SortControl

Class Overview

Requests that the results of a search operation be sorted by the LDAP server before being returned. The sort criteria are specified using an ordered list of one or more sort keys, with associated sort parameters. Search results are sorted at the LDAP server according to the parameters supplied in the sort control and then returned to the requestor. If sorting is not supported at the server (and the sort control is marked as critical) then the search operation is not performed and an error is returned.

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

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

     // Activate sorting
     String sortKey = "cn";
     ctx.setRequestControls(new Control[]{
         new SortControl(sortKey, Control.CRITICAL) });

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

     // Iterate over 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 sort control response
     Control[] controls = ctx.getResponseControls();
     if (controls != null) {
         for (int i = 0; i < controls.length; i++) {
             if (controls[i] instanceof SortResponseControl) {
                 SortResponseControl src = (SortResponseControl)controls[i];
                 if (! src.isSorted()) {
                     throw src.getException();
                 }
             } else {
                 // Handle other response controls (if any)
             }
         }
     }

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

 

This class implements the LDAPv3 Request Control for server-side sorting as defined in RFC 2891. The control's value has the following ASN.1 definition:

     SortKeyList ::= SEQUENCE OF SEQUENCE {
         attributeType     AttributeDescription,
         orderingRule  [0] MatchingRuleId OPTIONAL,
         reverseOrder  [1] BOOLEAN DEFAULT FALSE }

 

Summary

[Expand] Inherited Constants
From interface javax.naming.ldap.Control boolean CRITICAL Indicates a critical control. boolean NONCRITICAL Indicates a non-critical control.

[Expand] Inherited Fields
From class javax.naming.ldap.BasicControl 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.

[Expand] Inherited Methods
From class javax.naming.ldap.BasicControl 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.
From class java.lang.Object Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait() Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object. final void wait(long timeout, int nanos) Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed. final void wait(long timeout) Causes the current thread to wait until either another thread invokes the notify() method or the notifyAll() method for this object, or a specified amount of time has elapsed.
From interface javax.naming.ldap.Control abstract byte[] getEncodedValue() Retrieves the ASN.1 BER encoded value of the LDAP control. abstract String getID() Retrieves the object identifier assigned for the LDAP control. abstract boolean isCritical() Determines the criticality of the LDAP control.