public class User {
 
	String username;
	String password;
 
	//...getters and setters
}

    MongoOperations mongoOperation = (MongoOperations)ctx.getBean("mongoTemplate");	
    User user = new User("mkyong", "password123");
    mongoOperation.save(user, "users");

> db.users.find()
{ 
	"_class" : "com.mkyong.user.User", 
	"_id" : ObjectId("5050aef830041f24ff2bd16e"), 
	"password" : "new password", "username" : "mkyong" 
}

@Configuration
public class SpringMongoConfig{
 
  public @Bean
  MongoDbFactory mongoDbFactory() throws Exception {
	return new SimpleMongoDbFactory(new Mongo(), "database");
  }
 
  public @Bean
  MongoTemplate mongoTemplate() throws Exception {
 
	//remove _class
	MappingMongoConverter converter = 
		new MappingMongoConverter(mongoDbFactory(), new MongoMappingContext());
	converter.setTypeMapper(new DefaultMongoTypeMapper(null));
 
	MongoTemplate mongoTemplate = new MongoTemplate(mongoDbFactory(), converter);
 
	return mongoTemplate;
 
  }
 
}

{ 
	"_id" : ObjectId("id"), 
	"ic" : "1001", 
	"name" : "appleA", 
	"age" : 20, 
	"createdDate" : ISODate("2013-04-06T23:17:35.530Z") 
}

	Query query = new Query();
	query.addCriteria(Criteria.where("name").is("appleA"));
 
	User userTest1 = mongoOperation.findOne(query, User.class);
 
	System.out.println("userTest1 - " + userTest1);
 
	//modify and update with save()
	userTest1.setAge(99);
	mongoOperation.save(userTest1);
 
	//get the updated object again
	User userTest1_1 = mongoOperation.findOne(query, User.class);
 
	System.out.println("userTest1_1 - " + userTest1_1);

userTest1 - User [id=id, ic=1001, name=appleA, age=20, createdDate=Sat Apr 06 23:17:35 MYT 2013]
userTest1_1 - User [id=id, ic=1001, name=appleA, age=99, createdDate=Sat Apr 06 23:17:35 MYT 2013]

{ 
	"_id" : ObjectId("id"), 
	"ic" : "1002", 
	"name" : "appleB", 
	"age" : 20, 
	"createdDate" : ISODate("2013-04-06T15:22:34.530Z") 
}

		Query query = new Query();
		query.addCriteria(Criteria.where("name").is("appleB"));
		query.fields().include("name");
 
		User userTest2 = mongoOperation.findOne(query, User.class);
		System.out.println("userTest2 - " + userTest2);
 
		userTest2.setAge(99);
 
		mongoOperation.save(userTest2);
 
		// ooppss, you just override everything, it caused ic=null and
		// createdDate=null
 
		Query query1 = new Query();
		query1.addCriteria(Criteria.where("name").is("appleB"));
 
		User userTest2_1 = mongoOperation.findOne(query1, User.class);
		System.out.println("userTest2_1 - " + userTest2_1);

userTest2 - User [id=51603dba3004d7fffc202391, ic=null, name=appleB, age=0, createdDate=null]
userTest2_1 - User [id=51603dba3004d7fffc202391, ic=null, name=appleB, age=99, createdDate=null]

{ 
	"_id" : ObjectId("id"), 
	"ic" : "1003", 
	"name" : "appleC", 
	"age" : 20, 
	"createdDate" : ISODate("2013-04-06T23:22:34.530Z") 
}

		//returns only 'name' field
		Query query = new Query();
		query.addCriteria(Criteria.where("name").is("appleC"));
		query.fields().include("name");
 
		User userTest3 = mongoOperation.findOne(query, User.class);
		System.out.println("userTest3 - " + userTest3);
 
		Update update = new Update();
		update.set("age", 100);
 
		mongoOperation.updateFirst(query, update, User.class);
 
		//returns everything
		Query query1 = new Query();
		query1.addCriteria(Criteria.where("name").is("appleC"));
 
		User userTest3_1 = mongoOperation.findOne(query1, User.class);
		System.out.println("userTest3_1 - " + userTest3_1);

userTest3 - User [id=id, ic=null, name=appleC, age=0, createdDate=null]
userTest3_1 - User [id=id, ic=1003, name=appleC, age=100, createdDate=Sat Apr 06 23:22:34 MYT 2013]

