Java实现对MongoDB的AND、OR和IN操作 ，大于、小于等判断

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本文转自http://blog.csdn.net/mydeman/article/details/6652387

在MongoDB的官方文档中关于Java操作的介绍，只给出了很简单的几个例子。这些例子虽然可以满足一定的需求，但是还并不是太完全。下面是我根据网页中的提示写的几个例子。

1.背景。用JUnit4.8.2实现的单元测试的形式。测试数据：

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1. {uid:10,username:"Jim",age:23,agender:"male"}

2. {uid:27,username:"tom",age:13,agender:"male"}

3. {uid:12,username:"Jane",age:31,agender:"female"}

4. {uid:23,username:"Alex",age:47,agender:"male"}

5. {uid:109,username:"Lily",age:24,agender:"female"}

{uid:10,username:"Jim",age:23,agender:"male"}
{uid:27,username:"tom",age:13,agender:"male"}
{uid:12,username:"Jane",age:31,agender:"female"}
{uid:23,username:"Alex",age:47,agender:"male"}
{uid:109,username:"Lily",age:24,agender:"female"}

单元测试的初始化和清理工作，主要是建立数据库连接、写入测试数据、清理测试数据：

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1. private static List<BasicDBObject> documents = new ArrayList<BasicDBObject>();

2. private static DBCollection coll;

3. @BeforeClass

4. public static void init(){

5. try {

6. initConnection();

7. loadData();

8. } catch (Exception e) {

9. e.printStackTrace();

10. }

11. }

12. private static void initConnection() throws UnknownHostException, MongoException{

13. //Create a connection to Collection ‘user‘

14. Mongo mongo = new Mongo("localhost", 27017);

15. DB db = mongo.getDB("test");

16. coll = db.getCollection("user");

17. }

18. private static void loadData() throws Exception{

19. BufferedReader br = new BufferedReader(new InputStreamReader(MongoTest.class.getResourceAsStream("data")));

20. String line = null;

21. while((line = br.readLine()) != null){

22. JSONObject jo = new JSONObject(line);

23. //Convert JSONObject into BasicDBObject

24. BasicDBObject dbObject = new BasicDBObject();

25. Iterator<String> joKeys = jo.keys();

26. while(joKeys.hasNext()){

27. String key = joKeys.next();

28. dbObject.put(key, jo.get(key));

29. }

30. documents.add(dbObject);

31. }

32. }

33. @Before

34. public void setUp(){

35. //Insert all data into MongoDB

36. for(BasicDBObject bdo : documents){

37. coll.insert(bdo);

38. }

39. }

40. @After

41. public void cleanUp(){

42. //Drop the collection to remove all data.

43. //Note: it‘s not recommended.

44. coll.drop();

45. }

  private static List<BasicDBObject> documents = new ArrayList<BasicDBObject>();
        private static DBCollection coll;
        
        @BeforeClass
        public static void init(){
                try {
                        
                        initConnection();
                        
                        loadData();
                } catch (Exception e) {
                        e.printStackTrace();
                }
        }
        
        private static void initConnection() throws UnknownHostException, MongoException{
                //Create a connection to Collection ‘user‘
                Mongo mongo = new Mongo("localhost", 27017);
                DB db = mongo.getDB("test");
                coll = db.getCollection("user");
        }
        
        private static void loadData() throws Exception{
                BufferedReader br = new BufferedReader(new InputStreamReader(MongoTest.class.getResourceAsStream("data")));
                String line = null;
                while((line = br.readLine()) != null){
                        JSONObject jo = new JSONObject(line);
                        
                        //Convert JSONObject into BasicDBObject
                        BasicDBObject dbObject = new BasicDBObject();
                        Iterator<String> joKeys = jo.keys();
                        while(joKeys.hasNext()){
                                String key = joKeys.next();
                                dbObject.put(key, jo.get(key));
                        }
                        
                        documents.add(dbObject);
                }
        }
        
        @Before
        public void setUp(){
                //Insert all data into MongoDB
                for(BasicDBObject bdo : documents){
                        coll.insert(bdo);
                }
        }
        
        @After
        public void cleanUp(){
                //Drop the collection to remove all data.
                //Note: it‘s not recommended.
                coll.drop();
        }

2. AND是比较简单的。

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1. @Test

2. public void testAnd(){

3. //agender=‘female‘ AND age > 27

4. DBObject queryCondition = new BasicDBObject();

5. queryCondition.put("agender", "female");

6. queryCondition.put("age", new BasicDBObject("$gt", 27));

