How to fix AsyncTask params error?

Issue

I am working on a registration based project that uses asyncTask. But I am getting errors on its params and the background usage tasks.

Snippet -

public class signupActivity extends AppCompatActivity {
    EditText edit_name;
    EditText edit_usn;
    EditText edit_addnum;
    EditText edit_pass;
    EditText edit_repass;
    Button btn_sign;
private static final String REGISTER_URL="http://abcd.000webhostapp.com/signup.php";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_signup);
        edit_name=(EditText)findViewById(R.id.id_name);
        edit_usn=(EditText)findViewById(R.id.id_usn);
        edit_addnum=(EditText)findViewById(R.id.id_add);
        edit_pass=(EditText)findViewById(R.id.id_pass);
        edit_repass=(EditText)findViewById(R.id.id_repass);
        btn_sign=(Button)findViewById(R.id.btn_signup);
        btn_sign.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                registerUser();
            }
        });
    }

    private void registerUser() {
        String name=edit_name.getText().toString().trim().toLowerCase();
        String usn=edit_usn.getText().toString().trim().toLowerCase();
        String addnum=edit_addnum.getText().toString();
        String pass=edit_pass.getText().toString().trim().toLowerCase();
        String repass=edit_repass.getText().toString().trim().toLowerCase();
        register(name, usn, addnum, pass, repass);
    }
private void register(String name,String usn,String addnum,String pass,String repass) {

    String urlsuffix = "?name=" + name + "&usn=" + usn + "&ddnum=" + addnum + "&pass=" + pass + "&repass=" + repass;

    //Getting **illegal start of type** for void keyword here
    class RegisterUser extends AsyncTask <String, void, String> implements abcd.project2.RegisterUser {
        ProgressDialog loading;

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            loading = ProgressDialog.show(signupActivity.this, "please wait", null, true, true);
        }

        //Getting **method does not override or implement a method from a supertype** for override here
        @Override
        protected void onPostExecute() {
            super.onPreExecute();
            Toast.makeText(getApplicationContext(), "Internet not found", Toast.LENGTH_SHORT).show();

        }


        @Override
        protected String doInBackground(String... params) {
            String s = params[0];
            BufferedReader bufferReader = null;
            try {
                URL url = new URL(REGISTER_URL + s);
                HttpURLConnection con = (HttpURLConnection) url.openConnection();
                bufferReader = new BufferedReader(new InputStreamReader(con.getInputStream()));
                String result;
                result = bufferReader.readLine();
                return result;
            } catch (Exception e) {
                return null;
            }
        }
    }
    RegisterUser ur = new RegisterUser();
    ur.execute(urlsuffix);
}
    public void openCreateList(View view) {
        Intent i = new Intent(this, createActivity.class);
        startActivity(i);

    }}

Error messages -

Error:(56, 50) error: illegal start of type
Error:(65, 9) error: method does not override or implement a method from a supertype

How do I solve these? I tried changing the return type in params but still I am unable to solve the error.

Solution

Try this

1. Its Void not void in parameter of AsyncTask

2. You need to change your onPostExecute() method just pass String parameter in onPostExecute() method

Change your code like below code

SAMPLE CODE

private void register(String name,String usn,String addnum,String pass,String repass) {

    String urlsuffix = "?name=" + name + "&usn=" + usn + "&ddnum=" + addnum + "&pass=" + pass + "&repass=" + repass;

    //Getting **illegal start of type** for void keyword here
    class RegisterUser extends AsyncTask<String, Void, String> implements abcd.project2.RegisterUser {
        ProgressDialog loading;

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            loading = ProgressDialog.show(signupActivity.this, "please wait", null, true, true);
        }

        
        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
        }


        @Override
        protected String doInBackground(String... params) {
            String s = params[0];
            BufferedReader bufferReader = null;
            try {
                URL url = new URL(REGISTER_URL + s);
                HttpURLConnection con = (HttpURLConnection) url.openConnection();
                bufferReader = new BufferedReader(new InputStreamReader(con.getInputStream()));
                String result;
                result = bufferReader.readLine();
                return result;
            } catch (Exception e) {
                return null;
            }
        }
    }
    RegisterUser ur = new RegisterUser();
    ur.execute(urlsuffix);
}

You can read more about AsyncTask

Answered By - AskNilesh