ServletScopedContext.java

/*
 * Copyright 2013 eXo Platform SAS
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package juzu.impl.bridge.spi.servlet;

import juzu.impl.bridge.spi.ScopedContext;
import juzu.impl.common.Logger;
import juzu.impl.inject.Scoped;

import javax.servlet.http.HttpSessionBindingEvent;
import javax.servlet.http.HttpSessionBindingListener;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;

/**
 * <p></p>An helper class for managing scoped entries. It implements the {@link javax.servlet.http.HttpSessionBindingListener} interface
 * which invokes the {@link #close()} method when the servlet container invokes the {@link
 * #valueUnbound(javax.servlet.http.HttpSessionBindingEvent)} callback.</p> <p/> <p>At the moment we do not support
 * serialization.</p>
 *
 * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a>
 */
public class ServletScopedContext implements ScopedContext, HttpSessionBindingListener {

  /** . */
  private HashMap<Object, Scoped> state;

  /** . */
  private final Logger log;

  public ServletScopedContext(Logger log) {
    this.log = log;
  }

  public Scoped get(Object key) throws NullPointerException {
    if (key == null) {
      throw new NullPointerException("No null key accepted");
    }
    return state != null ? state.get(key) : null;
  }

  public void set(Object key, Scoped scoped) throws NullPointerException {
    if (key == null) {
      throw new NullPointerException("No null key accepted");
    }
    if (scoped == null) {
      if (state != null) {
        state.remove(key);
      }
    }
    else {
      if (state == null) {
        state = new HashMap<Object, Scoped>();
      }
      state.put(key, scoped);
    }
  }

  public int size() {
    return state != null ? state.size() : 0;
  }

  public Iterator<Scoped> iterator() {
    return state == null ? Collections.<Scoped>emptyList().iterator() : state.values().iterator();
  }

  public void valueBound(HttpSessionBindingEvent event) {
    // Nothing to do
  }

  public void valueUnbound(HttpSessionBindingEvent event) {
    close();
  }

  public void close() {
    if (state != null && state.size() > 0) {
      for (Iterator<Scoped> i = state.values().iterator();i.hasNext();) {
        Scoped scoped = i.next();
        i.remove();
        try {
          scoped.destroy();
        }
        catch (Throwable t) {
          log.info("Error when destroying object", t);
        }
      }
    }
  }
}