Use the search(DataObject) method to return a set of entities that match the search expression.
DataObject root = SDOHelper.createRootDataObject();
DataObject searchCtrl = SDOHelper.createControlDataObject(root, null, DO_SEARCH_CONTROL);
searchCtrl.getList(PROP_PROPERTIES).add("uid");
searchCtrl.getList(PROP_PROPERTIES).add("sn");
searchCtrl.getList(PROP_SEARCH_BASES).add("o=Sales,cn=users,dc=yourco,dc=com");
searchCtrl.setString(PROP_SEARCH_EXPRESSION, "@xsi:type='PersonAccount' and uid='*'");
root = service.search(root);
<?xml version="1.0" encoding="UTF-8"?>
<sdo:datagraph xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:sdo="commonj.sdo"
xmlns:wim="http://www.ibm.com/websphere/wim">
<wim:Root>
<wim:controls xsi:type="wim:SearchControl"
expression="@xsi:type='PersonAccount' and uid='*'">
<wim:properties>uid</wim:properties>
<wim:properties>sn</wim:properties>
<wim:searchBases>o=Sales,cn=users,dc=yourco,dc=com</wim:searchBases>
</wim:controls>
</wim:Root>
</sdo:datagraph>
<?xml version="1.0" encoding="UTF-8"?>
<sdo:datagraph xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:sdo="commonj.sdo"
xmlns:wim="http://www.ibm.com/websphere/wim">
<wim:Root>
<wim:entities xsi:type="wim:PersonAccount">
<wim:identifier externalName="uid=SalesPerson3,ou=US,o=Sales,cn=users,dc=yourco,dc=com"
repositoryId="LDAP1"
uniqueId="13ae346f-1e4c-40cd-8896-1c7f0b2b3079"
uniqueName="uid=SalesPerson3,ou=US,o=Sales,cn=users,dc=yourco,dc=com"/>
<wim:uid>SalesPerson3</wim:uid>
<wim:sn>SalesPerson3Sn</wim:sn>
</wim:entities>
<wim:entities xsi:type="wim:PersonAccount">
<wim:identifier externalName="uid=SalesPerson4,ou=US,o=Sales,cn=users,dc=yourco,dc=com"
repositoryId="LDAP1"
uniqueId="a2d1be42-212e-44f0-8396-0bfc2d7d346d"
uniqueName="uid=SalesPerson4,ou=US,o=Sales,cn=users,dc=yourco,dc=com"/>
<wim:uid>SalesPerson4</wim:uid>
<wim:sn>SalesPerson4Sn</wim:sn>
</wim:entities>
<wim:entities xsi:type="wim:PersonAccount">
<wim:identifier externalName="uid=SalesPerson2,ou=CA,o=Sales,cn=users,dc=yourco,dc=com"
repositoryId="LDAP1"
uniqueId="a3f9e8a1-117a-4252-840f-6d0cb079a7fb"
uniqueName="uid=SalesPerson2,ou=CA,o=Sales,cn=users,dc=yourco,dc=com"/>
<wim:uid>SalesPerson2</wim:uid>
<wim:sn>SalesPerson2Sn</wim:sn>
</wim:entities>
<wim:entities xsi:type="wim:PersonAccount">
<wim:identifier externalName="uid=SalesPerson1,ou=CA,o=Sales,cn=users,dc=yourco,dc=com"
repositoryId="LDAP1"
uniqueId="e7db8c0e-d2b3-43fe-be14-1475125606f4"
uniqueName="uid=SalesPerson1,ou=CA,o=Sales,cn=users,dc=yourco,dc=com"/>
<wim:uid>SalesPerson1</wim:uid>
<wim:sn>SalesPerson1Sn</wim:sn>
</wim:entities>
</wim:Root>
</sdo:datagraph>
Also see the topics, Sample code for performing a paged search with sorted results and Sample code for searching using search bases.