Is there a right way to build a URL? [duplicate]

You can use Apache URIBuilder

Sample code: Full Apache Example

URIBuilder builder = new URIBuilder()
    .setScheme("http")
    .setHost("apache.org")
    .setPath("/shindig")
    .addParameter("helloWorld", "foo&bar")
    .setFragment("foo");
builder.toString();

Output: http://apache.org/shindig?helloWorld=foo%26bar#foo