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Java Naming and Directory Interface(TM).
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New features in JDK 5.0 and JDK 6
Sort Control
The sort control is used when a client wants the server
to send the sorted search results. The server-side sorting
is useful in a situation where the client needs to sort the results
according to some criteria but is not equipped to perform
the sort process on its own.
The sort control is specified in
RFC 2891.
The classes below provide the functionality required to support
sort control.
The SortKey is an odered list of keys based upon which the server
sorts the result.
How to use Sort Control?
The example below illustrates the client-server interaction
between a client performing a search requesting a server-side sorting based
on the attribute "cn".
- Client sends a search request asking for
// Activate sorting
String sortKey = "cn";
ctx.setRequestControls(new Control[] {
new SortControl(sortKey, Control.CRITICAL) });
// Perform a search
NamingEnumeration results =
ctx.search("", "(objectclass=*)", new SearchControls());
- The server responds with entries that are sorted
based on the "cn" attribute and its corresponding matching rule.
// Iterate over sorted search results
while (results != null && results.hasMore()) {
// Display an entry
SearchResult entry = (SearchResult)results.next();
System.out.println(entry.getName());
// 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)
}
}
}
The complete JNDI example can be found here
Note:
The sort control is supported by both Sun Java Directory Server and the
Windows Active Directory server.
