如何在 Android 上获取重定向 URL？ [复制]

Question

我可以用这段代码在java中做到这一点：

  String url = "http://t.co/i5dE1K4vSs";

  URLConnection conn = new URL( url ).openConnection();
  System.out.println( "orignal url: " + conn.getURL() );
  conn.connect();
  System.out.println( "connected url: " + conn.getURL() );
  InputStream inputS = conn.getInputStream();
  System.out.println( "redirected url: " + conn.getURL() );
  inputS.close();

现在在 android 中，当单击按钮时，它会调用：

public void followRedirects(View v) throws ClientProtocolException, IOException, URISyntaxException
{
  String url = "http://t.co/i5dE1K4vSs";

  URLConnection conn = new URL( url ).openConnection();
  System.out.println( "orignal url: " + conn.getURL() );
  conn.connect();
  System.out.println( "connected url: " + conn.getURL() );
  InputStream inputS = conn.getInputStream();
  System.out.println( "redirected url: " + conn.getURL() );
  inputS.close();
}

这是我在android中的错误日志

Answer 1

如您所见，最底部的例外是NetworkOnMainThreadException。为确保性能，Android SDK 会阻止开发人员（及其应用程序）在主 (UI) 线程上进行非本地连接及其操作。您可以使用您发布的相同代码 sn-p，您只需要确保它在非 UI 线程上运行。

例如

new Thread(new Runnable() {
    @Override
    public void run() {
        followRedirects(null);
    }
}).start();

或者如果您希望它在点击时执行：

 public void followRedirects(View v) throws ClientProtocolException, IOException, URISyntaxException
{
  new Thread(new Runnable() {
    @Override
    public void run() {
        String url = "http://t.co/i5dE1K4vSs";

        URLConnection conn = new URL( url ).openConnection();
        System.out.println( "orignal url: " + conn.getURL() );
        conn.connect();
        System.out.println( "connected url: " + conn.getURL() );
        InputStream inputS = conn.getInputStream();
        System.out.println( "redirected url: " + conn.getURL() );
        inputS.close();
    }
  }).start();
}