/**
* 获取一个类的某个一个泛型参数
*
* @param klass 类
* @param index 参数下标 （从 0 开始）
* @return 泛型参数类型
*/
@SuppressWarnings("unchecked")
public static <T> Class<T> getTypeParam(Class<?> klass, int index) {
Type[] types = extractTypeParams(klass);
if (index >= 0 && index < types.length) {
Type t = types[index];
Class<T> tClass = (Class<T>) LE.asClass(t);
if (tClass == null) throw LE.makeThrow("Type '%s' is not a Class", t.toString());
return tClass;
}
throw LE.makeThrow("Class type param out of range %d/%d", index, types.length);
}
private static <T extends Map<Object, Object>> Map<Object, Object> createMap(Class<T> mapClass) {
Map<Object, Object> map;
try {
map = mapClass.newInstance();
} catch (Exception e) {
map = new HashMap<Object, Object>();
}
if (!mapClass.isAssignableFrom(map.getClass())) {
throw LE.makeThrow("Fail to create map [%s]", mapClass.getName());
}
return map;
}