• 好多新注册的开发者表示不太清楚如何获取AccessToken。首先还是建议大家看官网文档

http://ai.baidu.com/docs#/Begin/top

• 小帅帮大家写一个Java调用的示例
• 首先是创建了应用。并得知APIKEY SECRETKEY 

• 代码准备工作。先下载官网的HTTPUTIL工具类 稍做改动

下载地址:https://ai.baidu.com/file/544D677F5D4E4F17B4122FBD60DB82B3

package com.xiaoshuai.baidu.util;

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 generalUrl = requestUrl + "?access_token=" + accessToken;
        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", "application/json");
        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.writeBytes(params);
        out.flush();
        out.close();

        // 建立实际的连接
        connection.connect();
        // 获取所有响应头字段
        Map> headers = connection.getHeaderFields();
        // 遍历所有的响应头字段
        for (String key : headers.keySet()) {
            System.out.println(key + "--->" + headers.get(key));
        }
        // 定义 BufferedReader输入流来读取URL的响应
        BufferedReader in = null;
        if (requestUrl.contains("nlp"))
            in = new BufferedReader(new InputStreamReader(connection.getInputStream(), "GBK"));
        else
            in = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
        String result = "";
        String getLine;
        while ((getLine = in.readLine()) != null) {
            result += getLine;
        }
        in.close();
        System.out.println("result:" + result);
        return result;
    }
    //看这里。是修改过后获取AccessToken的方法。POST/GET都可以
    public static String postToken(String requestUrl,String params) throws Exception {
        String generalUrl = requestUrl;
        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", "application/json");
        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.writeBytes(params);
        out.flush();
        out.close();

        // 建立实际的连接
        connection.connect();
        // 获取所有响应头字段
        Map> headers = connection.getHeaderFields();
        // 遍历所有的响应头字段
        for (String key : headers.keySet()) {
            System.out.println(key + "--->" + headers.get(key));
        }
        // 定义 BufferedReader输入流来读取URL的响应
        BufferedReader in = null;
        if (requestUrl.contains("nlp"))
            in = new BufferedReader(new InputStreamReader(connection.getInputStream(), "GBK"));
        else
            in = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
        String result = "";
        String getLine;
        while ((getLine = in.readLine()) != null) {
            result += getLine;
        }
        in.close();
        System.out.println("result:" + result);
        return result;
    }
}

• 直接main函数获取AccessToken

package com.xiaoshuai.baidu.auth;

import com.xiaoshuai.baidu.util.HttpUtil;

/**
 * @author 小帅丶
 * @类名称  BDToken
 * @remark 
 * @date  2017-11-13
 */
public class BDToken {
	/**
	 * 获取百度AI的AccessToken
	 * @throws Exception
	 */
	public static void main(String[] args) throws Exception {
		/**
		 * 应用如何创建URL http://ai.baidu.com/docs#/Begin/top 这里是图文教程的哦。
		 */
		//在控制台复制自己应用的  API Key
		String APIKEY = "";
		//在控制台复制自己应用的 Secret Key
		String SECRETKEY = "";
		String url = "https://aip.baidubce.com/oauth/2.0/token?grant_type=client_credentials&client_id=APIKEY&client_secret=SECRETKEY";
		String requsetURL = url.replaceAll("APIKEY",APIKEY).replaceAll("SECRETKEY",SECRETKEY);
		System.out.println(requsetURL);
		String jsonObject = HttpUtil.postToken(requsetURL,"");
		System.err.println(jsonObject);
	}
}

• 替换了相关参数 运行即可

{
    "access_token": "24.397e884bd79b47632ad69ee47e0deb5b.2592000.1513130665.282335-10347832", 
    "session_key": "9mzdCP0Ce6jlSq5BCXG7VNqiTHCFeksfqnGWA1dMDhBxF4PZt4nbnnXv/NWGscOB6nvQFax2s12ziuakwxlxQoxJvo6paw==", 
    "scope": "public vis-faceverify_faceverify vis-faceattribute_faceattribute vis-faceverify_faceverify_v2 vis-faceverify_faceverify_match_v2 brain_all_scope vis-faceverify_vis-faceverify-detect wise_adapt lebo_resource_base lightservice_public hetu_basic lightcms_map_poi kaidian_kaidian ApsMisTest_Test权限 vis-classify_flower bnstest_fasf", 
    "refresh_token": "25.59c39518c00811b9f7352625371a1753.315360000.1825898665.282335-10347832", 
    "session_secret": "b837a61fba5df4f7182336d1b8963b96", 
    "expires_in": 2592000
}

以上就是Java获取AccessToken的示例 不错记得点赞哦