add DPRODUCT function support

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1901277 13f79535-47bb-0310-9956-ffa450edef68

poi/src/main/java/org/apache/poi/ss/formula/eval/FunctionEval.java

@@ -201,7 +201,7 @@ public final class FunctionEval {
         retval[183] = AggregateFunction.PRODUCT;
         retval[184] = NumericFunction.FACT;
 
-        // 189: DPRODUCT
+        retval[189] = new DStarRunner(DStarRunner.DStarAlgorithmEnum.DPRODUCT);
         retval[190] = LogicalFunction.ISNONTEXT;
 
         retval[194] = AggregateFunction.VARP;

poi/src/main/java/org/apache/poi/ss/formula/functions/DProduct.java

@@ -0,0 +1,53 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.functions;
+
+import org.apache.poi.ss.formula.eval.NumberEval;
+import org.apache.poi.ss.formula.eval.NumericValueEval;
+import org.apache.poi.ss.formula.eval.ValueEval;
+import org.apache.poi.ss.util.NumberToTextConverter;
+
+import java.math.BigDecimal;
+import java.util.ArrayList;
+
+/**
+ * Implementation of the DProduct function:
+ * Gets the product value of a column in an area with given conditions.
+ */
+public final class DProduct implements IDStarAlgorithm {
+    private double product;
+    private boolean initDone = false;
+
+    @Override
+    public boolean processMatch(ValueEval eval) {
+        if (eval instanceof NumericValueEval) {
+            if (initDone) {
+                product *= ((NumericValueEval) eval).getNumberValue();
+            } else {
+                product = ((NumericValueEval) eval).getNumberValue();
+                initDone = true;
+            }
+        }
+        return true;
+    }
+
+    @Override
+    public ValueEval getResult() {
+        return new NumberEval(product);
+    }
+}

poi/src/main/java/org/apache/poi/ss/formula/functions/DStarRunner.java

@@ -65,6 +65,8 @@ public final class DStarRunner implements Function3Arg {
         DSTDEV(DStdev::new),
         /** @see DVar */
         DVAR(DVar::new),
+        /** @see DProduct */
+        DPRODUCT(DProduct::new),
         ;
 
         private final Supplier<IDStarAlgorithm> implSupplier;

poi/src/test/java/org/apache/poi/ss/formula/functions/TestDProduct.java

@@ -0,0 +1,77 @@
+
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+package org.apache.poi.ss.formula.functions;
+
+import org.apache.poi.hssf.usermodel.HSSFCell;
+import org.apache.poi.hssf.usermodel.HSSFFormulaEvaluator;
+import org.apache.poi.hssf.usermodel.HSSFSheet;
+import org.apache.poi.hssf.usermodel.HSSFWorkbook;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+
+import static org.apache.poi.ss.util.Utils.addRow;
+import static org.apache.poi.ss.util.Utils.assertDouble;
+
+/**
+ * Testcase for function DPRODUCT()
+ */
+public class TestDProduct {
+
+    //https://support.microsoft.com/en-us/office/dproduct-function-4f96b13e-d49c-47a7-b769-22f6d017cb31
+    @Test
+    void testMicrosoftExample1() throws IOException {
+        try (HSSFWorkbook wb = initWorkbook1(false)) {
+            HSSFFormulaEvaluator fe = new HSSFFormulaEvaluator(wb);
+            HSSFCell cell = wb.getSheetAt(0).getRow(0).createCell(12);
+            assertDouble(fe, cell, "DPRODUCT(A5:E11, \"Yield\", A1:F3)", 800, 0.0000000001);
+        }
+    }
+
+    @Test
+    void testNoMatch() throws IOException {
+        try (HSSFWorkbook wb = initWorkbook1(true)) {
+            HSSFFormulaEvaluator fe = new HSSFFormulaEvaluator(wb);
+            HSSFCell cell = wb.getSheetAt(0).getRow(0).createCell(12);
+            assertDouble(fe, cell, "DPRODUCT(A5:E11, \"Yield\", A1:A2)", 0);
+            assertDouble(fe, cell, "DPRODUCT(A5:E11, \"Yield\", A1:A3)", 604800);
+        }
+    }
+
+    private HSSFWorkbook initWorkbook1(boolean noMatch) {
+        HSSFWorkbook wb = new HSSFWorkbook();
+        HSSFSheet sheet = wb.createSheet();
+        addRow(sheet, 0, "Tree", "Height", "Age", "Yield", "Profit", "Height");
+        if (noMatch) {
+            addRow(sheet, 1, "=NoMatch");
+            addRow(sheet, 2);
+        } else {
+            addRow(sheet, 1, "=Apple", ">10", null, null, null, "<16");
+            addRow(sheet, 2, "=Pear");
+        }
+        addRow(sheet, 3);
+        addRow(sheet, 4, "Tree", "Height", "Age", "Yield", "Profit");
+        addRow(sheet, 5, "Apple", 18, 20, 14, 105);
+        addRow(sheet, 6, "Pear", 12, 12, 10, 96);
+        addRow(sheet, 7, "Cherry", 13, 14, 9, 105);
+        addRow(sheet, 8, "Apple", 14, 15, 10, 75);
+        addRow(sheet, 9, "Pear", 9, 8, 8, 77);
+        addRow(sheet, 10, "Apple", 8, 9, 6, 45);
+        return wb;
+    }
+}