While LdapTemplate contains several overloaded
versions of the most common operations in DirContext,
we have not provided an alternative for each and every method signature,
mostly because there are so many of them. We have, however, provided a
means to call whichever DirContext method you want
and still get the benefits that LdapTemplate provides.
Let's say that you want to call the following DirContext
method:
NamingEnumeration search(Name name, String filterExpr, Object[] filterArgs, SearchControls ctls)
There is no corresponding overloaded method in LdapTemplate. The way to solve
this is to use a custom SearchExecutor implementation:
public interface SearchExecutor {
public NamingEnumeration executeSearch(DirContext ctx) throws NamingException;
}In your custom executor, you have access to a DirContext
object, which you use to call the method you want. You then provide a handler
that is responsible for mapping attributes and collecting the results. You can
for example use one of the available implementations of
CollectingNameClassPairCallbackHandler, which will collect
the mapped results in an internal list. In order to
actually execute the search, you call the search
method in LdapTemplate that takes an executor and a handler as arguments. Finally,
you return whatever your handler has collected.
Example 4.1. A custom search method using SearchExecutor and AttributesMapper
package com.example.dao;
public class PersonDaoImpl implements PersonDao {
...
public List search(final Name base, final String filter, final String[] params,
final SearchControls ctls) {
SearchExecutor executor = new SearchExecutor() {
public NamingEnumeration executeSearch(DirContext ctx) {
return ctx.search(base, filter, params, ctls);
}
};
CollectingNameClassPairCallbackHandler handler =
new AttributesMapperCallbackHandler(new PersonAttributesMapper());
ldapTemplate.search(executor, handler);
return handler.getList();
}
}If you prefer the ContextMapper to the
AttributesMapper, this is what it would look
like:
Example 4.2. A custom search method using SearchExecutor and ContextMapper
package com.example.dao;
public class PersonDaoImpl implements PersonDao {
...
public List search(final Name base, final String filter, final String[] params,
final SearchControls ctls) {
SearchExecutor executor = new SearchExecutor() {
public NamingEnumeration executeSearch(DirContext ctx) {
return ctx.search(base, filter, params, ctls);
}
};
CollectingNameClassPairCallbackHandler handler =
new ContextMapperCallbackHandler(new PersonContextMapper());
ldapTemplate.search(executor, handler);
return handler.getList();
}
}When using the
ContextMapperCallbackHandler you must
make sure that you have called
setReturningObjFlag(true) on your
SearchControls instance.