java - MongoDB 连接问题

Question

我正在尝试使用 java 代码连接到在远程 Linux 机器上运行的 mongodb 服务器，

public static void main(String[] args) {
    Properties prop = new Properties();
    try {           
        //load a properties file
        prop.load(new FileInputStream("src/main/resources/mongodb.properties"));            
        String server = prop.getProperty("server");
        String port = prop.getProperty("port");
        int portnum = Integer.parseInt(port);

        /**** Connect to MongoDB ****/
        MongoClient mongo = new MongoClient(server,portnum);
        System.out.println("Connected to database");

        /**** Get database ****/
        // if database doesn't exists, MongoDB will create it for you
        DB db = mongo.getDB("test");

        /**** Get collection / table from 'details' ****/
        // if collection doesn't exists, MongoDB will create it for you
        DBCollection table = db.getCollection("details");

        /**** Insert ****/
        // create a document to store key and value
        BasicDBObject document = new BasicDBObject();
        document.put("name", "test");
        document.put("age", 24);
        table.insert(document);

        /**** Find and display ****/
        BasicDBObject searchQuery = new BasicDBObject();
        searchQuery.put("name", "test");

        DBCursor cursor = table.find(searchQuery);

        while (cursor.hasNext()) {
            System.out.println(cursor.next());
        }


    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

}

我的本地 mongo 运行良好。但是在尝试连接 Linux 服务器时遇到问题。

这是错误信息，

Jan 18, 2016 12:23:02 AM com.mongodb.DBTCPConnector initDirectConnection
WARNING: Exception executing isMaster command on server:port
java.io.IOException: couldn't connect to [server port] bc:java.net.ConnectException: Connection refused: connect
    at com.mongodb.DBPort._open(DBPort.java:214)
    at com.mongodb.DBPort.go(DBPort.java:107)
    at com.mongodb.DBPort.go(DBPort.java:88)
    at com.mongodb.DBPort.findOne(DBPort.java:143)
    at com.mongodb.DBPort.runCommand(DBPort.java:148)
    at com.mongodb.DBTCPConnector.initDirectConnection(DBTCPConnector.java:548)
    at com.mongodb.Mongo.getMaxBsonObjectSize(Mongo.java:620)
    at com.mongodb.DBApiLayer$MyCollection.insert(DBApiLayer.java:254)
    at com.mongodb.DBApiLayer$MyCollection.insert(DBApiLayer.java:226)
    at com.mongodb.DBCollection.insert(DBCollection.java:75)
    at com.mongodb.DBCollection.insert(DBCollection.java:59)
    at com.mongodb.DBCollection.insert(DBCollection.java:104)
    at com.filecompare.util.MongoDBConnection.main(MongoDBConnection.java:42)

Jan 18, 2016 12:23:03 AM com.mongodb.DBTCPConnector initDirectConnection
WARNING: Exception executing isMaster command on sever port
java.io.IOException: couldn't connect to [server port] bc:java.net.ConnectException: Connection refused: connect
    at com.mongodb.DBPort._open(DBPort.java:214)
    at com.mongodb.DBPort.go(DBPort.java:107)
    at com.mongodb.DBPort.go(DBPort.java:88)
    at com.mongodb.DBPort.findOne(DBPort.java:143)
    at com.mongodb.DBPort.runCommand(DBPort.java:148)
    at com.mongodb.DBTCPConnector.initDirectConnection(DBTCPConnector.java:548)
    at com.mongodb.DBTCPConnector.checkMaster(DBTCPConnector.java:527)
    at com.mongodb.DBTCPConnector.say(DBTCPConnector.java:174)
    at com.mongodb.DBTCPConnector.say(DBTCPConnector.java:155)
    at com.mongodb.DBApiLayer$MyCollection.insert(DBApiLayer.java:270)
    at com.mongodb.DBApiLayer$MyCollection.insert(DBApiLayer.java:226)
    at com.mongodb.DBCollection.insert(DBCollection.java:75)
    at com.mongodb.DBCollection.insert(DBCollection.java:59)
    at com.mongodb.DBCollection.insert(DBCollection.java:104)
    at com.filecompare.util.MongoDBConnection.main(MongoDBConnection.java:42)

