Merge pull request #1944 from ebean-orm/feature/1943

#1943 - Use limit & offset via setFirstRow() and setMaxRows() on filterMany()

src/main/java/io/ebean/ExpressionList.java

@@ -506,7 +506,7 @@ public interface ExpressionList<T> {
    * @param expressions  Filter expressions with and, or and ? or ?1 type bind parameters
    * @param params       Bind parameters used in the expressions
    */
-  Query<T> filterMany(String manyProperty, String expressions, Object... params);
+  ExpressionList<T> filterMany(String manyProperty, String expressions, Object... params);
 
   /**
    * Specify specific properties to fetch on the main/root bean (aka partial
@@ -557,14 +557,14 @@ public interface ExpressionList<T> {
    *
    * @see Query#setFirstRow(int)
    */
-  Query<T> setFirstRow(int firstRow);
+  ExpressionList<T> setFirstRow(int firstRow);
 
   /**
    * Set the maximum number of rows to fetch.
    *
    * @see Query#setMaxRows(int)
    */
-  Query<T> setMaxRows(int maxRows);
+  ExpressionList<T> setMaxRows(int maxRows);
 
   /**
    * Set the name of the property which values become the key of a map.

src/main/java/io/ebeaninternal/api/SpiExpressionList.java

@@ -36,4 +36,11 @@ public interface SpiExpressionList<T> extends ExpressionList<T>, SpiExpression {
    * Write the top level where expressions taking into account possible extra idEquals expression.
    */
   void writeDocQuery(DocQueryContext context, SpiExpression idEquals) throws IOException;
+
+  /**
+   * Apply firstRow maxRows limits on the filterMany query.
+   */
+  default void applyRowLimits(SpiQuery<?> query) {
+    // do nothing by default
+  }
 }

src/main/java/io/ebeaninternal/server/expression/DefaultExpressionList.java

@@ -480,9 +480,8 @@ public class DefaultExpressionList<T> implements SpiExpressionList<T> {
   }
 
   @Override
-  public Query<T> filterMany(String manyProperty, String expressions, Object... params) {
-    query.filterMany(manyProperty).where(expressions, params);
-    return query;
+  public ExpressionList<T> filterMany(String manyProperty, String expressions, Object... params) {
+    return query.filterMany(manyProperty).where(expressions, params);
   }
 
   @Override
@@ -521,13 +520,15 @@ public class DefaultExpressionList<T> implements SpiExpressionList<T> {
   }
 
   @Override
-  public Query<T> setFirstRow(int firstRow) {
-    return query.setFirstRow(firstRow);
+  public ExpressionList<T> setFirstRow(int firstRow) {
+    query.setFirstRow(firstRow);
+    return this;
   }
 
   @Override
-  public Query<T> setMaxRows(int maxRows) {
-    return query.setMaxRows(maxRows);
+  public ExpressionList<T> setMaxRows(int maxRows) {
+    query.setMaxRows(maxRows);
+    return this;
   }
 
   @Override

src/main/java/io/ebeaninternal/server/expression/FilterExpressionList.java

@@ -9,6 +9,7 @@ import io.ebean.Junction;
 import io.ebean.OrderBy;
 import io.ebean.Query;
 import io.ebeaninternal.api.SpiExpressionList;
+import io.ebeaninternal.api.SpiQuery;
 
 import javax.persistence.PersistenceException;
 import java.util.Collection;
@@ -25,6 +26,9 @@ public class FilterExpressionList<T> extends DefaultExpressionList<T> {
 
   private final FilterExprPath pathPrefix;
 
+  private int firstRow;
+  private int maxRows;
+
   public FilterExpressionList(FilterExprPath pathPrefix, FilterExpressionList<T> original) {
     super(null, original.expr, null, original.getUnderlyingList());
     this.pathPrefix = pathPrefix;
@@ -144,19 +148,21 @@ public class FilterExpressionList<T> extends DefaultExpressionList<T> {
     throw new PersistenceException(notAllowedMessage);
   }
 
-  @Override
-  public Query<T> setFirstRow(int firstRow) {
-    return rootQuery.setFirstRow(firstRow);
-  }
-
   @Override
   public Query<T> setMapKey(String mapKey) {
     return rootQuery.setMapKey(mapKey);
   }
 
   @Override
-  public Query<T> setMaxRows(int maxRows) {
-    return rootQuery.setMaxRows(maxRows);
+  public ExpressionList<T> setMaxRows(int maxRows) {
+    this.maxRows = maxRows;
+    return this;
+  }
+
+  @Override
+  public ExpressionList<T> setFirstRow(int firstRow) {
+    this.firstRow = firstRow;
+    return this;
   }
 
   @Override
@@ -169,5 +175,14 @@ public class FilterExpressionList<T> extends DefaultExpressionList<T> {
     return rootQuery.where();
   }
 
+  @Override
+  public void applyRowLimits(SpiQuery<?> query) {
+    if (firstRow > 0) {
+      query.setFirstRow(firstRow);
+    }
+    if (maxRows > 0) {
+      query.setMaxRows(maxRows);
+    }
+  }
 
 }

src/main/java/io/ebeaninternal/server/expression/JunctionExpression.java

@@ -337,7 +337,7 @@ class JunctionExpression<T> implements SpiJunction<T>, SpiExpression, Expression
   }
 
   @Override
-  public Query<T> filterMany(String manyProperty, String expressions, Object... params) {
+  public ExpressionList<T> filterMany(String manyProperty, String expressions, Object... params) {
     throw new IllegalStateException("filterMany not allowed on Junction expression list");
   }
 
@@ -864,7 +864,7 @@ class JunctionExpression<T> implements SpiJunction<T>, SpiExpression, Expression
   }
 
   @Override
-  public Query<T> setFirstRow(int firstRow) {
+  public ExpressionList<T> setFirstRow(int firstRow) {
     return exprList.setFirstRow(firstRow);
   }
 
@@ -874,7 +874,7 @@ class JunctionExpression<T> implements SpiJunction<T>, SpiExpression, Expression
   }
 
   @Override
-  public Query<T> setMaxRows(int maxRows) {
+  public ExpressionList<T> setMaxRows(int maxRows) {
     return exprList.setMaxRows(maxRows);
   }
 

src/main/java/io/ebeaninternal/server/querydefn/OrmQueryProperties.java

@@ -245,9 +245,9 @@ public class OrmQueryProperties implements Serializable {
     }
 
     if (filterMany != null) {
+      filterMany.applyRowLimits(query);
       SpiExpressionList<?> trimPath = filterMany.trimPath(path.length() + 1);
-      List<SpiExpression> underlyingList = trimPath.getUnderlyingList();
-      for (SpiExpression spiExpression : underlyingList) {
+      for (SpiExpression spiExpression : trimPath.getUnderlyingList()) {
         query.where().add(spiExpression);
       }
     }