Почему в Java работает отправка запросов, но не работает в Android Studio?

Имеется код на Java для отправки запроса на сервер, написанный на Python. Он работает, но при запуске в Android Studio вылезает ошибка. Рабочий код на Java:

public static int getStructure(String link) throws IOException {
    Socket s = new Socket("127.0.0.1", 9090);
    InputStream in = s.getInputStream();
    OutputStream out = s.getOutputStream();
    System.out.println(out);
    String str = link;
    byte buf[] = str.getBytes();
    out.write(buf);
    int size;
    byte buf_out[] = new byte[1024];
    while ((size = in.read(buf_out)) != -1) {
        System.out.print(new String(buf_out, 0, size));
    }
    s.close();
    return 0;
}

Код сервера на Python:

import socket, json, githubmachine

sock = socket.socket()
sock.bind(('', 9090))
sock.listen(1)
conn, addr = sock.accept()
print('connected:', addr)
while True:
    data = conn.recv(1024)
    link = data
    if not data:
        break
    conn.send(bytes(json.dumps({"name": "Viktor", "age":  30}), encoding="utf-8"))
conn.close()

Не рабочий код в Android Studio:

public static int getStructure(String link) throws IOException {
    Socket s = new Socket("127.0.0.1", 9090);
    InputStream in = s.getInputStream();
    OutputStream out = s.getOutputStream();
    System.out.println(out);
    String str = link;
    byte buf[] = str.getBytes();
    out.write(buf);
    int size;
    byte buf_out[] = new byte[1024];
    while ((size = in.read(buf_out)) != -1) {
        System.out.print(new String(buf_out, 0, size));
    }
    s.close();
    return 0;
}


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    relativeLayout = (RelativeLayout) findViewById(R.id.relativeLayout);
    textView = (TextView) findViewById(R.id.textView);
    blockName = (EditText) findViewById(R.id.editTextTextPersonName);
    Button[] twoVertex = new Button[2]; // array that contain from 0 to 2 vertex to draw an edge between it
    vertexView = new DrawView(this, 0, 0, 100, 200);
    relativeLayout.addView(vertexView);
    try {
        getStructure("1 ");
    } catch (IOException e) {
        System.out.println(e.toString());
    }

}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.nitm">
    <uses-permission android:name="android.permission.INTERNET"/>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.Nitm">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>