一、mongodb客户端
mongodb提供诸多语言的客户端，也包括java的客户端。通过这些客户端，我们可以很方便地使用编写代码的方式对mongodb进行操作。这里使用java客户端进行示例。使用java客户端首先需要下载jmongodb数据库java驱动。驱动的源码地址为：https://github.com/mongodb/mongo-java-driver/ 。这里工程使用maven构建，需要添加的依赖如下：
<dependency> <groupId>org.mongodb</groupId> <artifactId>mongo-java-driver</artifactId> <version>2.12.4</version> </dependency>
二、示例
1、添加文档
DB db = null; @Before public void getDb() throws UnknownHostException { MongoClient mongoClient = new MongoClient(); // mongoClient = new MongoClient("localhost"); // mongoClient = new MongoClient( "localhost" , 27017 ); // mongoClient = new MongoClient(Arrays.asList(new ServerAddress("localhost", 27017), new ServerAddress("localhost", 27018), new ServerAddress("localhost", 27019))); //需要验证的如下 // MongoCredential credential = MongoCredential.createMongoCRCredential(userName, database, password); // MongoClient mongoClient = new MongoClient(new ServerAddress(), Arrays.asList(credential)); mongoClient.setWriteConcern(WriteConcern.JOURNALED); System.out.println("===========DatabaseName============="); for (String s : mongoClient.getDatabaseNames()) { System.out.println(s); } db = mongoClient.getDB("testdb"); } @Test public void addDoc() { DBCollection coll = db.getCollection("person"); BasicDBObject doc = new BasicDBObject("name", "张三")// .append("age", 20)// .append("gender", "mail")// .append("brithday", new Date()) // .append("info", new BasicDBObject("location_x", 203).append( "location_y", 303)); WriteResult result = coll.insert(doc); System.out.println(result); for (int i = 0; i < 10; i++) { BasicDBObject document = new BasicDBObject("name", "zhangsan" + i)// .append("age", 18 + i)// .append("brithday", new Date()); WriteResult result2 = coll.insert(document); System.out.println(result2); } }
2、查询文档
@Test public void findDoc() { DBCollection coll = db.getCollection("person"); DBObject person = coll.findOne();// 获取集合中的第一个文档 System.out.println("===============findOne======================"); System.out.println(person); // 根据条件查询;db.person.find({age:18}); DBObject query = new BasicDBObject("age", 18); DBObject person2 = coll.findOne(query); System.out.println(person2); System.out .println("===============findByCondtion======================"); // age小于25; db.person.find({age:{$lt:25}}); query = new BasicDBObject("age", new BasicDBObject("$lt", 25)); DBCursor cursor = coll.find(query); try { while (cursor.hasNext()) { System.out.println(cursor.next()); } } finally { cursor.close(); } System.out.println("===============findAll======================"); // 查询所有并按照age升序;db.person.find().sort({age:1}); cursor = coll.find().sort(new BasicDBObject("age", -1));// 1升序,-1降序 try { while (cursor.hasNext()) { System.out.println(cursor.next()); } } finally { cursor.close(); } }
3、更新文档
@Test public void updateDoc() { DBCollection coll = db.getCollection("person"); BasicDBObject query = new BasicDBObject("name", "张三"); DBObject update = coll.findOne(query); update.put("info", new BasicDBObject("location_x", 1999).append( "location_y", 2999)); // 方法一 DBObject person = coll.findAndModify(query, update);// 返回的是未更改前的文档对象 System.out.println(person); // 方法二 update.put("info", new BasicDBObject("location_x", 19998).append( "location_y", 29998)); WriteResult result = coll.update(query, update); System.out.println(result); }
4、删除文档
@Test public void deleteDoc() { DBCollection coll = db.getCollection("person"); BasicDBObject query = new BasicDBObject("name", "zhangsan8"); // 方法一 query = new BasicDBObject("name", "zhangsan9"); DBObject person = coll.findAndRemove(query);// 返回的是删除的文档对象 System.out.println(person); // 方法二 query = new BasicDBObject("name", "zhangsan9"); WriteResult result = coll.remove(query); System.out.println(result); }
5、集合相关操作
@Test public void testCollection() { Set<String> colls = db.getCollectionNames();// 数据库中的所有集合name for (String s : colls) { System.out.println(s); } System.out.println("======================================="); // 创建一个collection,并在collection中添加document DBCollection coll = db.createCollection("testCollection", new BasicDBObject("capped", true).append("size", 1048576)); System.out.println(coll); coll = db.getCollection("testCollection"); // collection中的索引 List<DBObject> list = coll.getIndexInfo(); for (DBObject o : list) { System.out.println(o); } coll.drop(); }
