MongoDB学习总结三

MogonDB的java驱动示例：

 

public class DataBase {

 

public static void main(String[] args) throws Exception {

 

try{

//1.建立一个mongo的数据库连接对象

Mongo mongo = new Mongo("127.0.0.1:27017");

//System.out.println(mongo);

//2.查询所有的DataBaseName

List<String > dbNameList = mongo.getDatabaseNames();

 

for(String name :dbNameList){

System.out.println(name);

}

 

//3.创建相关数据库（foobar）的连接

DB db = mongo.getDB("foobar");

 

//4.查询出数据库中所有集合的名称

Set<String> collNames = db.getCollectionNames();

System.out.println("===============================");

for(String name : collNames){

System.out.println(name);

}

System.out.println("===============================");

//查询出所有的数据

DBCollection users = db.getCollection("persons");

DBCursor cursor = users.find();

while(cursor.hasNext()){

DBObject obj = cursor.next();

System.out.println(obj.get("name"));

}

 

System.out.println(cursor.count());

 

 

System.out.println(JSON.serialize(cursor));

}catch(Exception e){

 

 }

}

}

 

 

一些操作案例：

 

public class MongoDb {

 

//建立一个Mongo的数据库连接对象

static Mongo conn = null;

//创建相关数据库的连接

static DB db =null;

 

public MongoDb(String dataBaseName) throws Exception{

conn = new Mongo("127.0.0.1:27017");

db = conn.getDB(dataBaseName);

}

 

public static void main(String[] args) throws Exception {

MongoDb mongoDb = new MongoDb("foobar");

//1.创建一个叫javadb的数据库集合

//mongoDb.createCollection("javadb");

//2.为集合javadb添加一条数据

// DBObject dbs = new BasicDBObject();

// dbs.put("name", "sml");

// dbs.put("age", 2);

//

// List<String> books = new ArrayList<String>();

// books.add("extjs");

// books.add("mongodb");

// dbs.put("books", books);

// mongoDb.insert(dbs,"javadb");

 

// //批量插入数据

// List<DBObject> dbObject = new ArrayList<DBObject>();

// DBObject jim = new BasicDBObject("name","jim");

// DBObject lisi = new BasicDBObject("name","lisi");

// dbObject.add(jim);

// dbObject.add(lisi);

// mongoDb.insertBatch(dbObject,"javadb");

 

//根据id删除数据

// int count  = mongoDb.deleteById("56a830f99dab9f50c2eff5dd","javadb");

// System.out.println(count);

 

//根据条件删除数据

// DBObject lisi = new BasicDBObject();

// lisi.put("name","lisi");

// int count = mongoDb.deleteByDbs(lisi,"javadb");

// System.out.println(count);

 

//更新操作，为集合增加email属性

// DBObject dbObject = new BasicDBObject();

// dbObject.put("$set", new BasicDBObject("email","[e-mail]"));

// int count = mongoDb.update(new BasicDBObject(),dbObject,false,true,"javadb");

// System.out.println(count);

 

//查询persons集合中的name和age

// DBObject keys = new BasicDBObject();

// keys.put("_id", false);

// keys.put("name", true);

// keys.put("age", true);

// DBCursor cursor = mongoDb.find(null,keys,"persons");

// while(cursor.hasNext()){

// DBObject obj = cursor.next();

// System.out.println(obj.get("name"));

// }

 

//分页查询

DBCursor cursor = mongoDb.find(null, null,6,3, "persons");

while(cursor.hasNext()){

DBObject obj = cursor.next();

System.out.print(obj.get("name")+"-->");

System.out.print(obj.get("age")+"-->");

System.out.println(obj.get("email"));

}

 

conn.close();

}

 

private DBCursor find(DBObject ref, DBObject keys, int start, int limit, String collName) {

DBCollection coll = db.getCollection(collName);

DBCursor cursor = find(ref, keys,collName);

return cursor.skip(start).limit(limit);

 

}

 

public DBCursor find(DBObject ref, DBObject keys, String collName) {

DBCollection coll = db.getCollection(collName);

DBCursor cursor = coll.find(ref, keys);

return cursor;

}

 

public int update(DBObject find, DBObject dbObject, boolean upsert, boolean multi, String collName) {

DBCollection coll = db.getCollection(collName);

int count = coll.update(find, dbObject,upsert,multi).getN();

return count;

}

 

public int deleteByDbs(DBObject lisi, String collName) {

DBCollection coll = db.getCollection(collName);

int count  = coll.remove(lisi).getN();

return count;

}

 

public int deleteById(String id, String collName) {

DBCollection coll = db.getCollection(collName);

int count = coll.remove(new BasicDBObject("_id",new ObjectId(id))).getN();

return count;

}

 

public void insertBatch(List<DBObject> dbObject, String collName) {

DBCollection coll = db.getCollection(collName);

coll.insert(dbObject);

}

 

//1.创建一个叫javadb的数据库集合

/*public void createCollection(String collName){

DBObject dbs = new BasicDBObject();

db.createCollection("javadb", dbs);

}*/

public void insert(DBObject dbs,String collName){

DBCollection coll = db.getCollection(collName);

coll.insert(dbs);

}

 

}