{ 
	"_id" : ObjectId("id"), 
	"ic" : "1004", 
	"name" : "appleD", 
	"age" : 20, 
	"createdDate" : ISODate("2013-04-06T15:22:34.530Z") 
}
{ 
	"_id" : ObjectId("id"), 
	"ic" : "1005", 
	"name" : "appleE", 
	"age" : 20, 
	"createdDate" : ISODate("2013-04-06T15:22:34.530Z") 
}

		//show the use of $or operator
		Query query = new Query();
		query.addCriteria(Criteria
				.where("name").exists(true)
				.orOperator(Criteria.where("name").is("appleD"),
						Criteria.where("name").is("appleE")));
		Update update = new Update();
 
		//update age to 11
		update.set("age", 11);
 
		//remove the createdDate field
		update.unset("createdDate");
 
		// if use updateFirst, it will update 1004 only.
		// mongoOperation.updateFirst(query4, update4, User.class);
 
		// update all matched, both 1004 and 1005
		mongoOperation.updateMulti(query, update, User.class);
 
		System.out.println(query.toString());
 
		List<User> usersTest4 = mongoOperation.find(query4, User.class);
 
		for (User userTest4 : usersTest4) {
			System.out.println("userTest4 - " + userTest4);
		}

Query: { "name" : { "$exists" : true} , 
	"$or" : [ { "name" : "appleD"} , { "name" : "appleE"}]}, Fields: null, Sort: null
 
userTest4 - User [id=id, ic=1004, name=appleD, age=11, createdDate=null]
userTest4 - User [id=id, ic=1005, name=appleE, age=11, createdDate=null]

{ 
	//no data
}

		//search a document that doesn't exist
		Query query = new Query();
		query.addCriteria(Criteria.where("name").is("appleZ"));
 
		Update update = new Update();
		update.set("age", 21);
 
		mongoOperation.upsert(query, update, User.class);
 
		User userTest5 = mongoOperation.findOne(query, User.class);
		System.out.println("userTest5 - " + userTest5);

userTest5 - User [id=id, ic=null, name=appleZ, age=21, createdDate=null]

{ 
	"_id" : ObjectId("id"), 
	"ic" : "1006", 
	"name" : "appleF", 
	"age" : 20, 
	"createdDate" : ISODate("2013-04-07T13:11:34.530Z") 
}

		Query query6 = new Query();
		query6.addCriteria(Criteria.where("name").is("appleF"));
 
		Update update6 = new Update();
		update6.set("age", 101);
		update6.set("ic", 1111);
 
		//FindAndModifyOptions().returnNew(true) = newly updated document
		//FindAndModifyOptions().returnNew(false) = old document (not update yet)
		User userTest6 = mongoOperation.findAndModify(
				query6, update6, 
				new FindAndModifyOptions().returnNew(true), User.class);
		System.out.println("userTest6 - " + userTest6);

userTest6 - User [id=id, ic=1111, name=appleF, age=101, createdDate=Sun Apr 07 13:11:34 MYT 2013]

package com.mkyong.core;
 
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
 
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.data.mongodb.core.FindAndModifyOptions;
import org.springframework.data.mongodb.core.MongoOperations;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.data.mongodb.core.query.Update;
 
import com.mkyong.config.SpringMongoConfig;
import com.mkyong.model.User;
 
public class UpdateApp {
 
	public static void main(String[] args) {
		// For Annotation
		ApplicationContext ctx = 
			new AnnotationConfigApplicationContext(SpringMongoConfig.class);
		MongoOperations mongoOperation = 
			(MongoOperations) ctx.getBean("mongoTemplate");
 
		// insert 6 users for testing
		List<User> users = new ArrayList<User>();
 
		User user1 = new User("1001", "appleA", 20, new Date());
		User user2 = new User("1002", "appleB", 20, new Date());
		User user3 = new User("1003", "appleC", 20, new Date());
		User user4 = new User("1004", "appleD", 20, new Date());
		User user5 = new User("1005", "appleE", 20, new Date());
		User user6 = new User("1006", "appleF", 20, new Date());
		users.add(user1);
		users.add(user2);
		users.add(user3);
		users.add(user4);
		users.add(user5);
		users.add(user6);
		mongoOperation.insert(users, User.class);
 
		// Case 1 ... find and update
		System.out.println("Case 1");
 
		Query query1 = new Query();
		query1.addCriteria(Criteria.where("name").is("appleA"));
 
		User userTest1 = mongoOperation.findOne(query1, User.class);
 
		System.out.println("userTest1 - " + userTest1);
 
		userTest1.setAge(99);
		mongoOperation.save(userTest1);
 
		User userTest1_1 = mongoOperation.findOne(query1, User.class);
 
