问题
Not any errors are showing but data are not fetching form server.
my Main Activity
public class RetroMain extends AppCompatActivity implements ListView.OnItemClickListener {
public static final String ROOT_URL = "http://www.myeducationhunt.com/api/v1/colleges";
//Strings to bind with intent will be used to send data to other activity
public static final String KEY_BOOK_ID = "id";
public static final String KEY_BOOK_NAME = "name";
public static final String KEY_BOOK_ADDRESS = "address";
public static final String KEY_BOOK_DISTRICT = "district";
private ListView listView;
//List of type books this list will store type Book which is our data model
private List<Book> books;
@Override
public void onCreate(Bundle savedInstanceState, PersistableBundle persistentState) {
super.onCreate(savedInstanceState, persistentState);
setContentView(R.layout.activity_retro_main);
listView = (ListView) findViewById(R.id.listViewBooks);
getBooks();
listView.setOnItemClickListener(this);
}
private void getBooks() {
//While the app fetched data we are displaying a progress dialog
final ProgressDialog loading = ProgressDialog.show(this, "Fetching Data", "Please wait...", false, false);
//Creating a rest adapter
RestAdapter adapter = new RestAdapter.Builder().setEndpoint(ROOT_URL).build();
//Creating an object of our api interface
BooksAPI api = adapter.create(BooksAPI.class);
//Defining the method
api.getBooks(new Callback<List<Book>>() {
@Override
public void success(List<Book> list, Response response) {
//Dismissing the loading progressbar
loading.dismiss();
//Storing the data in our list
books = list;
//Calling a method to show the list
showList();
}
@Override
public void failure(RetrofitError error) {
//you can handle the errors here
}
});
}
//Our method to show list
private void showList() {
//String array to store all the book names
String[] items = new String[books.size()];
//Traversing through the whole list to get all the names
for (int i = 0; i < books.size(); i++) {
//Storing names to string array
items[i] = books.get(i).getName();
}
//Creating an array adapter for list view
ArrayAdapter adapter = new ArrayAdapter<String>(this, R.layout.simple_list, items);
//Setting adapter to listview
listView.setAdapter(adapter);
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//Creating an intent
Intent intent = new Intent(this, ShowBookDetails.class);
//Getting the requested book from the list
Book book = books.get(position);
//Adding book details to intent
intent.putExtra(KEY_BOOK_ID, book.getId());
intent.putExtra(KEY_BOOK_NAME, book.getName());
intent.putExtra(KEY_BOOK_ADDRESS, book.getAddress());
intent.putExtra(KEY_BOOK_DISTRICT, book.getDistrict());
//Starting another activity to show book details
startActivity(intent);
}
}
my getter and setters
public class Book {
private int id;
private String name;
private String address;
private String district;
public int getId() {
return id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAddress() {
return address;
}
public String getDistrict() {
return district;
}
public void setDistrict(String district) {
this.district = district;
}
public void setAddress(String address) {
this.address = address;
}
public void setId(int id) {
this.id = id;
}
}
my API Interface
public interface BooksAPI {
@GET("/api/v1/colleges")
public void getBooks(Callback<List<Book>> response);
}
ShowBookDetails class
public class ShowBookDetails extends AppCompatActivity {
//Defining views
private TextView id;
private TextView name;
private TextView address;
private TextView district;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_show_book_details);
//Initializing Views
id = (TextView) findViewById(R.id.id);
name = (TextView) findViewById(R.id.name);
address = (TextView) findViewById(R.id.address);
district = (TextView) findViewById(R.id.district);
//Getting intent
Intent intent = getIntent();
//Displaying values by fetching from intent
id.setText(String.valueOf(intent.getIntExtra(RetroMain.KEY_BOOK_ID, 0)));
name.setText(intent.getStringExtra(RetroMain.KEY_BOOK_NAME));
address.setText(intent.getStringExtra(RetroMain.KEY_BOOK_ADDRESS));
district.setText(String.valueOf(intent.getIntExtra(RetroMain.KEY_BOOK_DISTRICT, 0)));
}
}
my main xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Mystic.activity.RetroMain">
<ListView
android:id="@+id/listViewBooks"
android:layout_width="match_parent"
android:layout_height="wrap_content"></ListView>
</RelativeLayout>
my activity_show_book_detail
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin">
<TextView
android:id="@+id/id"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="24dp" />
<TextView
android:id="@+id/name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="24dp" />
<TextView
android:id="@+id/address"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="24dp" />
<TextView
android:id="@+id/district"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="24dp" />
</LinearLayout>
simple_list
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="10dp"
android:textSize="20sp">
</TextView>
i am not able to fetch data from server?
回答1:
You are adding full url here "public static final String ROOT_URL = "http://www.myeducationhunt.com/api/v1/colleges";"
which is not correct you just needs to add the base url here.
Modify this url to
public static final String ROOT_URL = "http://www.myeducationhunt.com/";
Also in your interface remove the initial "/"
This @GET("/api/v1/colleges") to this ... @GET("api/v1/colleges")
Edit1: Your problem with oncreate method.. remove your oncreate method with the following code
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.listViewBooks);
getBooks();
listView.setOnItemClickListener(this);
}
来源：https://stackoverflow.com/questions/41886821/not-able-to-fetch-data-from-server-using-retrofit