added a simple UpdateBuilder implementation

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

@@ -0,0 +1,46 @@
+/*
+ * 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;
+
+import java.util.Collections;
+import java.util.LinkedHashMap;
+
+import com.mongodb.BasicDBObject;
+import com.mongodb.DBObject;
+
+public class UpdateBuilder {
+	
+	private LinkedHashMap<String, Object> criteria = new LinkedHashMap<String, Object>();
+
+	public UpdateBuilder set(String key, Object value) {
+		criteria.put("$set", Collections.singletonMap(key, value));
+		return this;
+	}
+
+	public UpdateBuilder inc(String key, long inc) {
+		criteria.put("$inc", Collections.singletonMap(key, inc));
+		return this;
+	}
+
+	public DBObject build() {
+		DBObject dbo = new BasicDBObject();
+		for (String k : criteria.keySet()) {
+			dbo.put(k, criteria.get(k));
+		}
+		return dbo;
+	}
+
+}

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

@@ -0,0 +1,47 @@
+/*
+ * 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;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class UpdateBuilderTests {
+
+	@Test
+	public void testSetUpdate() {
+		UpdateBuilder ub = new UpdateBuilder()
+			.set("directory", "/Users/Test/Desktop");
+		Assert.assertEquals("{ \"$set\" : { \"directory\" : \"/Users/Test/Desktop\"}}", ub.build().toString());
+	}
+
+	@Test
+	public void testIncUpdate() {
+		UpdateBuilder ub = new UpdateBuilder()
+			.inc("size", 1);
+		Assert.assertEquals("{ \"$inc\" : { \"size\" : 1}}", ub.build().toString());
+	}
+
+	@Test
+	public void testIncAndSetUpdate() {
+		UpdateBuilder ub = new UpdateBuilder()
+			.inc("size", 1)
+			.set("directory", "/Users/Test/Desktop");
+		Assert.assertEquals("{ \"$inc\" : { \"size\" : 1} , \"$set\" : { \"directory\" : \"/Users/Test/Desktop\"}}", 
+				ub.build().toString());
+	}
+
+
+}