7. DBCursor dbCursor = coll.find(queryCondition);

8. assertEquals(1, dbCursor.size());

9. assertEquals("Jane", dbCursor.next().get("username"));

10. }

  @Test
        public void testAnd(){
                //agender=‘female‘ AND age > 27      
                DBObject queryCondition = new BasicDBObject();
                queryCondition.put("agender", "female");
                queryCondition.put("age", new BasicDBObject("$gt", 27));
                DBCursor dbCursor = coll.find(queryCondition);
                assertEquals(1, dbCursor.size());
                assertEquals("Jane", dbCursor.next().get("username"));
        }

3.单个字段的OR操作。

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1. @Test

2. public void testOrSingleField(){

3. DBObject queryCondition = new BasicDBObject();

4. //age<15 OR age>27

5. queryCondition = new BasicDBObject();

6. BasicDBList values = new BasicDBList();

7. values.add(new BasicDBObject("age", new BasicDBObject("$gt", 27)));

8. values.add(new BasicDBObject("age", new BasicDBObject("$lt", 15)));

9. queryCondition.put("$or", values);

10. DBCursor dbCursor = coll.find(queryCondition);

11. assertEquals(3, dbCursor.size());

12. assertEquals("tom", dbCursor.next().get("username"));

13. }

  @Test
        public void testOrSingleField(){
                DBObject queryCondition = new BasicDBObject();          
                //age<15 OR age>27
                queryCondition = new BasicDBObject();
                BasicDBList values = new BasicDBList();
                values.add(new BasicDBObject("age", new BasicDBObject("$gt", 27)));
                values.add(new BasicDBObject("age", new BasicDBObject("$lt", 15)));
                queryCondition.put("$or", values);
                
                DBCursor dbCursor = coll.find(queryCondition);
                assertEquals(3, dbCursor.size());
                assertEquals("tom", dbCursor.next().get("username"));
        }

4. 多个字段之间的OR操作

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1. @Test

2. public void testOrMultiFields(){

3. DBObject queryCondition = new BasicDBObject();

4. //agender=female OR age<=23

5. queryCondition = new BasicDBObject();

6. BasicDBList values = new BasicDBList();

7. values.add(new BasicDBObject("agender", "female"));

8. values.add(new BasicDBObject("age", new BasicDBObject("$lte", 23)));

9. queryCondition.put("$or", values);

10. DBCursor dbCursor = coll.find(queryCondition);

11. assertEquals(4, dbCursor.size());

12. assertEquals("Jim", dbCursor.next().get("username"));

13. }

  @Test
        public void testOrMultiFields(){
                DBObject queryCondition = new BasicDBObject();          
                //agender=female OR age<=23
                queryCondition = new BasicDBObject();
                BasicDBList values = new BasicDBList();
                values.add(new BasicDBObject("agender", "female"));
                values.add(new BasicDBObject("age", new BasicDBObject("$lte", 23)));
                queryCondition.put("$or", values);
                
                DBCursor dbCursor = coll.find(queryCondition);
                assertEquals(4, dbCursor.size());
                assertEquals("Jim", dbCursor.next().get("username"));
        }

5. 单个字段的IN操作。对于类似 where age=13 OR age=47的查询条件，就可以考虑使用IN代替

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1. @Test

2. public void testIn(){

3. DBObject queryCondition = new BasicDBObject();

4. //age in [13, 47]

5. queryCondition = new BasicDBObject();

6. BasicDBList values = new BasicDBList();

7. values.add(13);

8. values.add(47);

9. queryCondition.put("age", new BasicDBObject("$in", values));

10. DBCursor dbCursor = coll.find(queryCondition);

11. assertEquals(2, dbCursor.size());

12. assertEquals("tom", dbCursor.next().get("username"));

13. }

  @Test
        public void testIn(){
                DBObject queryCondition = new BasicDBObject();          
                //age in [13, 47]
                queryCondition = new BasicDBObject();
                BasicDBList values = new BasicDBList();
                values.add(13);
                values.add(47);
                queryCondition.put("age", new BasicDBObject("$in", values));
                
                DBCursor dbCursor = coll.find(queryCondition);
                assertEquals(2, dbCursor.size());
                assertEquals("tom", dbCursor.next().get("username"));
        }

从以上几个例子可以看出，通过BasicDBList与BasicDBObject的相结合可以得出比较复杂的查询条件。

Java实现对MongoDB的AND、OR和IN操作 ，大于、小于等判断

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原文地址：http://my.oschina.net/hetiangui/blog/314844