java - 从 MongoDB 删除时出现 com.mongodb.MongoTimeoutException

Question

我已经在 https://mlab.com/ 创建了一个 MongoDB 数据库现在我尝试通过 Android 应用程序从该数据库中删除文档，但收到异常 com.mongodb.MongoTimeoutException。所以请帮忙。

代码

package com.example.abc.mongodatabase;

import android.content.Context;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;
import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.MongoClient;
import java.net.URL;


public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        new MongoDeletion().execute(MainActivity.this);
    }
}



class MongoDeletion extends AsyncTask<Context, Void, Object> {

    @Override
    protected Object doInBackground(Context... params) {
        try {
            URL requestUrl = new URL("https://api.mongolab.com/api/1/databases/my_database/collections/my_table/?apiKey=################################");
            MongoClient mongoClient = new MongoClient(new ServerAddress(requestUrl.getHost(),requestUrl.getPort()));
            DB db = mongoClient.getDB("my_database");
            DBCollection table = db.getCollection("my_table");
            BasicDBObject searchQuery = new BasicDBObject();
            searchQuery.put("name", "my_name");
            table.remove(searchQuery);
            Toast.makeText(params[0], "Deleted...", Toast.LENGTH_SHORT).show();
        }
        catch (Exception e) {
            Log.e("ERROR","MongoDB", e);
        }
        return null;
    }
}

我要删除的文档

{
    "_id": {
        "$oid": "5735d2e50a00b27acd69e10b"
    },
    "date": "14/5/2016",
    "longitude": "72.98868477344513",
    "name": "my_name",
    "latitude": "33.639541155896275"
}

异常

05-15 11:20:02.122 2651-2680/com.example.mongodatabase.mongo2 E/ERROR: MongoDB
com.mongodb.MongoTimeoutException: Timed out after 10000 ms while waiting for a server that matches AnyServerSelector{}. Client view of cluster state is {type=Unknown, servers=[{address=api.mongolab.com:-1, type=Unknown, state=Connecting, exception={java.lang.IllegalArgumentException: port=-1}}]
at com.mongodb.BaseCluster.getServer(BaseCluster.java:82)
at com.mongodb.DBTCPConnector.getServer(DBTCPConnector.java:656)
at com.mongodb.DBTCPConnector.access$500(DBTCPConnector.java:40)
at com.mongodb.DBTCPConnector$MyPort.getConnection(DBTCPConnector.java:505)
at com.mongodb.DBTCPConnector$MyPort.get(DBTCPConnector.java:448)
at com.mongodb.DBTCPConnector.getPrimaryPort(DBTCPConnector.java:407)
at com.mongodb.DBCollectionImpl.remove(DBCollectionImpl.java:219)
at com.mongodb.DBCollectionImpl.remove(DBCollectionImpl.java:203)
at com.mongodb.DBCollection.remove(DBCollection.java:300)
at com.mongodb.DBCollection.remove(DBCollection.java:327)
at com.example.mongodatabase.mongo2.MongoDeletion.doInBackground(MainActivity.java:43)
at com.example.mongodatabase.mongo2.MongoDeletion.doInBackground(MainActivity.java:32)
at android.os.AsyncTask$2.call(AsyncTask.java:287)
at java.util.concurrent.FutureTask.run(FutureTask.java:234)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:838)

Answer 1

错误消息告诉您出了什么问题:

com.mongodb.MongoTimeoutException:WAITING与 AnyServerSelector{} 匹配的服务器时，10000 毫秒后超时。集群状态的客户端 View 为 {type=Unknown,servers=[{address=api.mongolab.com:-1, type=Unknown,state=Connecting,Exception={java.lang.IllegalArgumentException: port=-1}}]


它告诉您存在非法端口参数:java.lang.IllegalArgumentException: port=-1

在您的 MongoClient 构造函数中，您使用 requestUrl.getPort() 作为端口参数，但 docs for URL明确指出getPort():

返回此 URL 的端口号，如果此 URL 没有显式端口，则返回 -1

您的 requestUrl 字符串没有端口值，因此 getPort() 返回 -1。 MongoDB 实例不接受 -1 作为端口号，因此它最终会超时并给出您所看到的异常。