HTTP URL Address Encoding in Java

Question

My Java standalone application gets a URL (which points to a file) from the user and I need to hit it and download it. The problem I am facing is that I am not able to encod

Answer 1

If you have a URL, you can pass url.toString() into this method. First decode, to avoid double encoding (for example, encoding a space results in %20 and encoding a percent sign results in %25, so double encoding will turn a space into %2520). Then, use the URI as explained above, adding in all the parts of the URL (so that you don't drop the query parameters).

public URL convertToURLEscapingIllegalCharacters(String string){
    try {
        String decodedURL = URLDecoder.decode(string, "UTF-8");
        URL url = new URL(decodedURL);
        URI uri = new URI(url.getProtocol(), url.getUserInfo(), url.getHost(), url.getPort(), url.getPath(), url.getQuery(), url.getRef()); 
        return uri.toURL(); 
    } catch (Exception ex) {
        ex.printStackTrace();
        return null;
    }
}