Okhttp3实现爬取验证码及获取Cookie的示例

compile'com.squareup.okhttp3:okhttp:3.5.0

<uses-permissionandroid:name="android.permission.INTERNET" />

  /**
   * 初始化验证码
   */
  public void initCode(){
    Request request = new Request.Builder().url(eduBean.getCodeUrl()).build();
    Call call = okHttpClient.newCall(request);
    call.enqueue(new Callback() {
      @Override
      public void onFailure(Call call, IOException e) {
//        showToast("验证码加载失败");
      }
      @Override
      public void onResponse(Call call, Response response) throws IOException {
        byte[] byte_image = response.body().bytes();
        //通过handler更新UI
        Message message = handler.obtainMessage();
        message.obj = byte_image;
        message.what = 1;
        handler.sendMessage(message);
        //获取session的操作，session放在cookie头，且取出后含有“；”，取出后为下面的 s （也就是jsesseionid）
        Headers headers = response.headers();
//        Log.d("info_headers", "header " + headers);
        List<String> cookies = headers.values("Set-Cookie");
        String session = cookies.get(0);
//        Log.d("info_cookies", "onResponse-size: " + cookies);
        String sessionID = session.substring(0, session.indexOf(";"));
        eduBean.setSessionID(sessionID);
//        Log.i("info_s", "session is :" + sessionID);
      }
    });
  }

public Handler handler = new Handler(){
    public void handleMessage(Message msg){
      switch (msg.what){
        case 1:
            //加载网络成功进行UI的更新,处理得到的图片资源
            //通过message，拿到字节数组
            byte[] Picture = (byte[]) msg.obj;
            //使用BitmapFactory工厂，把字节数组转化为bitmap
            Bitmap bitmap = BitmapFactory.decodeByteArray(Picture, 0, Picture.length);
            //通过imageview，设置图片
            iv_code.setImageBitmap(bitmap);//ImageView 显示验证码的组件
            break;
      }
    }