search algorithm

gistfile1.java

/*
Class Subject
  id
  Map<String,Participant> participants
Class Participant
  Map<String,List<String>>attributes
*/

//This method is within a DAO class and under Spring context

public List<Subject> lookUp(String entityName) {
		Long timer1 = new Date().getTime();
		String sql = "select * from xref where entity_name='"+entityName
				+"' order by id,participant,attribute,attribute_index";
		final List<Subject> results;
		final Map<Integer,Subject> subjectIdMap = new HashMap<Integer,Subject>();
		
		jdbcTemplate.query(sql, new RowCallbackHandler() {
			
			@Override
			public void processRow(ResultSet rs) throws SQLException {
				int subjectId = rs.getInt("id");
				String participantName = rs.getString("participant");
				String attributeName = rs.getString("attribute");
				String value = rs.getString("value");
				int attributeIndex = rs.getInt("attribute_Index");
				
				if(!subjectIdMap.containsKey(subjectId)) {
					List<String> values = new ArrayList<String>();
					values.add(value);
					Map<String,List<String>> attributes = new HashMap<String,List<String>>();
					attributes.put(attributeName, values);
					Participant participant = new Participant();
					participant.setAttributes(attributes);
					Map<String,Participant> participants = new HashMap<String,Participant>();
					participants.put(participantName, participant);
					Subject subject = new Subject();
					subject.setId(subjectId);
					subject.setParticipants(participants);
					
					subjectIdMap.put(subjectId, subject);
					
				}else {
					Subject subject1 = subjectIdMap.get(subjectId);
					Map<String,Participant> participants1 = subject1.getParticipants();
					if(!participants1.containsKey(participantName)) {
						List<String> values1 = new ArrayList<String>();
						values1.add(value);
						Map<String,List<String>> attributes1 = new HashMap<String,List<String>>();
						attributes1.put(attributeName, values1);
						Participant participant1 = new Participant();
						participant1.setAttributes(attributes1);
						participants1.put(participantName, participant1);
						subject1.setParticipants(participants1);
						
						subjectIdMap.put(subjectId, subject1);
					}else {
						Participant participant2 = participants1.get(participantName);
						Map<String,List<String>> attributes2 = participant2.getAttributes();
						if(!attributes2.containsKey(attributeName)) {
							List<String> values2 = new ArrayList<String>();
							values2.add(value);
							attributes2.put(attributeName,values2);
							participant2.setAttributes(attributes2);
							participants1.put(participantName, participant2);
							subject1.setParticipants(participants1);
							
							subjectIdMap.put(subjectId,subject1);
						}else {
							List<String> values3 = attributes2.get(attributeName);
							values3.add(value);
							attributes2.put(attributeName, values3);
							participant2.setAttributes(attributes2);
							participants1.put(participantName, participant2);
							subject1.setParticipants(participants1);
							
							subjectIdMap.put(subjectId, subject1);
						}
					}
				}//first if
			}
			
		});
		System.out.println("generated nested map"+subjectIdMap);
		Long timer2 = new Date().getTime();
		results = new ArrayList<Subject>(subjectIdMap.values());
		System.out.println("finished in "+(timer2-timer1));
		return results;
	}