Java tutorial
/* * Copyright (C) 2009 The Android Open Source Project * * 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. */ package com.gadelkareem.serverload; import android.app.Activity; import android.appwidget.AppWidgetManager; import android.content.Context; import android.content.Intent; import android.content.SharedPreferences; import android.os.Bundle; import android.util.Log; import android.view.View; import android.webkit.URLUtil; import android.widget.EditText; import android.widget.Toast; import java.io.ByteArrayOutputStream; import java.io.InputStream; import java.util.ArrayList; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.StatusLine; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.DefaultHttpClient; public class ServerLoadConfig extends Activity { static final String TAG = "ServerLoadConfig"; private static final String PREFS_NAME = "com.gadelkareem.serverload.ServerLoadProvider"; private static final String PREF_PREFIX_KEY = "SERVERLOAD_"; int appWidgetId = AppWidgetManager.INVALID_APPWIDGET_ID; EditText servername_Input, URL_Input; public ServerLoadConfig() { super(); } @Override public void onCreate(Bundle icicle) { super.onCreate(icicle); // Set the result to CANCELED. This will cause the widget host to cancel // out of the widget placement if they press the back button. setResult(RESULT_CANCELED); // Set the view layout resource to use. setContentView(R.layout.serverload_config); // Find the EditText URL_Input = (EditText) findViewById(R.id.URL); servername_Input = (EditText) findViewById(R.id.servername); // Bind the action for the save button. findViewById(R.id.save_button).setOnClickListener(mOnClickListener); // Find the widget id from the intent. Intent intent = getIntent(); Bundle extras = intent.getExtras(); if (extras != null) { appWidgetId = extras.getInt(AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID); } // If they gave us an intent without the widget id, just bail. if (appWidgetId == AppWidgetManager.INVALID_APPWIDGET_ID) { Log.d(TAG, "Widget id is invalid"); finish(); } URL_Input.setText(loadPref(ServerLoadConfig.this, appWidgetId, "URL")); servername_Input.setText(loadPref(ServerLoadConfig.this, appWidgetId, "servername")); } View.OnClickListener mOnClickListener = new View.OnClickListener() { public void onClick(View v) { final Context context = ServerLoadConfig.this; // When the button is clicked, save the string in our prefs and // return that they // clicked OK. String URL = URL_Input.getText().toString(); String servername = servername_Input.getText().toString(); String error = ""; // check URL syntax if (!URLUtil.isValidUrl(URL)) { error = "Please enter a valid URL"; } else if (getUrlContent(URL) == "") { error = "Could not retrieve your URL, Check your connection"; } if (error != "") { Toast toast = Toast.makeText(context, error, Toast.LENGTH_LONG); toast.show(); return; } savePref(context, appWidgetId, "URL", URL); savePref(context, appWidgetId, "servername", servername); // Log.d(TAG, "Prefs saved :" + titlePrefix); // Push widget update to surface with newly set prefix AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context); ServerLoadProvider.updateAppWidget(context, appWidgetManager, appWidgetId, URL, servername); // Make sure we pass back the original appWidgetId Intent resultValue = new Intent(); resultValue.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId); setResult(RESULT_OK, resultValue); finish(); } }; // Write the prefix to the SharedPreferences object for this widget static void savePref(Context context, int appWidgetId, String type, String text) { SharedPreferences.Editor prefs = context.getSharedPreferences(PREFS_NAME, 0).edit(); prefs.putString(PREF_PREFIX_KEY + type + appWidgetId, text); prefs.commit(); } // Read the prefix from the SharedPreferences object for this widget. // If there is no preference saved, get the default from a resource static String loadPref(Context context, int appWidgetId, String type) { SharedPreferences prefs = context.getSharedPreferences(PREFS_NAME, 0); String result = prefs.getString(PREF_PREFIX_KEY + type + appWidgetId, null); if (result != null) { return result; } else { return ""; } } /** * Pull the raw text content of the given URL. This call blocks until the * operation has completed, and is synchronized because it uses a shared * * @param url The exact URL to request. * @return The raw content returned by the server. */ protected static synchronized String getUrlContent(String url) { byte[] sBuffer = new byte[512]; // Create client and set our specific user-agent string HttpClient client = new DefaultHttpClient(); HttpGet request = new HttpGet(url); Log.d(TAG, "opening : " + url); try { HttpResponse response = client.execute(request); // Log.d( TAG, "getting status : " + url ); // Check if server response is valid StatusLine status = response.getStatusLine(); if (status.getStatusCode() != 200) { Log.d(TAG, "Invalid response from server: " + status.toString()); return ""; } // Pull content stream from response HttpEntity entity = response.getEntity(); InputStream inputStream = entity.getContent(); ByteArrayOutputStream content = new ByteArrayOutputStream(); // Read response into a buffered stream int readBytes = 0; while ((readBytes = inputStream.read(sBuffer)) != -1) { content.write(sBuffer, 0, readBytes); } // Return result from buffered stream return new String(content.toByteArray()); } catch (Exception e) { Log.d(TAG, "Problem communicating with API : " + e); return ""; } } static void deletePref(Context context, int appWidgetId) { } static void loadAllPrefs(Context context, ArrayList<Integer> appWidgetIds, ArrayList<String> URLs, ArrayList<String> servernames) { } }