Question

in twitter-compatible API what is setAPIRootURL value ?

 twitter=new Twitter("username","password");
 twitter.setAPIRootUrl("http://yamba.marakana.com/api");

JTwitter library home page

Answer 1

This just points to the api endpoint of your twitter compatible service.

Actual queries then go “below that” like http://yamba.marakana.com/api/timeline/home.json etc.
This Marakana is a public Twitter-like service based on status.net.
Others are identi.ca (api endpoint is http://identi.ca/api/ ) and so on.

As Daniel wrote, Twitter is the default. The javadoc for setAPIRootUrl says:

/**
 * Set this to access sites other than Twitter that support the Twitter API.
 * E.g. WordPress or Identi.ca. Note that not all methods may work! Also,
 * search uses a separate url and is not affected by this method (it will
 * continue to point to Twitter).
 * 
 * @param url
 *            Format: "http://domain-name", e.g. "http://twitter.com" by
 *            default.
 */
public void setAPIRootUrl(String url) {

So basically to connect to Twitter you don’t need to care about that method.