Question

我有占位符网站的压缩网址（http://placehold.it/600/24f355）。如何从Android中的压缩网址获取完整的网址（https://placeholdit.imgix.net/~text?txtsize=56&bg=24f355&txt=600%C3%97600&w=600&h=600）？

我尝试了以下内容，但我得到了相同的网址。

public static void main(String[] args) {
String shortURL = "http://placehold.it/600/24f355";

System.out.println("Short URL: " + shortURL);
URLConnection urlConn = connectURL(shortURL);
urlConn.getHeaderFields();
System.out.println("Original URL: " + urlConn.getURL());
}

static URLConnection connectURL(String strURL) {
    URLConnection conn = null;
    try {
        URL inputURL = new URL(strURL);
        conn = inputURL.openConnection();
    } catch (MalformedURLException e) {
        System.out.println("Please input a valid URL");
    } catch (IOException ioe) {
        System.out.println("Can not connect to the URL");
    }
    return conn;
}

Answer 1

如this article中所述，您需要检查响应代码（conn.getResponseCode()），如果它是3xx（=重定向），您可以从＆＃34;中获取新的URL。位置和＃34;标题字段。

String newUrl = conn.getHeaderField("Location");

Answer 2

试试这个：

public static void main(String[] args) throws IOException {
    URL address=new URL("your short URL");


    //Connect & check for the location field
    HttpURLConnection connection = null;
    try {
        connection = (HttpURLConnection) address.openConnection(Proxy.NO_PROXY);
        connection.setInstanceFollowRedirects(false);
        connection.connect();
        String expandedURL = connection.getHeaderField("Location");
        if(expandedURL != null) {
            URL expanded = new URL(expandedURL);
            address= expanded;
        }
    } catch (Throwable e) {
        System.out.println("Problem while expanding {}"+ address+ e);
    } finally {
        if(connection != null) {
            System.out.println(connection.getInputStream());
        }
    }

    System.out.println("Original URL"+address);
}

如何从Android中的压缩URL获取完整的URL？

2 个答案: