Class SortControl

java.lang.Object

javax.naming.ldap.BasicControl

javax.naming.ldap.SortControl

All Implemented Interfaces:

Serializable, Control

public final class SortControl
extends BasicControl

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 }

Since:

1.5

See Also:

• SortKey
• SortResponseControl
• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static final String	OID	The server-side sort control's assigned object identifier is 1.2.840.113556.1.4.473.

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
SortControl(String[] sortBy, boolean criticality)	Constructs a control to sort on a list of attributes in ascending order.
SortControl(String sortBy, boolean criticality)	Constructs a control to sort on a single attribute in ascending order.
SortControl(SortKey[] sortBy, boolean criticality)	Constructs a control to sort on a list of sort keys.

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 server-side sort control's assigned object identifier is 1.2.840.113556.1.4.473.

See Also:

• Constant Field Values

Constructor Details

SortControl

public SortControl(String sortBy,
 boolean criticality)
            throws IOException

Constructs a control to sort on a single attribute in ascending order. Sorting will be performed using the ordering matching rule defined for use with the specified attribute.

Parameters:

sortBy - An attribute ID to sort by.

criticality - If true then the server must honor the control and return the search results sorted as requested 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.

SortControl

public SortControl(String[] sortBy,
 boolean criticality)
            throws IOException

Constructs a control to sort on a list of attributes in ascending order. Sorting will be performed using the ordering matching rule defined for use with each of the specified attributes.

Parameters:

sortBy - A non-null list of attribute IDs to sort by. The list is in order of highest to lowest sort key precedence.

criticality - If true then the server must honor the control and return the search results sorted as requested 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.

SortControl

public SortControl(SortKey[] sortBy,
 boolean criticality)
            throws IOException

Constructs a control to sort on a list of sort keys. Each sort key specifies the sort order and ordering matching rule to use.

Parameters:

sortBy - A non-null list of keys to sort by. The list is in order of highest to lowest sort key precedence.

criticality - If true then the server must honor the control and return the search results sorted as requested 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.