Android 常见工具类封装
1,MD5工具类:
public class MD5Util { public final static String MD5(String s) { char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; try { byte[] btInput = s.getBytes(); // 获得MD5摘要算法的 MessageDigest 对象 MessageDigest mdInst = MessageDigest.getInstance("MD5"); // 使用指定的字节更新摘要 mdInst.update(btInput); // 获得密文 byte[] md = mdInst.digest(); // 把密文转换成十六进制的字符串形式 int j = md.length; char str[] = new char[j * 2]; int k = 0; for (int i = 0; i < j; i++) { byte byte0 = md[i]; str[k++] = hexDigits[byte0 >>> 4 & 0xf]; str[k++] = hexDigits[byte0 & 0xf]; } return new String(str); } catch (Exception e) { return null; } } public static void main(String[] args) { System.out.print(MD5Util.MD5("password")); } }
2,线程睡眠
public class CSleep { public static final long DEFAULT_SLEEP_TIME = 500; private boolean isRuning = false; public boolean isRuning() { return isRuning; } public void runWithTime(final long defaultSleepTime) { isRuning = true; new Thread() { @Override public void run() { try { sleep(defaultSleepTime, 0); } catch (InterruptedException e) { e.printStackTrace(); } isRuning = false; super.run(); } }.start(); } }
3,检查网络是否连通
/** * 检查网络是否连通 * * @return boolean * @since V1.0 */ public boolean isNetworkAvailable(Context context) { // 创建并初始化连接对象 ConnectivityManager connMan = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); // 判断初始化是否成功并作出相应处理 if (connMan != null) { // 调用getActiveNetworkInfo方法创建对象,如果不为空则表明网络连通,否则没连通 NetworkInfo info = connMan.getActiveNetworkInfo(); if (info != null) { return info.isAvailable(); } } return false; }
4,异常类捕捉
/** * UncaughtException处理类,当程序发生Uncaught异常的时候,由该类来接管程序,并记录发送错误报告. 需要在Application中注册,为了要在程序启动器就监控整个程序。 */ public class CrashHandler implements UncaughtExceptionHandler { /** TAG */ public static final String TAG = "CrashHandler"; /** 系统默认的UncaughtException处理类 */ private Thread.UncaughtExceptionHandler mDefaultHandler; /** CrashHandler实例 */ private static CrashHandler mCrashHandler; /** 程序的Context对象 */ private Context mContext; /** 用来存储设备信息和异常信息 */ private Map<String, String> infos = new HashMap<String, String>(); /** 用于格式化日期,作为日志文件名的一部分 */ private DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss"); /** * 私有构造函数 */ private CrashHandler() { } /** * 获取CrashHandler实例 ,单例模式 * * @return * @since V1.0 */ public static CrashHandler getInstance() { if (mCrashHandler == null) mCrashHandler = new CrashHandler(); return mCrashHandler; } /** * 初始化 * * @param context * @since V1.0 */ public void init(Context context) { mContext = context; // 获取系统默认的UncaughtException处理器 mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler(); // 设置该CrashHandler为程序的默认处理器 Thread.setDefaultUncaughtExceptionHandler(this); } /** * 当UncaughtException发生时会转入该函数来处理 */ @Override public void uncaughtException(Thread thread, Throwable ex) { if (!handleException(ex) && mDefaultHandler != null) { // 如果用户没有处理则让系统默认的异常处理器来处理 mDefaultHandler.uncaughtException(thread, ex); } else { try { Thread.sleep(3000); } catch (InterruptedException e) { CLog.e(TAG, "uncaughtException() InterruptedException:" + e); } // 退出程序 android.os.Process.killProcess(android.os.Process.myPid()); System.exit(1); } } /** * 自定义错误处理,收集错误信息 发送错误报告等操作均在此完成. * * @param ex * @return true:如果处理了该异常信息;否则返回false. * @since V1.0 */ private boolean handleException(Throwable ex) { if (ex == null) { return false; } // 收集设备参数信息 collectDeviceInfo(mContext); // 使用Toast来显示异常信息 new Thread() { @Override public void run() { Looper.prepare(); Toast.makeText(mContext, "很抱歉,程序出现异常,即将退出.", Toast.LENGTH_SHORT).show(); Looper.loop(); } }.start(); // 保存日志文件 saveCatchInfo2File(ex); return true; } /** * 收集设备参数信息 * * @param ctx * @since V1.0 */ public void collectDeviceInfo(Context ctx) { try { PackageManager pm = ctx.getPackageManager(); PackageInfo pi = pm.getPackageInfo(ctx.getPackageName(), PackageManager.GET_ACTIVITIES); if (pi != null) { String versionName = pi.versionName == null ? "null" : pi.versionName; String versionCode = pi.versionCode + ""; infos.put("versionName", versionName); infos.put("versionCode", versionCode); } } catch (NameNotFoundException e) { CLog.e(TAG, "collectDeviceInfo() an error occured when collect package info NameNotFoundException:", e); } Field[] fields = Build.class.getDeclaredFields(); for (Field field : fields) { try { field.setAccessible(true); infos.put(field.getName(), field.get(null).toString()); CLog.d(TAG, field.getName() + " : " + field.get(null)); } catch (Exception e) { CLog.e(TAG, "collectDeviceInfo() an error occured when collect crash info Exception:", e); } } } /** * 保存错误信息到文件中 * * @param ex * @return 返回文件名称,便于将文件传送到服务器 */ private String saveCatchInfo2File(Throwable ex) { StringBuffer sb = new StringBuffer(); for (Map.Entry<String, String> entry : infos.entrySet()) { String key = entry.getKey(); String value = entry.getValue(); sb.append(key + "=" + value + "\n"); } Writer writer = new StringWriter(); PrintWriter printWriter = new PrintWriter(writer); ex.printStackTrace(printWriter); Throwable cause = ex.getCause(); while (cause != null) { cause.printStackTrace(printWriter); cause = cause.getCause(); } printWriter.close(); String result = writer.toString(); sb.append(result); try { long timestamp = System.currentTimeMillis(); String time = formatter.format(new Date()); String fileName = "crash-" + time + "-" + timestamp + ".log"; if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { String path = FilePathUtil.getiVMSDirPath() + "/crash/"; File dir = new File(path); if (!dir.exists()) { dir.mkdirs(); } FileOutputStream fos = new FileOutputStream(path + fileName); fos.write(sb.toString().getBytes()); // 发送给开发人员 sendCrashLog2PM(path + fileName); fos.close(); } return fileName; } catch (Exception e) { CLog.e(TAG, "saveCatchInfo2File() an error occured while writing file... Exception:", e); } return null; } /** * 将捕获的导致崩溃的错误信息发送给开发人员 目前只将log日志保存在sdcard 和输出到LogCat中,并未发送给后台。 * * @param fileName * @since V1.0 */ private void sendCrashLog2PM(String fileName) { if (!new File(fileName).exists()) { CLog.e(TAG, "sendCrashLog2PM() 日志文件不存在"); return; } FileInputStream fis = null; BufferedReader reader = null; String s = null; try { fis = new FileInputStream(fileName); reader = new BufferedReader(new InputStreamReader(fis, "GBK")); while (true) { s = reader.readLine(); if (s == null) break; // 由于目前尚未确定以何种方式发送,所以先打出log日志。 CLog.e(TAG, s); } } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { // 关闭流 try { reader.close(); fis.close(); } catch (IOException e) { e.printStackTrace(); } } } }
5,弹出框提醒
public static Dialog showDialog(Context ctx, int layViewID, int ThemeType) { Dialog res = new Dialog(ctx, ThemeType); res.setContentView(layViewID); return res; }
6,图片API类
public class ImageAPI { public static Bitmap getImageByFilePath(String filePath, int scale) { Bitmap res = null; BitmapFactory.Options options = new BitmapFactory.Options(); options.inJustDecodeBounds = true; BitmapFactory.decodeFile(filePath, options); options.inJustDecodeBounds = false; options.inSampleSize = scale; options.inPreferredConfig = Bitmap.Config.ARGB_4444; return res; } public static Bitmap getImageByFilePath(String filePath, int Towidth, int ToHeight) { Bitmap res = null; BitmapFactory.Options options = new BitmapFactory.Options(); options.inJustDecodeBounds = true; if (!new File(filePath).exists()) return res; BitmapFactory.decodeFile(filePath, options); int origionalWidth = options.outHeight; int origionalHeight = options.outWidth; options.inJustDecodeBounds = false; int scale = Math.max(origionalWidth / Towidth, origionalHeight / ToHeight); options.inSampleSize = scale; options.inPreferredConfig = Bitmap.Config.ARGB_4444; try { res = BitmapFactory.decodeFile(filePath, options); } catch (Exception e) { e.printStackTrace(); return null; } catch (OutOfMemoryError e) { e.printStackTrace(); return null; } return res; } }
10,提醒封装类
public static void showToast(Context ctx, int id, String str) { if (str == null) { return; } Toast toast = Toast.makeText(ctx, ctx.getString(id) + str, Toast.LENGTH_SHORT); toast.setGravity(Gravity.CENTER, 0, 0); toast.show(); } public static void showToast(Context ctx, String errInfo) { if (errInfo == null) { return; } Toast toast = Toast.makeText(ctx, errInfo, Toast.LENGTH_SHORT); toast.setGravity(Gravity.CENTER, 0, 0); toast.show(); }
阅读扩展
源于对掌握的Android开发基础点进行整理,罗列下已经总结的文章,从中可以看到技术积累的过程。
17,View 的事件体系
18,View 的工作原理
22,Android 性能优化
23,Android 消息机制