		System.out.println("userTest1_1 - " + userTest1_1);
 
		// Case 2 ... select single field only
		System.out.println("\nCase 2");
 
		Query query2 = new Query();
		query2.addCriteria(Criteria.where("name").is("appleB"));
		query2.fields().include("name");
 
		User userTest2 = mongoOperation.findOne(query2, User.class);
		System.out.println("userTest2 - " + userTest2);
 
		userTest2.setAge(99);
 
		mongoOperation.save(userTest2);
 
		// ooppss, you just override everything, it caused ic=null and
		// createdDate=null
 
		Query query2_1 = new Query();
		query2_1.addCriteria(Criteria.where("name").is("appleB"));
 
		User userTest2_1 = mongoOperation.findOne(query2_1, User.class);
		System.out.println("userTest2_1 - " + userTest2_1);
 
		System.out.println("\nCase 3");
		Query query3 = new Query();
		query3.addCriteria(Criteria.where("name").is("appleC"));
		query3.fields().include("name");
 
		User userTest3 = mongoOperation.findOne(query3, User.class);
		System.out.println("userTest3 - " + userTest3);
 
		Update update3 = new Update();
		update3.set("age", 100);
 
		mongoOperation.updateFirst(query3, update3, User.class);
 
		Query query3_1 = new Query();
		query3_1.addCriteria(Criteria.where("name").is("appleC"));
 
		User userTest3_1 = mongoOperation.findOne(query3_1, User.class);
		System.out.println("userTest3_1 - " + userTest3_1);
 
		System.out.println("\nCase 4");
		Query query4 = new Query();
		query4.addCriteria(Criteria
				.where("name")
				.exists(true)
				.orOperator(Criteria.where("name").is("appleD"),
						Criteria.where("name").is("appleE")));
		Update update4 = new Update();
		update4.set("age", 11);
		update4.unset("createdDate");
 
		// update 1004 only.
		// mongoOperation.updateFirst(query4, update4, User.class);
 
		// update all matched
		mongoOperation.updateMulti(query4, update4, User.class);
 
		System.out.println(query4.toString());
 
		List<User> usersTest4 = mongoOperation.find(query4, User.class);
 
		for (User userTest4 : usersTest4) {
			System.out.println("userTest4 - " + userTest4);
		}
 
		System.out.println("\nCase 5");
		Query query5 = new Query();
		query5.addCriteria(Criteria.where("name").is("appleZ"));
 
		Update update5 = new Update();
		update5.set("age", 21);
 
		mongoOperation.upsert(query5, update5, User.class);
 
		User userTest5 = mongoOperation.findOne(query5, User.class);
		System.out.println("userTest5 - " + userTest5);
 
		System.out.println("\nCase 6");
		Query query6 = new Query();
		query6.addCriteria(Criteria.where("name").is("appleF"));
 
		Update update6 = new Update();
		update6.set("age", 101);
		update6.set("ic", 1111);
 
		User userTest6 = mongoOperation.findAndModify(query6, update6,
				new FindAndModifyOptions().returnNew(true), User.class);
		System.out.println("userTest6 - " + userTest6);
 
		mongoOperation.dropCollection(User.class);
 
	}
 
}

Case 1
userTest1 - User [id=id, ic=1001, name=appleA, age=20, createdDate=Sun Apr 07 13:22:48 MYT 2013]
userTest1_1 - User [id=id, ic=1001, name=appleA, age=99, createdDate=Sun Apr 07 13:22:48 MYT 2013]
 
Case 2
userTest2 - User [id=id, ic=null, name=appleB, age=0, createdDate=null]
userTest2_1 - User [id=id, ic=null, name=appleB, age=99, createdDate=null]
 
Case 3
userTest3 - User [id=id, ic=null, name=appleC, age=0, createdDate=null]
userTest3_1 - User [id=id, ic=1003, name=appleC, age=100, createdDate=Sun Apr 07 13:22:48 MYT 2013]
 
Case 4
Query: { "name" : { "$exists" : true} , "$or" : [ { "name" : "appleD"} , { "name" : "appleE"}]}, Fields: null, Sort: null
userTest4 - User [id=id, ic=1004, name=appleD, age=11, createdDate=null]
userTest4 - User [id=id, ic=1005, name=appleE, age=11, createdDate=null]
 
Case 5
userTest5 - User [id=id, ic=null, name=appleZ, age=21, createdDate=null]
 
Case 6
userTest6 - User [id=id, ic=1006, name=appleF, age=20, createdDate=Sun Apr 07 13:22:48 MYT 2013]