Java数据转化工具类

最近在做项目的过程中涉及到许多数据转化，比如int转byte等，然后为了简化单独做类一个工具类，里面有大多数数据转化的方法可以直接调用，放在博客里面记录一下。

package com.example.rkt.utils;

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.ImageFormat;
import android.graphics.Rect;
import android.graphics.YuvImage;

import com.example.rkt.ui.NV21ToBitmap;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import android.util.Base64;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

public class ConvertUtil {
    private static NV21ToBitmap nv21ToBitmap;
    public static int byteArrayToInt(byte[] bytes) {
        int value = 0;
        // 由高位到低位
        for (int i = 0; i < bytes.length; i++) {
            int shift = (bytes.length - 1 - i) * 8;
            value += (bytes[i] & 0x000000FF) << shift;// 往高位游
        }
        return value;
    }

    public static int byteArrayToInt(byte[] bytes, int index, int len) {
        int value = 0;
        // 由高位到低位
        for (int i = 0; i < len; i++) {
            int shift = (len - 1 - i) * 8;
            value += (bytes[index + i] & 0x000000FF) << shift;// 往高位游
        }
        return value;
    }

    public static byte[] intToByteArray(int it, int byteLen) {
        byte[] result = new byte[byteLen];

        for(int i = 0; i < byteLen; ++i) {
            result[byteLen - i - 1] = (byte)(it >> 8 * i & 255);
        }
        return result;
    }

    public static byte[] longToByteArray(long it, int byteLen) {
        byte[] result = new byte[byteLen];

        for(int i = 0; i < byteLen; ++i) {
            result[byteLen - i - 1] = (byte)(it >> 8 * i & 65535);
        }

        return result;
    }

    public static String bytesToHexString(byte[] src, int start, int len) {
        StringBuilder stringBuilder = new StringBuilder("");
        if (src != null && len > 0) {
            for(int i = start; i < start + len; ++i) {
                int v = src[i] & 255;
                String hv = Integer.toHexString(v).toUpperCase();
                if (hv.length() < 2) {
                    stringBuilder.append(0);
                }

                stringBuilder.append(hv);
            }

            return stringBuilder.toString();
        } else {
            return null;
        }
    }

    public static int byteToStringInt(byte b) {
        return Integer.valueOf(bytesToHexString(new byte[]{b}, 0, 1));
    }

    public static byte[] hexStringToBytes(String hexString) {
        if (hexString != null && !hexString.equals("")) {
            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;
        } else {
            return null;
        }
    }
    private static byte charToByte(char c) {
        return (byte)"0123456789ABCDEF".indexOf(c);
    }

    public static byte[] float2byte(float f) {
         // 把float转换为byte[]
         int fbit = Float.floatToIntBits(f);
         byte[] b = new byte[4];
         for (int i = 0; i < 4; i++) {
             b[i] = (byte) (fbit >> (24 - i * 8));
         }
         // 翻转数组
         int len = b.length;
         // 建立一个与源数组元素类型相同的数组
         byte[] dest = new byte[len];
         // 为了防止修改源数组，将源数组拷贝一份副本
         System.arraycopy(b, 0, dest, 0, len);
         byte temp;
         // 将顺位第i个与倒数第i个交换
         for (int i = 0; i < len / 2; ++i) {
             temp = dest[i];
             dest[i] = dest[len - i - 1];
             dest[len - i - 1] = temp;
         }
         return dest;
    }

    public static float byte2float(byte[] b) {
        int l;
        l = b[0];
        l &= 0xff;
        l |= ((long) b[1] << 8);
        l &= 0xffff;
        l |= ((long) b[2] << 16);
        l &= 0xffffff;
        l |= ((long) b[3] << 24);
        return Float.intBitsToFloat(l);
    }

    public static Bitmap createQRCode(byte[] bytes, int widthPix, int heightPix) {
        try {
            String content =hexToString(bytesToHexString(bytes, 0, bytes.length));

