package com.horizon.action;

import java.io.ByteArrayOutputStream;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.IOException;

import javax.imageio.stream.FileImageInputStream;

import javax.imageio.stream.FileImageOutputStream;

public class Hello {

    // 图片到byte数组

    public byte[] image2byte(String path) {

        byte[] data = null;

        FileImageInputStream input = null;

        try {

            input = new FileImageInputStream(new File(path));

            ByteArrayOutputStream output = new ByteArrayOutputStream();

            byte[] buf = new byte[];

            int numBytesRead = ;

            while ((numBytesRead = input.read(buf)) != -) {

                output.write(buf, , numBytesRead);

            }

            data = output.toByteArray();

            output.close();

            input.close();

        } catch (FileNotFoundException ex1) {

            ex1.printStackTrace();

        } catch (IOException ex1) {

            ex1.printStackTrace();

        }

        return data;

    }

    // byte数组到图片

    public void byte2image(byte[] data, String path) {

        if (data.length <  || path.equals(""))

            return;

        try {

            FileImageOutputStream imageOutput = new FileImageOutputStream(

                    new File(path));

            imageOutput.write(data, , data.length);

            imageOutput.close();

            System.out.println("Make Picture success,Please find image in "

                    + path);

        } catch (Exception ex) {

            System.out.println("Exception: " + ex);

            ex.printStackTrace();

        }

    }

    /**

     * 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 <= ) {

            return null;

        }

        for (int i = ; i < src.length; i++) {

            int v = src[i] & 0xFF;

            String hv = Integer.toHexString(v);

            if (hv.length() < ) {

                stringBuilder.append();

            }

            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() / ;

        char[] hexChars = hexString.toCharArray();

        byte[] d = new byte[length];

        for (int i = ; i < length; i++) {

            int pos = i * ;

            d[i] = (byte) (charToByte(hexChars[pos]) <<  | charToByte(hexChars[pos + ]));

        }

        return d;

    }

    /**

     * Convert char to byte

     *

     * @param c

     *            char

     * @return byte

     */

    private static byte charToByte(char c) {

        return (byte) "0123456789ABCDEF".indexOf(c);

    }

    @SuppressWarnings("static-access")

    public static void main(String[] args) {

        String fromPath = "C:/Users/Administrator/123.jpg";

        String toPath = "C:/Users/Administrator/456.jpg";

        Hello hello = new Hello();

        byte[] bytes = hello.image2byte(fromPath);

        String hexString = hello.bytesToHexString(bytes);

        byte[] bytes2 = hello.hexStringToBytes(hexString);

        hello.byte2image(bytes2, toPath);

    }

}