org.forgerock.opendj.ldap.controls.SimplePagedResultsControl

All Implemented Interfaces:: Control

public final class SimplePagedResultsControl extends Object implements Control

The simple paged results request and response control as defined in RFC 2696. This control allows a client to control the rate at which an LDAP server returns the results of an LDAP search operation. This control may be useful when the LDAP client has limited resources and may not be able to process the entire result set from a given LDAP query, or when the LDAP client is connected over a low-bandwidth connection.

This control is included in the searchRequest and searchResultDone messages and has the following structure:

 realSearchControlValue ::= SEQUENCE {
         size            INTEGER (0..maxInt),
                                 -- requested page size from client
                                 -- result set size estimate from server
         cookie          OCTET STRING
 }

The following example demonstrates use of simple paged results to handle three entries at a time.

 ByteString cookie = ByteString.empty();
 SearchRequest request;
 SearchResultHandler resultHandler = new MySearchResultHandler();
 Result result;

 int page = 1;
 do {
      System.out.println("# Simple paged results: Page " + page);

      request = Requests.newSearchRequest(
              "dc=example,dc=com", SearchScope.WHOLE_SUBTREE, "(sn=Jensen)", "cn")
              .addControl(SimplePagedResultsControl.newControl(true, 3, cookie));

      result = connection.search(request, resultHandler);
      try {
          SimplePagedResultsControl control = result.getControl(
                  SimplePagedResultsControl.DECODER, new DecodeOptions());
          cookie = control.getCookie();
      } catch (final DecodeException e) {
          // Failed to decode the response control.
      }

      ++page;
 } while (!cookie.isEmpty());

The search result handler in this case displays pages of results as LDIF on standard out.

 private static class MySearchResultHandler implements SearchResultHandler {

     @Override
     public void handleExceptionResult(LdapException error) {
         // Ignore.
     }

     @Override
     public void handleResult(Result result) {
         // Ignore.
     }

     @Override
     public boolean handleEntry(SearchResultEntry entry) {
         final LDIFEntryWriter writer = new LDIFEntryWriter(System.out);
         try {
             writer.writeEntry(entry);
             writer.flush();
         } catch (final IOException e) {
             // The writer could not write to System.out.
         }
         return true;
     }

     @Override
     public boolean handleReference(SearchResultReference reference) {
         System.out.println("Got a reference: " + reference.toString());
         return false;
     }
 }

See Also:

RFC 2696 - LDAP Control Extension for Simple Paged Results Manipulation

Field Summary

Fields

Modifier and Type

Field

Description

static final List<String>

ALIASES

The user-friendly aliases for the simple paged results control.

static final ControlDecoder<SimplePagedResultsControl>

DECODER

A decoder which can be used for decoding the simple paged results control.

static final String

OID

The OID for the paged results request/response control defined in RFC 2696.
Method Summary

Modifier and Type

Method

Description

String

getAlias()

Returns the control "friendly name" alias for the control.

ByteString

getCookie()

Returns the opaque cookie which is used by the server to track its position in the set of search results.

String

getOid()

Returns the numeric OID associated with this control.

int

getSize()

Returns the requested page size when used in a request control from the client, or an estimate of the result set size when used in a response control from the server (may be 0, indicating that the server does not know).

ByteString

getValue()

Returns the value, if any, associated with this control.

boolean

hasValue()

Returns true if this control has a value.

boolean

isCritical()

Returns true if it is unacceptable to perform the operation without applying the semantics of this control.

static SimplePagedResultsControl

newControl(boolean isCritical, int size, ByteString cookie)

Creates a new simple paged results control with the provided criticality, size, and cookie.

String

toString()

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

Field Details
- OID
  
  public static final String OID
  
  The OID for the paged results request/response control defined in RFC 2696.
  See Also:
  
  Constant Field Values
- ALIASES
  
  public static final List<String> ALIASES
  
  The user-friendly aliases for the simple paged results control.
- DECODER
  
  public static final ControlDecoder<SimplePagedResultsControl> DECODER
  
  A decoder which can be used for decoding the simple paged results control.
Method Details
- newControl
  
  public static SimplePagedResultsControl newControl(boolean isCritical, int size, ByteString cookie)
  
  Creates a new simple paged results control with the provided criticality, size, and cookie.
  
  Parameters:
  
  isCritical - true if it is unacceptable to perform the operation without applying the semantics of this control, or false if it can be ignored.
  
  size - The requested page size when used in a request control from the client, or an estimate of the result set size when used in a response control from the server (may be 0, indicating that the server does not know).
  
  cookie - An opaque cookie which is used by the server to track its position in the set of search results. The cookie must be empty in the initial search request sent by the client. For subsequent search requests the client must include the cookie returned with the previous search result, until the server returns an empty cookie indicating that the final page of results has been returned.
  
  Returns:
  
  The new control.
  
  Throws:
  
  NullPointerException - If cookie was null.
- getCookie
  
  public ByteString getCookie()
  
  Returns the opaque cookie which is used by the server to track its position in the set of search results. The cookie must be empty in the initial search request sent by the client. For subsequent search requests the client must include the cookie returned with the previous search result, until the server returns an empty cookie indicating that the final page of results has been returned.
  
  Returns:
  
  The opaque cookie which is used by the server to track its position in the set of search results. It is not null and will be empty for the final page of results.
- getOid
  
  public String getOid()
  
  Description copied from interface: Control
  
  Returns the numeric OID associated with this control.
  
  Specified by:
  
  getOid in interface Control
  
  Returns:
  
  The numeric OID associated with this control.
- getSize
  
  public int getSize()
  
  Returns the requested page size when used in a request control from the client, or an estimate of the result set size when used in a response control from the server (may be 0, indicating that the server does not know).
  
  Returns:
  
  The requested page size when used in a request control from the client, or an estimate of the result set size when used in a response control from the server.
- getValue
  
  public ByteString getValue()
  
  Description copied from interface: Control
  
  Returns the value, if any, associated with this control. Its format is defined by the specification of this control.
  
  Specified by:
  
  getValue in interface Control
  
  Returns:
  
  The value associated with this control, or null if there is no value.
- hasValue
  
  public boolean hasValue()
  
  Description copied from interface: Control
  
  Returns true if this control has a value. In some circumstances it may be useful to determine if a control has a value, without actually calculating the value and incurring any performance costs.
  
  Specified by:
  
  hasValue in interface Control
  
  Returns:
  
  true if this control has a value, or false if there is no value.
- isCritical
  
  public boolean isCritical()
  
  Description copied from interface: Control
  
  Returns true if it is unacceptable to perform the operation without applying the semantics of this control.
  The criticality field only has meaning in controls attached to request messages (except UnbindRequest). For controls attached to response messages and the UnbindRequest, the criticality field SHOULD be false, and MUST be ignored by the receiving protocol peer. A value of true indicates that it is unacceptable to perform the operation without applying the semantics of the control.
  
  Specified by:
  
  isCritical in interface Control
  
  Returns:
  
  true if this control must be processed by the Directory Server, or false if it can be ignored.
- toString
  
  public String toString()
  
  Overrides:
  
  toString in class Object
- getAlias
  
  public String getAlias()
  
  Description copied from interface: Control
  
  Returns the control "friendly name" alias for the control.
  
  Specified by:
  
  getAlias in interface Control
  
  Returns:
  
  "Friendly name" alias for the control.

Class SimplePagedResultsControl

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Details

OID

ALIASES

DECODER

Method Details

newControl

getCookie

getOid

getSize

getValue

hasValue

isCritical

toString

getAlias