LDAPVirtualListControl

java.lang.Object
- netscape.ldap.LDAPControl
- - netscape.ldap.controls.LDAPVirtualListControl

All Implemented Interfaces:: java.io.Serializable, java.lang.Cloneable

public class LDAPVirtualListControl
extends LDAPControl

Represents control data for returning paged results from a search. Example of usage, with JFC:


  // Call this to initialize the list box, whenever the search
  // conditions change.
  // "filter" may be "objectclass=person", for example
  void initListBox( String host, int port, String base, String filter ) {

  // Create list box if not already done
   if ( _dataList == null ) {
       _dataList = new JList();
       JScrollPane scrollPane = new JScrollPane(_dataList);
       add( scrollPane );
   }

   // Create a virtual data model
   vlistModel model = new vlistModel( host, port, base, filter );
   // Keep a buffer of one page before and one after
   model.setPageSize( getScrollVisibleSize() );
   _dataList.setModel( model );
  }

 // Data model to supply buffer list data
class vlistModel extends AbstractListModel {
  vlistModel( String host, int port, String base, String filter ) {
      _base = base;
      _filter = filter;

      // Connect to the server
      try {
          _ldc = new LDAPConnection();
          System.out.println( "Connecting to " + host +
                              ":" + port );
          _ldc.connect( host, port );
      } catch ( LDAPException e ) {
          System.out.println( e );
          _ldc = null;
      }
  }

  // Called by JList to get virtual list size
    public int getSize() {
      if ( !_initialized ) {
          _initialized = true;
          _pageControls = new LDAPControl[2];
          // Paged results also require a sort control
          _pageControls[0] =
              new LDAPSortControl( new LDAPSortKey("cn"),
                                   true );
          // Do an initial search to get the virtual list size
          // Keep one page before and one page after the start
          _beforeCount = _pageSize;
          _afterCount = _pageSize;
          // Create the initial paged results control
          LDAPVirtualListControl cont =
              new LDAPVirtualListControl( "A",
                                          _beforeCount,
                                          _afterCount );
          _pageControls[1] = cont;
          _vlc = (LDAPVirtualListControl)_pageControls[1];
          getPage( 0 );
      }
      return _size;
  }

  // Get a page starting at first (although we may also fetch
  // some preceding entries)
  boolean getPage( int first ) {
      _vlc.setRange( first, _beforeCount, _afterCount );
      return getPage();
  }

  boolean getEntries() {
      // Specify necessary controls for vlv
      if ( _pageControls != null ) {
          try {
              _ldc.setOption( _ldc.SERVERCONTROLS, _pageControls );
          } catch ( LDAPException e ) {
              System.out.println( e + ", setting vlv control" );
          }
      }
      // Empty the buffer
      _entries.removeAllElements();
      // Do a search
      try {
          String[] attrs = { "cn" };
          LDAPSearchResults result =
              _ldc.search( _base,
                           LDAPConnection.SCOPE_SUB,
                           _filter,
                           attrs, false );
          while ( result.hasMoreElements() ) {
              LDAPEntry entry = (LDAPEntry)result.nextElement();
              LDAPAttribute attr = entry.getAttribute( attrs[0] );
              if ( attr != null ) {
                  Enumeration en = attr.getStringValues();
                  while( en.hasMoreElements() ) {
                      String name = (String)en.nextElement();
                      _entries.addElement( name );
                  }
              }
          }
      } catch ( LDAPException e ) {
          System.out.println( e + ", searching" );
          return false;
      }
      return true;
  }

  // Fetch a buffer
  boolean getPage() {
      // Get the actual entries
      if ( !getEntries() )
          return false;

      // Check if we have a control returned
      LDAPControl[] c = _ldc.getResponseControls();
      LDAPVirtualListResponse nextCont = null;
      for ( int i = 0; i < c.length; i++ ) {
          if ( c[i] instanceof LDAPVirtualListResponse ) {
              nextCont = (LDAPVirtualListResponse)c[i];
              break;
          }
      }
      if ( nextCont != null ) {
          _selectedIndex = nextCont.getFirstPosition() - 1;
          _top = Math.max( 0, _selectedIndex - _beforeCount );
          // Now we know the total size of the virtual list box
          _size = nextCont.getContentCount();
          _vlc.setListSize( _size );
      } else {
          System.out.println( "Null response control" );
      }
      return true;
  }

