Restful API服务
我正在寻找可以用来调用基于Web的REST API的服务。
基本上我想在app init上启动一个服务,然后我希望能够请求该服务请求一个url并返回结果。 同时我希望能够显示进度窗口或类似的东西。
我已经创建了一个使用IDL的服务,我已经在某处读过你只需要跨平台应用程序交流的地方,所以认为这些需求会被剥离出来,但不确定如何在没有它的情况下进行回调。 同样,当我点击post(Config.getURL("login"), values)
应用程序似乎暂停了一段时间(看起来很奇怪 - 认为服务背后的想法是它运行在不同的线程上)!
目前我有一个服务与邮政和内部的http方法,几个AIDL文件(用于双向通信),一个ServiceManager,处理启动,停止,绑定等服务,我动态创建一个处理程序与特定的代码根据需要进行回调。
我不希望任何人给我一个完整的代码库来处理,但一些指针将不胜感激。
代码(大部分)已满:
public class RestfulAPIService extends Service {
final RemoteCallbackList<IRemoteServiceCallback> mCallbacks = new RemoteCallbackList<IRemoteServiceCallback>();
public void onStart(Intent intent, int startId) {
super.onStart(intent, startId);
}
public IBinder onBind(Intent intent) {
return binder;
}
public void onCreate() {
super.onCreate();
}
public void onDestroy() {
super.onDestroy();
mCallbacks.kill();
}
private final IRestfulService.Stub binder = new IRestfulService.Stub() {
public void doLogin(String username, String password) {
Message msg = new Message();
Bundle data = new Bundle();
HashMap<String, String> values = new HashMap<String, String>();
values.put("username", username);
values.put("password", password);
String result = post(Config.getURL("login"), values);
data.putString("response", result);
msg.setData(data);
msg.what = Config.ACTION_LOGIN;
mHandler.sendMessage(msg);
}
public void registerCallback(IRemoteServiceCallback cb) {
if (cb != null)
mCallbacks.register(cb);
}
};
private final Handler mHandler = new Handler() {
public void handleMessage(Message msg) {
// Broadcast to all clients the new value.
final int N = mCallbacks.beginBroadcast();
for (int i = 0; i < N; i++) {
try {
switch (msg.what) {
case Config.ACTION_LOGIN:
mCallbacks.getBroadcastItem(i).userLogIn( msg.getData().getString("response"));
break;
default:
super.handleMessage(msg);
return;
}
} catch (RemoteException e) {
}
}
mCallbacks.finishBroadcast();
}
public String post(String url, HashMap<String, String> namePairs) {...}
public String get(String url) {...}
};
几个AIDL文件:
package com.something.android
oneway interface IRemoteServiceCallback {
void userLogIn(String result);
}
和
package com.something.android
import com.something.android.IRemoteServiceCallback;
interface IRestfulService {
void doLogin(in String username, in String password);
void registerCallback(IRemoteServiceCallback cb);
}
和服务经理:
public class ServiceManager {
final RemoteCallbackList<IRemoteServiceCallback> mCallbacks = new RemoteCallbackList<IRemoteServiceCallback>();
public IRestfulService restfulService;
private RestfulServiceConnection conn;
private boolean started = false;
private Context context;
public ServiceManager(Context context) {
this.context = context;
}
public void startService() {
if (started) {
Toast.makeText(context, "Service already started", Toast.LENGTH_SHORT).show();
} else {
Intent i = new Intent();
i.setClassName("com.something.android", "com.something.android.RestfulAPIService");
context.startService(i);
started = true;
}
}
public void stopService() {
if (!started) {
Toast.makeText(context, "Service not yet started", Toast.LENGTH_SHORT).show();
} else {
Intent i = new Intent();
i.setClassName("com.something.android", "com.something.android.RestfulAPIService");
context.stopService(i);
started = false;
}
}
public void bindService() {
if (conn == null) {
conn = new RestfulServiceConnection();
Intent i = new Intent();
i.setClassName("com.something.android", "com.something.android.RestfulAPIService");
context.bindService(i, conn, Context.BIND_AUTO_CREATE);
} else {
Toast.makeText(context, "Cannot bind - service already bound", Toast.LENGTH_SHORT).show();
}
}
protected void destroy() {
releaseService();
}
private void releaseService() {
if (conn != null) {
context.unbindService(conn);
conn = null;
Log.d(LOG_TAG, "unbindService()");
} else {
Toast.makeText(context, "Cannot unbind - service not bound", Toast.LENGTH_SHORT).show();
}
}
class RestfulServiceConnection implements ServiceConnection {
public void onServiceConnected(ComponentName className, IBinder boundService) {
restfulService = IRestfulService.Stub.asInterface((IBinder) boundService);
try {
restfulService.registerCallback(mCallback);
} catch (RemoteException e) {}
}
public void onServiceDisconnected(ComponentName className) {
restfulService = null;
}
};
private IRemoteServiceCallback mCallback = new IRemoteServiceCallback.Stub() {
public void userLogIn(String result) throws RemoteException {
mHandler.sendMessage(mHandler.obtainMessage(Config.ACTION_LOGIN, result));
}
};
private Handler mHandler;
public void setHandler(Handler handler) {
mHandler = handler;
}
}
服务初始化和绑定:
// this I'm calling on app onCreate
servicemanager = new ServiceManager(this);
servicemanager.startService();
servicemanager.bindService();
application = (ApplicationState)this.getApplication();
application.setServiceManager(servicemanager);
服务函数调用:
// this lot i'm calling as required - in this example for login
progressDialog = new ProgressDialog(Login.this);
progressDialog.setMessage("Logging you in...");
progressDialog.show();
application = (ApplicationState) getApplication();
servicemanager = application.getServiceManager();
servicemanager.setHandler(mHandler);
try {
servicemanager.restfulService.doLogin(args[0], args[1]);
} catch (RemoteException e) {
e.printStackTrace();
}
...later in the same file...
Handler mHandler = new Handler() {
public void handleMessage(Message msg) {
switch (msg.what) {
case Config.ACTION_LOGIN:
if (progressDialog.isShowing()) {
progressDialog.dismiss();
}
try {
...process login results...
}
} catch (JSONException e) {
Log.e("JSON", "There was an error parsing the JSON", e);
}
break;
default:
super.handleMessage(msg);
}
}
};
如果你的服务将成为你应用程序的一部分,那么你正在使它变得比它需要的复杂。 由于您从RESTful Web服务获取某些数据的简单用例,您应该查看ResultReceiver和IntentService。
此Service + ResultReceiver模式的工作方式是,当您想要执行某些操作时,使用startService()启动或绑定到该服务。 您可以指定操作来执行并通过Intent中的附加组件传递ResultReceiver(活动)。
在实现onHandleIntent的服务中,执行Intent中指定的操作。 当操作完成时,您使用传入的ResultReceiver将消息发送回Activity,在此时将调用onReceiveResult。
例如,你想从Web服务中提取一些数据。
我知道你提到你不想要代码库,但开源的Google I / O 2010应用程序使用我描述的这种方式的服务。
已更新以添加示例代码:
活动。
public class HomeActivity extends Activity implements MyResultReceiver.Receiver {
public MyResultReceiver mReceiver;
public void onCreate(Bundle savedInstanceState) {
mReceiver = new MyResultReceiver(new Handler());
mReceiver.setReceiver(this);
...
final Intent intent = new Intent(Intent.ACTION_SYNC, null, this, QueryService.class);
intent.putExtra("receiver", mReceiver);
intent.putExtra("command", "query");
startService(intent);
}
public void onPause() {
mReceiver.setReceiver(null); // clear receiver so no leaks.
}
public void onReceiveResult(int resultCode, Bundle resultData) {
switch (resultCode) {
case RUNNING:
//show progress
break;
case FINISHED:
List results = resultData.getParcelableList("results");
// do something interesting
// hide progress
break;
case ERROR:
// handle the error;
break;
}
}
服务:
public class QueryService extends IntentService {
protected void onHandleIntent(Intent intent) {
final ResultReceiver receiver = intent.getParcelableExtra("receiver");
String command = intent.getStringExtra("command");
Bundle b = new Bundle();
if(command.equals("query") {
receiver.send(STATUS_RUNNING, Bundle.EMPTY);
try {
// get some data or something
b.putParcelableArrayList("results", results);
receiver.send(STATUS_FINISHED, b)
} catch(Exception e) {
b.putString(Intent.EXTRA_TEXT, e.toString());
receiver.send(STATUS_ERROR, b);
}
}
}
}
ResultReceiver扩展 - 编辑即将实现MyResultReceiver.Receiver
public class MyResultReceiver implements ResultReceiver {
private Receiver mReceiver;
public MyResultReceiver(Handler handler) {
super(handler);
}
public void setReceiver(Receiver receiver) {
mReceiver = receiver;
}
public interface Receiver {
public void onReceiveResult(int resultCode, Bundle resultData);
}
@Override
protected void onReceiveResult(int resultCode, Bundle resultData) {
if (mReceiver != null) {
mReceiver.onReceiveResult(resultCode, resultData);
}
}
}
开发Android REST客户端应用程序对我来说是一个很棒的资源。 演讲者没有显示任何代码,他只是在设计考虑和技术上将Android中的一个坚实的Rest Api放在一起。 如果你的播客有点不喜欢,我建议至少给一个听一个听,但个人来说,我已经听过这样的4到5次了,我可能会再听一次。
开发Android REST客户端应用程序
作者:Virgil Dobjanschi
描述:
此会话将介绍在Android平台上开发RESTful应用程序的体系结构注意事项。 它专注于Android平台特有的设计模式,平台集成和性能问题。
在我的API的第一个版本中,我真的没有做过很多考虑,我不得不重构
同样,当我点击帖子(Config.getURL(“login”))时,应用程序似乎暂停了一段时间(看起来很奇怪 - 认为服务背后的想法是它运行在不同的线程上)!
不,你必须自己创建一个线程,本地服务默认在UI线程中运行。
链接地址: http://www.djcxy.com/p/34405.html上一篇: Restful API service
下一篇: Android speech recognition conflicting with Text to Speech