Tag: URL

Explicit Intent with URL

Open a third party app to view a webpage using implicit Intent.

    private void openWebPage(String url) {
        /*
         * We wanted to demonstrate the Uri.parse method because its usage occurs frequently. You
         * could have just as easily passed in a Uri as the parameter of this method.
         */
        Uri webpage = Uri.parse(url);

        /*
         * Here, we create the Intent with the action of ACTION_VIEW. This action allows the user
         * to view particular content. In this case, our webpage URL.
         */
        Intent intent = new Intent(Intent.ACTION_VIEW, webpage);

        /*
         * This is a check we perform with every implicit Intent that we launch. In some cases,
         * the device where this code is running might not have an Activity to perform the action
         * with the data we've specified. Without this check, in those cases your app would crash.
         */
        if (intent.resolveActivity(getPackageManager()) != null) {
            startActivity(intent);
        }
    }

Build a URL with Uri Builder includes HttpURLConnection function

URL is a specific class of Uri. Use the following function to compile a valid URL. HttpURLConnection will require this when making a connection.

Method to build URL

    final static String BASE_URL =
            "https://api.github.com/search/repositories"; // Query the GitHub repositories
    final static String PARAM_QUERY = "q";
    final static String PARAM_SORT = "sort";
    final static String sortBy = "stars"; // Sorted by the number of stars the repo has

    public static URL buildUrl(String searchQuery) {
        Uri builtURI = Uri.parse(BASE_URL)
                .buildUpon()
                .appendQueryParameter(PARAM_QUERY, searchQuery)
                .appendQueryParameter(PARAM_SORT, sortBy)
                .build();
        try {
            URL url = new URL(builtURI.toString());
            Log.d("buildUrl produced URL ", url.toString()); // Produces URL: https://api.github.com/search/repositories?q=android&sort=stars
            return url;
        } catch (MalformedURLException e) {
            e.printStackTrace();
            Log.d("buildUrl", "Exception thrown");
        }
        return null;
    }



A typical helper method for fetching the results of the query based on the URL.


    public static String getResponseFromHttpUrl(URL url) throws IOException {
        HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
        try {
            InputStream in = urlConnection.getInputStream();

            Scanner scanner = new Scanner(in);
            scanner.useDelimiter("\\A"); // \A represents the beginning of the stream. Forces the scanner to read the entire contents of the stream
// It buffers the data and also converts the stream from UTF-8 (JSON/JS) to UTF-16 (which Android uses)
            boolean hasInput = scanner.hasNext();
            if (hasInput) {
                return scanner.next();
            } else {
                return null;
            }
        } finally {
            urlConnection.disconnect();
        }
    }



ud851-Exercises-student\Lesson02-GitHub-Repo-Search\T02.06-Exercise-AddPolish