public Evaluator<List<Object[]>> createEvaluator(QueryMetadata metadata,
            List<JoinExpression> joins, @Nullable Predicate filter) {
        List<String> sourceNames = new ArrayList<String>();
        List<Type> sourceTypes = new ArrayList<Type>();
        List<Class<?>> sourceClasses = new ArrayList<Class<?>>();
        StringBuilder vars = new StringBuilder();
        CollQuerySerializer ser = new CollQuerySerializer(templates);
        ser.append("java.util.List<Object[]> rv = new java.util.ArrayList<Object[]>();\n");

        List<String> anyJoinMatchers = new ArrayList<String>();

        // creating context
        for (JoinExpression join : joins) {
            Expression<?> target = join.getTarget();
            String typeName = com.querydsl.codegen.utils.support.ClassUtils.getName(target.getType());
            if (vars.length() > 0) {
                vars.append(",");
            }
            switch (join.getType()) {
            case DEFAULT:
                ser.append("for (" + typeName + " " + target + " : " + target + "_) {\n");
                vars.append(target);
                sourceNames.add(target + "_");
                sourceTypes.add(new SimpleType(Types.ITERABLE, new ClassType(TypeCategory.SIMPLE,target.getType())));
                sourceClasses.add(Iterable.class);
                break;

            case INNERJOIN:
            case LEFTJOIN:
                Operation<?> alias = (Operation<?>) join.getTarget();
                boolean colAnyJoin = join.getCondition() != null && join.getCondition().toString().equals("any");
                boolean leftJoin = join.getType() == JoinType.LEFTJOIN;
                String matcher = null;
                if (colAnyJoin) {
                    matcher = alias.getArg(1).toString() + "_matched";
                    ser.append("boolean " + matcher + " = false;\n");
                    anyJoinMatchers.add(matcher);
                }
                ser.append("for (" + typeName + " " + alias.getArg(1) + " : ");
                if (leftJoin) {
                    ser.append(CollQueryFunctions.class.getName() + ".leftJoin(");
                }
                if (colAnyJoin) {
                    Context context = new Context();
                    Expression<?> replacement = alias.getArg(0)
                            .accept(collectionAnyVisitor, context);
                    ser.handle(replacement);
                } else {
                    ser.handle(alias.getArg(0));
                }
                if (alias.getArg(0).getType().equals(Map.class)) {
                    ser.append(".values()");
                }
                if (leftJoin) {
                    ser.append(")");
                }
                ser.append(") {\n");
                if (matcher != null) {
                    ser.append("if (!" + matcher + ") {\n");
                }
                vars.append(alias.getArg(1));
                break;

            default:
                throw new IllegalArgumentException("Illegal join expression " + join);
            }
        }

        // filter
        if (filter != null) {
            ser.append("try {\n");
            ser.append("if (");
            ser.handle(filter).append(") {\n");
            for (String matcher : anyJoinMatchers) {
                ser.append("    " + matcher + " = true;\n");
            }
            ser.append("    rv.add(new Object[]{" + vars + "});\n");
            ser.append("}\n");
            ser.append("} catch (NullPointerException npe) { }\n");
        } else {
            ser.append("rv.add(new Object[]{" + vars + "});\n");
        }

        // closing context
        int amount = joins.size() + anyJoinMatchers.size();
        for (int i = 0; i < amount; i++) {
            ser.append("}\n");
        }
        ser.append("return rv;");

        Map<Object,String> constantToLabel = ser.getConstantToLabel();
        Map<String, Object> constants = getConstants(metadata, constantToLabel);

        ClassType projectionType = new ClassType(TypeCategory.LIST, List.class, Types.OBJECTS);
        return factory.createEvaluator(
                ser.toString(),
                projectionType,
                sourceNames.toArray(new String[0]),
                sourceTypes.toArray(new Type[0]),
                sourceClasses.toArray(new Class<?>[0]),
                constants);
    }
Create an Evaluator for the given sources and the given optional filter

@param metadata query metadata
@param joins joins
@param filter where condition
@return evaluator
querydsl-collections/src/main/java/com/querydsl/collections/DefaultEvaluatorFactory.java