nutz中实现多数据库切换
nutz很好的实现了表切换
根据它的思路写了个数据库切换，测试可行！

public class DataSourceNames {private static final ThreadLocal<String> ds = new ThreadLocal<String>();public static String get() {return ds.get();}public static String set(String obj) {String re = get();ds.set(obj);return re;}public static void clear() {set(null);}}