Java圖片與二進(jìn)制相互轉(zhuǎn)換實(shí)現(xiàn)示例講解

更新時(shí)間：2023年03月17日 10:58:11 作者：跟著飛哥學(xué)編程

這篇文章主要介紹了Java圖片與二進(jìn)制相互轉(zhuǎn)換實(shí)現(xiàn)示例，文中通過示例代碼介紹的非常詳細(xì)，對大家的學(xué)習(xí)或者工作具有一定的參考學(xué)習(xí)價(jià)值，需要的朋友們下面隨著小編來一起學(xué)習(xí)吧

1、下面是一個(gè)完整的代碼示例

指定文件路徑轉(zhuǎn)為二進(jìn)制
將網(wǎng)絡(luò)圖片轉(zhuǎn)為二進(jìn)制
base64 轉(zhuǎn)為圖片資源

package com.xxx.example.file;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import javax.imageio.ImageIO;
import com.zxtc.syonline.support.common.StringUtil;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
public class ImageBioChangeUtil {
	static BASE64Encoder encoder = new sun.misc.BASE64Encoder();   
    static BASE64Decoder decoder = new sun.misc.BASE64Decoder();
    //從文件路徑中獲取圖片轉(zhuǎn)為二進(jìn)制
	public static String getImageBinary(String filePath){
		if(StringUtil.isEmpty(filePath)) {
			return null;
		}
        File f = new File(filePath);	//這里gif動態(tài)圖不可以，雖然在后面也能輸出gif格式，但是卻不是動圖
        BufferedImage bi;   
        try {   
            bi = ImageIO.read(f);   
            ByteArrayOutputStream baos = new ByteArrayOutputStream();   
            ImageIO.write(bi, "jpg", baos);   
            byte[] bytes = baos.toByteArray();   
            return encoder.encodeBuffer(bytes).trim();   
        } catch (IOException e) {   
            e.printStackTrace();   
        }   
        return null;   
    }
	//從URl中獲取圖片轉(zhuǎn)為二進(jìn)制
	public static String getImageBinaryFromUrl(String urlPath) throws Exception{
		if(StringUtil.isEmpty(urlPath)) {
			return "";
		}
		URL url=new URL(urlPath);
        HttpURLConnection conn= (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("GET");
        conn.setConnectTimeout(3000);//超時(shí)提示1秒=1000毫秒
        InputStream inStream=conn.getInputStream();//獲取輸出流
        byte[] data=readInputStream(inStream);
		return encoder.encodeBuffer(data).trim();   
	}   
	 //readInputStream方法
    private static byte[] readInputStream(InputStream inStream) throws Exception{
        ByteArrayOutputStream outStream=new ByteArrayOutputStream();
        byte[] buffer=new byte[1024];//轉(zhuǎn)換為二進(jìn)制
        int len=0;
        while((len =inStream.read(buffer))!=-1){
            outStream.write(buffer,0,len);
        }
        return  outStream.toByteArray();
    }
    //將二進(jìn)制轉(zhuǎn)為圖片
    public static void base64StringToImage(String base64String,String outFilePath){
    	if(StringUtil.isNotEmpty(base64String)&&StringUtil.isNotEmpty(outFilePath)) {
    		try {   
                byte[] bytes1 = decoder.decodeBuffer(base64String);   
                ByteArrayInputStream bais = new ByteArrayInputStream(bytes1);   
                BufferedImage bi1 =ImageIO.read(bais);   
                File w2 = new File(outFilePath);//可以是jpg,png格式   
                if (!w2.exists()) {   //文件不存在則創(chuàng)建文件，先創(chuàng)建目錄
                    File dir = new File(w2.getParent());
                    dir.mkdirs();
                    w2.createNewFile(); // 創(chuàng)建新文件
                }
                ImageIO.write(bi1, "jpg", w2);//不管輸出什么格式圖片，此處不需改動   
            } catch (IOException e) {   
                e.printStackTrace();   
            }   
		}
    }
    public static void main(String[] args) {
    	String imageBinary=null;
		try {
			imageBinary = getImageBinaryFromUrl("");
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
        System.out.println(imageBinary);   
        String outFilePath= "E://test//bio//zhh/aa.png";   
        base64StringToImage(imageBinary,outFilePath);   
    }
}

