QueryService in GemFire 8.2.x Function return null values - spring-data

Question

I have created function to select data from Partition region Individual. When I try to execute the function at client side getting null.
output
[[], null]
public class MySelectPartitionFunction extends FunctionAdapter implements Declarable{
private static final long serialVersionUID = 1L;
#Override
public void execute(FunctionContext context) {
Cache cache = CacheFactory.getAnyInstance();
QueryService queryService = cache.getQueryService();
String qstr = (String) context.getArguments();
try {
Query query = queryService.newQuery(qstr);
RegionFunctionContext rContext = (RegionFunctionContext)context;
SelectResults results = (SelectResults) query.execute(rContext);
context.getResultSender().sendResult((ArrayList) (results).asList());
context.getResultSender().lastResult(null);
} catch (Exception e) {
throw new FunctionException(e);
}
}
#Override
public String getId() {
return getClass().getName();
}
#Override
public boolean hasResult() {
return true;
}
#Override
public boolean isHA() {
return false;
}
public void init(Properties arg0) {
}
}
public class TestFunctionQuery {
public static void main(String[] args) {
ResultCollector rcollector = null;
ClientCache cache;
Region<?, ?> individual;
cache = new ClientCacheFactory().set("name", "ClientWorker").set("cache-xml-file", "xml/clientCache.xml")
.create();
individual = cache.getRegion("Individual");
String qStr = "SELECT * FROM /Individual";
try {
Set keyFilter = new HashSet();
keyFilter.add(1);
rcollector = FunctionService
.onRegion(individual)
.withArgs(qStr)
.withFilter(keyFilter)
.execute("com.xxx.logic.MySelectPartitionFunction");
Object result = rcollector.getResult();
ArrayList resultList = (ArrayList)result;
List queryResults = new ArrayList();
if (resultList.size()!=0) {
for (Object obj: resultList) {
if (obj != null) {
queryResults.addAll((ArrayList)obj);
}
}
}
System.out.println((queryResults));
} catch (FunctionException ex) {
System.out.println("Exception");
}
}
}
gfsh>describe region --name=Individual
..........................................................
Name : Individual
Data Policy : partition
Hosting Members : server2
server1
Non-Default Attributes Shared By Hosting Members
Type | Name | Value
--------- | ---------------- | -----
Region | size | 3
Partition | redundant-copies | 1

Answer 1

I was able to retrieve the record after making changes in Function and client code
#Override
public void execute(FunctionContext context) {
Cache cache = CacheFactory.getAnyInstance();
QueryService queryService = cache.getQueryService();
String qstr = (String) context.getArguments();
try {
Query query = queryService.newQuery(qstr);
SelectResults<?> result = (SelectResults<?>) query.execute((RegionFunctionContext) context);
ArrayList<?> arrayResult = (ArrayList<?>) result.asList();
context.getResultSender().sendResult(arrayResult);
context.getResultSender().lastResult(null);
} catch (Exception e) {
throw new FunctionException(e);
}
}
ClientCache cache;
Region<?, ?> individual;
cache = new ClientCacheFactory().set("name", "ClientWorker").set("cache-xml-file", "xml/clientCache.xml")
.create();
individual = cache.getRegion("Individual");
String qStr = "SELECT r1.id,r1.firstName, r1.lastName FROM /Individual r1";
try {
Object result = FunctionService.onRegion(individual)
.withArgs(qStr).execute("com.xxx.logic.MySelectPartitionFunction").getResult();
Output
[[struct(id:2,firstName:Basha,lastName:Shaik), struct(id:1,firstName:Krish,lastName:Chaitu), struct(id:5,firstName:Vigneshwaran,lastName:Ganesan)], null, [struct(id:4,firstName:Arun,lastName:Kishore), struct(id:3,firstName:Anurag,lastName:Kshirsagar)], null]