An error is reported when java connects to mongodb.

An error is reported when java connects to mongodb.

<Span style = "background-color: rgb (255,255,255); font-family: Arial, Helvetica, sans-serif;"> An error is returned when you write a short test program, depressing </span>

<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);"></span><pre name="code" class="html">public static void main(String[] args) {          try {           Mongo mongo = new Mongo("10.2.167.27",27017);           DB db = mongo.getDB("company");           DBCollection collection = db.getCollection("employees");           BasicDBObject employee = new BasicDBObject();       employee.put("name", "Hannah");       employee.put("no", 2);           collection.insert(employee);           BasicDBObject searchEmployee = new BasicDBObject();       searchEmployee.put("no", 2);           DBCursor cursor = collection.find(searchEmployee);           while (cursor.hasNext()) {        System.out.println(cursor.next());       }           System.out.println("The Search Query has Executed!");          } catch (UnknownHostException e) {       e.printStackTrace();      } catch (MongoException e) {       e.printStackTrace();      }         }    

The error message is as follows:

Java. io. IOException: couldn't connect to [/10.20.7.27: 27017] bc: java.net. ConnectException: Connection refused: connect
At com. mongodb. DBPort. _ open (DBPort. java: 224)
At com. mongodb. DBPort. go (DBPort. java: 101)
At com. mongodb. DBPort. go (DBPort. java: 82)
At com. mongodb. DBPort. findOne (DBPort. java: 142)
At com. mongodb. DBPort. runCommand (DBPort. java: 151)
At com. mongodb. DBTCPConnector. fetchMaxBsonObjectSize (DBTCPConnector. java: 429)
At com. mongodb. Mongo. getMaxBsonObjectSize (Mongo. java: 544)
At com. mongodb. DBApiLayer $ MyCollection. insert (DBApiLayer. java: 244)
At com. mongodb. DBApiLayer $ MyCollection. insert (DBApiLayer. java: 217)
At com. mongodb. DBCollection. insert (DBCollection. java: 87)
At mongodb. MongoDBClient. main (MongoDBClient. java: 28)

Check the server port: tcp 0 127.0.0.1: 27017 0.0.0.0: * LISTEN 31933/mongod

The port listening is OK. That is the configuration problem.

Open vim/etc/mongod. conf

# Listen to local interface only. Comment out to listen on all interfaces.
Bind_ip = 127.0.0.1

You can see a record like this. Who is the port open. Commented out. OK.

The correct result is as follows:

{"_ Id": {"$ oid": "54a8fcad2d1dc6f5db50564b"}, "name": "hanhannah", "no": 2}
The Search Query has Executed!