How to write complex mongodb query using QueryBuilder

public List searchUsers(Map map){
		return searchDao.searchUsers(map);
}

public List searchUsers(Map map){
		return searchDao.searchUsers(map);
}

public DBCollection getDBCollection(String collectionName){
		try {
			return datasource.mongo().getDB(datasource.getDatabaseName()).getCollection(collectionName);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			// throw exception
		}
	}

public QueryBuilder mongoQueryBuilder(Map map){
		Iterator> it = map.entrySet().iterator();
		QueryBuilder queryBuilder = QueryBuilder.start();
		while(it.hasNext()){
			Entry keyValue = it.next();
			if(!isInteger(keyValue.getValue()))
				queryBuilder.and(keyValue.getKey().trim()).regex(Pattern.compile(keyValue.getValue().trim()+".*",Pattern.CASE_INSENSITIVE));
			else
				queryBuilder.and(keyValue.getKey().trim()).is(Integer.parseInt(keyValue.getValue()));
		}
		return queryBuilder;
	}

public static boolean isInteger(String s) {
	    return isInteger(s,10);
	}

	public static boolean isInteger(String s, int radix) {
	    if(s.isEmpty()) return false;
	    for(int i = 0; i < s.length(); i++) {
	        if(i == 0 && s.charAt(i) == '-') {
	            if(s.length() == 1) return false;
	            else continue;
	        }
	        if(Character.digit(s.charAt(i),radix) < 0) return false;
	    }
	    return true;
	}

Step 6

create class datasource

@Configuration
public class Datasource extends AbstractMongoConfiguration{
	
	@Override
	public String getDatabaseName() {
		return "samepinch";
	}
 
	@Override
	@Bean
	public Mongo mongo() throws Exception {
		return new MongoClient("127.0.0.1");
	}

}