慕课网 小慕机器人总结

1.向第三方API发起请求，解析返回数据

public class HttpUtil {
	public static ChatMessage sendMessage(String msg) {
		ChatMessage message = new ChatMessage();
		String jsonStr = doGet(msg);
		Gson gson = new Gson();
		try {

			//gson解析XML，转成对象，需要gson.jar包
			Result result = gson.fromJson(jsonStr, Result.class);
			message.setMsg(result.getText());
		} catch (JsonSyntaxException e) {
			message.setMsg("服务器繁忙，请稍后再试。");
		}
		message.setDate(new Date());
		message.setType(Type.ANSWER);

		return message;
	}

	public static String doGet(String msg) {
		String url = "";
		String result = "";
		try {
			url = "http://www.tuling123.com/openapi/api?key=87f43665ef51fe960fd4d3950ec021ad&info="
					+ URLEncoder.encode(msg, "utf-8");
		} catch (Exception e) {
			e.printStackTrace();
		}
		InputStream is = null;
		ByteArrayOutputStream baos = null;
		try {
			URL urlNet = new URL(url);// 获得url地址
			HttpURLConnection conn = (HttpURLConnection) urlNet
					.openConnection();// 通过url获得连接
			conn.setReadTimeout(3000);// 设置读数据的时限
			conn.setConnectTimeout(3000);// 设置连接时限
			conn.setRequestMethod("GET");// 设置请求连接方式

			is = conn.getInputStream();
			baos = new ByteArrayOutputStream();
			int len = -1;
			byte[] buf = new byte[128];
			while ((len = is.read(buf)) != -1) {
				baos.write(buf, 0, len);
			}
			result = new String(baos.toByteArray());

		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				if (baos != null) {
					baos.close();
				}
				if (is != null) {
					is.close();
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return result;
	}
}

2.listview+adapter+数据源

public class ChatMessageAdapter extends BaseAdapter {
	private LayoutInflater mInflater;// 布局压榨器，需要上下文对象来获得
	private List<ChatMessage> mData;
	//从activity中传来的context，数据源来初始化这两个必备成员变量
	public ChatMessageAdapter(Context context, List<ChatMessage> mData) {
		mInflater = LayoutInflater.from(context);
		this.mData = mData;
	}

	// 集合的总个数
	@Override
	public int getCount() {
		return mData.size();
	}

	// 获取mData中的对象
	@Override
	public Object getItem(int pos) {
		return mData.get(pos);
	}

	// mData中对象的下标
	@Override
	public long getItemId(int pos) {
		return pos;
	}
////////////////////////////////////////////////////////
这两个方法是listview中有两种/两种以上的item时，用到的
	@Override
	public int getViewTypeCount() {
		return 2;
	}

	@Override
	public int getItemViewType(int pos) {
		return mData.get(pos).getType() == Type.ANSWER ? 0 : 1;
	}
////////////////////////////////////////////////////////
	@Override
	public View getView(int pos, View view, ViewGroup parent) {
		ChatMessage message = mData.get(pos);
		ViewHolder holder = null;// 布局中要更改的值
		if (view == null) {// 当view为空时，创建view
			holder = new ViewHolder();
			// 通过ItemType
			if (getItemViewType(pos) == 0) {
				//把XML压成布局
				view = mInflater.inflate(R.layout.layout_answer, parent, false);
				holder.mDate = (TextView) view
						.findViewById(R.id.tv_answer_date);
				holder.mMsg = (TextView) view.findViewById(R.id.tv_answer_msg);
			} else {
				view = mInflater.inflate(R.layout.layout_send, parent, false);
				holder.mDate = (TextView) view.findViewById(R.id.tv_send_date);
				holder.mMsg = (TextView) view.findViewById(R.id.tv_send_msg);
			}
			view.setTag(holder);//给view设置tag,
		} else {
			holder = (ViewHolder) view.getTag();//从view中得到，tag
		}
		// 设置数据，时间的处理！！！！！   积累呀！！！
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		holder.mDate.setText(sdf.format(message.getDate()));
		holder.mMsg.setText(message.getMsg());

		return view;
	}

	// 布局中要修改的值，建立一个对象
	private final class ViewHolder {
		TextView mDate;
		TextView mMsg;
	}
}
3.activity中的写法
public class MainActivity extends Activity {
	// 适配器的三个必备,ListView/adapter/lists
	private ListView mLvMsgs;
	private ChatMessageAdapter mAdapter;
	private List<ChatMessage> mDatas;

	private EditText mEtInput;
	private Button mBtnSend;

	// 等待接收，子线程完成数据的返回
	//把线程中的要处理的东西放到handler中，分离声明和处理
	private Handler mHandler = new Handler() {
		public void handleMessage(Message msg) {
			ChatMessage message = (ChatMessage) msg.obj;
			mDatas.add(message);
			mAdapter.notifyDataSetChanged();//通知adapter更新！！！
			mLvMsgs.setSelection(mDatas.size() - 1);// 最后一个被选中
		}
	};

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		inti();
		initDatas();
		registeListener();

	}

	private void registeListener() {
		mBtnSend.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				final String sendMsg = mEtInput.getText().toString();
				if (TextUtils.isEmpty(sendMsg)) {
					Toast.makeText(MainActivity.this, "消息不能为空",
							Toast.LENGTH_SHORT).show();
					return;
				}
				ChatMessage sendMessage = new ChatMessage(sendMsg, Type.SEND,
						new Date());
				mDatas.add(sendMessage);
				mAdapter.notifyDataSetChanged();
				mLvMsgs.setSelection(mDatas.size() - 1);

				mEtInput.setText("");
				new Thread() {
					public void run() {
						ChatMessage answerMessage = HttpUtil
								.sendMessage(sendMsg);
						Message m = Message.obtain();//Handler处理的Message的对象,静态方法获得
						m.obj = answerMessage;//把要处理的对象装到message的obj中
						// 创建线程和处理分开
						mHandler.sendMessage(m);//交给Handler处理
					}

				}.start();
			}
		});
	}

	public void inti() {
		mLvMsgs = (ListView) findViewById(R.id.lv_main);
		mEtInput = (EditText) findViewById(R.id.et_input);
		mBtnSend = (Button) findViewById(R.id.btn_send);
	}

	public void initDatas() {
		mDatas = new ArrayList<ChatMessage>();
		mDatas.add(new ChatMessage("你好，小慕为您服务", Type.ANSWER, new Date()));
		mAdapter = new ChatMessageAdapter(this, mDatas);
		mLvMsgs.setAdapter(mAdapter);//为listview绑定适配器
	}
}
4.单独说一下{（把XML转成对象，XML中结点的名字要与对象成员变量的名字一样，利用gson.jar包），
		（java中的enum，枚举类型
		public enum Type {
		    SEND, ANSWER
		}
		在没有枚举类型之前，我们定义常量都是public static final ...,比较不方便，是同一类型的，却还要单独定义....
		有了enum就好了，可以定义在一个枚举类型中了。注意！！！ 如上，SEND和ANSWER并不像是C/C++中是从0开始的，它就是它自己！
		更详细的可以参考：http://www.cnblogs.com/happyPawpaw/archive/2013/04/09/3009553.html
）}