无法解析符号 'connect'

Question

这里有什么问题？为什么我总是无法解析符号 'connect'。我从文档中获得了这段代码，我的依赖项都是正确的。

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import org.jivesoftware.smack.AbstractXMPPConnection;
import org.jivesoftware.smack.tcp.XMPPTCPConnection;

public class MainActivity extends AppCompatActivity {
    AbstractXMPPConnection conn1 = new XMPPTCPConnection("username", "password" ,"jabber.org");
conn1.connect();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

Answer 1

你不能这样做：

public class MainActivity extends AppCompatActivity {
    AbstractXMPPConnection conn1 = new XMPPTCPConnection("username", "password" ,"jabber.org");
conn1.connect();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

因为 conn1.connect() 未在有效范围内调用...（应在方法内完成）而是做

public class MainActivity extends AppCompatActivity {
    AbstractXMPPConnection conn1 = new XMPPTCPConnection("username", "password" ,"jabber.org");

     public void connectToSomething()   ... some exceptions here must be thrown{

          conn1.connect();
    }    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

    }
}

无法解析符号 'connect'

cannot resolve symbol 'connect'

java

android

xmpp

smack