DATADOC-72 added support for Mongo's $elemMatch and chained Criteria

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

@@ -26,6 +26,8 @@ import org.springframework.data.document.InvalidDocumentStoreApiUsageException;
 public class Criteria implements CriteriaDefinition {
 
   private String key;
+  
+  private List<Criteria> criteriaChain;
 
   private LinkedHashMap<String, Object> criteria = new LinkedHashMap<String, Object>();
 
@@ -33,9 +35,16 @@ public class Criteria implements CriteriaDefinition {
 
 
   public Criteria(String key) {
+    this.criteriaChain = new ArrayList<Criteria>();
+    this.criteriaChain.add(this);
     this.key = key;
   }
 
+  protected Criteria(List<Criteria> criteriaChain, String key) {
+    this.criteriaChain = criteriaChain;
+    this.criteriaChain.add(this);
+    this.key = key;
+  }
 
   /**
    * Static factory method to create a Criteria using the provided key
@@ -47,6 +56,16 @@ public class Criteria implements CriteriaDefinition {
     return new Criteria(key);
   }
 
+  /**
+   * Static factory method to create a Criteria using the provided key
+   *
+   * @param key
+   * @return
+   */
+  public Criteria and(String key) {
+    return new Criteria(this.criteriaChain, key);
+  }
+
   /**
    * Creates a criterion using the $is operator
    *
@@ -207,6 +226,16 @@ public class Criteria implements CriteriaDefinition {
     return this;
   }
 
+  /**
+   * Creates a criterion using the $elemMatch operator
+   *
+   * @param t
+   * @return
+   */
+  public Criteria elemMatch(Criteria c) {
+    criteria.put("$elemMatch", c.getCriteriaObject());
+    return this;
+  }
   /**
    * Creates an or query using the $or operator for all of the provided queries
    *
@@ -224,6 +253,19 @@ public class Criteria implements CriteriaDefinition {
     * @see org.springframework.datastore.document.mongodb.query.Criteria#getCriteriaObject(java.lang.String)
     */
   public DBObject getCriteriaObject() {
+    if (this.criteriaChain.size() == 1) {
+      return criteriaChain.get(0).getSingleCriteriaObject();
+    }
+    else {
+      DBObject criteriaObject = new BasicDBObject();
+      for (Criteria c : this.criteriaChain) {
+        criteriaObject.putAll(c.getSingleCriteriaObject());
+      }
+      return criteriaObject;
+    }    
+  }
+  
+  protected DBObject getSingleCriteriaObject() {
     DBObject dbo = new BasicDBObject();
     boolean not = false;
     for (String k : this.criteria.keySet()) {

spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/query/CriteriaTests.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2010-2011 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.query;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.springframework.data.document.mongodb.query.Index.Duplicates;
+
+public class CriteriaTests {
+
+  @Test
+  public void testSimpleCriteria() {
+    Criteria c = new Criteria("name").is("Bubba");
+    Assert.assertEquals("{ \"name\" : \"Bubba\"}", c.getCriteriaObject().toString());
+  }
+
+  @Test
+  public void testChainedCriteria() {
+    Criteria c = new Criteria("name").is("Bubba").and("age").lt(21);
+    Assert.assertEquals("{ \"name\" : \"Bubba\" , \"age\" : { \"$lt\" : 21}}", c.getCriteriaObject().toString());
+  }
+}

spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/query/QueryTests.java

@@ -29,6 +29,13 @@ public class QueryTests {
     Assert.assertEquals(expected, q.getQueryObject().toString());
   }
 
+  @Test
+  public void testSimpleQueryWithChainedCriteria() {
+    Query q = new Query(where("name").is("Thomas").and("age").lt(80));
+    String expected = "{ \"name\" : \"Thomas\" , \"age\" : { \"$lt\" : 80}}";
+    Assert.assertEquals(expected, q.getQueryObject().toString());
+  }
+
   @Test
   public void testQueryWithNot() {
     Query q = new Query(where("name").is("Thomas")).and(where("age").not().mod(10, 0));
@@ -74,4 +81,10 @@ public class QueryTests {
     Assert.assertEquals(expected, q.getQueryObject().toString());
   }
 
+  @Test
+  public void testQueryWithElemMatch() {
+    Query q = new Query(where("openingHours").elemMatch(where("dayOfWeek").is("Monday").and("open").lte("1800")));
+    String expected = "{ \"openingHours\" : { \"$elemMatch\" : { \"dayOfWeek\" : \"Monday\" , \"open\" : { \"$lte\" : \"1800\"}}}}";
+    Assert.assertEquals(expected, q.getQueryObject().toString());
+  }
 }