|
1 package org.prevayler.demos.scalability.prevayler;
2
3 import java.util.ArrayList  ;
4 import java.util.Collections ;
5 import java.util.HashMap ;
6 import java.util.Iterator ;
7 import java.util.List ;
8 import java.util.Map ;
9
10 import org.prevayler.demos.scalability.Record;
11 import org.prevayler.demos.scalability.RecordIterator;
12
13 class QuerySystem implements ScalabilitySystem {
14
15 private Map recordsByName = new HashMap ();
16
17
18 public List queryByName(String name) {
19 return (List )recordsByName.get(name);
20 }
21
22
23 public void replaceAllRecords(RecordIterator newRecords) {
24 recordsByName.clear();
25
26 while (newRecords.hasNext()) {
27 put(newRecords.next());
28 }
29
30 makeReadOnly();
31 }
32
33
34 private void put(Record newRecord) {
35 List records = queryByName(newRecord.getName());
36 if (records == null) {
37 records = new ArrayList ();
38 recordsByName.put(newRecord.getName(), records);
39 }
40
41 records.add(newRecord);
42 }
43
44
45
47 private void makeReadOnly() {
48 Iterator entries = recordsByName.entrySet().iterator();
49 while (entries.hasNext()) {
50 Map.Entry entry = (Map.Entry )entries.next();
51 entry.setValue(Collections.unmodifiableList((List )entry.getValue()));
52 }
53 }
54 }
55 |
Popular Tags |
Java API By Example, From Geeks To Geeks.