基于apache httpclient 调用Face++ API

简要：

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本文简要介绍使用Apache HttpClient工具调用旷世科技的Face API。

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前期准备：

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依赖包maven地址：

<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
<dependency>
	<groupId>org.apache.httpcomponents</groupId>
	<artifactId>httpclient</artifactId>
	<version>4.5.4</version>
</dependency>

api_key、api_secret的获取，可以登录旷世科技官网注册获取免费的key和secret。

Detect API说明文档

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java 测试代码：

package buct.edu.cn;

import java.net.URI;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class HttpClientDemo {

	public static void main(String[] args) {
		
		HttpClient httpclient = HttpClients.createDefault();
		
		//设置请求参数
		String api_key = "<api_key>";
		String api_secret = "<api_secret>";
		String image_url = "http://gb.cri.cn/mmsource/images/2013/02/19/27/12679377093283173211.jpg";
		String return_attributes = "gender,age";
		
        try
        {
            URIBuilder builder = new URIBuilder("https://api-cn.faceplusplus.com/facepp/v3/detect");
            URI uri = builder.build();
            HttpPost request = new HttpPost(uri);  
                     
            StringEntity reqEntity = new StringEntity("api_key="+api_key+"&api_secret="+api_secret+"&image_url="+image_url+"&return_attributes="+return_attributes+"");
            reqEntity.setContentType("application/x-www-form-urlencoded"); 
            request.setEntity(reqEntity);
            
            HttpResponse response = httpclient.execute(request);
            HttpEntity entity = response.getEntity();

            if (entity != null) 
            {
                System.out.println(EntityUtils.toString(entity));
            }
        }
        catch (Exception e)
        {
            System.out.println(e.getMessage());
        }
	}
}

测试结果：

{"image_id": "qVohAsm0QmanSo9LBNtUcQ==", "request_id": "1514360502,7fc98900-59ca-4ac1-bbf0-95d5ada7588f", "time_used": 308, "faces": [{"attributes": {"gender": {"value": "Female"}, "age": {"value": 25}}, "face_rectangle": {"width": 173, "top": 160, "left": 215, "height": 173}, "face_token": "949f896eca7e645f27afc080971479f5"}]}

注意：

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免费版key的QPS(每秒钟支持的调用次数):10，但是这个在后台是与其他用户共享的，所以经常会出现：

{"error_message":"CONCURRENCY_LIMIT_EXCEEDED"}

这个是操过了QPS限制所致，也可以理解，毕竟是免费的产品。

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