MongoDB學習筆記(三) java中如何操作MongoDB
阿新 • • 發佈：2019-02-03
1. mongoDB對Java支援的驅動包
驅動包下載地址：http://repo1.maven.org/maven2/org/mongodb/mongo-java-driver/
mongoDB對Java的相關支援、技術：http://www.mongodb.org/display/DOCS/Java+Language+Center
驅動原始碼下載：https://download.github.com/mongodb-mongo-java-driver-r2.6.1-7-g6037357.zip
2. Java操作MongoDB示例
(2) CRUD操作
驅動包下載地址：http://repo1.maven.org/maven2/org/mongodb/mongo-java-driver/
mongoDB對Java的相關支援、技術：http://www.mongodb.org/display/DOCS/Java+Language+Center
驅動原始碼下載：https://download.github.com/mongodb-mongo-java-driver-r2.6.1-7-g6037357.zip
線上檢視原始碼：https://github.com/mongodb/mongo-java-driver
maven配置：
<dependency> <groupId>org.mongodb</groupId> <artifactId>mongo-java-driver</artifactId> <version>2.11.1</version> </dependency>
2. Java操作MongoDB示例
(1) 簡單的mongoDB資料庫操作
public class SimpleTest { public static void main(final String[] args) throws UnknownHostException { Mongo mg = new Mongo(); // 查詢所有的Database for (String name : mg.getDatabaseNames()) { System.out.println("dbName: " + name); } DB db = mg.getDB("test"); // 查詢所有的聚集集合 for (String name : db.getCollectionNames()) { System.out.println("collectionName: " + name); } DBCollection users = db.getCollection("users"); // 查詢所有的資料 DBCursor cur = users.find(); while (cur.hasNext()) { System.out.println(cur.next()); } System.out.println(cur.count()); System.out.println(cur.getCursorId()); System.out.println(JSON.serialize(cur)); } }
(2) CRUD操作
public class CRUDTest { private Mongo mg = null; private DB db; private DBCollection users; public static void main(String[] args) { CRUDTest tobj = new CRUDTest(); tobj.init(); tobj.add(); // tobj.query(); // tobj.modify(); // tobj.remove(); // tobj.testOthers(); tobj.destory(); } private void init() { try { mg = new Mongo(); // mg = new Mongo("localhost", 27017); } catch (UnknownHostException e) { e.printStackTrace(); } catch (MongoException e) { e.printStackTrace(); } // 獲取test DB；如果預設沒有建立，mongodb會自動建立 db = mg.getDB("test"); // 獲取users DBCollection；如果預設沒有建立，mongodb會自動建立 users = db.getCollection("users"); } private void destory() { if (mg != null) { mg.close(); } mg = null; db = null; users = null; System.gc(); } public void print(Object o) { System.out.println(o); } /** * 查詢所有資料 */ private void queryAll() { print("查詢users的所有資料："); DBCursor cur = users.find(); while (cur.hasNext()) { print(cur.next()); } } /** * 新增操作 */ public void add() { // 查詢資料 queryAll(); print("count: " + users.count()); DBObject user = new BasicDBObject(); user.put("name", "lilei"); user.put("age", 20); user.put("sex", "male"); // users.save(user)儲存，getN()獲取影響行數 print(users.save(user).getN()); // 新增多條資料，傳遞Array物件 DBObject user2 = new BasicDBObject("name", "hanmeimei"); user2.put("age", 18); print(users.insert(user2, new BasicDBObject("name", "jim")).getN()); // 新增多條資料，傳遞List集合 List<DBObject> list = new ArrayList<DBObject>(); DBObject user3 = new BasicDBObject("name", "lucy"); user3.put("age", 22); list.add(user3); DBObject user4 = new BasicDBObject("name", "tom"); user4.put("age", 22); list.add(user4); print(users.insert(list).getN()); // 查詢資料 print("count: " + users.count()); queryAll(); } public void query() { // 查詢id