单击按钮即可从Firebase数据库检索数据，这些数据以其他格式显示在列表中

Question

public class HomeActivity extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home);
   Button ten, twelve;
    ten=(Button) findViewById(R.id.tenth) ;
    twelve=(Button) findViewById(R.id.twelth) ;
    ten.setOnClickListener(new View.OnClickListener() {

        DatabaseReference ref = FirebaseDatabase.getInstance().getReference().child("Customer_details");



        @Override
        public void onClick(View v) {

        }
    });

我的课

包com.example.shikshaMela.sm;

公共课程Course_tenth {

    String name = "";
    String college_list = "";

    String fee = "";
    String duration = "";
    String higher_study = "";
    String job_aspects = "";
    String entrance_exam = "";





public course_tenth() {

}

public course_tenth(String name, String college_list, String fee, String duration, String higher_study, String job_aspects, String entrance_exam)
    {


        this.name = name;
        this.college_list = college_list;

        this.fee = fee;
        this.duration = duration;
        this.higher_study = higher_study;
        this.job_aspects = job_aspects;
        this.entrance_exam = entrance_exam;
    }

public String getname() {
    return name;
}

public String getCollege_list() {
    return college_list;
}



public String getFee() {
    return fee;
}

public String getDuration() {
    return duration;
}

public String getHigher_study() {
    return higher_study;
}

public String getJob_aspects() {
    return job_aspects;
}

public String getEntrance_exam() {
    return entrance_exam;
}

}

我想从数据库中获取所有课程列表（如bca），并显示在其他活动的列表中。 这些项目（bca）是可单击的，因此，当我们单击这些项目（bca）时，其内部数据（例如大学资格等）将被获取。

我怎样才能做到这一点？

我的firebase数据库

Answer 1

 // refer --> your DatabaseReference
 refer.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {

            Iterator<DataSnapshot> dataSnapshotsChat = dataSnapshot.getChildren().iterator();

            User user = null; // User is Model class
            while (dataSnapshotsChat.hasNext()) {
                DataSnapshot dataSnapshotChild = dataSnapshotsChat.next();
                user = dataSnapshotChild.getValue(User.class);

                if (!Lists.contains(user.id)) { // here List is array list of type User
                    Lists.add(user);
                }
       }

}）;