百度人脸识别api实现及demo

摘要: 百度人脸识别api实现及demo

要说人脸检测、识别国内最好的还是face++，但是无奈，face++的技术支持太差了，既没有交流群，技术支持邮件也没人理。没办法，最后尝试使用百度的。

地址：https://bce.baidu.com/product/bfr.html

注意，虽然该服务表面上是免费的，但是对象存储BOS 是收费的，没有bos你没办法上传图片，不过也很便宜。

百度的人脸识别使用了rest风格的api，只需要简单的http请求即可。整个api的难点在于权限认证，

足足调了2天。

完整实例下载：https://pan.baidu.com/s/1mh4rjZy

权限认证实现：

package com.baidubce;

import java.io.UnsupportedEncodingException;

import java.sql.Timestamp;

import java.text.DateFormat;

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.Arrays;

import java.util.Calendar;

import java.util.Map;

import javax.crypto.Mac;

import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Hex;

/**

* 认证字符串生成

* @author pc

*

*/

public class BceAuthString {

/**

* 生成BceAuthString(认证字符串)

*/

public String createBceAuthString(String accessKeyID, String secretAccessKey, String httpMethod, String path, Map<String, String> header, String UTCTime){

String authStringPrefix = "bce-auth-v1/{accessKeyId}/{timestamp}/{expirationPeriodInSeconds}";

authStringPrefix = authStringPrefix.replace("{accessKeyId}", accessKeyID);

authStringPrefix = authStringPrefix.replace("{timestamp}", UTCTime);

authStringPrefix = authStringPrefix.replace("{expirationPeriodInSeconds}", "1800");

String canonicalRequest = this.createCanonicalRequest(httpMethod, path, header);

String signingKey = this.createSigningKey(secretAccessKey, authStringPrefix);

String signature = this.createSignature(signingKey, canonicalRequest);

String signedHeaders = createSignedHeaders(header);

String bceAuthString = authStringPrefix + "/" + signedHeaders + "/" + signature;

return bceAuthString;

}

/**

* 创建CanonicalRequest

* CanonicalRequest = HTTP Method + "\n" + CanonicalURI + "\n" + CanonicalQueryString + "\n" + CanonicalHeaders

*/

private String createCanonicalRequest(String httpMethod, String path, Map<String, String> header){

httpMethod = httpMethod.toUpperCase();

if(path == null || path.trim().equals(""))

path  = "";

String canonicalURI = path;

String canonicalQueryString = "";

int index = path.indexOf("?");

if(index != -1){

canonicalURI = path.substring(0, index);

canonicalQueryString = path.substring(index + 1);

}

//生成CanonicalURI

if(!canonicalURI.startsWith("/"))

canonicalURI = "/" + canonicalURI;

canonicalURI = uriEncode(canonicalURI, false);

//生成CanonicalQueryString

String[] queryArray = canonicalQueryString.split("&");

for(int i = 0; i<queryArray.length; i++){

String item = queryArray[i];

if(item == null || item.trim().equals(""))

continue;

String key = item.split("=")[0];

String value = item.split("=")[1];

key = uriEncode(key, true);

value = uriEncode(value, true);

queryArray[i] = key + "=" + value;

}

Arrays.sort(queryArray);

StringBuffer sb = new StringBuffer();

for(int i = 0; i<queryArray.length; i++){

String item = queryArray[i];

if(item == null || item.trim().equals(""))

continue;

sb.append(item + "&");

}

if(sb.length() > 0)

sb.deleteCharAt(sb.length() - 1);

canonicalQueryString = sb.toString();

//生成CanonicalHeaders

String[] headerArray = new String[header.size()];

index = 0;

for (Map.Entry<String, String> entry : header.entrySet()) {

String key = entry.getKey().toLowerCase();

String value = entry.getValue().trim();

headerArray[index] = uriEncode(key, true) + ":" + uriEncode(value, true);

index++;

}

Arrays.sort(headerArray);

sb = new StringBuffer();

for(int i = 0; i<headerArray.length; i++){

String item = headerArray[i];

sb.append(item + "\n");

}

String canonicalHeaders = sb.toString();

if(canonicalHeaders.length() > 0)

canonicalHeaders = canonicalHeaders.substring(0, canonicalHeaders.lastIndexOf("\n"));

return httpMethod + "\n" + canonicalURI + "\n" + canonicalQueryString + "\n" + canonicalHeaders;

}

/**

* 生成SigningKey

* @param input

* @param encodeSlash

* @return

*/

private String createSigningKey(String secretAccessKey, String authStringPrefix){

String signingKey  = sha256Hex(secretAccessKey, authStringPrefix);

return signingKey;

}

/**

* 生成Signature

* @param input

* @param encodeSlash

* @return

*/

private String createSignature(String signingKey, String canonicalRequest){

String signature = sha256Hex(signingKey, canonicalRequest);

return signature;

}

/**

* 创建signedHeaders

* @param input

* @param encodeSlash

* @return

*/

private String createSignedHeaders(Map<String, String> header){

String[] headerArray = new String[header.size()];

int index = 0;

for (Map.Entry<String, String> entry : header.entrySet()) {

String key = entry.getKey().toLowerCase();

headerArray[index] = key;

index++;

}

Arrays.sort(headerArray);

StringBuffer sb = new StringBuffer();

for(int i = 0; i<headerArray.length; i++){

String item = headerArray[i];

sb.append(item + ";");

}

if(sb.length() > 0)

sb.deleteCharAt(sb.length() - 1);

String signedHeaders = sb.toString();

return signedHeaders;

}

public String uriEncode(CharSequence input, boolean encodeSlash) {

StringBuilder result = new StringBuilder();

try {

for (int i = 0; i < input.length(); i++) {

char ch = input.charAt(i);

if ((ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z') || (ch >= '0' && ch <= '9') || ch == '_' || ch == '-' || ch == '~' || ch == '.') {

result.append(ch);

} else if (ch == '/') {

result.append(encodeSlash ? "%2F" : ch);

} else {

result.append(toHexUTF8(ch));

}

}

} catch (Exception e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

return result.toString();

}

private String toHexUTF8(char c){

try {

byte[] b = String.valueOf(c).getBytes(BceConstants.ENCODING);

for (int j = 0; j < b.length; j++) {

int k = b[j];

if (k < 0)

k += 256;

return "%" + Integer.toHexString(k).toUpperCase();

}

} catch (Exception e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

return "";

}

private String sha256Hex(String signingKey, String stringToSign) {

try {

Mac mac = Mac.getInstance("HmacSHA256");

mac.init(new SecretKeySpec(signingKey.getBytes(BceConstants.ENCODING), "HmacSHA256"));

return new String(Hex.encodeHex(mac.doFinal(stringToSign.getBytes(BceConstants.ENCODING))));

} catch (Exception e) {

e.printStackTrace();

}

return "";

}

}