        loginButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            User currUser ;
            currUser = MainActivity.mainMenuPrompt(theBank, UserID, password, bankView, errorLogin);

            Intent intent = new Intent(MainActivity.this, MainActivity2.class);

            intent.putExtra("USER", currUser);
            startActivity(intent);
        }
    });

I can't pass my "currUser" variable with intent. Is there any other way to do it?

CodePudding user response：

If we want to pass an object between activities we use Parcelable or Serialazable. Generally, we use Parcelabel as it is faster than Serialazable.In order to use it the User class must implement Parcelable interface and provide the implementation of method and then we create Parcelable constructor and send data as we used to send with intent.putExtra() method and in the other activity we receive data using getIntent().getParcelableExtra() method.
User.class

public class User implements Parcelable {
private String theBank;
private int userId;
private String password;
private String bankView;
private String errorLogin;

public User(String theBank, int userId, String password, String bankView, String errorLogin) {
    this.theBank = theBank;
    this.userId = userId;
    this.password = password;
    this.bankView = bankView;
    this.errorLogin = errorLogin;
}

public String getTheBank() {
    return theBank;
}

public void setTheBank(String theBank) {
    this.theBank = theBank;
}

public int getUserId() {
    return userId;
}

public void setUserId(int userId) {
    this.userId = userId;
}

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}

public String getBankView() {
    return bankView;
}

public void setBankView(String bankView) {
    this.bankView = bankView;
}

public String getErrorLogin() {
    return errorLogin;
}

public void setErrorLogin(String errorLogin) {
    this.errorLogin = errorLogin;
}

protected User(Parcel in) {
    theBank = in.readString();
    userId = in.readInt();
    password = in.readString();
    errorLogin = in.readString();
}

public static final Creator<User> CREATOR = new Creator<User>() {
    @Override
    public User createFromParcel(Parcel in) {
        return new User(in);
    }

    @Override
    public User[] newArray(int size) {
        return new User[size];
    }
};

@Override
public int describeContents() {
    return 0;
}
@Override
public void writeToParcel(Parcel parcel, int i) {
    parcel.writeString(theBank);
    parcel.writeInt(userId);
    parcel.writeString(password);
    parcel.writeString(errorLogin);
    }
}

MainActivity.java

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // User class initialization
    User userObj = new User("SBI", 001, "stackOverFlow", "OpenBank", "Sorry!!");

    // Passing data with key-name as user
    Intent intent = new Intent(this, MainActivity2.class);
    intent.putExtra("user", userObj);
    startActivity(intent);

    }
}

MainActivity2.java

public class MainActivity2 extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main2);

    // Receiving the user objet using getIntent().getParcelableExtra() method
    User user = getIntent().getParcelableExtra("user");
    String bank = user.getTheBank();
    int id = user.getUserId();
    String password = user.getPassword();
    String bankView = user.getBankView();
    String error = user.getErrorLogin();

    Toast.makeText(this, bank   id   password   bankView   error, Toast.LENGTH_SHORT).show();
    }
}

CodePudding user response：

It is better to use live data to save the object. It is easy to configurate in the project.

The android's page is https://developer.android.com/topic/libraries/architecture/livedata?hl=es-419

The first you need to use the next library

// Live data
implementation "androidx.annotation:annotation:$versions.annotation"
api "androidx.lifecycle:lifecycle-extensions:$versions.archComponents"

   annotation      : '1.0.0',
   archComponents  : '2.0.0',

If you don't want to use livedata, you could use The gson library to convert object to string. After you need to convert the string to class

CodePudding user response：

Easy use EventBus.

Add EventBus to your project

implementation("org.greenrobot:eventbus:3.3.1")

Create a class to store the data you want to send

public class User {
    private String theBank;
    private int userId;
    private String password;
    private String bankView;
    private String errorLogin;

    public User(String theBank, int userId, String password, String bankView, String errorLogin) {
        this.theBank = theBank;
        this.userId = userId;
        this.password = password;
        this.bankView = bankView;
        this.errorLogin = errorLogin;
    }

    public String getTheBank() {
        return theBank;
    }

    public void setTheBank(String theBank) {
        this.theBank = theBank;
    }

    public int getUserId() {
        return userId;
    }

    public void setUserId(int userId) {
        this.userId = userId;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getBankView() {
        return bankView;
    }

    public void setBankView(String bankView) {
        this.bankView = bankView;
    }

    public String getErrorLogin() {
        return errorLogin;
    }

    public void setErrorLogin(String errorLogin) {
        this.errorLogin = errorLogin;
    }
}

In the activity/fragment that received the data

@Override
public void onStart() {
    super.onStart();
    EventBus.getDefault().register(this);
}

@Override
public void onStop() {
    super.onStop();
    EventBus.getDefault().unregister(this);
}

Message will be received in here

private User _user;

@Subscribe(threadMode = ThreadMode.MAIN)  
public void onMessageEvent(User user) {
    Log.d("theBank", user.getTheBank());
    Log.d("userId", user.getUserId());
    Log.d("password", user.getPassword());
    Log.d("bankView", user.getBankView());
    Log.d("errorLogin", user.getErrorLogin());

    // save user in member variable (_user), 
    //   so you can access _user from other place in this activity or fragment
    _user  = user;
}

In the activity/fragment that sends the data

User user = new User();
user.setTheBank = "my bank";
user.setUserId = 1;
user.setPassword = "my password";
user.setBankView = "my bank view";
user.setErrorLogin = "my error login";

EventBus.getDefault().post(user);