Android常用数据类型转换

String转int、float、double、byte[]、bitmap

Int i = Integer.parseInt(str); Float f = Float.parseFloat(str); Double d = Double.parseDouble(str);   //将16进制字符串转byte数组public static byte[] hexStringToByte(String str) {        if(str == null || str.trim().equals("")) {             return new byte[0];        }    　　 byte[] bytes = new byte[str.length() / 2];        for(int i = 0; i < str.length() / 2; i++) {            String subStr = str.substring(i * 2, i * 2 + 2);            bytes[i] = (byte) Integer.parseInt(subStr, 16);        }        return bytes;}String.format("%04x", i);//将10进制整形转16进制字符串，%04x2字节表示不足位补0//将String字符串转回Bitmappublic Bitmap stringToBitmap(String string) {    　　Bitmap bitmap = null;    　　try {         　　byte[] bitmapArray;        　　 bitmapArray = Base64.decode(string, Base64.DEFAULT);        　　 bitmap = BitmapFactory.decodeByteArray(bitmapArray, 0,bitmapArray.length);    　　} catch (Exception e) {        　　e.printStackTrace();    　　}    　　return bitmap;}

Int转string、byte[]

String str = String.valueOf(i);//效率最高//将Int转byte[]数组public static byte[] intToBytes2(int n){      byte[] b = new byte[4];      for(int i = 0;i < 4;i++){          b[i] = (byte)(n >> (24 - i * 8));       }      return b;}

Byte[]转string、int、bitmap

//byte数组转16进制字符串private String bytes2HexString(byte[] b, int length) {      StringBuilder r = new StringBuilder();      for (int i = 0; i < length; i++) {           String hex = Integer.toHexString(b[i] & 0xFF);           if (hex.length() == 1) {              hex = "0" + hex;           }           r.append(hex.toUpperCase());     }      return r.toString();}//byte数组转16进制字符串public static int byteToInt(byte[] b) {      int mask=0xff;      int temp=0;      int n=0;      for(int i=0;i){          n<<=8;          temp=b[i]&mask;          n|=temp;      }      return n;}//byte数组转bitmapbyte[] b = getIntent().getByteArrayExtra("bitmap");  Bitmap bitmap = BitmapFactory.decodeByteArray(b, 0, b.length); //将byte数组以16进制的形式打印到控制台public static void printHexString( byte[] b) {    StringBuilder str= new StringBuilder();    for (byte aB : b) {        String hex = Integer.toHexString(aB & 0xFF);        if (hex.length() == 1) {            hex = '0' + hex;        }        str.append(hex.toUpperCase()).append(" ");    }    Log.i("cmd", str.toString());}

Bitmap转string、byte[]

//将Bitmap转base64字符串ByteArrayOutputStream outputStream = new ByteArrayOutputStream();bitmap.compress(Bitmap.CompressFormat.JPEG,90,outputStream );//压缩90%byte[] imagebyte = outputStream.toByteArray();String imageStr = Base64.encode(imagebyte);//将Bitmap转byte[]ByteArrayOutputStream baos = new ByteArrayOutputStream();bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);byte[] datas = baos.toByteArray();

View转Bitmap

public static Bitmap view2Bitmap(View view) {      if (view == null) return null;      Bitmap ret = Bitmap.createBitmap(view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_8888);      Canvas canvas = new Canvas(ret);      Drawable bgDrawable = view.getBackground();      if (bgDrawable != null) {          bgDrawable.draw(canvas);      } else {          canvas.drawColor(Color.WHITE);      }      view.draw(canvas);      return ret;}

Gson高精度String、Float[]互转(测试可保留6位数以上)

//Float[]转Stringfloat feature[] = new float[256];Gson gson = new Gson();String str = gson.toJson(feature.clone());//String高精度还原Float[]Gson gson = new Gson();float[] f = gson.fromJson(str, float[].class);

CRC16检验

private int CRC16_Check(byte Pushdata[]){        int Reg_CRC=0xffff;        int temp;        int i,j;        //帧头校验字去掉        for( i = 2; i)        {            temp = Pushdata[i];            if(temp < 0) temp += 256;            temp &= 0xff;            Reg_CRC^= temp;            for (j = 0; j<8; j++)            {                if ((Reg_CRC & 0x0001) == 0x0001)                    Reg_CRC=(Reg_CRC>>1)^0xA001;                else                    Reg_CRC >>=1;            }        }        return (Reg_CRC&0xffff);    }