我正在使用nano在android工作室上创建登录/注册,并想询问如何检查nanoscale.io中是否已经存在用户名。
以下代码允许用户注册和帐户,并将其保存到nanoscale.io中。但是,用户可以创建多个相同的用户名。有没有想法我能做些什么来防止这种情况发生?谢谢!
public void signUp(View view) {
EditText username = (EditText) findViewById(R.id.registerUsername);
EditText password = (EditText) findViewById(R.id.registerPassword);
Map<String, String> params = new HashMap();
params.put("username", username.getText().toString());
params.put("password", md5(password.getText().toString()));
JSONObject parameters = new JSONObject(params); // collect to be sent to web api aka request
JsonObjectRequest jsonRequest = new JsonObjectRequest(Request.Method.POST, url, parameters, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
//TODO: handle success
try {
finish();
Toast.makeText(RegisterActivity.this, response.getString("$id").toString() + "Account is registered", Toast.LENGTH_SHORT).show();
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
error.printStackTrace();
//TODO: handle failure
}
});
Volley.newRequestQueue(getApplication()).add(jsonRequest);
}