BlockOutputBuilder.java

package com.sissi.pipeline.out;

import java.util.HashSet;
import java.util.Set;

import com.sissi.context.JID;
import com.sissi.context.JIDBuilder;
import com.sissi.context.JIDContext;
import com.sissi.pipeline.Output;
import com.sissi.pipeline.OutputBuilder;
import com.sissi.protocol.Element;
import com.sissi.protocol.iq.IQ;
import com.sissi.protocol.message.Message;
import com.sissi.protocol.presence.Presence;
import com.sissi.ucenter.block.BlockContext;

/**
 * 黑名单策略
 * 
 * @author kim 2013年12月9日
 */
abstract class BlockOutputBuilder implements OutputBuilder {

	private final Set<Class<? extends Element>> blockSupports = new HashSet<Class<? extends Element>>();

	private final BlockContext context;

	protected final JIDBuilder jidBuilder;

	public BlockOutputBuilder(BlockContext context, JIDBuilder jidBuilder) {
		super();
		this.context = context;
		this.jidBuilder = jidBuilder;
		this.blockSupports.add(Presence.class);
		this.blockSupports.add(Message.class);
		this.blockSupports.add(IQ.class);
	}

	abstract protected class BlockOutput implements Output {

		@Override
		public boolean output(JIDContext context, Element node) {
			JID applicant = this.applicant(context.jid(), node);
			if (this.isEmpty(context.jid(), applicant) || !BlockOutputBuilder.this.blockSupports.contains(node.getClass())) {
				return true;
			}
			return !BlockOutputBuilder.this.context.isBlock(this.verifier(context.jid(), node), applicant);
		}

		/**
		 * 请求者
		 * 
		 * @param current
		 * @param node
		 * @return
		 */
		abstract protected JID applicant(JID current, Element node);

		/**
		 * 校验者
		 * 
		 * @param current
		 * @param node
		 * @return
		 */
		abstract protected JID verifier(JID current, Element node);

		private boolean isEmpty(JID jid) {
			return (jid == null || jid.user() == null);
		}

		private boolean isEmpty(JID user, JID contact) {
			return this.isEmpty(user) || this.isEmpty(contact);
		}

		@Override
		public Output close() {
			return this;
		}
	}
}