我想用他们的令牌注册用户，我想在android中使用retrofit注册用户，但我一直收到这个错误：
ERROR::: Attempt to invoke virtual method 'void com.signup.User.setUsername(java.lang.String)' on a null object reference
这是我的代码：
public class Session {
Context context;
private SharedPreferences prefs;
public Session(Context cntx) {
// TODO Auto-generated constructor stub
this.context = cntx;
prefs = PreferenceManager.getDefaultSharedPreferences(context);
}
public void setJwtToken(String token) {
prefs.edit().putString("JwtToken", token).commit();
}
public String getJwtToken() {
String token = prefs.getString("JwtToken", "");
if (token == null || token.isEmpty()) {
token = "Bearer eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJleHAiOjIxNzc0NTI3OTksImlhdCI6MTUxNjAyMjk5OSwiaXNzIjoiQmFzb2JhYXMgTmVwYWwiLCJuYmYiOjE1MTYwMjI5OTksImp0aSI6Ikd1ZXN0VG9rZW4iLCJzdWIiOjB9.QikmNgBYmqch5HREGFEpUs4Xk3x-zFfDg5mhYJO7jM8";
}
return token;
}
}
public interface ApiInterface {
@POST("/api/users/signup")
Call<ResponseBody> signMeUp(@Header("Authorization") String token ,@Body User user);
}
public class MainActivity extends AppCompatActivity {
private EditText et_name, et_address, et_phone, et_username, et_email, et_password, et_confipassword;
private Button register;
private User user;
private SharedPreferences prefs;
private ApiInterface apiInterface;
private Session session;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_name = findViewById(R.id.edit_text_name);
et_address = findViewById(R.id.edit_text_address);
et_phone = findViewById(R.id.edit_text_phonenumber);
et_username = findViewById(R.id.edit_text_username);
et_email = findViewById(R.id.edit_text_email);
et_password = findViewById(R.id.edit_text_password);
et_confipassword = findViewById(R.id.edit_text_confirm_password);
register = findViewById(R.id.signupButton);
register.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Login();
}
});
}
private void Login() {
user.setUsername(et_name.getText().toString());
user.setAddress(et_address.getText().toString());
user.setPhone(et_phone.getText().toString());
user.setName(et_name.getText().toString());
user.setEmail(et_email.getText().toString());
user.setPassword(et_password.getText().toString());
user.setPasswordConfirmation(et_confipassword.getText().toString());
signupUser(user);
}
private void signupUser(final User user) {
// Set up progressbar before call
apiInterface = ApiClient.getClient().create(ApiInterface.class);
Call<ResponseBody> call1 = apiInterface.signMeUp(session.getJwtToken(),user);
final Gson gson = new Gson();
final String json = gson.toJson(user);
call1.enqueue(new Callback<ResponseBody>() {
@Override
public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
if (response.code() == 201) {
try {
JSONObject jsonObject = new JSONObject(response.body().string());
//Starting main activity after user sees dialog
} catch (JSONException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
} else if (response.code() == 500) {
try {
JSONObject jsonObject = new JSONObject(response.errorBody().string());
Log.e("SignupFragment", jsonObject.toString());
} catch (JSONException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}else
Log.e("SignupFragment", response.raw().toString());
}
@Override
public void onFailure(Call<ResponseBody> call, Throwable t) {
}
});
}
}
public class User {
@SerializedName("name")
@Expose
private String name;
@SerializedName("email")
@Expose
private String email;
@SerializedName("password")
@Expose
private String password;
@SerializedName("password_confirmation")
@Expose
private String passwordConfirmation;
@SerializedName("image")
@Expose
private String image;
@SerializedName("phone")
@Expose
private String phone;
@SerializedName("address")
@Expose
private String address;
@SerializedName("username")
@Expose
private String username;
@SerializedName("pan_no")
@Expose
private String panNo;
@SerializedName("birthday")
@Expose
private String birthday;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getPasswordConfirmation() {
return passwordConfirmation;
}
public void setPasswordConfirmation(String passwordConfirmation) {
this.passwordConfirmation = passwordConfirmation;
}
public String getImage() {
return image;
}
public void setImage(String image) {
this.image = image;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPanNo() {
return panNo;
}
public void setPanNo(String panNo) {
this.panNo = panNo;
}
public String getBirthday() {
return birthday;
}
public void setBirthday(String birthday) {
this.birthday = birthday;
}
}
public class ApiClient {
public static final String BASE_URL = "https://myapp.herokuapp.com/";
private static Retrofit retrofit = null;
public static Retrofit getClient() {
if (retrofit == null) {
retrofit = new Retrofit.Builder()
.baseUrl(BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.build();
}
return retrofit;
}
ApiInterface apiInterface=retrofit.create(ApiInterface.class);
}
我想通过我的应用注册用户，但我一直收到错误。并且，如果我从接口中删除auth标题，我会收到一条消息，询问令牌，当我提供令牌时，它会给我一个空对象引用错误!!
答案 0 :(得分：0)
您应该在访问变量之前实例化变量：User user = new User();
更新：在void Login()
答案 1 :(得分：0)
在onCreate方法中创建一个User实例，或在那里声明它的
答案 2 :(得分：0)
试试这个
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
user = new User();
session = new Session(this);
}