
      Parameters:
      listener - The PropertyChangeListener to be added.

    • removePropertyChangeListener

      public void removePropertyChangeListener(PropertyChangeListener listener)
      Remove a PropertyChangeListener from the listener list. This removes a registered PropertyChangeListener.
      Parameters:
      listener - The PropertyChangeListener to be removed.

    • getStrings

      public String getStrings()
      Return the textual contents of the URL. This is the primary output of the bean.
      Returns:
      The user visible (what would be seen in a browser) text.

    • getLinks

      public boolean getLinks()
      Get the current 'include links' state.
      Returns:
      true if link text is included in the text extracted from the URL, false otherwise.

    • setLinks

      public void setLinks(boolean links)
      Set the 'include links' state. If the setting is changed after the URL has been set, the text from the URL will be reacquired, which is possibly expensive.
      Parameters:
      links - Use true if link text is to be included in the text extracted from the URL, false otherwise.

    • getURL

      public String getURL()
      Get the current URL.
      Returns:
      The URL from which text has been extracted, or null if this property has not been set yet.

    • setURL

      public void setURL(String url)
      Set the URL to extract strings from. The text from the URL will be fetched, which may be expensive, so this property should be set last.
      Parameters:
      url - The URL that text should be fetched from.

    • getReplaceNonBreakingSpaces

      public boolean getReplaceNonBreakingSpaces()
      Get the current 'replace non breaking spaces' state.
      Returns:
      true if non-breaking spaces (character '\u00a0', numeric character reference &#160; or character entity reference &nbsp;) are to be replaced with normal spaces (character '\u0020').

    • setReplaceNonBreakingSpaces

      public void setReplaceNonBreakingSpaces(boolean replace)
      Set the 'replace non breaking spaces' state. If the setting is changed after the URL has been set, the text from the URL will be reacquired, which is possibly expensive.
      Parameters:
      replace - true if non-breaking spaces (character '\u00a0', numeric character reference &#160; or character entity reference &nbsp;) are to be replaced with normal spaces (character '\u0020').

    • getCollapse

      public boolean getCollapse()
      Get the current 'collapse whitespace' state. If set to true this emulates the operation of browsers in interpretting text where user agents should collapse input white space sequences when producing output inter-word space. See HTML specification section 9.1 White space http://www.w3.org/TR/html4/struct/text.html#h-9.1.
      Returns:
      true if sequences of whitespace (space '\u0020', tab '\u0009', form feed '\u000C', zero-width space '\u200B', carriage-return '\r' and NEWLINE '\n') are to be replaced with a single space.

    • setCollapse

      public void setCollapse(boolean collapse)
      Set the current 'collapse whitespace' state. If the setting is changed after the URL has been set, the text from the URL will be reacquired, which is possibly expensive. The internal state of the collapse state machine can be reset with code like this: setCollapse (getCollapse ());
      Parameters:
      collapse - If true, sequences of whitespace will be reduced to a single space.

    • getConnection

      public URLConnection getConnection()
      Get the current connection.
      Returns:
      The connection that the parser has or null if it hasn't been set or the parser hasn't been constructed yet.

    • setConnection

      public void setConnection(URLConnection connection)
      Set the parser's connection. The text from the URL will be fetched, which may be expensive, so this property should be set last.
      Parameters:
      connection - New value of property Connection.

    • visitStringNode

      public void visitStringNode(Text string)
      Appends the text to the output.
      Overrides:
      visitStringNode in class NodeVisitor
      Parameters:
      string - The text node.

    • visitTag

      public void visitTag(Tag tag)
      Appends a NEWLINE to the output if the tag breaks flow, and possibly sets the state of the PRE and SCRIPT flags.
      Overrides:
      visitTag in class NodeVisitor
      Parameters:
      tag - The tag to examine.

    • visitEndTag

      public void visitEndTag(Tag tag)
      Resets the state of the PRE and SCRIPT flags.
      Overrides:
      visitEndTag in class NodeVisitor
      Parameters:
      tag - The end tag to process.

    • main

      public static void main(String[] args)
      Unit test.
      Parameters:
      args - Pass arg[0] as the URL to process.