2、如何判斷 base64 圖片的格式

//判斷圖片base64字符串的文件格式
	public static String checkImageBase64Format(String base64ImgData) {
		byte[] b = Base64Util.decode(base64ImgData);
		String type = "";
		if (0x424D == ((b[0] & 0xff) << 8 | (b[1] & 0xff))) {
			type = "bmp";
		} else if (0x8950 == ((b[0] & 0xff) << 8 | (b[1] & 0xff))) {
			type = "png";
		} else if (0xFFD8 == ((b[0] & 0xff) << 8 | (b[1] & 0xff))) {
			type = "jpg";
		}
		return type;
	}

3、將網(wǎng)絡(luò)圖片轉(zhuǎn)為 base64 字符串

	/**
     * 將網(wǎng)絡(luò)路徑圖片轉(zhuǎn)為base64的格式
     * @param requestUrl 請求網(wǎng)絡(luò)路徑
     * @throws Exception
     */
    public static String getUrlImageToBase64(String requestUrl) throws Exception {
        ByteArrayOutputStream data = new ByteArrayOutputStream();
        try {
            // 創(chuàng)建URL
            URL url = new URL(requestUrl);
            byte[] by = new byte[1024];
            // 創(chuàng)建鏈接
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");
            conn.setConnectTimeout(5 * 1000);
            InputStream is = conn.getInputStream();
            // 將內(nèi)容讀取內(nèi)存中
            int len = -1;
            while ((len = is.read(by)) != -1) {
                data.write(by, 0, len);
            }
            // 關(guān)閉流
            is.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        // 對字節(jié)數(shù)組Base64編碼
        Base64.Encoder encoder = Base64.getEncoder();
//        return "data:image/" + photoType + ";base64," + encoder.encodeToString(data.toByteArray());
        return encoder.encodeToString(data.toByteArray());
    }

4、將 base64 字符串轉(zhuǎn)為圖片輸出

	/**
	 * 將Base64編碼的字符串轉(zhuǎn)為文件輸出
	 * @param base64String 字符串
     * @param path 輸出文件保存路徑
	 * @param fileName 輸出文件名稱
	 * @return 是否轉(zhuǎn)換成功
	 */
	public static boolean writeFileFromBase64(String base64String, String path, String fileName) {
		if (base64String == null){
			return false;
		}
		try	{
			byte[] b = Base64Util.decode(base64String);
			File file = new File(path);
			if(!file.exists()){
				makeDir(file);
			}
			OutputStream out = new FileOutputStream(path + fileName);
			out.write(b);
			out.flush();
			out.close();
			return true;
		}catch(Exception e){
			e.printStackTrace();
			return false;
		}
	}

注：該方法的入?yún)ⅲ琤ase64 格式文件不得有文件頭部標(biāo)識信息，否則會轉(zhuǎn)換失敗。所以這里我們需要自行判斷是否包含有頭部信息。

String urlImageToBase64 = "";//這里就是我們圖片的base64字符串
if(urlImageToBase64.indexOf(",")>-1) {//包含頭信息
				System.out.println("包含頭部信息");
				urlImageToBase64 = urlImageToBase64.substring(urlImageToBase64.indexOf(",")+1);
}

5、將文件轉(zhuǎn)為 base64 字符串

	/**
	 * 讀入文件轉(zhuǎn)換為Base64編碼并返回
	 * @param filePath 文件路徑
	 * @return base64 的文件
	 * @throws Exception
	 */
	public static String readAsBase64FromFile(String filePath) {	
		InputStream in = null;
		byte[] data = null;
		try	{
			in = new FileInputStream(fileName);
			data = new byte[in.available()];
			in.read(data);
			in.close();
		} catch(Exception e) {
			e.printStackTrace();
			return null;
		}
		return Base64Util.encode(data);
	}