  // Called by JList to fetch data to paint a single list item
    public Object getElementAt(int index) {
      if ( (index < _top) || (index >= _top + _entries.size()) ) {
          getPage( index );
      }
      int offset = index - _top;
      if ( (offset < 0) || (offset >= _entries.size()) )
          return new String( "No entry at " + index );
      else
          return _entries.elementAt( offset );
  }

  // Called by application to find out the virutal selected index
    public int getSelectedIndex() {
      return _selectedIndex;
  }

  // Called by application to find out the top of the buffer
    public int getFirstIndex() {
      return _top;
  }

  public void setPageSize( int size ) {
      _pageSize = size;
  }

  Vector _entries = new Vector();
  protected boolean _initialized = false;
  private int _top = 0;
  protected int _beforeCount;
  protected int _afterCount;
  private int _pageSize = 10;
  private int _selectedIndex = 0;
  protected LDAPControl[] _pageControls = null;
  protected LDAPVirtualListControl _vlc = null;
  protected int _size = -1;
  private String _base;
  private String _filter;
  private LDAPConnection _ldc;
}

   VirtualListViewRequest ::= SEQUENCE {
            beforeCount    INTEGER (0 .. maxInt),
            afterCount     INTEGER (0 .. maxInt),
            CHOICE {
                byIndex [0] SEQUENCE {
                    index           INTEGER,
                    contentCount    INTEGER
                }
                byFilter [1] jumpTo    Substring
            },
            contextID     OCTET STRING OPTIONAL
  }

See Also:: Serialized Form

Field Summary

Fields
Modifier and Type Field Description

static java.lang.String VIRTUALLIST
- Fields inherited from class netscape.ldap.LDAPControl
  m_critical, m_value, MANAGEDSAIT, PWEXPIRED, PWEXPIRING

Fields
Modifier and Type	Field	Description
`static java.lang.String`	`VIRTUALLIST`

Constructor Summary

Constructors
Constructor	Description
`LDAPVirtualListControl(int startIndex, int beforeCount, int afterCount, int contentCount)`	Constructs a new `LDAPVirtualListControl` object.
`LDAPVirtualListControl(int startIndex, int beforeCount, int afterCount, int contentCount, java.lang.String context)`
`LDAPVirtualListControl(java.lang.String jumpTo, int beforeCount, int afterCount)`	Constructs a new `LDAPVirtualListControl` object.
`LDAPVirtualListControl(java.lang.String jumpTo, int beforeCount, int afterCount, java.lang.String context)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`getAfterCount()`	Gets the number of results after the top/center to return per page.
`int`	`getBeforeCount()`	Gets the number of results before the top/center to return per page.
`java.lang.String`	`getContext()`	Gets the optional context cookie.
`int`	`getIndex()`	Gets the size of the virtual result set.
`int`	`getListSize()`	Gets the size of the virtual result set.
`void`	`setContext(java.lang.String context)`	Sets the optional context cookie.
`void`	`setListSize(int listSize)`	Sets the size of the virtual result set.
`void`	`setRange(int startIndex, int beforeCount, int afterCount)`	Sets the starting index, and the number of entries before and after to return.
`void`	`setRange(java.lang.String jumpTo, int beforeCount, int afterCount)`	Sets the search expression, and the number of entries before and after to return.
`java.lang.String`	`toString()`	Return a string representation of the control for debugging

Methods inherited from class netscape.ldap.LDAPControl
clone, createControl, flattenBER, getID, getValue, isCritical, lookupControlClass, newInstance, register

Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - VIRTUALLIST
```
public static final java.lang.String VIRTUALLIST
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - LDAPVirtualListControl
```
public LDAPVirtualListControl(java.lang.String jumpTo,
                              int beforeCount,
                              int afterCount)
```
    Constructs a new LDAPVirtualListControl object. Use this constructor on an initial search operation, specifying the first entry to be matched, or the initial part of it.
    
    Parameters:
    
    jumpTo - an LDAP search expression defining the result set
    
    beforeCount - the number of results before the top/center to return per page
    
    afterCount - the number of results after the top/center to return per page
    
    See Also:
    
    LDAPControl
  - LDAPVirtualListControl
```
public LDAPVirtualListControl(java.lang.String jumpTo,
                              int beforeCount,
                              int afterCount,
                              java.lang.String context)
```
  - LDAPVirtualListControl
```
public LDAPVirtualListControl(int startIndex,
                              int beforeCount,
                              int afterCount,
                              int contentCount)
```
    Constructs a new LDAPVirtualListControl object. Use this constructor on a subsquent search operation, after we know the size of the virtual list, to fetch a subset.
    
    Parameters:
    
    startIndex - the index into the virtual list of an entry to return
    
    beforeCount - the number of results before the top/center to return per page
    
    afterCount - the number of results after the top/center to return per page
    
    See Also:
    
    LDAPControl
  - LDAPVirtualListControl
```
public LDAPVirtualListControl(int startIndex,
                              int beforeCount,
                              int afterCount,
                              int contentCount,
                              java.lang.String context)
```
- Method Detail
  - setRange
```
public void setRange(int startIndex,
                     int beforeCount,
                     int afterCount)
```
    Sets the starting index, and the number of entries before and after to return. Apply this method to a control returned from a previous search, to specify what result range to return on the next search.
    
    Parameters:
    
    startIndex - the index into the virtual list of an entry to return
    
    beforeCount - the number of results before startIndex to return per page
    
    afterCount - the number of results after startIndex to return per page
    
    See Also:
    
    LDAPControl
  - setRange
```
public void setRange(java.lang.String jumpTo,
                     int beforeCount,
                     int afterCount)
```
    Sets the search expression, and the number of entries before and after to return.
    
    Parameters:
    
    jumpTo - an LDAP search expression defining the result set return.
    
    beforeCount - the number of results before startIndex to return per page
    
    afterCount - the number of results after startIndex to return per page
    
    See Also:
    
    LDAPControl
  - getIndex
```
public int getIndex()
```
    Gets the size of the virtual result set.
    
    Returns:
    
    the size of the virtual result set, or -1 if not known.
  - getListSize
```
public int getListSize()
```
    Gets the size of the virtual result set.
    
    Returns:
    
    the size of the virtual result set, or -1 if not known.
  - setListSize
```
public void setListSize(int listSize)
```
    Sets the size of the virtual result set.
    
    Parameters:
    
    listSize - the virtual result set size
  - getBeforeCount
```
public int getBeforeCount()
```
    Gets the number of results before the top/center to return per page.
    
    Returns:
    
    the number of results before the top/center to return per page.
  - getAfterCount
```
public int getAfterCount()
```
    Gets the number of results after the top/center to return per page.
    
    Returns:
    
    the number of results after the top/center to return per page.
  - getContext
```
public java.lang.String getContext()
```
    Gets the optional context cookie.
    
    Returns:
    
    the optional context cookie.
  - setContext
```
public void setContext(java.lang.String context)
```
    Sets the optional context cookie.
    
    Parameters:
    
    context - the optional context cookie
  - toString
```
public java.lang.String toString()
```
    Description copied from class: LDAPControl
    
    Return a string representation of the control for debugging
    
    Overrides:
    
    toString in class LDAPControl
    
    Returns:
    
    a string representation of the control.

Class LDAPVirtualListControl

Field Summary

Fields inherited from class netscape.ldap.LDAPControl

Constructor Summary

Method Summary

Methods inherited from class netscape.ldap.LDAPControl

Methods inherited from class java.lang.Object

Field Detail

VIRTUALLIST

Constructor Detail

LDAPVirtualListControl

LDAPVirtualListControl

LDAPVirtualListControl

LDAPVirtualListControl

Method Detail

setRange

setRange

getIndex

getListSize

setListSize

getBeforeCount

getAfterCount

getContext

setContext

toString