print("查詢 id = 54f511b4e4b0ded60d95c333: " + users.find(new BasicDBObject("_id", new ObjectId("54f511b4e4b0ded60d95c333"))).toArray()); // 查詢age print("查詢 age = 24: " + users.find(new BasicDBObject("age", 24)).toArray()); print("查詢 age >= 24: " + users.find(new BasicDBObject("age", new BasicDBObject("$gte", 24))).toArray()); print("查詢 age <= 24: " + users.find(new BasicDBObject("age", new BasicDBObject("$lte", 24))).toArray()); print("查詢 age != 25：" + users.find(new BasicDBObject("age", new BasicDBObject("$ne", 25))).toArray()); print("查詢 age in 25/26/27：" + users.find(new BasicDBObject("age", new BasicDBObject(QueryOperators.IN, new int[] { 25, 26, 27 }))) .toArray()); print("查詢age not in 25/26/27：" + users.find(new BasicDBObject("age", new BasicDBObject(QueryOperators.NIN, new int[] { 25, 26, 27 }))) .toArray()); print("查詢age exists 排序：" + users.find(new BasicDBObject("age", new BasicDBObject(QueryOperators.EXISTS, true))).toArray()); print("只查詢age屬性：" + users.find(null, new BasicDBObject("age", true)).toArray()); print("只查屬性：" + users.find(null, new BasicDBObject("age", true), 0, 2).toArray()); print("只查屬性：" + users.find(null, new BasicDBObject("age", true), 0, 2, Bytes.QUERYOPTION_NOTIMEOUT).toArray()); // 只查詢一條資料，多條去第一條 print("findOne: " + users.findOne()); print("findOne: " + users.findOne(new BasicDBObject("age", 26))); print("findOne: " + users.findOne(new BasicDBObject("age", 26), new BasicDBObject("name", true))); // 查詢修改、刪除 print("findAndRemove 查詢age=25的資料，並且刪除: " + users.findAndRemove(new BasicDBObject("age", 25))); // 查詢age=26的資料，並且修改name的值為Abc print("findAndModify: " + users.findAndModify(new BasicDBObject("age", 26), new BasicDBObject("name", "Abc"))); print("findAndModify: " + users.findAndModify(new BasicDBObject("age", 28), // 查詢age=28的資料 new BasicDBObject("name", true), // 查詢name屬性 new BasicDBObject("age", true), // 按照age排序 false, // 是否刪除，true表示刪除 new BasicDBObject("name", "Abc"), // 修改的值，將name修改成Abc true, true)); queryAll(); } /** * 修改操作 */ public void modify() { print("修改：" + users.update(new BasicDBObject("name", "hanmeimei"), new BasicDBObject("age", 25)).getN()); print("修改：" + users.update(new BasicDBObject("age", new BasicDBObject("$gte", 22)), new BasicDBObject("age", 121), true,// 如果資料庫不存在，是否新增 false// false只修改第一條，true如果有多條就不修改 ).getN()); } /** * 刪除操作 */ public void remove() { print("刪除id = 54f511b4e4b0ded60d95c333：" + users.remove(new BasicDBObject("_id", new ObjectId("54f511b4e4b0ded60d95c333"))).getN()); print("remove age >= 22: " + users.remove(new BasicDBObject("age", new BasicDBObject("$gte", 22))).getN()); } /** * 其他操作 */ public void testOthers() { DBObject user = new BasicDBObject(); user.put("name", "demo"); user.put("age", 24); // JSON 物件轉換 print("serialize: " + JSON.serialize(user)); // 反序列化 print("parse: " + JSON.parse("{ \"name\" : \"demo\" , \"age\" : 24}")); // 如果不存在就建立 if (!db.collectionExists("temp")) { DBObject options = new BasicDBObject(); options.put("size", 20); options.put("capped", 20); options.put("max", 20); print(db.createCollection("account", options)); } // 設定db為只讀 db.setReadOnly(true); // 只讀不能寫入資料 db.getCollection("test").save(user); } }