上面用到了一個(gè) Base64Util.java

package com.xxx.example.util;
public final class Base64Util {
	static private final int BASELENGTH = 128;
	static private final int LOOKUPLENGTH = 64;
	static private final int TWENTYFOURBITGROUP = 24;
	static private final int EIGHTBIT = 8;
	static private final int SIXTEENBIT = 16;
	static private final int FOURBYTE = 4;
	static private final int SIGN = -128;
	static private final char PAD = '=';
	static private final boolean fDebug = false;
	static final private byte[] base64Alphabet = new byte[BASELENGTH];
	static final private char[] lookUpBase64Alphabet = new char[LOOKUPLENGTH];
	static {
		for (int i = 0; i < BASELENGTH; ++i) {
			base64Alphabet[i] = -1;
		}
		for (int i = 'Z'; i >= 'A'; i--) {
			base64Alphabet[i] = (byte) (i - 'A');
		}
		for (int i = 'z'; i >= 'a'; i--) {
			base64Alphabet[i] = (byte) (i - 'a' + 26);
		}
		for (int i = '9'; i >= '0'; i--) {
			base64Alphabet[i] = (byte) (i - '0' + 52);
		}
		base64Alphabet['+'] = 62;
		base64Alphabet['/'] = 63;
		for (int i = 0; i <= 25; i++) {
			lookUpBase64Alphabet[i] = (char) ('A' + i);
		}
		for (int i = 26, j = 0; i <= 51; i++, j++) {
			lookUpBase64Alphabet[i] = (char) ('a' + j);
		}
		for (int i = 52, j = 0; i <= 61; i++, j++) {
			lookUpBase64Alphabet[i] = (char) ('0' + j);
		}
		lookUpBase64Alphabet[62] = (char) '+';
		lookUpBase64Alphabet[63] = (char) '/';
	}
	private static boolean isWhiteSpace(char octect) {
		return (octect == 0x20 || octect == 0xd || octect == 0xa || octect == 0x9);
	}
	private static boolean isPad(char octect) {
		return (octect == PAD);
	}
	private static boolean isData(char octect) {
		return (octect < BASELENGTH && base64Alphabet[octect] != -1);
	}
	/**
	 * Encodes hex octects into Base64
	 *
	 * @param binaryData
	 *            Array containing binaryData
	 * @return Encoded Base64 array
	 */
	public static String encode(byte[] binaryData) {
		if (binaryData == null) {
			return null;
		}
		int lengthDataBits = binaryData.length * EIGHTBIT;
		if (lengthDataBits == 0) {
			return "";
		}
		int fewerThan24bits = lengthDataBits % TWENTYFOURBITGROUP;
		int numberTriplets = lengthDataBits / TWENTYFOURBITGROUP;
		int numberQuartet = fewerThan24bits != 0 ? numberTriplets + 1 : numberTriplets;
		char encodedData[] = null;
		encodedData = new char[numberQuartet * 4];
		byte k = 0, l = 0, b1 = 0, b2 = 0, b3 = 0;
		int encodedIndex = 0;
		int dataIndex = 0;
		if (fDebug) {
			System.out.println("number of triplets = " + numberTriplets);
		}
		for (int i = 0; i < numberTriplets; i++) {
			b1 = binaryData[dataIndex++];
			b2 = binaryData[dataIndex++];
			b3 = binaryData[dataIndex++];
			if (fDebug) {
				System.out.println("b1= " + b1 + ", b2= " + b2 + ", b3= " + b3);
			}
			l = (byte) (b2 & 0x0f);
			k = (byte) (b1 & 0x03);
			byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
			byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
			byte val3 = ((b3 & SIGN) == 0) ? (byte) (b3 >> 6) : (byte) ((b3) >> 6 ^ 0xfc);
			if (fDebug) {
				System.out.println("val2 = " + val2);
				System.out.println("k4   = " + (k << 4));
				System.out.println("vak  = " + (val2 | (k << 4)));
			}
			encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];
			encodedData[encodedIndex++] = lookUpBase64Alphabet[val2 | (k << 4)];
			encodedData[encodedIndex++] = lookUpBase64Alphabet[(l << 2) | val3];
			encodedData[encodedIndex++] = lookUpBase64Alphabet[b3 & 0x3f];
		}
		// form integral number of 6-bit groups
		if (fewerThan24bits == EIGHTBIT) {
			b1 = binaryData[dataIndex];
			k = (byte) (b1 & 0x03);
			if (fDebug) {
				System.out.println("b1=" + b1);
				System.out.println("b1<<2 = " + (b1 >> 2));
			}
			byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
			encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];
			encodedData[encodedIndex++] = lookUpBase64Alphabet[k << 4];
			encodedData[encodedIndex++] = PAD;
			encodedData[encodedIndex++] = PAD;
		} else if (fewerThan24bits == SIXTEENBIT) {
