Class PagedResultsControl

java.lang.Object

javax.naming.ldap.BasicControl

javax.naming.ldap.PagedResultsControl

All Implemented Interfaces:

Serializable, Control

public final class PagedResultsControl
extends BasicControl

Requests that the results of a search operation be returned by the LDAP server in batches of a specified size. The requestor controls the rate at which batches are returned by the rate at which it invokes search operations.

The following code sample shows how the class may be used:

    // Open an LDAP association
    LdapContext ctx = new InitialLdapContext();

    // Activate paged results
    int pageSize = 20; // 20 entries per page
    byte[] cookie = null;
    int total;
    ctx.setRequestControls(new Control[]{
        new PagedResultsControl(pageSize, Control.CRITICAL) });

    do {
        // Perform the search
        NamingEnumeration results =
            ctx.search("", "(objectclass=*)", new SearchControls());

        // Iterate over a batch of search results
        while (results != null && results.hasMore()) {
            // Display an entry
            SearchResult entry = (SearchResult)results.next();
            System.out.println(entry.getName());
            System.out.println(entry.getAttributes());

            // Handle the entry's response controls (if any)
            if (entry instanceof HasControls) {
                // ((HasControls)entry).getControls();
            }
        }
        // Examine the paged results control response
        Control[] controls = ctx.getResponseControls();
        if (controls != null) {
            for (int i = 0; i < controls.length; i++) {
                if (controls[i] instanceof PagedResultsResponseControl) {
                    PagedResultsResponseControl prrc =
                        (PagedResultsResponseControl)controls[i];
                    total = prrc.getResultSize();
                    cookie = prrc.getCookie();
                } else {
                    // Handle other response controls (if any)
                }
            }
        }

        // Re-activate paged results
        ctx.setRequestControls(new Control[]{
            new PagedResultsControl(pageSize, cookie, Control.CRITICAL) });
    } while (cookie != null);

    // Close the LDAP association
    ctx.close();
    ...

 

This class implements the LDAPv3 Control for paged-results as defined in RFC 2696. The control's value has the following ASN.1 definition:

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

Since:

1.5

See Also:

• PagedResultsResponseControl
• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static final String	OID	The paged-results control's assigned object identifier is 1.2.840.113556.1.4.319.

Fields declared in class BasicControl

criticality, id, value

Modifier and Type	Field	Description
protected boolean	criticality	The control's criticality.
protected String	id	The control's object identifier string.
protected byte[]	value	The control's ASN.1 BER encoded value.

Fields declared in interface Control

CRITICAL, NONCRITICAL

Modifier and Type	Field	Description
static final boolean	CRITICAL	Indicates a critical control.
static final boolean	NONCRITICAL	Indicates a non-critical control.

Constructor Summary

Constructors

Constructor	Description
PagedResultsControl(int pageSize, boolean criticality)	Constructs a control to set the number of entries to be returned per page of results.
PagedResultsControl(int pageSize, byte[] cookie, boolean criticality)	Constructs a control to set the number of entries to be returned per page of results.

Method Summary

Methods declared in class BasicControl

getEncodedValue, getID, isCritical

Modifier and Type	Method	Description
byte[]	getEncodedValue()	Retrieves the control's ASN.1 BER encoded value.
String	getID()	Retrieves the control's object identifier string.
boolean	isCritical()	Determines the control's criticality.

Methods declared in class Object

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

Modifier and Type	Method	Description
protected Object	clone()	Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. May cause performance issues, deadlocks and hangs.
final Class<? extends Object>	getClass()	Answers the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode()	Answers an integer hash code for the receiver.
final void	notify()	Causes one thread which is waiting on the receiver to be made ready to run.
final void	notifyAll()	Causes all threads which are waiting on the receiver to be made ready to run.
String	toString()	Answers a string containing a concise, human-readable description of the receiver.
final void	wait()	Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
final void	wait(long time)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
final void	wait(long time, int frac)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

Field Details

OID

public static final String OID

The paged-results control's assigned object identifier is 1.2.840.113556.1.4.319.

See Also:

• Constant Field Values

Constructor Details

PagedResultsControl

public PagedResultsControl(int pageSize,
 boolean criticality)
                    throws IOException

Constructs a control to set the number of entries to be returned per page of results.

Parameters:

pageSize - The number of entries to return in a page.

criticality - If true then the server must honor the control and return search results as indicated by pageSize or refuse to perform the search. If false, then the server need not honor the control.

Throws:

IOException - If an error was encountered while encoding the supplied arguments into a control.

PagedResultsControl

public PagedResultsControl(int pageSize,
 byte[] cookie,
 boolean criticality)
                    throws IOException

Constructs a control to set the number of entries to be returned per page of results. The cookie is provided by the server and may be obtained from the paged-results response control.

A sequence of paged-results can be abandoned by setting the pageSize to zero and setting the cookie to the last cookie received from the server.

Parameters:

pageSize - The number of entries to return in a page.

cookie - A possibly null server-generated cookie.

criticality - If true then the server must honor the control and return search results as indicated by pageSize or refuse to perform the search. If false, then the server need not honor the control.

Throws:

IOException - If an error was encountered while encoding the supplied arguments into a control.