Java tutorial
/*** Copyright (c) 2008-2014 CommonsWare, LLC Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0. Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. From _The Busy Coder's Guide to Advanced Android Development_ https://commonsware.com/AdvAndroid */ package com.commonsware.android.advservice.remotebinding.sigcheck; import android.app.Application; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.content.ServiceConnection; import android.content.pm.ResolveInfo; import android.content.pm.ServiceInfo; import android.os.Bundle; import android.os.IBinder; import android.os.RemoteException; import android.support.v4.app.Fragment; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import android.widget.Button; import android.widget.Toast; import com.commonsware.android.advservice.remotebinding.IDownload; import com.commonsware.cwac.security.SignatureUtils; import java.util.List; public class DownloadFragment extends Fragment implements OnClickListener, ServiceConnection { private static final String TO_DOWNLOAD = "https://commonsware.com/Android/excerpt.pdf"; private IDownload binding = null; private Button btn = null; private Application appContext = null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setRetainInstance(true); appContext = (Application) getActivity().getApplicationContext(); Intent implicit = new Intent(IDownload.class.getName()); List<ResolveInfo> matches = getActivity().getPackageManager().queryIntentServices(implicit, 0); if (matches.size() == 0) { Toast.makeText(getActivity(), "Cannot find a matching service!", Toast.LENGTH_LONG).show(); } else if (matches.size() > 1) { Toast.makeText(getActivity(), "Found multiple matching services!", Toast.LENGTH_LONG).show(); } else { ServiceInfo svcInfo = matches.get(0).serviceInfo; try { String otherHash = SignatureUtils.getSignatureHash(getActivity(), svcInfo.applicationInfo.packageName); String expected = getActivity().getString(R.string.expected_sig_hash); if (expected.equals(otherHash)) { Intent explicit = new Intent(implicit); ComponentName cn = new ComponentName(svcInfo.applicationInfo.packageName, svcInfo.name); explicit.setComponent(cn); appContext.bindService(explicit, this, Context.BIND_AUTO_CREATE); } else { Toast.makeText(getActivity(), "Unexpected signature found!", Toast.LENGTH_LONG).show(); } } catch (Exception e) { Log.e(getClass().getSimpleName(), "Exception trying to get signature hash", e); } } } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View result = inflater.inflate(R.layout.main, container, false); btn = (Button) result.findViewById(R.id.go); btn.setOnClickListener(this); btn.setEnabled(binding != null); return (result); } @Override public void onDestroy() { if (binding != null) { appContext.unbindService(this); } disconnect(); super.onDestroy(); } @Override public void onClick(View view) { try { binding.download(TO_DOWNLOAD); } catch (RemoteException e) { Log.e(getClass().getSimpleName(), "Exception requesting download", e); Toast.makeText(getActivity(), e.getMessage(), Toast.LENGTH_LONG).show(); } } @Override public void onServiceConnected(ComponentName className, IBinder binder) { binding = IDownload.Stub.asInterface(binder); btn.setEnabled(true); } @Override public void onServiceDisconnected(ComponentName className) { disconnect(); } private void disconnect() { binding = null; btn.setEnabled(false); } }