Apache Solr Search show only currrent user language
One way to do this is to implement hook_apachesolr_query_alter() to automatically filter on the current language. In a custom module called "mymodule", the code snippet would look similar to the following:

/**
 * Implement hook_apachesolr_query_alter()
 */
function mymodule_apachesolr_query_alter($query) {
  global $language;
  $query-&gt;addFilter("ss_language", $language-&gt;language);
}