javax.naming.ldap: public final class: PagedResultsControl

javax.naming.ldap
public final class: PagedResultsControl [javadoc | source]

java.lang.Object
   javax.naming.ldap.BasicControl
      javax.naming.ldap.PagedResultsControl

All Implemented Interfaces:
Control

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
}

Also see:

PagedResultsResponseControl

since: 1.5 -

author: Vincent - Ryan

Field Summary
public static final String	OID	The paged-results control's assigned object identifier is 1.2.840.113556.1.4.319.

Fields inherited from javax.naming.ldap.BasicControl:
id, criticality, value

Constructor:

Constructor:
public PagedResultsControl(int pageSize, boolean criticality) throws IOException { super(OID, criticality, null); value = setEncodedValue(pageSize, EMPTY_COOKIE); } 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. exception: `IOException` - If an error was encountered while encoding the supplied arguments into a control.
public PagedResultsControl(int pageSize, byte[] cookie, boolean criticality) throws IOException { super(OID, criticality, null); if (cookie == null) { cookie = EMPTY_COOKIE; } value = setEncodedValue(pageSize, cookie); } 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. exception: `IOException` - If an error was encountered while encoding the supplied arguments into a control.

 public PagedResultsControl(int pageSize,
    boolean criticality) throws IOException {
                                                                                                                                                                                                                                    
        super(OID, criticality, null);
        value = setEncodedValue(pageSize, EMPTY_COOKIE);
}

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.

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

 public PagedResultsControl(int pageSize,
    byte[] cookie,
    boolean criticality) throws IOException {
        super(OID, criticality, null);
        if (cookie == null) {
            cookie = EMPTY_COOKIE;
        }
        value = setEncodedValue(pageSize, cookie);
}

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.

Throws:

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

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

Methods from javax.naming.ldap.BasicControl:
getEncodedValue, getID, isCritical

Methods from java.lang.Object:
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait