DATADOC-22 - Added pagination and sorting to repository and finders.

- added CursorCallback to be able to apply limit, skip and sorting to the query execution
- added paged execution for queries and extended SimpleMongoRepository to support paging and sorting as well
- minor JavaDoc polishing.

spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/CursorPreparer.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2002-2010 the original author or authors.
+ *
+ * Licensed 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.springframework.data.document.mongodb;
+
+import com.mongodb.DBCursor;
+
+
+/**
+ * Simple callback interface to allow customization of a {@link DBCursor}.
+ * 
+ * @author Oliver Gierke
+ */
+public interface CursorPreparer {
+
+    /**
+     * Prepare the given cursor (apply limits, skips and so on).
+     * 
+     * @param cursor
+     */
+    void prepare(DBCursor cursor);
+}

spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/MongoTemplate.java

@@ -33,6 +33,7 @@ import com.mongodb.BasicDBObject;
 import com.mongodb.CommandResult;
 import com.mongodb.DB;
 import com.mongodb.DBCollection;
+import com.mongodb.DBCursor;
 import com.mongodb.DBObject;
 import com.mongodb.Mongo;
 import com.mongodb.MongoException;
@@ -142,9 +143,37 @@ public class MongoTemplate implements InitializingBean {
 			return action.doInDB(db);
 		} catch (MongoException e) {
 			throw MongoDbUtils.translateMongoExceptionIfPossible(e);
-		} 
+		}
 	}
-	
+
+	/**
+	 * Executes the given {@link CollectionCallback} on the default collection.
+	 * 
+	 * @param <T>
+	 * @param callback
+	 * @return
+	 */
+	public <T> T execute(CollectionCallback<T> callback) {
+		return execute(callback, defaultCollectionName);
+	}
+
+	/**
+	 * Executes the given {@link CollectionCallback} on the collection of the given name.
+	 * 
+	 * @param <T>
+	 * @param callback
+	 * @param collectionName
+	 * @return
+	 */
+	public <T> T execute(CollectionCallback<T> callback, String collectionName) {
+
+		try {
+			return callback.doInCollection(getCollection(collectionName));
+		} catch (MongoException e) {
+			throw MongoDbUtils.translateMongoExceptionIfPossible(e);
+		}
+	}
+
 	public <T> T executeInSession(DBCallback<T> action) {
 		DB db = getDb();
 		db.requestStart();
@@ -339,14 +368,26 @@ public class MongoTemplate implements InitializingBean {
 		return query(getDefaultCollectionName(), query, targetClass); //
 	}
 	
+	public <T> List<T> query(DBObject query, Class<T> targetClass, CursorPreparer preparer) {
+		return query(getDefaultCollectionName(), query, targetClass, preparer); //
+	}
+
 	public <T> List<T> query(DBObject query, Class<T> targetClass, MongoReader<T> reader) {
 		return query(getDefaultCollectionName(), query, targetClass, reader);
 	}
 	
 	public <T> List<T> query(String collectionName, DBObject query, Class<T> targetClass) {	
+		return query(collectionName, query, targetClass, (CursorPreparer) null);
+	}
+
+	public <T> List<T> query(String collectionName, DBObject query, Class<T> targetClass, CursorPreparer preparer) {
 		DBCollection collection = getDb().getCollection(collectionName);
 		List<T> results = new ArrayList<T>();
-		for (DBObject dbo : collection.find(query)) {
+		DBCursor cursor = collection.find(query);
+		if (preparer != null) {
+			preparer.prepare(cursor);
+		}
+		for (DBObject dbo : cursor) {
 			Object obj = mongoConverter.read(targetClass,dbo);
 			//effectively acts as a query on the collection restricting it to elements of a specific type
 			if (targetClass.isInstance(obj)) {

spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/repository/MongoCursorUtils.java

@@ -0,0 +1,153 @@
+/*
+ * Copyright 2010 the original author or authors.
+ *
+ * Licensed 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.springframework.data.document.mongodb.repository;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.springframework.data.document.mongodb.CursorPreparer;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
+import org.springframework.data.domain.Sort.Direction;
+import org.springframework.data.domain.Sort.Order;
+
+import com.mongodb.BasicDBObject;
+import com.mongodb.DBCursor;
+
+
+/**
+ * Collection of utility methods to apply sorting and pagination to a
+ * {@link DBCursor}.
+ * 
+ * @author Oliver Gierke
+ */
+class MongoCursorUtils {
+
+    /**
+     * Creates a {@link CursorPreparer} applying the given {@link Pageable} to
+     * the cursor.
+     * 
+     * @param pageable
+     * @return
+     */
+    public static CursorPreparer withPagination(Pageable pageable) {
+
+        return new PaginationCursorPreparer(pageable);
+    }
+
+
+    /**
+     * Creates a {@link CursorPreparer} to apply the given {@link Sort} to the
+     * cursor.
+     * 
+     * @param sort
+     * @return
+     */
+    public static CursorPreparer withSorting(Sort sort) {
+
+        return new SortingCursorPreparer(sort);
+    }
+
+    /**
+     * Applies the given {@link Pageable} to the given {@link DBCursor}.
+     * 
+     * @author Oliver Gierke
+     */
+    private static class PaginationCursorPreparer implements CursorPreparer {
+
+        private final Pageable pageable;
+        private final SortingCursorPreparer sortingPreparer;
+
+
+        /**
+         * Creates a new {@link PaginationCursorPreparer}.
+         * 
+         * @param pageable
+         */
+        public PaginationCursorPreparer(Pageable pageable) {
+
+            this.pageable = pageable;
+            this.sortingPreparer =
+                    new SortingCursorPreparer(pageable.getSort());
+        }
+
+
+        /*
+         * (non-Javadoc)
+         * 
+         * @see
+         * org.springframework.data.document.mongodb.CursorPreparer#prepare(
+         * com.mongodb.DBCursor)
+         */
+        public void prepare(DBCursor cursor) {
+
+            if (pageable == null) {
+                return;
+            }
+
+            int toSkip = pageable.getPageSize() * pageable.getPageNumber();
+            int first = pageable.getPageSize();
+
+            cursor.limit(first).skip(toSkip);
+            sortingPreparer.prepare(cursor);
+        }
+    }
+
+    /**
+     * Applies the given {@link Sort} to the given {@link DBCursor}.
+     * 
+     * @author Oliver Gierke
+     */
+    private static class SortingCursorPreparer implements CursorPreparer {
+
+        private final Sort sort;
+
+
+        /**
+         * Creates a new {@link SortingCursorPreparer}.
+         * 
+         * @param sort
+         */
+        public SortingCursorPreparer(Sort sort) {
+
+            this.sort = sort;
+        }
+
+
+        /*
+         * (non-Javadoc)
+         * 
+         * @see
+         * org.springframework.data.document.mongodb.CursorPreparer#prepare(
+         * com.mongodb.DBCursor)
+         */
+        public void prepare(DBCursor cursor) {
+
+            if (sort == null) {
+                return;
+            }
+
+            Map<String, Integer> sorts = new HashMap<String, Integer>();
+
+            for (Order order : sort) {
+                sorts.put(order.getProperty(),
+                        Direction.ASC.equals(order.getDirection()) ? 1 : -1);
+            }
+
+            cursor.sort(new BasicDBObject(sorts));
+        }
+    }
+}

spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/repository/MongoQuery.java

@@ -15,15 +15,22 @@
  */
 package org.springframework.data.document.mongodb.repository;
 
+import static org.springframework.data.document.mongodb.repository.MongoCursorUtils.*;
+
 import java.util.List;
 
+import org.springframework.data.document.mongodb.CollectionCallback;
 import org.springframework.data.document.mongodb.MongoTemplate;
+import org.springframework.data.domain.PageImpl;
+import org.springframework.data.domain.Pageable;
 import org.springframework.data.repository.query.QueryMethod;
 import org.springframework.data.repository.query.RepositoryQuery;
 import org.springframework.data.repository.query.SimpleParameterAccessor;
 import org.springframework.data.repository.query.parser.PartTree;
 import org.springframework.util.Assert;
 
+import com.mongodb.DBCollection;
+import com.mongodb.DBCursor;
 import com.mongodb.DBObject;
 
 
@@ -50,8 +57,6 @@ public class MongoQuery implements RepositoryQuery {
 
         Assert.notNull(template);
         Assert.notNull(method);
-        Assert.isTrue(!method.isPageQuery(),
-                "Pagination queries not supported!");
 
         this.method = method;
         this.template = template;
@@ -73,13 +78,106 @@ public class MongoQuery implements RepositoryQuery {
         MongoQueryCreator creator = new MongoQueryCreator(tree, accessor);
         DBObject query = creator.createQuery();
 
