Question

在运行此教程后，我使用本教程http://www.tutecentral.com/restful-api-for-android-part-1/创建了一个安静的Web服务，我得到了一个自动生成的java文件，其中包含以下代码。

public class RestAPI {

    private final String urlString = "http://125.0.0.174/Handler1.ashx"; 
    private static String convertStreamToUTF8String(InputStream stream) throws IOException {
    String result = "";
    StringBuilder sb = new StringBuilder();
    try {
        InputStreamReader reader = new InputStreamReader(stream, "UTF-8");
        char[] buffer = new char[4096];
        int readedChars = 0;
        while (readedChars != -1) {
            readedChars = reader.read(buffer);
            if (readedChars > 0)
               sb.append(buffer, 0, readedChars);
        }
        result = sb.toString();
    } catch (UnsupportedEncodingException e){
        e.printStackTrace();
    }
    return result;
}

private String load(String contents) throws IOException {
    URL url = new URL(urlString);
    HttpURLConnection conn = (HttpURLConnection)url.openConnection();
    conn.setRequestMethod("POST");
    conn.setConnectTimeout(60000);
    Log.e("load r2","load r2");
    conn.setDoOutput(true);
    conn.setDoInput(true);
    OutputStreamWriter w = new OutputStreamWriter(conn.getOutputStream());
    w.write(contents);
    w.flush();
    InputStream istream = conn.getInputStream();
    String result = convertStreamToUTF8String(istream);
    return result;
}

private Object mapObject(Object o) {
    Object finalValue = null;
    if (o.getClass() == String.class) {
        finalValue = o;
    }
    else if (Number.class.isInstance(o)) {
        finalValue = String.valueOf(o);
    } else if (Date.class.isInstance(o)) {
        SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy hh:mm:ss", new Locale("en", "USA"));
        finalValue = sdf.format((Date)o);
    }
    else if (Collection.class.isInstance(o)) {
        Collection<?> col = (Collection<?>) o;
        JSONArray jarray = new JSONArray();
        for (Object item : col) {
            jarray.put(mapObject(item));
        }
        finalValue = jarray;
    } else {
        Map<String, Object> map = new HashMap<String, Object>();
        Method[] methods = o.getClass().getMethods();
        for (Method method : methods) {
            if (method.getDeclaringClass() == o.getClass()
                    && method.getModifiers() == Modifier.PUBLIC
                    && method.getName().startsWith("get")) {
                String key = method.getName().substring(3);
                try {
                    Object obj = method.invoke(o, null);
                    Object value = mapObject(obj);
                    map.put(key, value);
                    finalValue = new JSONObject(map);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }
    return finalValue;
}

public JSONObject GetDoctors(String Terr_Code) throws Exception {
    JSONObject result = null;
    JSONObject o = new JSONObject();
    JSONObject p = new JSONObject();
    o.put("interface","RestAPI");
    o.put("method", "GetDoctors");
    p.put("Terr_Code",mapObject(Terr_Code));
    o.put("parameters", p);
    String s = o.toString();
    String r = load(s);
    result = new JSONObject(r);
    return result;
}

public JSONObject GetUserDetail(String IMEINO) throws Exception {
    JSONObject result = null;
    JSONObject o = new JSONObject();
    JSONObject p = new JSONObject();
    o.put("interface","RestAPI");
    o.put("method", "GetUserDetail");
    p.put("IMEINO",mapObject(IMEINO));
    o.put("parameters", p);
    String s = o.toString();
    String r = load(s);
    result = new JSONObject(r);
    return result;
}
}

我在异步任务中调用此类，一切正常，但我想通过齐射使用它，因为异步任务很慢。这个类只有一个网址我不明白如何为个别方法调用这个网址我尝试了下面的代码，但是我的网址异常坏了。请告诉我如何使用单独的URL访问rest api的方法。

public void requestJSON() {

          String tag_json_obj = "json_obj_req";

          final ProgressDialog pDialog = new ProgressDialog(context);
          pDialog.setMessage("Loading...");
          pDialog.show();
          JsonObjectRequest jsonObjReq = new JsonObjectRequest(Method.GET, null,
                null, new Response.Listener<JSONObject>() {

                   @Override
                   public void onResponse(JSONObject response) {
                        try {
                             RestAPI restAPI = new RestAPI(); 
                             response = restAPI.GetDoctors(terrcode);                            
                        }   
                        catch (Exception e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }

                 display.setText(response.toString());

                      pDialog.hide();
                   }

              }, new Response.ErrorListener() {

                   @Override
                   public void onErrorResponse(VolleyError error) {
                      display.setText(error.toString());
                      pDialog.hide();
                   }
                });

          // Adding request to request queue
          VolleySingleton.getInstance().addToRequestQueue(jsonObjReq,
                tag_json_obj);
       }

Answer 1

将Volley用作VolleyService：

public class VolleyService {

    private static VolleyService instance;
    private RequestQueue requestQueue;
    private ImageLoader imageLoader;

    private VolleyService(Context context) {
        requestQueue = Volley.newRequestQueue(context);

        imageLoader = new ImageLoader(requestQueue, new ImageLoader.ImageCache() {
            private final LruCache<String, Bitmap> cache = new LruCache<String, Bitmap>(20);

            @Override
            public Bitmap getBitmap(String url) {
                return cache.get(url);
            }

            @Override
            public void putBitmap(String url, Bitmap bitmap) {
                cache.put(url,bitmap);
            }
        });
    }

    public static VolleyService getInstance(Context context) {
        if (instance == null) {
            synchronized(VolleyService.class) {
                if (instance == null) {
                    instance = new VolleyService(context);
                }
            }
        }
        return instance;
    }

    public RequestQueue getRequestQueue() {
        return requestQueue;
    }

    public ImageLoader getImageLoader() {
        return imageLoader;
    }
}

然后在Activity或Fragment中使用VolleyService：

RequestQueue queue = VolleyService.getInstance(this.getContext()).getRequestQueue();
StringRequest request = new StringRequest(url, new Response.Listener<String>() {    
                @Override
                public void onResponse(String response) {
                    // we got the response, now our job is to handle it
                    try {
//Here you parse your JSON - best approach is to use GSON for deserialization
                        getJsonFromResponse(response);
                    } catch (RemoteException | OperationApplicationException e) {
                        e.printStackTrace();
                    }
                }
            }, new Response.ErrorListener() {

                @Override
                public void onErrorResponse(VolleyError error) {
                    //something happened, treat the error.
                    Log.e("Error", error.toString());
                }
            });

            queue.add(request);

如何使用volley库访问restful web服务方法

1 个答案: