Java 如果在Android中注册成功，我如何进入登录活动？

服务器端的一切都正常工作。我的问题是，如果HTTP响应为“注册成功”，我不确定如何返回登录页面

我的Login和Register类都依赖于BackgroundTask来处理异步操作

下面是BackgroundTask的代码

public class BackgroundTask extends AsyncTask<String, Void, String> {
    AlertDialog mAlertDialog;
    Context context;
    private CheckTask mCheckTask;


    BackgroundTask(Context context, Boolean login, Boolean register) {
        this.context = context;
        mCheckTask = new CheckTask(login, register);
    }

    @Override
    protected String doInBackground(String... params) {

        String reg_url = "http://www.myegotest.com/register.php";
        String login_url = "http://www.myegotest.com/login.php";

        ////////////////////////REGISTER SCRIPT/////////////////////////////
        if (mCheckTask.getIsRegisterTask()) {
            String first_name = params[0];
            String last_name = params[1];
            String username = params[2];
            String password = params[3];
            try {
                //Set the URL we are working with
                URL url = new URL(reg_url);

                //Open a url connection and set params for the url connection
                HttpURLConnection LucasHttpURLConnection = (HttpURLConnection) url.openConnection();
                LucasHttpURLConnection.setRequestMethod("POST");
                LucasHttpURLConnection.setDoOutput(true);
                LucasHttpURLConnection.setDoInput(true);
                //Retrieve the output stream
                OutputStream os = LucasHttpURLConnection.getOutputStream();
                //Create a buffered writer to write the data to the output stream output stream.
                BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
                //Encode Data we are sending on the output stream
                String data = URLEncoder.encode("first_name", "UTF-8") + "=" + URLEncoder.encode(first_name, "UTF-8") + "&" +
                                      URLEncoder.encode("last_name", "UTF-8") + "=" + URLEncoder.encode(last_name, "UTF-8") + "&" +
                                      URLEncoder.encode("username", "UTF-8") + "=" + URLEncoder.encode(username, "UTF-8") + "&" +
                                      URLEncoder.encode("password", "UTF-8") + "=" + URLEncoder.encode(password, "UTF-8");
                //Write the data to the output stream, and close buffered writer
                bufferedWriter.write(data);
                bufferedWriter.flush();
                bufferedWriter.close();
                //Close output stream
                os.close();
                //InputStream to get response
                InputStream IS = LucasHttpURLConnection.getInputStream();
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(IS, "iso-8859-1"));
                String response = "";
                String line;
                while ((line = bufferedReader.readLine()) != null) {
                    response += line;
                }
                bufferedReader.close();
                IS.close();
                //LucasHttpURLConnection.disconnect();
                return response;
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            //////////////////////////////////LOGIN SCRIPT/////////////////////////////////////////
        } else if (mCheckTask.getIsLoginTask()) {
            String username = params[0];
            String password = params[1];
            try {
                URL url = new URL(login_url);
                HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
                httpURLConnection.setRequestMethod("POST");
                httpURLConnection.setDoOutput(true);
                httpURLConnection.setDoInput(true);
                OutputStream outputStream = httpURLConnection.getOutputStream();
                BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
                String data = URLEncoder.encode("username", "UTF-8") + "=" + URLEncoder.encode(username, "UTF-8") + "&" +
                                      URLEncoder.encode("password", "UTF-8") + "=" + URLEncoder.encode(password, "UTF-8");
                bufferedWriter.write(data);
                bufferedWriter.flush();
                bufferedWriter.close();
                outputStream.close();
                //InputStream to get response
                InputStream IS = httpURLConnection.getInputStream();
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(IS, "iso-8859-1"));
                String response = "";
                String line;
                while ((line = bufferedReader.readLine()) != null) {
                    response += line;
                }
                bufferedReader.close();
                IS.close();
                httpURLConnection.disconnect();
                return response;

            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    @Override
    protected void onPreExecute() {
        if (mCheckTask.getIsLoginTask()) {
            mAlertDialog = new AlertDialog.Builder(context).create();
            mAlertDialog.setTitle("Login Information... ");
        } else {
            mAlertDialog = new AlertDialog.Builder(context).create();
            mAlertDialog.setTitle("Register Information... ");
        }
    }

    @Override
    protected void onProgressUpdate(Void... values) {
        super.onProgressUpdate(values);
    }

    @Override
    protected void onPostExecute(String result) {
        if (result.equals("Please choose another username")) {
            mAlertDialog.setMessage(result);
            mAlertDialog.setButton("Ok", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {
                }
            });
            mAlertDialog.show();

        } else if (result.equals("Registration success!")) {
            mAlertDialog.setMessage(result);
            mAlertDialog.setButton("Ok", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {

                }
            });
            mAlertDialog.show();
        } else {
            mAlertDialog.setMessage(result);
            mAlertDialog.show();
        }
    }
}