-        List<?> result =
-                template.query(template.getDefaultCollectionName(), query,
-                        method.getDomainClass());
-
         if (method.isCollectionQuery()) {
-            return result;
+            return new CollectionExecution().execute(query);
+        } else if (method.isPageQuery()) {
+            return new PagedExecution(creator, accessor.getPageable())
+                    .execute(query);
         } else {
+            return new SingleEntityExecution().execute(query);
+        }
+    }
+
+    private abstract class Execution {
+
+        abstract Object execute(DBObject query);
+
+
+        protected List<?> readCollection(DBObject query) {
+
+            return template.query(template.getDefaultCollectionName(), query,
+                    method.getDomainClass());
+        }
+    }
+
+    class CollectionExecution extends Execution {
+
+        @Override
+        public Object execute(DBObject query) {
+
+            return readCollection(query);
+        }
+    }
+
+    /**
+     * {@link Execution} for pagination queries.
+     * 
+     * @author Oliver Gierke
+     */
+    class PagedExecution extends Execution {
+
+        private final Pageable pageable;
+        private final MongoQueryCreator creator;
+
+
+        /**
+         * Creates a new {@link PagedExecution}.
+         * 
+         * @param pageable
+         */
+        public PagedExecution(MongoQueryCreator creator, Pageable pageable) {
+
+            Assert.notNull(creator);
+            Assert.notNull(pageable);
+            this.creator = creator;
+            this.pageable = pageable;
+        }
+
+
+        /*
+         * (non-Javadoc)
+         * 
+         * @see
+         * org.springframework.data.document.mongodb.repository.MongoQuery.Execution
+         * #execute(com.mongodb.DBObject)
+         */
+        @Override
+        @SuppressWarnings({ "rawtypes", "unchecked" })
+        Object execute(DBObject query) {
+
+            int count = getCollectionCursor(creator.createQuery()).count();
+            List<?> result =
+                    template.query(query, method.getDomainClass(),
+                            withPagination(pageable));
+
+            return new PageImpl(result, pageable, count);
+        }
+
+
+        private DBCursor getCollectionCursor(final DBObject query) {
+
+            return template.execute(new CollectionCallback<DBCursor>() {
+
+                public DBCursor doInCollection(DBCollection collection) {
+
+                    return collection.find(query);
+                }
+            });
+        }
+    }
+
+    /**
+     * {@link Execution} to return a single entity.
+     * 
+     * @author Oliver Gierke
+     */
+    class SingleEntityExecution extends Execution {
+
+        @Override
+        Object execute(DBObject query) {
+
+            List<?> result = readCollection(query);
+
             return result.isEmpty() ? null : result.get(0);
         }
     }

spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/repository/MongoRepository.java

@@ -17,6 +17,7 @@ package org.springframework.data.document.mongodb.repository;
 
 import java.io.Serializable;
 
+import org.springframework.data.repository.PagingAndSortingRepository;
 import org.springframework.data.repository.Repository;
 
 
@@ -26,6 +27,6 @@ import org.springframework.data.repository.Repository;
  * @author Oliver Gierke
  */
 public interface MongoRepository<T, ID extends Serializable> extends
-        Repository<T, ID> {
+        PagingAndSortingRepository<T, Serializable> {
 
 }

spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/repository/SimpleMongoRepository.java

@@ -15,15 +15,23 @@
  */
 package org.springframework.data.document.mongodb.repository;
 
+import static org.springframework.data.document.mongodb.repository.MongoCursorUtils.*;
+
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
 
 import org.springframework.data.document.mongodb.MongoTemplate;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageImpl;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
+import org.springframework.data.repository.PagingAndSortingRepository;
 import org.springframework.data.repository.support.IsNewAware;
 import org.springframework.data.repository.support.RepositorySupport;
 import org.springframework.util.Assert;
 
+import com.mongodb.BasicDBObject;
 import com.mongodb.QueryBuilder;
 
 
@@ -33,7 +41,7 @@ import com.mongodb.QueryBuilder;
  * @author Oliver Gierke
  */
 public class SimpleMongoRepository<T, ID extends Serializable> extends
-        RepositorySupport<T, ID> {
+        RepositorySupport<T, ID> implements PagingAndSortingRepository<T, ID> {
 
     private final MongoTemplate template;
     private MongoEntityInformation entityInformation;
@@ -132,7 +140,8 @@ public class SimpleMongoRepository<T, ID extends Serializable> extends
      */
     public Long count() {
 
-        return Long.valueOf(findAll().size());
+        return template.getCollection(template.getDefaultCollectionName())
+                .count();
     }
 
 
@@ -176,6 +185,39 @@ public class SimpleMongoRepository<T, ID extends Serializable> extends
     }
 
