如何正确调用百度AI开放平台的API进行图像识别

一、注册一个百度账号

二、点击下方链接使用百度账号登录百度智能云

百度智能云登录地址：https://login.bce.baidu.com/

三、进入百度智能云个人中心，找到图像识别

四、点击创建图像识别应用

五、创建成功(一定要记住这个API Key和Secret Key)

六、打开百度AI开放平台，找到图像识别

百度AI开发平台地址：http://ai.baidu.com/

七、打开动物识别界面，打开技术文档

八、点击下方链接进行Access Token获取

方式一：查找动物识别的文档，稍微往下翻一下就看到了下面的内容，然后点击Access Token获取

方式二：点击链接地址：https://ai.baidu.com/docs#/Auth/top 进行Access Token获取

九、打开IDEA创建一个包

十、创建一个类名为AuthService的java文件

这里的 API Key和Secret Key下面的代码会用到

代码如下

package com.baidu.ai.aip.auth;import org.json.JSONObject;import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.List;
import java.util.Map;/*** 获取token类*/
public class AuthService {public static void main(String[] args) {getAuth();   }    //百度技术文档里面是没有主方法的，这里需要自己创建，然后调用getAuth()/*** 获取权限token* @return 返回示例：* {* "access_token": "24.460da4889caad24cccdb1fea17221975.2592000.1491995545.282335-1234567",* "expires_in": 2592000* }*/public static String getAuth() {// 官网获取的 API Key 更新为你注册的(唯一需要收到的更改的地方  将百度云应用的AK---->API Key)String clientId = "百度云应用的AK";// 官网获取的 Secret Key 更新为你注册的(唯一需要收到的更改的地方  将百度云应用的AK---->Secret Key)String clientSecret = "百度云应用的SK";return getAuth(clientId, clientSecret);}/*** 获取API访问token* 该token有一定的有效期，需要自行管理，当失效时需重新获取.* @param ak - 百度云官网获取的 API Key* @param sk - 百度云官网获取的 Securet Key* @return assess_token 示例：* "24.460da4889caad24cccdb1fea17221975.2592000.1491995545.282335-1234567"*/public static String getAuth(String ak, String sk) {// 获取token地址String authHost = "https://aip.baidubce.com/oauth/2.0/token?";String getAccessTokenUrl = authHost// 1. grant_type为固定参数+ "grant_type=client_credentials"// 2. 官网获取的 API Key+ "&client_id=" + ak// 3. 官网获取的 Secret Key+ "&client_secret=" + sk;try {URL realUrl = new URL(getAccessTokenUrl);// 打开和URL之间的连接HttpURLConnection connection = (HttpURLConnection) realUrl.openConnection();connection.setRequestMethod("GET");connection.connect();// 获取所有响应头字段Map<String, List<String>> map = connection.getHeaderFields();// 遍历所有的响应头字段for (String key : map.keySet()) {System.err.println(key + "--->" + map.get(key));}// 定义 BufferedReader输入流来读取URL的响应BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));String result = "";String line;while ((line = in.readLine()) != null) {result += line;}/*** 返回结果示例*/System.err.println("result:" + result);JSONObject jsonObject = new JSONObject(result);String access_token = jsonObject.getString("access_token");return access_token;} catch (Exception e) {System.err.printf("获取token失败！");e.printStackTrace(System.err);}return null;}}

十一、点击运行获取access_token的值（一串数字）

小编这里运行产生的值是（一定要记住，最好找一个记事本复制进去）：24.0e499aea1d600d794a1f4226604d3df1.2592000.1576589696.282335-17789002

十二、回到我们的动物识别的技术文档

十三、找到请求代码示例，选择Java

十四、下面需要下载四个FileUtil,Base64Util,HttpUtil,GsonUtils.java文件

百度官方提供的所需工具类的下载地址

/*** 重要提示代码中所需工具类* FileUtil,Base64Util,HttpUtil,GsonUtils请从* https://ai.baidu.com/file/658A35ABAB2D404FBF903F64D47C1F72* https://ai.baidu.com/file/C8D81F3301E24D2892968F09AE1AD6E2* https://ai.baidu.com/file/544D677F5D4E4F17B4122FBD60DB82B3* https://ai.baidu.com/file/470B3ACCA3FE43788B5A963BF0B625F3* 下载*/

