Using ThreadLocal to cache data in Request scope

/** * aim to cache the data that‘s accessed frequently and costly. * @param <K> * @param <V> */public interface Cache<K,V> { V get(K k); void put(K k, V v); void clean(); int size();}

/** *this class is a implementor from Cache.and It caches data in thread local. * @see Cache * @see ThreadLocal */public class threadlocalcache<k,v> implements cache<k,v>{private Threadl    ocal<map<k,v>> threadLocal = new threadlocal<> ();    Public threadlocal<map<k, V>> getthreadlocal () {return ThreadLocal;    } public void Setthreadlocal (threadlocal<map<k, v>> ThreadLocal) {this.threadlocal = ThreadLocal;        } private Map<k, v> Getthreadlocalmap () {map<k, v> Map = getthreadlocal (). get ();            if (map = = null) {map = new HashMap ();        Getthreadlocal (). Set (map);    } return map;        } protected void Cleanthreadlocal () {map<k, v> Map = getthreadlocal (). get ();        if (map! = null) map.clear ();    Getthreadlocal (). remove ();        } private int sizethreadlocal () {map<k, v> Map = Threadlocal.get (); return map = = Null?    0:map.size ();    } @Override public V get (k k) {return Getthreadlocalmap (). get (k);    } @Override public void put (k K, v V) {getthreadlocalmap (). put (K,V);    } @Override public void Clean () {cleanthreadlocal ();    } @Override public int size () {return sizethreadlocal (); }}

 /** * This class was to create a threadLocal through Factory. * @see threadlocalfactory * @see com.pretang.cl Oud.service.agent.AgentRpcService */public class Factorythreadlocalcache<k,v> extends Threadlocalcache<k,v        > {public Factorythreadlocalcache () {super ();    Super.setthreadlocal (Threadlocalfactory.getthreadlocal ()); }}

 /** * This class is a building ThreadLocal factory. And to manage the lifetime of the threadLocal.    * @see Factorythreadlocalcache */public abstract class Threadlocalfactory {//a sharing ThreadLocal in heap.    private static final ThreadLocal ThreadLocal = new ThreadLocal ();     /** * Get a threadLocal instance.    * @return */public static ThreadLocal getthreadlocal () {return ThreadLocal; }/** * Clean the threadLocal */public static void Cleanthreadlocal () {Object obj = Threadlocal.get (        );        if (null! = obj && obj instanceof Collection) ((Collection) obj). Clear ();    Threadlocal.remove (); }}

@Component@WebFilterpublic class CustomerFilter implements Filter {    @Override    public void init(FilterConfig filterConfig) throws ServletException {    }    @Override    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {        filterChain.doFilter(servletRequest,servletResponse);        // clean the variables in threads for a request        ThreadLocalFactory.cleanThreadLocal();    }    @Override    public void destroy() {    }}

    private static final Cache<Integer, AgentDto> agentDtoCache = new FactoryThreadLocalCache<>();    private static final Cache<Integer, AgentUser> agentUserCache = new FactoryThreadLocalCache<>();

Using ThreadLocal to cache data in Request scope