 
+    /*
+     * (non-Javadoc)
+     * 
+     * @see
+     * org.springframework.data.repository.PagingAndSortingRepository#findAll
+     * (org.springframework.data.domain.Pageable)
+     */
+    public Page<T> findAll(final Pageable pageable) {
+
+        Long count = count();
+
+        List<T> list =
+                template.query(new BasicDBObject(), getDomainClass(),
+                        withPagination(pageable));
+
+        return new PageImpl<T>(list, pageable, count);
+    }
+
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see
+     * org.springframework.data.repository.PagingAndSortingRepository#findAll
+     * (org.springframework.data.domain.Sort)
+     */
+    public List<T> findAll(final Sort sort) {
+
+        return template.query(new BasicDBObject(), getDomainClass(),
+                withSorting(sort));
+    }
+
+
     /*
      * (non-Javadoc)
      * 

spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/repository/Person.java

@@ -32,7 +32,15 @@ public class Person {
 
     public Person() {
 
+        this(null, null);
+    }
+
+
+    public Person(String firstname, String lastname) {
+
         this.id = ObjectId.get().toString();
+        this.firstname = firstname;
+        this.lastname = lastname;
     }
 
 

spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/repository/PersonRepository.java

@@ -17,6 +17,9 @@ package org.springframework.data.document.mongodb.repository;
 
 import java.util.List;
 
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+
 
 /**
  * Sample repository managing {@link Person} entities.
@@ -25,8 +28,32 @@ import java.util.List;
  */
 public interface PersonRepository extends MongoRepository<Person, Long> {
 
+    /**
+     * Returns all {@link Person}s with the given lastname.
+     * 
+     * @param lastname
+     * @return
+     */
     List<Person> findByLastname(String lastname);
 
 
+    /**
+     * Returns all {@link Person}s with a firstname matching the given one
+     * (*-wildcard supported).
+     * 
+     * @param firstname
+     * @return
+     */
     List<Person> findByFirstnameLike(String firstname);
+
+
+    /**
+     * Returns a page of {@link Person}s with a lastname mathing the given one
+     * (*-wildcards supported).
+     * 
+     * @param lastname
+     * @param pageable
+     * @return
+     */
+    Page<Person> findByLastnameLike(String lastname, Pageable pageable);
 }

spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/repository/PersonRepositoryIntegrationTests.java

@@ -18,11 +18,16 @@ package org.springframework.data.document.mongodb.repository;
 import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
 
+import java.util.Arrays;
 import java.util.List;
 
+import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Sort.Direction;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
@@ -39,23 +44,63 @@ public class PersonRepositoryIntegrationTests {
     @Autowired
     PersonRepository repository;
 
+    Person dave, carter, boyd, stefan, leroi;
 
-    @Test
-    public void createAndExecuteFinderRoundtrip() throws Exception {
+
+    @Before
+    public void setUp() {
 
         repository.deleteAll();
 
-        Person person = new Person();
-        person.setFirstname("Oliver");
-        person.setLastname("Gierke");
-        person = repository.save(person);
+        dave = new Person("Dave", "Matthews");
+        carter = new Person("Carter", "Beauford");
+        boyd = new Person("Boyd", "Tinsley");
+        stefan = new Person("Stefan", "Lessard");
+        leroi = new Person("Leroi", "Moore");
+
+        repository.save(Arrays.asList(dave, carter, boyd, stefan, leroi));
+    }
+
 
-        List<Person> result = repository.findByLastname("Gierke");
+    @Test
+    public void findsPersonsByLastname() throws Exception {
+
+        List<Person> result = repository.findByLastname("Beauford");
         assertThat(result.size(), is(1));
-        assertThat(result, hasItem(person));
+        assertThat(result, hasItem(carter));
+    }
+
+
+    @Test
+    public void findsPersonsByFirstnameLike() throws Exception {
 
-        result = repository.findByFirstnameLike("Oli*");
+        List<Person> result = repository.findByFirstnameLike("Bo*");
         assertThat(result.size(), is(1));
-        assertThat(result, hasItem(person));
+        assertThat(result, hasItem(boyd));
+    }
+
+
+    @Test
+    public void findsPagedPersons() throws Exception {
+
+        Page<Person> result =
+                repository.findAll(new PageRequest(1, 2, Direction.ASC,
+                        "lastname"));
+        assertThat(result.isFirstPage(), is(false));
+        assertThat(result.isLastPage(), is(false));
+        assertThat(result, hasItems(dave, leroi));
+    }
+
+
+    @Test
+    public void executesPagedFinderCorrectly() throws Exception {
+
+        Page<Person> page =
+                repository.findByLastnameLike("*a*", new PageRequest(0, 2,
+                        Direction.ASC, "lastname"));
+        assertThat(page.isFirstPage(), is(true));
+        assertThat(page.isLastPage(), is(false));
+        assertThat(page.getNumberOfElements(), is(2));
+        assertThat(page, hasItems(carter, stefan));
     }
 }