将这四个.java文件放入你的项目下面

package baiduapi;/*** Base64 工具类*/
public class Base64Util {private static final char last2byte = (char) Integer.parseInt("00000011", 2);private static final char last4byte = (char) Integer.parseInt("00001111", 2);private static final char last6byte = (char) Integer.parseInt("00111111", 2);private static final char lead6byte = (char) Integer.parseInt("11111100", 2);private static final char lead4byte = (char) Integer.parseInt("11110000", 2);private static final char lead2byte = (char) Integer.parseInt("11000000", 2);private static final char[] encodeTable = new char[]{'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'};public Base64Util() {}public static String encode(byte[] from) {StringBuilder to = new StringBuilder((int) ((double) from.length * 1.34D) + 3);int num = 0;char currentByte = 0;int i;for (i = 0; i < from.length; ++i) {for (num %= 8; num < 8; num += 6) {switch (num) {case 0:currentByte = (char) (from[i] & lead6byte);currentByte = (char) (currentByte >>> 2);case 1:case 3:case 5:default:break;case 2:currentByte = (char) (from[i] & last6byte);break;case 4:currentByte = (char) (from[i] & last4byte);currentByte = (char) (currentByte << 2);if (i + 1 < from.length) {currentByte = (char) (currentByte | (from[i + 1] & lead2byte) >>> 6);}break;case 6:currentByte = (char) (from[i] & last2byte);currentByte = (char) (currentByte << 4);if (i + 1 < from.length) {currentByte = (char) (currentByte | (from[i + 1] & lead4byte) >>> 4);}}to.append(encodeTable[currentByte]);}}if (to.length() % 4 != 0) {for (i = 4 - to.length() % 4; i > 0; --i) {to.append("=");}}return to.toString();}
}

package baiduapi;import java.io.*;/*** 文件读取工具类*/
public class FileUtil {/*** 读取文件内容，作为字符串返回*/public static String readFileAsString(String filePath) throws IOException {File file = new File(filePath);if (!file.exists()) {throw new FileNotFoundException(filePath);} if (file.length() > 1024 * 1024 * 1024) {throw new IOException("File is too large");} StringBuilder sb = new StringBuilder((int) (file.length()));// 创建字节输入流  FileInputStream fis = new FileInputStream(filePath);  // 创建一个长度为10240的Bufferbyte[] bbuf = new byte[10240];  // 用于保存实际读取的字节数  int hasRead = 0;  while ( (hasRead = fis.read(bbuf)) > 0 ) {  sb.append(new String(bbuf, 0, hasRead));  }  fis.close();  return sb.toString();}/*** 根据文件路径读取byte[] 数组*/public static byte[] readFileByBytes(String filePath) throws IOException {File file = new File(filePath);if (!file.exists()) {throw new FileNotFoundException(filePath);} else {ByteArrayOutputStream bos = new ByteArrayOutputStream((int) file.length());BufferedInputStream in = null;try {in = new BufferedInputStream(new FileInputStream(file));short bufSize = 1024;byte[] buffer = new byte[bufSize];int len1;while (-1 != (len1 = in.read(buffer, 0, bufSize))) {bos.write(buffer, 0, len1);}byte[] var7 = bos.toByteArray();return var7;} finally {try {if (in != null) {in.close();}} catch (IOException var14) {var14.printStackTrace();}bos.close();}}}
}

下面的这个GsonUtils.java会报错，解决方面在下面！

/** Copyright (C) 2017 Baidu, Inc. All Rights Reserved.*/
package baiduapi;import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonParseException;import java.lang.reflect.Type;/*** Json工具类.*/
public class GsonUtils {private static Gson gson = new GsonBuilder().create();public static String toJson(Object value) {return gson.toJson(value);}public static <T> T fromJson(String json, Class<T> classOfT) throws JsonParseException {return gson.fromJson(json, classOfT);}public static <T> T fromJson(String json, Type typeOfT) throws JsonParseException {return (T) gson.fromJson(json, typeOfT);}
}

