状态模式

[img]http://dl2.iteye.com/upload/attachment/0117/5733/460dfb3c-45ab-375a-9054-866e774e819b.png[/img]

package pattern;
public interface VoteState {

    public void vote(String user, String voteItem, VoteManager manager);
}


package pattern;
public class BlackVoteState implements VoteState {
    @Override
    public void vote(String user, String voteItem, VoteManager manager) {
        System.out.println("你进入了黑名单。");
    }
}


package pattern;
public class NormalVoteState implements VoteState {
    @Override
    public void vote(String user, String voteItem, VoteManager manager) {
        manager.getMapVote().put(user, voteItem);
        System.out.println("投票成功！");
        manager.getMapState().put(user, new RepeatVoteState());
    }
}

package pattern;
public class RepeatVoteState implements VoteState {
    @Override
    public void vote(String user, String voteItem, VoteManager manager) {
    	System.out.println("请不要重复投票。");

        if (manager.getMapVoteCount().get(user) >= 4) {
            manager.getMapState().put(user, new SpiteVoteState());
        }
    }
}


package pattern;
public class SpiteVoteState implements VoteState {
    @Override
    public void vote(String user, String voteItem, VoteManager manager) {
        String s = manager.getMapVote().get(user);

        if (s != null) {
            manager.getMapVote().remove(user);
        }

        System.out.println("你有恶意刷票行为，取消投票资格。");

        if (manager.getMapVoteCount().get(user) >= 7) {
            manager.getMapState().put(user, new BlackVoteState());
        }
    }
}

package pattern;
import java.util.HashMap;
import java.util.Map;

public class VoteManager {

	  /**
	   * 记录当前每个用户对应的状态处理对象，每个用户当前的状态是不同的
	   * Map<String, VoteState>对应Map<用户名，当前对应的状态处理对象>
	   */
	  private Map<String, VoteState> mapState = new HashMap<String, VoteState>();

	  /**
	   * 记录用户投票的结果，Map<String,String>对应Map<用户名，投票的选项>
	   */
	  private Map<String, String> mapVote = new HashMap<String, String>();

	  /**
	   * 记录用户投票次数，Map<String,Integer> 对应Map<用户名，投票的次数>
	   */
	  private Map<String, Integer> mapVoteCount = new HashMap<String, Integer>();

	  /**
	   * 获取记录用户投票结果的Map
	   * @return 记录用户投票结果的Map
	   */
	  public Map<String, String> getMapVote() {
	            return mapVote;
	  }

	  /**
	   * 获取记录当前每个用户对应的状态处理对象
	   * @return
	   */
	  public Map<String, VoteState> getMapState() {
	            return mapState;
	  }

	  /**
	   * 获取记录每个用户对应的投票次数的Map
	   * @return
	   */
      public Map<String, Integer> getMapVoteCount() {
          return mapVoteCount;
      }

      public void vote(String user, String voteItem){
          Integer oldVoteCount = mapVoteCount.get(user);
          if(oldVoteCount == null){
              oldVoteCount = 0;
          }
          oldVoteCount++;
          mapVoteCount.put(user, oldVoteCount);

          VoteState state = mapState.get(user);
          if(state == null){
              state = new NormalVoteState();
          }
          state.vote(user, voteItem, this);
      } 
}

package pattern;
public class Client {
    public static void main(String[] args) {
        VoteManager manager = new VoteManager();

        for (int i = 0; i < 8; i++) {
            manager.vote("JOE", "A");
        }
    }
}