Android OKHTTP的单例和再封装的实例

/**
 * Created by zm on 16-2-1
 * okhttp的再封装,对于2.x版本，3.x版本将原有对okhttpclient配置
 * 改成了builder模式配
 * 置,对于超时、代理、dns，okhttp已经做好了配置，
 * 若不需要特殊配置，可以跳过
 */
public class OkHttpUtil
{
  private static OkHttpClient singleton;
  //非常有必要，要不此类还是可以被new，但是无法避免反射，好恶心
  private OkHttpUtil(){

  }
  public static OkHttpClient getInstance() {
    if (singleton == null)
    {
      synchronized (OkHttpUtil.class)
      {
        if (singleton == null)
        {
          singleton = new OkHttpClient();
        }
      }
    }
    return singleton;
  }
}

/**
 * okhttp再次封装
 * Created by zm on 16-2-1
 * update by zm on 16-3-19 增加Builder，方便以后内容或者字段的扩展
 * 
 */
public class HttpTools
{
  private Context context;
  private final RequestParams req;
  private final Handler handler;

  public HttpTools(Builder builder)
  {
    // TODO Auto-generated constructor stub
    context = builder.context;
    req = builder.req;
    handler = builder.handler;
  }

  public static class Builder
  {
    private final RequestParams req;
    private final Context context;
    private final Handler handler;

    public Builder(RequestParams req, Context mContext, Handler handler)
    {
      // TODO Auto-generated constructor stub
      this.req = req;
      this.context = mContext;
      this.handler = handler;
    }

    public HttpTools build() {
      return new HttpTools(this);
    }
  }

  public void requestBuilder() {
    // TODO Auto-generated method stub
    if(req==null||context==null||handler==null){
      throw new NullPointerException("NullPointerException");
    }
    requestGet(req, context, handler);
  }

  private static void parse(Call call, final Handler handler,
      final RequestParams req) {
    // 请求加入调度
    call.enqueue(new Callback()
    {
      @Override
      public void onResponse(Call call, Response response)
          throws IOException {
        // TODO Auto-generated method stub
        String result = response.body().string();
        if (result != null)
        {
          Message message = Message.obtain();
          message.obj = result;
          message.what = req.getSuccessMsgWhat();
          handler.sendMessage(message);
        }
      }

      @Override
      public void onFailure(Call call, IOException e) {
        // TODO Auto-generated method stub
        handler.sendEmptyMessage(req.getFailMsgWhat());
      }
    });
  }

  /**
   * 
   * @param req
   * @param context
   * @param handler
   * 
   *      get请求
   */
  public static void requestGet(final RequestParams req,
      final Context context, final Handler handler) {
    // 创建一个Request
    final Request request = new Request.Builder().url(req.getRequestUrl()).build();
    Call call = OkHttpUtil.getInstance().newCall(request);
    parse(call, handler, req);
  }

  /**
   * post请求
   */
  public static void requestPost(final RequestParams req,
      final Context context, final Handler handler) {
    FormBody.Builder builder = new FormBody.Builder();
    //此处是对RequestParams的遍历，RequestParams类省略
    for (Map.Entry<String, Object> mEntry : req.getParamEntry())
    {
      String mEntryKey = mEntry.getKey();
      Object mEntryValue = mEntry.getValue();
      if (TextUtils.isEmpty(mEntryKey))
      {
        continue;
      }
      builder.add(mEntryKey, mEntryValue.toString());
    }
    RequestBody body = builder.build();
    Request request = new Request.Builder().url(req.getUrl()).post(body).build();

    Call call = OkHttpUtil.getInstance().newCall(request);
    parse(call, handler, req);
  }

  /**
   *      数据请求的集中管理，方便以后一键替换，从get到post
   */
  public static void request(RequestParams req, Context mContext,
      Handler handler) {
    // TODO Auto-generated method stub
    requestGet(req, mContext, handler);
  }
}

/**
 * 
 * Created by zm on 16-2-1
 * 基于Gson的json转model封装类
 *
 */
public class JsonToModel
{

private static String info = "info";

  public static String getInfo()
  {
    return info;
  }

  public static void setInfo(String info)
  {
    JsonToModel.info = info;
  }
  /**
   * 
   * @param msg
   * @param t
   *      model类
   * @param model
   *      model对象
   * @return
   */
  public static <T> List<T> getJsonArrayToModel(Message msg, Class<T> t,
      T model) {
    // TODO Auto-generated method stub
    List<T> list = new ArrayList<T>();
    try {
      JSONObject json = new JSONObject(msg.obj.toString());
      for (int i = 0; i < json.getJSONArray(getInfo()).length(); i++) {
        model = GsonHelper.toType(json.getJSONArray(getInfo()).get(i).toString(), t);
        list.add(model);
      }
      return list;
    } catch (Exception e) {
      // TODO Auto-generated catch block
      Log.e("getJsonArrayToModel", "error");
      e.printStackTrace();
    }
    return null;
  }
}