Add AbstractAggregate as a base class

h2/src/main/org/h2/command/Parser.java

@@ -170,6 +170,7 @@ import org.h2.expression.UnaryOperation;
 import org.h2.expression.ValueExpression;
 import org.h2.expression.Variable;
 import org.h2.expression.Wildcard;
+import org.h2.expression.aggregate.AbstractAggregate;
 import org.h2.expression.aggregate.Aggregate;
 import org.h2.expression.aggregate.Aggregate.AggregateType;
 import org.h2.expression.aggregate.JavaAggregate;
@@ -2967,27 +2968,11 @@ public class Parser {
         }
         read(CLOSE_PAREN);
         if (r != null) {
-            r.setFilterCondition(readFilterCondition());
-            Window over = readOver();
-            if (over != null) {
-                r.setOverCondition(over);
-                currentSelect.setWindowQuery();
-            } else {
-                currentSelect.setGroupQuery();
-            }
+            readFilterAndOver(r);
         }
         return r;
     }
 
-    private Window readOver() {
-        if (readIf("OVER")) {
-            read(OPEN_PAREN);
-            read(CLOSE_PAREN);
-            return new Window();
-        }
-        return null;
-    }
-
     private void setModeAggOrder(Aggregate r, Expression expr) {
         ArrayList<SelectOrderBy> orderList = new ArrayList<>(1);
         SelectOrderBy order = new SelectOrderBy();
@@ -3040,28 +3025,28 @@ public class Parser {
         do {
             params.add(readExpression());
         } while (readIfMore(true));
-        Expression filterCondition = readFilterCondition();
         Expression[] list = params.toArray(new Expression[0]);
-        JavaAggregate agg = new JavaAggregate(aggregate, list, currentSelect, distinct, filterCondition);
-        Window over = readOver();
-        if (over != null) {
-            agg.setOverCondition(over);
-            currentSelect.setWindowQuery();
-        } else {
-            currentSelect.setGroupQuery();
-        }
+        JavaAggregate agg = new JavaAggregate(aggregate, list, currentSelect, distinct);
+        readFilterAndOver(agg);
         return agg;
     }
 
-    private Expression readFilterCondition() {
+    private void readFilterAndOver(AbstractAggregate aggregate) {
         if (readIf("FILTER")) {
             read(OPEN_PAREN);
             read(WHERE);
             Expression filterCondition = readExpression();
             read(CLOSE_PAREN);
-            return filterCondition;
+            aggregate.setFilterCondition(filterCondition);
+        }
+        if (readIf("OVER")) {
+            read(OPEN_PAREN);
+            read(CLOSE_PAREN);
+            aggregate.setOverCondition(new Window());
+            currentSelect.setWindowQuery();
+        } else {
+            currentSelect.setGroupQuery();
         }
-        return null;
     }
 
     private AggregateType getAggregateType(String name) {

h2/src/main/org/h2/expression/aggregate/AbstractAggregate.java

+/*
+ * Copyright 2004-2018 H2 Group. Multiple-Licensed under the MPL 2.0,
+ * and the EPL 1.0 (http://h2database.com/html/license.html).
+ * Initial Developer: H2 Group
+ */
+package org.h2.expression.aggregate;
+
+import org.h2.expression.Expression;
+
+/**
+ * A base class for aggregates.
+ */
+public abstract class AbstractAggregate extends Expression {
+
+    protected Expression filterCondition;
+
+    protected Window over;
+
+    /**
+     * Sets the FILTER condition.
+     *
+     * @param filterCondition
+     *            FILTER condition
+     */
+    public void setFilterCondition(Expression filterCondition) {
+        this.filterCondition = filterCondition;
+    }
+
+    /**
+     * Sets the OVER condition.
+     *
+     * @param over
+     *            OVER condition
+     */
+    public void setOverCondition(Window over) {
+        this.over = over;
+    }
+
+}

h2/src/main/org/h2/expression/aggregate/Aggregate.java

@@ -42,7 +42,7 @@ import org.h2.value.ValueString;
 /**
  * Implements the integrated aggregate functions, such as COUNT, MAX, SUM.
  */
-public class Aggregate extends Expression {
+public class Aggregate extends AbstractAggregate {
 
     public enum AggregateType {
         /**
@@ -166,10 +166,6 @@ public class Aggregate extends Expression {
     private int displaySize;
     private int lastGroupRowId;
 
-    private Expression filterCondition;
-
-    private Window over;
-
     /**
      * Create a new aggregate object.
      *
@@ -257,24 +253,6 @@ public class Aggregate extends Expression {
         this.groupConcatSeparator = separator;
     }
 
-    /**
-     * Sets the FILTER condition.
-     *
-     * @param filterCondition condition
-     */
-    public void setFilterCondition(Expression filterCondition) {
-        this.filterCondition = filterCondition;
-    }
-
-    /**
-     * Sets the OVER condition.
-     *
-     * @param over OVER condition
-     */
-    public void setOverCondition(Window over) {
-        this.over = over;
-    }
-
     private SortOrder initOrder(Session session) {
         int size = orderByList.size();
         int[] index = new int[size];

h2/src/main/org/h2/expression/aggregate/JavaAggregate.java

@@ -28,35 +28,22 @@ import org.h2.value.ValueNull;
 /**
  * This class wraps a user-defined aggregate.
  */
-public class JavaAggregate extends Expression {
+public class JavaAggregate extends AbstractAggregate {
 
     private final UserAggregate userAggregate;
     private final Select select;
     private final Expression[] args;
     private int[] argTypes;
     private final boolean distinct;
-    private Expression filterCondition;
-    private Window over;
     private int dataType;
     private Connection userConnection;
     private int lastGroupRowId;
 
-    public JavaAggregate(UserAggregate userAggregate, Expression[] args,
-            Select select, boolean distinct, Expression filterCondition) {
+    public JavaAggregate(UserAggregate userAggregate, Expression[] args, Select select, boolean distinct) {
         this.userAggregate = userAggregate;
         this.args = args;
         this.select = select;
         this.distinct = distinct;
-        this.filterCondition = filterCondition;
-    }
-
-    /**
-     * Sets the OVER condition.
-     *
-     * @param over OVER condition
-     */
-    public void setOverCondition(Window over) {
-        this.over = over;
     }
 
     @Override