java - 如何检查url是否可达

Question

我正在尝试检查服务器 url 在 android 中是否可达。我想检查的网址如下:https://mydomain.se:8081/，也可以通过互联网访问。但遇到问题，因为下面的方法有时返回 true，有时返回 false。

  public boolean isBackendAccessAble(String serverUrl) {
    String host = serverUrl.substring(serverUrl.indexOf("://") + 3, serverUrl.lastIndexOf(":"));
    int port = Integer.parseInt(serverUrl.substring(serverUrl.lastIndexOf(":") + 1, serverUrl.length() - 1));
    boolean isReachable = false;
    try {
        SocketAddress sockAddress = new InetSocketAddress(host, port);
        Socket sock = new Socket();
        int timeoutMs = 2000; // 2 seconds
        sock.connect(sockAddress, timeoutMs);
        isReachable = true;
    } catch (Exception e) {
        Log.w(TAG, "Unable to check serverUrl:" +   serverUrl);
    }
    return isReachable;
}

还有其他替代方法可以通过移动数据从 Android 检查服务器吗？

Answer 1

 public boolean isBackendAccessAble(String serverUrl) {
    String host = serverUrl.substring(serverUrl.indexOf("://") + 3, serverUrl.lastIndexOf(":"));
    int port = Integer.parseInt(serverUrl.substring(serverUrl.lastIndexOf(":") + 1, serverUrl.length() - 1));
    boolean isReachable = false;
    try {
        SocketAddress sockAddress = new InetSocketAddress(host, port);
        Socket sock = new Socket();
        int timeoutMs = 2000; // 2 seconds
        sock.connect(sockAddress, timeoutMs);
        isReachable = true;
    } catch (Exception e) {
        Log.w(TAG, "Unable to check serverUrl:" +   serverUrl);
 if (e instanceof SocketTimeoutException ){
   //the url is not reachable
isReachable=false;
 }
    }
    return isReachable;
}