Android annotations REST

使用前：

 public class BookmarksToClipboardActivity extends Activity {

   BookmarkAdapter adapter;

   ListView bookmarkList;

   EditText search;

   BookmarkApplication application;

   Animation fadeIn;

   ClipboardManager clipboardManager;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);

     requestWindowFeature(Window.FEATURE_NO_TITLE);
     getWindow().setFlags(FLAG_FULLSCREEN, FLAG_FULLSCREEN);

     setContentView(R.layout.bookmarks);

     bookmarkList = (ListView) findViewById(R.id.bookmarkList);
     search = (EditText) findViewById(R.id.search);
     application = (BookmarkApplication) getApplication();
     fadeIn = AnimationUtils.loadAnimation(this, anim.fade_in);
     clipboardManager = (ClipboardManager) getSystemService(CLIPBOARD_SERVICE);

     View updateBookmarksButton1 = findViewById(R.id.updateBookmarksButton1);
     updateBookmarksButton1.setOnClickListener(new OnClickListener() {

       @Override
       public void onClick(View v) {
         updateBookmarksClicked();
       }
     });

     View updateBookmarksButton2 = findViewById(R.id.updateBookmarksButton2);
     updateBookmarksButton2.setOnClickListener(new OnClickListener() {

       @Override
       public void onClick(View v) {
         updateBookmarksClicked();
       }
     });

     bookmarkList.setOnItemClickListener(new OnItemClickListener() {

       @Override
       public void onItemClick(AdapterView<?> p, View v, int pos, long id) {
         Bookmark selectedBookmark = (Bookmark) p.getAdapter().getItem(pos);
         bookmarkListItemClicked(selectedBookmark);
       }
     });

     initBookmarkList();
   }

   void initBookmarkList() {
     adapter = new BookmarkAdapter(this);
     bookmarkList.setAdapter(adapter);
   }

   void updateBookmarksClicked() {
     UpdateBookmarksTask task = new UpdateBookmarksTask();

     task.execute(search.getText().toString(), application.getUserId());
   }

   private static final String BOOKMARK_URL = //
   "http://www.bookmarks.com/bookmarks/{userId}?search={search}";

   class UpdateBookmarksTask extends AsyncTask<String, Void, Bookmarks> {

     @Override
     protected Bookmarks doInBackground(String... params) {
       String searchString = params[0];
       String userId = params[1];

       RestTemplate client = new RestTemplate();
       HashMap<String, Object> args = new HashMap<String, Object>();
       args.put("search", searchString);
       args.put("userId", userId);
       HttpHeaders httpHeaders = new HttpHeaders();
       HttpEntity<Bookmarks> request = new HttpEntity<Bookmarks>(httpHeaders);
       ResponseEntity<Bookmarks> response = client.exchange( //
           BOOKMARK_URL, HttpMethod.GET, request, Bookmarks.class, args);
       Bookmarks bookmarks = response.getBody();

       return bookmarks;
     }

     @Override
     protected void onPostExecute(Bookmarks result) {
       adapter.updateBookmarks(result);
       bookmarkList.startAnimation(fadeIn);
     }

   }

   void bookmarkListItemClicked(Bookmark selectedBookmark) {
     clipboardManager.setText(selectedBookmark.getUrl());
   }

 }

使用后：

 @NoTitle
 @Fullscreen
 @EActivity(R.layout.bookmarks)
 public class BookmarksToClipboardActivity extends Activity {

   BookmarkAdapter adapter;

   @ViewById
   ListView bookmarkList;

   @ViewById
   EditText search;

   @App
   BookmarkApplication application;

   @RestService
   BookmarkClient restClient;

   @AnimationRes
   Animation fadeIn;

   @SystemService
   ClipboardManager clipboardManager;

   @AfterViews
   void initBookmarkList() {
     adapter = new BookmarkAdapter(this);
     bookmarkList.setAdapter(adapter);
   }

   @Click({R.id.updateBookmarksButton1, R.id.updateBookmarksButton2})
   void updateBookmarksClicked() {
     searchAsync(search.getText().toString(), application.getUserId());
   }

   @Background
   void searchAsync(String searchString, String userId) {
     Bookmarks bookmarks = restClient.getBookmarks(searchString, userId);
     updateBookmarks(bookmarks);
   }

   @UiThread
   void updateBookmarks(Bookmarks bookmarks) {
     adapter.updateBookmarks(bookmarks);
     bookmarkList.startAnimation(fadeIn);
   }

   @ItemClick
   void bookmarkListItemClicked(Bookmark selectedBookmark) {
     clipboardManager.setText(selectedBookmark.getUrl());
   }

 }

 @Rest("http://www.bookmarks.com")
 public interface BookmarkClient {

   @Get("/bookmarks/{userId}?search={search}")
   Bookmarks getBookmarks(String search, String userId);

 }

且利用androidannotations的Rest注解替换手工建立Spring Android RestTemplate对象，不仅可以减少很多代码，同时使工程结构更简洁、严谨，利于复用。

自己构造RestTemplate的原生写法：

 HttpHeaders requestHeaders = new HttpHeaders();
 List<MediaType> acceptableMediaTypes = new ArrayList<MediaType>();
 acceptableMediaTypes.add(MediaType.APPLICATION_JSON);
 requestHeaders.setAccept(acceptableMediaTypes);  

 HttpEntity<?> requestEntity = new HttpEntity<Object>(requestHeaders);  

 RestTemplate restTemplate = new RestTemplate();
 restTemplate.getMessageConverters().add(new MappingJackson2HttpMessageConverter());  

 ResponseEntity<User[]> responseEntity = restTemplate.exchange(url, HttpMethod.GET, requestEntity, User[].class);  

利用androidannotations的Rest注解替换后的代码：

 //初始化
 @RestService
 RestApiService restApiService;
 ResponseEntity<User[]> responseEntity = restApiService.getByStatus(); 

 @Rest(rootUrl = "http://10.0.2.2:8080/together/api", converters = { MappingJackson2HttpMessageConverter.class })
 public interface RestApiService {  

     @Get("/user/getByStatus.do?status=1")
     ResponseEntity<User[]> getUsersByStatus();  

 }  

wiki api :

https://github.com/excilys/androidannotations/wiki/Rest-API