package baiduapi;import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.List;
import java.util.Map;/*** http 工具类*/
public class HttpUtil {public static String post(String requestUrl, String accessToken, String params)throws Exception {String contentType = "application/x-www-form-urlencoded";return HttpUtil.post(requestUrl, accessToken, contentType, params);}public static String post(String requestUrl, String accessToken, String contentType, String params)throws Exception {String encoding = "UTF-8";if (requestUrl.contains("nlp")) {encoding = "GBK";}return HttpUtil.post(requestUrl, accessToken, contentType, params, encoding);}public static String post(String requestUrl, String accessToken, String contentType, String params, String encoding)throws Exception {String url = requestUrl + "?access_token=" + accessToken;return HttpUtil.postGeneralUrl(url, contentType, params, encoding);}public static String postGeneralUrl(String generalUrl, String contentType, String params, String encoding)throws Exception {URL url = new URL(generalUrl);// 打开和URL之间的连接HttpURLConnection connection = (HttpURLConnection) url.openConnection();connection.setRequestMethod("POST");// 设置通用的请求属性connection.setRequestProperty("Content-Type", contentType);connection.setRequestProperty("Connection", "Keep-Alive");connection.setUseCaches(false);connection.setDoOutput(true);connection.setDoInput(true);// 得到请求的输出流对象DataOutputStream out = new DataOutputStream(connection.getOutputStream());out.write(params.getBytes(encoding));out.flush();out.close();// 建立实际的连接connection.connect();// 获取所有响应头字段Map<String, List<String>> headers = connection.getHeaderFields();// 遍历所有的响应头字段for (String key : headers.keySet()) {System.err.println(key + "--->" + headers.get(key));}// 定义 BufferedReader输入流来读取URL的响应BufferedReader in = null;in = new BufferedReader(new InputStreamReader(connection.getInputStream(), encoding));String result = "";String getLine;while ((getLine = in.readLine()) != null) {result += getLine;}in.close();System.err.println("result:" + result);return result;}
}

十五、如何解决GsonUtils.java报错警告呢？？这里需要下载两个json包，分别是google和org的json包

两个jar包的百度网盘下载地址如下所示

链接：https://pan.baidu.com/s/1uXB7WQJWqJ2mbBKhEA1BWg
提取码：y9kv 链接：https://pan.baidu.com/s/1rheup48ht06kWkHRcoBlyQ
提取码：uo5p

十六、最重要的一步来了，如何在IDEA项目里面导入jar包呢？

第一步：打开file下的project structure

第二步：找到modules的你的项目放的位置，然后选择dependencies，然后找到“+”

第三步：点击“+”，然后点击JARs or directories，然后找到你下载的两个jar包所在的位置，点击ok

最后选择apply，然后点击OK，就不会报错了

十七、创建一个Animal的类，然后将动物识别的那段代码复制粘贴过去

package com.baidu.ai.aip;  //这里导你自己项目的Animal所在的包的路径/*import com.baidu.ai.aip.utils.Base64Util;
import com.baidu.ai.aip.utils.FileUtil;
import com.baidu.ai.aip.utils.HttpUtil;*/import java.net.URLEncoder;/**
* 动物识别
*/
public class Animal {/*** 重要提示代码中所需工具类* FileUtil,Base64Util,HttpUtil,GsonUtils请从* https://ai.baidu.com/file/658A35ABAB2D404FBF903F64D47C1F72* https://ai.baidu.com/file/C8D81F3301E24D2892968F09AE1AD6E2* https://ai.baidu.com/file/544D677F5D4E4F17B4122FBD60DB82B3* https://ai.baidu.com/file/470B3ACCA3FE43788B5A963BF0B625F3* 下载*/public static String animal() {// 请求urlString url = "https://aip.baidubce.com/rest/2.0/image-classify/v1/animal";try {// 本地文件路径String filePath = "[本地文件路径]";   //需要改两处，第一处就将引号内部的[本地文件路径]替换为你想要识别的动物图片的地址，小编这里填的是“D:\甲骨文代码\学习总结图片\Animal\three.jpeg”（要具体到图片）byte[] imgData = FileUtil.readFileByBytes(filePath);String imgStr = Base64Util.encode(imgData);String imgParam = URLEncoder.encode(imgStr, "UTF-8");String param = "image=" + imgParam;// 注意这里仅为了简化编码每一次请求都去获取access_token，线上环境access_token有过期时间， 客户端可自行缓存，过期后重新获取。String accessToken = "[调用鉴权接口获取的token]";  //第二处改的值为小编要大家复制到记事本的那个token值String result = HttpUtil.post(url, accessToken, param);System.out.println(result);return result;} catch (Exception e) {e.printStackTrace();}return null;}public static void main(String[] args) {Animal.animal();}
}

十七、点击运行，获取识别结果如下所示

{"log_id": 4508637444409713969, "result": [{"score": "0.903391", "name": "金毛犬"}, {"score": "0.0613776", "name": "拉布拉多"}, {"score": "0.004973", "name": "中华田园犬"}, {"score": "0.00133911", "name": "豹犬"}, {"score": "0.00120851", "name": "腊肠犬"}, {"score": "0.000717416", "name": "串串狗"}]}

如果小伙伴们成功出现了这样的返回结果，代表步骤和方法都操作正确，恭喜你们！！
如果小伙伴们出现了错误，也别着急，请再认真仔细的参考小编编写的步骤，相信你们一定会成功的！！