			b1 = binaryData[dataIndex];
			b2 = binaryData[dataIndex + 1];
			l = (byte) (b2 & 0x0f);
			k = (byte) (b1 & 0x03);
			byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
			byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
			encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];
			encodedData[encodedIndex++] = lookUpBase64Alphabet[val2 | (k << 4)];
			encodedData[encodedIndex++] = lookUpBase64Alphabet[l << 2];
			encodedData[encodedIndex++] = PAD;
		}
		return new String(encodedData);
	}
	/**
	 * Decodes Base64 data into octects
	 *
	 * @param encoded
	 *            string containing Base64 data
	 * @return Array containind decoded data.
	 */
	public static byte[] decode(String encoded) {
		if (encoded == null) {
			return null;
		}
		char[] base64Data = encoded.toCharArray();
		// remove white spaces
		int len = removeWhiteSpace(base64Data);
		if (len % FOURBYTE != 0) {
			return null;// should be divisible by four
		}
		int numberQuadruple = (len / FOURBYTE);
		if (numberQuadruple == 0) {
			return new byte[0];
		}
		byte decodedData[] = null;
		byte b1 = 0, b2 = 0, b3 = 0, b4 = 0;
		char d1 = 0, d2 = 0, d3 = 0, d4 = 0;
		int i = 0;
		int encodedIndex = 0;
		int dataIndex = 0;
		decodedData = new byte[(numberQuadruple) * 3];
		for (; i < numberQuadruple - 1; i++) {
			if (!isData((d1 = base64Data[dataIndex++])) || !isData((d2 = base64Data[dataIndex++]))
					|| !isData((d3 = base64Data[dataIndex++])) || !isData((d4 = base64Data[dataIndex++]))) {
				return null;
			} // if found "no data" just return null
			b1 = base64Alphabet[d1];
			b2 = base64Alphabet[d2];
			b3 = base64Alphabet[d3];
			b4 = base64Alphabet[d4];
			decodedData[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);
			decodedData[encodedIndex++] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
			decodedData[encodedIndex++] = (byte) (b3 << 6 | b4);
		}
		if (!isData((d1 = base64Data[dataIndex++])) || !isData((d2 = base64Data[dataIndex++]))) {
			return null;// if found "no data" just return null
		}
		b1 = base64Alphabet[d1];
		b2 = base64Alphabet[d2];
		d3 = base64Data[dataIndex++];
		d4 = base64Data[dataIndex++];
		if (!isData((d3)) || !isData((d4))) {// Check if they are PAD characters
			if (isPad(d3) && isPad(d4)) {
				if ((b2 & 0xf) != 0)// last 4 bits should be zero
				{
					return null;
				}
				byte[] tmp = new byte[i * 3 + 1];
				System.arraycopy(decodedData, 0, tmp, 0, i * 3);
				tmp[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
				return tmp;
			} else if (!isPad(d3) && isPad(d4)) {
				b3 = base64Alphabet[d3];
				if ((b3 & 0x3) != 0)// last 2 bits should be zero
				{
					return null;
				}
				byte[] tmp = new byte[i * 3 + 2];
				System.arraycopy(decodedData, 0, tmp, 0, i * 3);
				tmp[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);
				tmp[encodedIndex] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
				return tmp;
			} else {
				return null;
			}
		} else { // No PAD e.g 3cQl
			b3 = base64Alphabet[d3];
			b4 = base64Alphabet[d4];
			decodedData[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);
			decodedData[encodedIndex++] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
			decodedData[encodedIndex++] = (byte) (b3 << 6 | b4);
		}
		return decodedData;
	}
	/**
	 * remove WhiteSpace from MIME containing encoded Base64 data.
	 *
	 * @param data
	 *            the byte array of base64 data (with WS)
	 * @return the new length
	 */
	private static int removeWhiteSpace(char[] data) {
		if (data == null) {
			return 0;
		}
		// count characters that's not whitespace
		int newSize = 0;
		int len = data.length;
		for (int i = 0; i < len; i++) {
			if (!isWhiteSpace(data[i])) {
				data[newSize++] = data[i];
			}
		}
		return newSize;
	}
}

到此這篇關(guān)于Java圖片與二進(jìn)制相互轉(zhuǎn)換實(shí)現(xiàn)示例講解的文章就介紹到這了,更多相關(guān)Java圖片與二進(jìn)制轉(zhuǎn)換內(nèi)容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！

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