我就廢話不多說了，還是直接看代碼吧

public static byte[] readStream(String imagepath) throws Exception { FileInputStream fs = new FileInputStream(imagepath); ByteArrayOutputStream outStream = new ByteArrayOutputStream(); byte[] buffer = new byte[1024]; int len = 0; while (-1 != (len = fs.read(buffer))) { outStream.write(buffer, 0, len); } outStream.close(); fs.close(); return outStream.toByteArray();}// 二進制轉字符串public static String byte2hex(byte[] b){ StringBuffer sb = new StringBuffer(); String tmp = ''; for (int i = 0; i < b.length; i++) { tmp = Integer.toHexString(b[i] & 0XFF); if (tmp.length() == 1){ sb.append('0' + tmp); }else{ sb.append(tmp); } } return sb.toString();}

補充知識：圖片（bitmap）轉化為byte[]，并上傳到服務器

壓縮為3:1bitmap

/** * 壓縮bitmap * * @param bitmap * @return */ private Bitmap compressBitmap(Bitmap bitmap) { // 創建操作圖片用的matrix對象 Matrix matrix = new Matrix(); matrix.postScale((float) 300 / bitmap.getWidth(),(float) 100 / bitmap.getHeight()); Log.e('', 'bitmap_width' + bitmap.getWidth()); Log.e('', 'bitmap_height' + bitmap.getHeight()); Bitmap compressBitmap = Bitmap.createBitmap(bitmap, 0, 0,bitmap.getWidth(), bitmap.getHeight(), matrix, true); return compressBitmap; }

