android记事本app源码

package stu.memo.login; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.io.RandomAccessFile; import java.net.HttpURLConnection; import java.net.MalformedURLException; import java.net.URL; import java.net.URLConnection; import junit.framework.Assert; import android.app.Activity; import android.app.AlertDialog; import android.app.Dialog; import android.app.ProgressDialog; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Bitmap.CompressFormat; import android.graphics.BitmapFactory; import android.text.TextUtils; import android.util.Log; import android.widget.Toast; public class Util { private static final String TAG = "SDK_Sample.Util"; private static Dialog mProgressDialog; private static Toast mToast; /* * Convert byte[] to hex * string.这里我们可以将byte转换成int，然后利用Integer.toHexString(int)来转换成16进制字符串。 * * @param src byte[] data * * @return hex string */ public static String bytesToHexString(byte[] src) { StringBuilder stringBuilder = new StringBuilder(""); if (src == null || src.length <= 0) { return null; } for (int i = 0; i < src.length; i++) { int v = src[i] & 0xFF; String hv = Integer.toHexString(v); if (hv.length() < 2) { stringBuilder.append(0); } stringBuilder.append(hv); } return stringBuilder.toString(); } /** * Convert hex string to byte[] * * @param hexString * the hex string * @return byte[] */ public static byte[] hexStringToBytes(String hexString) { if (hexString == null || hexString.equals("")) { return null; } hexString = hexString.toUpperCase(); int length = hexString.length() / 2; char[] hexChars = hexString.toCharArray(); byte[] d = new byte[length]; for (int i = 0; i < length; i++) { int pos = i * 2; d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1])); } return d; } /** * Convert char to byte * * @param c * char * @return byte */ private static byte charToByte(char c) { return (byte) "0123456789ABCDEF".indexOf(c); } /* * 16进制数字字符集 */ private static String hexString = "0123456789ABCDEF"; /* * 将字符串编码成16进制数字,适用于所有字符（包括中文） */ public static String toHexString(String str) { // 根据默认编码获取字节数组 byte[] bytes = str.getBytes(); StringBuilder sb = new StringBuilder(bytes.length * 2); // 将字节数组中每个字节拆解成2位16进制整数 for (int i = 0; i < bytes.length; i++) { sb.append(hexString.charAt((bytes[i] & 0xf0) >> 4)); sb.append(hexString.charAt((bytes[i] & 0x0f) >> 0)); } return sb.toString(); } // 转换十六进制编码为字符串 public static String hexToString(String s) { if ("0x".equals(s.substring(0, 2))) { s = s.substring(2); } byte[] baKeyword = new byte[s.length() / 2]; for (int i = 0; i < baKeyword.length; i++) { try { baKeyword[i] = (byte) (0xff & Integer.parseInt(s.substring(i * 2, i * 2 + 2), 16)); } catch (Exception e) { e.printStackTrace(); } } try { s = new String(baKeyword, "utf-8");// UTF-16le:Not } catch (Exception e1) { e1.printStackTrace(); } return s; } public static byte[] bmpToByteArray(final Bitmap bmp, final boolean needRecycle) { ByteArrayOutputStream output = new ByteArrayOutputStream(); bmp.compress(CompressFormat.PNG, 100, output); if (needRecycle) { bmp.recycle(); } byte[] result = output.toByteArray(); try { output.close(); } catch (Exception e) { e.printStackTrace(); } return result; } public static byte[] getHtmlByteArray(final String url) { URL htmlUrl = null; InputStream inStream = null; try { htmlUrl = new URL(url); URLConnection connection = htmlUrl.openConnection(); HttpURLConnection httpConnection = (HttpURLConnection) connection; int responseCode = httpConnection.getResponseCode(); if (responseCode == HttpURLConnection.HTTP_OK) { inStream = httpConnection.getInputStream(); } } catch (MalformedURLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } byte[] data = inputStreamToByte(inStream); return data; } public static byte[] inputStreamToByte(InputStream is) { try { ByteArrayOutputStream bytestream = new ByteArrayOutputStream(); int ch; while ((ch = is.read()) != -1) { bytestream.write(ch); } byte imgdata[] = bytestream.toByteArray(); bytestream.close(); return imgdata; } catch (Exception e) { e.printStackTrace(); } return null; } public static byte[] readFromFile(String fileName, int offset, int len) { if (fileName == null) { return null; } File file = new File(fileName); if (!file.exists()) { Log.i(TAG, "readFromFile: file not found"); return null; } if (len == -1) { len = (int) file.length(); } Log.d(TAG, "readFromFile : offset = " + offset + " len = " + len + " offset + len = " + (offset + len)); if (offset < 0) { Log.e(TAG, "readFromFile invalid offset:" + offset); return null; } if (len <= 0) { Log.e(TAG, "readFromFile invalid len:" + len); return null; } if (offset + len > (int) file.length()) { Log.e(TAG, "readFromFile invalid file len:" + file.length()); return null; } byte[] b = null; try { RandomAccessFile in = new RandomAccessFile(fileName, "r"); b = new byte[len]; in.seek(offset); in.readFully(b); in.close(); } catch (Exception e) { Log.e(TAG, "readFromFile : errMsg = " + e.getMessage()); e.printStackTrace(); } return b; } public static int computeSampleSize(BitmapFactory.Options options, int minSideLength, int maxNumOfPixels) { int initialSize = computeInitialSampleSize(options, minSideLength, maxNumOfPixels); int roundedSize; if (initialSize <= 8) { roundedSize = 1; while (roundedSize < initialSize) { roundedSize <<= 1; } } else { roundedSize = (initialSize + 7) / 8 * 8; } return roundedSize; } private static int computeInitialSampleSize(BitmapFactory.Options options, int minSideLength, int maxNumOfPixels) { double w = options.outWidth; double h = options.outHeight; int lowerBound = (maxNumOfPixels == -1) ? 1 : (int) Math.ceil(Math.sqrt(w * h / maxNumOfPixels)); int upperBound = (minSideLength == -1) ? 128 : (int) Math.min(Math.floor(w / minSideLength), Math.floor(h / minSideLength)); if (upperBound < lowerBound) { // return the larger one when there is no overlapping zone. return lowerBound; } if ((maxNumOfPixels == -1) && (minSideLength == -1)) { return 1; } else if (minSideLength == -1) { return lowerBound; } else { return upperBound; } } /** * 以最省内存的方式读取图片 */ public static Bitmap readBitmap(final String path) { try { FileInputStream stream = new FileInputStream(new File(path + "test.jpg")); BitmapFactory.Options opts = new BitmapFactory.Options(); opts.inSampleSize = 8; opts.inPurgeable = true; opts.inInputShareable = true; Bitmap bitmap = BitmapFactory.decodeStream(stream, null, opts); return bitmap; } catch (Exception e) { return null; } } private static final int MAX_DECODE_PICTURE_SIZE = 1920 * 1440; public static Bitmap extractThumbNail(final String path, final int height, final int width, final boolean crop) { Assert.assertTrue(path != null && !path.equals("") && height > 0 && width > 0); BitmapFactory.Options options = new BitmapFactory.Options(); try { options.inJustDe