公共类BackgroundTask扩展了AsyncTask{
AlertDialog-mAlertDialog；
语境；
私有检查任务mCheckTask；
背景任务（上下文、布尔登录、布尔寄存器）{
this.context=上下文；
mCheckTask=新的检查任务（登录、注册）；
}
@凌驾
受保护的字符串doInBackground（字符串…参数）{
字符串注册表url=”http://www.myegotest.com/register.php";
字符串登录\u url=”http://www.myegotest.com/login.php";
////////////////////////注册脚本/////////////////////////////
if（mCheckTask.getIsRegisterTask（））{
字符串first_name=params[0]；
字符串last_name=params[1]；
字符串username=params[2]；
字符串密码=参数[3]；
试一试{
//设置我们正在使用的URL
URL=新URL（注册URL）；
//打开url连接并设置url连接的参数
HttpURLConnection lucashttppurlconnection=（HttpURLConnection）url.openConnection（）；
LucasHttpURLConnection.setRequestMethod（“POST”）；
LucasHttpURLConnection.setDoOutput（true）；
LucasHttpURLConnection.setDoInput（true）；
//检索输出流
OutputStream os=LucasHttpURLConnection.getOutputStream（）；
//创建一个缓冲写入器，将数据写入输出流。
BufferedWriter BufferedWriter=新的BufferedWriter（新的OutputStreamWriter（os，“UTF-8”））；
//对我们在输出流上发送的数据进行编码
字符串数据=urlcoder.encode（“名字”，“UTF-8”）+”=“+urlcoder.encode（名字，“UTF-8”）+”&”+
URLEncoder.encode（“姓氏”，“UTF-8”）+”=“+URLEncoder.encode（姓氏，“UTF-8”）+”&”+
URLEncoder.encode（“用户名”，“UTF-8”）+”=“+URLEncoder.encode（用户名，“UTF-8”）+”&”+
urlcoder.encode（“密码”，“UTF-8”）+“=”+urlcoder.encode（密码，“UTF-8”）；
//将数据写入输出流，并关闭缓冲写入器
bufferedWriter.write（数据）；
bufferedWriter.flush（）；
bufferedWriter.close（）；
//关闭输出流
os.close（）；
//InputStream以获取响应
InputStream IS=LucasHttpURLConnection.getInputStream（）；
BufferedReader BufferedReader=新的BufferedReader（新的InputStreamReader（IS，“iso-8859-1”）；
字符串响应=”；
弦线；
而（（line=bufferedReader.readLine（））！=null）{
响应+=行；
}
bufferedReader.close（）；
IS.close（）；
//LucasHttpURLConnection.disconnect（）；
返回响应；
}捕获（格式错误）{
e、 printStackTrace（）；
}捕获（IOE异常）{
e、 printStackTrace（）；
}
//////////////////////////////////登录脚本/////////////////////////////////////////
}else if（mCheckTask.getIsLoginTask（））{
字符串username=params[0]；
字符串密码=参数[1]；
试一试{
URL=新URL（登录\ URL）；
HttpURLConnection HttpURLConnection=（HttpURLConnection）url.openConnection（）；
httpURLConnection.setRequestMethod（“POST”）；
httpURLConnection.setDoOutput（true）；
httpURLConnection.setDoInput（true）；
OutputStream OutputStream=httpURLConnection.getOutputStream（）；
BufferedWriter BufferedWriter=新的BufferedWriter（新的OutputStreamWriter（outputStream，UTF-8））；
字符串数据=URLEncoder.encode（“用户名”，“UTF-8”）+”=“+URLEncoder.encode（用户名，“UTF-8”）+”&”+
urlcoder.encode（“密码”，“UTF-8”）+“=”+urlcoder.encode（密码，“UTF-8”）；
bufferedWriter.write（数据）；
bufferedWriter.flush（）；
bufferedWriter.close（）；
outputStream.close（）；
//InputStream以获取响应
InputStream=httpURLConnection.getInputStream（）；
BufferedReader BufferedReader=新的BufferedReader（新的InputStreamReader（IS，“iso-8859-1”）；
字符串响应=”；
弦线；
而（（line=bufferedReader.readLine（））！=null）{
响应+=行；
}
bufferedReader.close（）；
IS.close（）；
httpURLConnection.disconnect（）；
返回响应；
}捕获（格式错误）{
e、 printStackTrace（）；
}捕获（IOE异常）{
e、 printStackTrace（）；
}
}
返回null；
}
@凌驾
受保护的void onPreExecute（）{
if（mCheckTask.getIsLoginTask（））{
mAlertDialog=新建AlertDialog.Builder（context.create（）；
setTitle（“登录信息…”）；
}否则{
mAlertDialog=新建AlertDialog.Builder（context.create（）；
setTitle（“注册信息…”）；
}
}
@凌驾
受保护的void onProgressUpdate（void…值）{
Public class Dispatch extends ActionBarActivity {

  @Override
  public void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    // Check if there is current user info
    if (ParseUser.getCurrentUser() != null) {
        // Start an intent for the logged in activity
        startActivity(new Intent(this, Home.class));
    } else {
        // Start and intent for the logged out activity
        startActivity(new Intent(this, login.class));
    }
}

}