上傳壓縮后的bitmap

private void eleSignature() { WritePadDialog writeTabletDialog = new WritePadDialog(this, new DialogListener() { public void refreshActivity(Object object) {Bitmap mSignBitmap = (Bitmap) object;mSignBitmap = compressBitmap(mSignBitmap); //Bitmap newsrcImage = mSignBitmap.copy(Bitmap.Config.RGB_565, true);saveBmp(mSignBitmap);Log.e('', 'after bitmap_width:' + mSignBitmap.getWidth());Log.e('', 'after bitmap_height:' + mSignBitmap.getHeight());File file = new File(file_name);Log.e('Jeny', 'file.exists():' + file.exists());if (!file.exists()) { return;}byte[] eleSignatureData = null;try { eleSignatureData = InputStreamTOByte();} catch (IOException e) { }Log.e('Jeny', 'eleSignatureData:' + eleSignatureData.length);if (eleSignatureData == null) { return;} //byte[] eleSignatureData = InputStreamTOByte();//byte[] eleSignatureData = Bitmap2Bytes(newsrcImage);mController.startSavingElecSignatureDataOfSDPay(SalesCollectActivity.this, voucherNo, eleSignatureData);mSignBitmap.recycle(); } } ); writeTabletDialog.setCanceledOnTouchOutside(false); writeTabletDialog.setOnKeyListener(new DialogInterface.OnKeyListener() { @Override public boolean onKey(DialogInterface dialogInterface, int keyCode, KeyEvent keyEvent) {if (keyCode == KeyEvent.KEYCODE_BACK) { return true;} else { return false; //默認返回 false} } }); writeTabletDialog.show(); } /** * 將InputStream轉換成byte數組 * <p/> * InputStream * * @return byte[] * @throws IOException */ @SuppressWarnings('resource') public byte[] InputStreamTOByte() throws IOException { File file = new File(file_name); if (!file.exists()) { return null; } FileInputStream is = new FileInputStream(file_name); ByteArrayOutputStream outStream = new ByteArrayOutputStream(); byte[] data = new byte[BUFFER_SIZE]; int count = -1; while ((count = is.read(data, 0, BUFFER_SIZE)) != -1) outStream.write(data, 0, count); // data = null; byte[] alldata = outStream.toByteArray(); /**top = new byte[62]; for (int i = 0; i < 62; i++) { top[i] = alldata[i]; } writefile(top_name, top); */// byte[] other = new byte[alldata.length - 62];// for (int i = 0; i < (alldata.length - 62); i++)// {// other[i] = alldata[i + 62];// } /* * String b = * Environment.getExternalStorageDirectory().getPath()+'/other.txt'; * writefile(b, other); */ return alldata; } /** * @param bitmap 圖片以bmp格式存儲的方法 */ private void saveBmp(Bitmap bitmap) { if (bitmap == null) return; // 位圖大小 int nBmpWidth = bitmap.getWidth(); int nBmpHeight = bitmap.getHeight(); int DataSizePerLine = 40; // 圖像數據大小 int bufferSize = nBmpHeight * DataSizePerLine; try { // 存儲文件名 File file = new File(file_name); Log.i('SurFace', 'filename:' + file_name); if (!file.exists()) {file.createNewFile(); } FileOutputStream fileos = new FileOutputStream(file_name); // bmp文件頭 int bfType = 0x4d42; long bfSize = 14 + 40 + 8 + bufferSize; int bfReserved1 = 0; int bfReserved2 = 0; long bfOffBits = 14 + 40 + 8; // 保存bmp文件頭 writeWord(fileos, bfType); writeDword(fileos, bfSize); writeWord(fileos, bfReserved1); writeWord(fileos, bfReserved2); writeDword(fileos, bfOffBits); // bmp信息頭 long biSize = 40L; long biWidth = nBmpWidth; long biHeight = nBmpHeight; int biPlanes = 1; int biBitCount = 1; long biCompression = 0L; long biSizeImage = 0L; long biXpelsPerMeter = 0L; long biYPelsPerMeter = 0L; long biClrUsed = 0L; long biClrImportant = 0L; // 保存bmp信息頭 writeDword(fileos, biSize); writeLong(fileos, biWidth); writeLong(fileos, biHeight); writeWord(fileos, biPlanes); writeWord(fileos, biBitCount); writeDword(fileos, biCompression); writeDword(fileos, biSizeImage); writeLong(fileos, biXpelsPerMeter); writeLong(fileos, biYPelsPerMeter); writeDword(fileos, biClrUsed); writeDword(fileos, biClrImportant); // 調色板 byte[] c = new byte[4]; c[0] = 0; c[1] = 0; c[2] = 0; c[3] = 0; fileos.write(c); byte[] w = new byte[4]; w[0] = (byte) 255; w[1] = (byte) 255; w[2] = (byte) 255; w[3] = 0; fileos.write(w); int wWidth = DataSizePerLine; // 像素掃描 byte bmpData[] = new byte[bufferSize]; for (int ibuf = 0; ibuf < bufferSize; ibuf++)bmpData[ibuf] = (byte) 0xff; int iByte = 0; int iCount = 0; byte bPix = 0; for (int nCol = nBmpHeight - 1, nRealCol = nBmpHeight; nCol > 0; nCol--, nRealCol--) {wWidth = DataSizePerLine;iCount = 0;iByte = 0;for (int wRow = 0; wRow < nBmpWidth; wRow++) { int clr = bitmap.getPixel(wRow, nCol); int r = (clr | 0xff00ffff) >> 16 & 0x00ff; int g = Color.green(clr); int b = Color.blue(clr); // byte a = (byte) Color.blue(clr); // byte b = (byte) Color.green(clr); // byte d = (byte) Color.red(clr); // System.out.println('r:'+r); if (r != 255 || g != 255 || b != 255)// 黑色 { // bPix = (byte)(bPix & (0x7f>>iByte | // 0x7f<<(8-iByte))); bPix = (byte) (bPix & ~(byte) Math.pow(2, iByte)); // System.out.println( ' 黑色 ' + bPix ); } else { // bPix = (byte)(bPix & (0xff>>iByte | // 0xff<<(8-iByte))); bPix = (byte) (bPix | (byte) Math.pow(2, iByte)); // System.out.println( ' 白色 ' + bPix); } if (iCount != 0 && iCount % 8 == 0) { bmpData[nRealCol * wWidth - wRow / 8] = bPix; iByte = 0; } else { iByte++; } iCount++; /* * //if(a==b && b==d && a>0) if (nRealCol%2 == 0) { //為白色 * bmpData[nRealCol * wWidth] = (byte)255; }else{ //為黑色 * bmpData[nRealCol * wWidth] = 0; } */ // Arrays.fill(x, value); /* * bmpData[nRealCol * wWidth + wByteIdex] = (byte) Color .b; * bmpData[nRealCol * wWidth + wByteIdex + 1] = (byte) Color * .green(clr); bmpData[nRealCol * wWidth + wByteIdex + 2] = * (byte) Color .red(clr); */} } // System.out.println( ' iCount= ' + iCount); /* * byte[] writeByte = new byte[bmpData.length]; for(int * i=0;i<writeByte.length;i++){ writeByte[i] = * bmpData[bmpData.length-i-1]; } */ fileos.write(bmpData); fileos.flush(); fileos.close(); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } protected void writeWord(FileOutputStream stream, int value) throws IOException { byte[] b = new byte[2]; b[0] = (byte) (value & 0xff); b[1] = (byte) (value >> 8 & 0xff); stream.write(b); } protected void writeDword(FileOutputStream stream, long value) throws IOException { byte[] b = new byte[4]; b[0] = (byte) (value & 0xff); b[1] = (byte) (value >> 8 & 0xff); b[2] = (byte) (value >> 16 & 0xff); b[3] = (byte) (value >> 24 & 0xff); stream.write(b); } protected void writeLong(FileOutputStream stream, long value) throws IOException { byte[] b = new byte[4]; b[0] = (byte) (value & 0xff); b[1] = (byte) (value >> 8 & 0xff); b[2] = (byte) (value >> 16 & 0xff); b[3] = (byte) (value >> 24 & 0xff); stream.write(b); } /** * 壓縮bitmap * * @param bitmap * @return */ private Bitmap compressBitmap(Bitmap bitmap) { // 創建操作圖片用的matrix對象 Matrix matrix = new Matrix(); matrix.postScale((float) 300 / bitmap.getWidth(),(float) 100 / bitmap.getHeight()); Log.e('', 'bitmap_width' + bitmap.getWidth()); Log.e('', 'bitmap_height' + bitmap.getHeight()); Bitmap compressBitmap = Bitmap.createBitmap(bitmap, 0, 0,bitmap.getWidth(), bitmap.getHeight(), matrix, true); return compressBitmap; }

以上這篇Android 實現圖片轉二進制流及二進制轉字符串就是小編分享給大家的全部內容了，希望能給大家一個參考，也希望大家多多支持好吧啦網。