Jan 18, 2016 12:23:04 AM com.mongodb.DBPortPool gotError
WARNING: emptying DBPortPool to server:port b/c of error
java.io.IOException: couldn't connect to [server:port] bc:java.net.ConnectException: Connection refused: connect
    at com.mongodb.DBPort._open(DBPort.java:214)
    at com.mongodb.DBPort.go(DBPort.java:107)
    at com.mongodb.DBPort.go(DBPort.java:84)
    at com.mongodb.DBPort.say(DBPort.java:79)
    at com.mongodb.DBTCPConnector.say(DBTCPConnector.java:181)
    at com.mongodb.DBTCPConnector.say(DBTCPConnector.java:155)
    at com.mongodb.DBApiLayer$MyCollection.insert(DBApiLayer.java:270)
    at com.mongodb.DBApiLayer$MyCollection.insert(DBApiLayer.java:226)
    at com.mongodb.DBCollection.insert(DBCollection.java:75)
    at com.mongodb.DBCollection.insert(DBCollection.java:59)
    at com.mongodb.DBCollection.insert(DBCollection.java:104)
    at com.filecompare.util.MongoDBConnection.main(MongoDBConnection.java:42)

Exception in thread "main" com.mongodb.MongoException$Network: can't say something
    at com.mongodb.DBTCPConnector.say(DBTCPConnector.java:194)
    at com.mongodb.DBTCPConnector.say(DBTCPConnector.java:155)
    at com.mongodb.DBApiLayer$MyCollection.insert(DBApiLayer.java:270)
    at com.mongodb.DBApiLayer$MyCollection.insert(DBApiLayer.java:226)
    at com.mongodb.DBCollection.insert(DBCollection.java:75)
    at com.mongodb.DBCollection.insert(DBCollection.java:59)
    at com.mongodb.DBCollection.insert(DBCollection.java:104)
    at com.filecompare.util.MongoDBConnection.main(MongoDBConnection.java:42)
Caused by: java.io.IOException: couldn't connect to [server port] bc:java.net.ConnectException: Connection refused: connect
    at com.mongodb.DBPort._open(DBPort.java:214)
    at com.mongodb.DBPort.go(DBPort.java:107)
    at com.mongodb.DBPort.go(DBPort.java:84)
    at com.mongodb.DBPort.say(DBPort.java:79)
    at com.mongodb.DBTCPConnector.say(DBTCPConnector.java:181)
    ... 7 more

我在 linux 上连接 mongo 通常遵循的步骤是，

1. 使用 Putty(windows) 或 ssh 命令(Mac) 登录服务器。
2. 输入 mongo。
3. 连接到 mongo，运行 mongo 命令以查看/插入数据。

但是，在上面的 java 代码中，我没有包含任何登录凭据。我必须这样做吗？如果是这样，请有人指导我。

Answer 1

您确定在 mongodb.properties 中为您的 server 和 port 属性变量提供了正确的值吗？

MongoDB 的默认端口是 27017。

此外，检查 MongoDB 服务器上的 mongod.conf。此文件默认位于 /etc/mongod.conf 并查找以下属性:

bind_ip = 127.0.0.1

如果设置为 127.0.0.1 或 localhost，那么您将无法从外部公开访问您的 MongoDB 服务器。

现在要解决这个问题，请更改 bind_ip 的值以包含您的公共(public) IP 地址，因此如果您的公共(public)地址是 46.12.212.34，bind_ip 看起来像:

bind_ip = 127.0.0.1, 46.12.212.34

保存并退出文件并重新启动您的 MongoDB 数据库。您的 Java 应用程序现在应该可以运行了。