            // 配置参数
            Map hints = new HashMap<>();
            hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
            // 容错级别
            hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
            // 图像数据转换，使用了矩阵转换
            BitMatrix bitMatrix = new QRCodeWriter().encode(content, BarcodeFormat.QR_CODE, widthPix,
                    heightPix, hints);
            int[] pixels = new int[widthPix * heightPix];
            // 下面这里按照二维码的算法，逐个生成二维码的图片，
            // 两个for循环是图片横列扫描的结果
            for (int y = 0; y < heightPix; y++) {
                for (int x = 0; x < widthPix; x++) {
                    if (bitMatrix.get(x, y)) {
                        pixels[y * widthPix + x] = 0xff000000;
                    } else {
                        pixels[y * widthPix + x] = 0xffffffff;
                    }
                }
            }
            // 生成二维码图片的格式，使用ARGB_8888
            Bitmap bitmap = Bitmap.createBitmap(widthPix, heightPix, Bitmap.Config.ARGB_8888);
            bitmap.setPixels(pixels, 0, widthPix, 0, 0, widthPix, heightPix);
            return bitmap;
        } catch (WriterException e) {
            e.printStackTrace();
        }
        return null;
    }

    public static String hexToString(String hex) {
        StringBuilder sb = new StringBuilder();
        for (int count = 0; count < hex.length() - 1; count += 2) {
            String output = hex.substring(count, (count + 2));    //grab the hex in pairs
            int decimal = Integer.parseInt(output, 16);    //convert hex to decimal
            sb.append((char) decimal);    //convert the decimal to character
        }
        return sb.toString();
    }

    public static int dip2Px(int dip, Context context) {
        // px/dip = density;
        // density = dpi/160
        // 320*480 density = 1 1px = 1dp
        // 1280*720 density = 2 2px = 1dp
        float density = context.getResources().getDisplayMetrics().density;
        int px = (int) (dip * density + 0.5f);
        return px;
    }

    public static short bytes2Short(byte[] b, int index) {
        return (short) (((b[index + 1] << 8) | b[index + 0] & 0xff));
    }

    public static byte[] getBytesFrombytes(byte[] bytes, int index, int len) {
        byte[] newBytes = new byte[len];
        System.arraycopy(bytes, index, newBytes, 0, len);
        return newBytes;
    }

    public static boolean equals(byte[] data0, byte[] data1) {
        if (data0.length != data1.length){
            return false;
        }
        for(int i = 0; i < data1.length; i++){
            if (data0[i] != data1[i]){
                return false;
            }
        }
        return true;
    }

    public static boolean isDateExpire(Date currentDate, byte cardDay, byte cardMonth, byte cardYear) {
        int currentYear = currentDate.getYear() - 2000;
        if (currentYear == cardYear){
            if (cardMonth == currentDate.getMonth()){
                return currentDate.getDay() > cardDay;
            }else {
                return currentDate.getMonth() > cardMonth;
            }
        }else {
            return currentYear > cardYear;
        }
    }

    public static void setNv21ToBitmap(Context context){
        nv21ToBitmap = new NV21ToBitmap(context);
    }

    public static Bitmap nv21ToBitmap(byte[] nv21, int width, int height) {
        return nv21ToBitmap.nv21ToBitmap(nv21, width, height);
    }


    public static byte[] base64ToBytes(String faceFeature) {
        return Base64.decode(faceFeature, Base64.NO_WRAP);
    }

    public static Bitmap cropBitmap(Bitmap bitmap, Rect rect) {
        int x = rect.left;
        if (rect.left - 20 > 0){
            x = rect.left - 20;
        }
        int y = rect.right;
        if (rect.top - 40 > 0){
            y = rect.top-40;
        }
        int width = rect.right - rect.left;
        if ((rect.right - rect.left + 40 + x) < bitmap.getWidth() && (rect.right - rect.left + 40) < bitmap.getWidth()){
            width = rect.right - rect.left + 40;
        }
        int height = rect.bottom - rect.top;
        if ((rect.bottom - rect.top+80+ y) < bitmap.getHeight() &&  (rect.bottom - rect.top+80) < bitmap.getHeight()){
            height = rect.bottom - rect.top+80;
        }
        return Bitmap.createBitmap(bitmap, x, y, width, height, null, false);
    }

    public static String asciiToString(char code) {
        StringBuffer sbu = new StringBuffer();
        sbu.append((char) code);
        return sbu.toString();
    }
}