android Uri.Buildr 与string 互转

转自：http://dai-lm.iteye.com/blog/1631526

Uri.Builder -> String

Uri.Builder builder = new Uri.Builder();
builder.encodedPath("http://xxx.xxx.xxx.xxx:xxxx");
builder.appendEncodedPath("xxx/xxx/xxx");
builder.appendQueryParameter("key", "value");

String url = builder.toString();

String -> Uri.Builder

Uri.Builder builder = Uri.parse(url).buildUpon();