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指定文件路径转为二进制
将网络图片转为二进制
base64 转为图片资源
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(); //从文件路径中获取图片转为二进制 public static String getImageBinary(String filePath){ if(StringUtil.isEmpty(filePath)) { return null; } File f = new File(filePath); //这里gif动态图不可以,虽然在后面也能输出gif格式,但是却不是动图 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; } //从URl中获取图片转为二进制 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);//超时提示1秒=1000毫秒 InputStream inStream=conn.getInputStream();//获取输出流 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];//转换为二进制 int len=0; while((len =inStream.read(buffer))!=-1){ outStream.write(buffer,0,len); } return outStream.toByteArray(); } //将二进制转为图片 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()) { //文件不存在则创建文件,先创建目录 File dir = new File(w2.getParent()); dir.mkdirs(); w2.createNewFile(); // 创建新文件 } ImageIO.write(bi1, "jpg", w2);//不管输出什么格式图片,此处不需改动 } 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); } }
//判断图片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; }
/** * 将网络路径图片转为base64的格式 * @param requestUrl 请求网络路径 * @throws Exception */ public static String getUrlImageToBase64(String requestUrl) throws Exception { ByteArrayOutputStream data = new ByteArrayOutputStream(); try { // 创建URL URL url = new URL(requestUrl); byte[] by = new byte[1024]; // 创建链接 HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.setRequestMethod("GET"); conn.setConnectTimeout(5 * 1000); InputStream is = conn.getInputStream(); // 将内容读取内存中 int len = -1; while ((len = is.read(by)) != -1) { data.write(by, 0, len); } // 关闭流 is.close(); } catch (IOException e) { e.printStackTrace(); } // 对字节数组Base64编码 Base64.Encoder encoder = Base64.getEncoder(); // return "data:image/" + photoType + ";base64," + encoder.encodeToString(data.toByteArray()); return encoder.encodeToString(data.toByteArray()); }
/** * 将Base64编码的字符串转为文件输出 * @param base64String 字符串 * @param path 输出文件保存路径 * @param fileName 输出文件名称 * @return 是否转换成功 */ 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:该方法的入参,base64 格式文件不得有 文件头部标识信息,否则会转换失败。所以这里我们需要自行判断是否包含有头部信息。
String urlImageToBase64 = "";//这里就是我们图片的base64字符串 if(urlImageToBase64.indexOf(",")>-1) {//包含头信息 System.out.println("包含头部信息"); urlImageToBase64 = urlImageToBase64.substring(urlImageToBase64.indexOf(",")+1); }
/** * 读入文件转换为Base64编码并返回 * @param filePath 文件路径 * @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); }
上面用到了一个 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; } }
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