通过调用API在JavaWeb项目中实现证件识别

本文详细介绍自己如何在JavaWeb项目中通过调用API实现证件识别。

一，Face++使用简介

二，两种方式（图片URL与本地上传）实现证件识别

一，Face++使用简介

Face++旷视人工智能开放平台，核心技术有人脸识别，人体识别，文字识别以及图像识别。具体详情可查看官方网站

首先需要在官方网站上注册，然后在API应用管理创建API Key，便可得到API Key和API Secret。两者是之后调用API的必要请求参数。

具体操作方式也可查看API文档

        

 

API调用原理：使用者向服务器发起HTTP请求，并加上合适的参数，服务器将会对请求进行处理，得到结果将会返回给使用者。

API调用鉴权：帐号下每创建一个应用程序会生成一组对应的API Key和API Secret，用于识别用户是否有权限调用API，所有的API调用必须提供对应的一组API Key和API Secret。

API调用参数：调用每个API需要根据需求传输不同的参数，身份证识别需要的必须参数有API的URL，API Key，API Secret，image_url或image_file或image_base64以及可选参数legality。

API调用提示：为了避免因网络问题而造成的阻塞，建议将API调用放进异步线程里执行。

 

二，两种方式（图片URL与本地上传）实现证件识别

不管是通过URL方式还是通过本地上传，调用API之前首先需要将图片转为字节型数组byte[]。官方给的案例只介绍了通过本地上传，我在其基础上添加了一个函数 'getBytesFromInputStream'实现将输入流转为字节型数组，代码如下。

package com.aiit.util;

import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Random;

import javax.net.ssl.SSLException;

/**
 * 身份证识别
 * @ClassName:CertificateRecognition.java
 */
public class CertificateRecognition {
    
    
    private final static int CONNECT_TIME_OUT = 30000;
    private final static int READ_OUT_TIME = 50000;
    private static String boundaryString = getBoundary();
    
    //url参数为身份证识别API的URL，map参数存放的是api_key、api_secret等值，fileMap参数存放的是图片字节型数组
    public static byte[] post(String url, HashMap<String, String> map, HashMap<String, byte[]> fileMap) throws Exception {
        HttpURLConnection conne;
        URL url1 = new URL(url);
        conne = (HttpURLConnection) url1.openConnection();
        conne.setDoOutput(true);
        conne.setUseCaches(false);
        conne.setRequestMethod("POST");
        conne.setConnectTimeout(CONNECT_TIME_OUT);
        conne.setReadTimeout(READ_OUT_TIME);
        conne.setRequestProperty("accept", "*/*");
        conne.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundaryString);
        conne.setRequestProperty("connection", "Keep-Alive");
        conne.setRequestProperty("user-agent", "Mozilla/4.0 (compatible;MSIE 6.0;Windows NT 5.1;SV1)");
        DataOutputStream obos = new DataOutputStream(conne.getOutputStream());
        Iterator iter = map.entrySet().iterator();
        while(iter.hasNext()){
            Map.Entry<String, String> entry = (Map.Entry) iter.next();
            String key = entry.getKey();
            String value = entry.getValue();
            obos.writeBytes("--" + boundaryString + "\r\n");
            obos.writeBytes("Content-Disposition: form-data; name=\"" + key + "\"\r\n");
            obos.writeBytes("\r\n");
            obos.writeBytes(value + "\r\n");
        }
        if(fileMap != null && fileMap.size() > 0){
            Iterator fileIter = fileMap.entrySet().iterator();
            while(fileIter.hasNext()){
                Map.Entry<String, byte[]> fileEntry = (Map.Entry<String, byte[]>) fileIter.next();
                obos.writeBytes("--" + boundaryString + "\r\n");
                obos.writeBytes("Content-Disposition: form-data; name=\"" + fileEntry.getKey() + "\"; filename=\"" + encode(" ") + "\"\r\n");
                obos.writeBytes("\r\n");
                obos.write(fileEntry.getValue());
                obos.writeBytes("\r\n");
            }
        }
        obos.writeBytes("--" + boundaryString + "--" + "\r\n");
        obos.writeBytes("\r\n");
        obos.flush();
        obos.close();
        InputStream ins = null;
        int code = conne.getResponseCode();
        try{
            if(code == 200){
                ins = conne.getInputStream();
            }else{
                ins = conne.getErrorStream();
            }
        }catch (SSLException e){
            e.printStackTrace();
            return new byte[0];
        }
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        byte[] buff = new byte[4096];
        int len;
        while((len = ins.read(buff)) != -1){
            baos.write(buff, 0, len);
        }
        byte[] bytes = baos.toByteArray();
        ins.close();
        return bytes;
    }
    
    private static String getBoundary() {
        StringBuilder sb = new StringBuilder();
        Random random = new Random();
        for(int i = 0; i < 32; ++i) {
            sb.append("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_-".charAt(random.nextInt("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_".length())));
        }
        return sb.toString();
    }
    
    //设置字符编码格式为UTF-8
    private static String encode(String value) throws Exception{
        return URLEncoder.encode(value, "UTF-8");
    }
    
    //将二进制文件转为字节型数组
    public static byte[] getBytesFromFile(File f) {
        if (f == null) {
            return null;
        }
        try {
            FileInputStream stream = new FileInputStream(f);
            ByteArrayOutputStream out = new ByteArrayOutputStream(1000);
            byte[] b = new byte[1000];
            int n;
            while ((n = stream.read(b)) != -1)
                out.write(b, 0, n);
            stream.close();
            out.close();
            return out.toByteArray();
        } catch (IOException e) {
        }
        return null;
    }
    
    //将输入流转为字节型数组
    public static  byte[] getBytesFromInputStream(InputStream inputStream) throws IOException {    
        byte[] buffer = new byte[1024];    
        int len = 0;    
        ByteArrayOutputStream bos = new ByteArrayOutputStream();    
        while((len = inputStream.read(buffer)) != -1) {    
            bos.write(buffer, 0, len);    
        }    
        bos.close();    
        return bos.toByteArray();    
    }

}

①通过URL方式

当输入图片URL，点击检测按钮，触发js的click事件，首先根据URL完成修改img标签的背景图片，并将其传给 'readPhoto1' 函数。该函数将URL通过AJAX异步请求传至Controller层，Controller层通过URL首先建立网络连接得到输入流，输入流通过上述代码转为字节型数组，并put至HashMap中作为参数之一。另外两个参数已经是规定好的，这时再调用post函数，得到返回值转为JSON格式返回至 'readPhoto1' 函数，该函数再取值通过id赋值给相应的标签。参考代码如下。

$("#bg-model4_button2").click(function(){
 var photoURL = document.getElementById("bg-model4_input").value;
 document.getElementById('bg-model4_img').src = photoURL;
 readPhoto1(photoURL);
});

/*通过URL读取图片*/
function readPhoto1(photoURL){
    $.post("readPhotoInfo1.do",{photoURL},function(data){
       document.getElementById("name").innerHTML = data.cards[0].name;
       document.getElementById("sex").innerHTML = data.cards[0].gender;
       document.getElementById("race").innerHTML = data.cards[0].race;
       document.getElementById("birthday").innerHTML = data.cards[0].birthday;
       document.getElementById("address").innerHTML = data.cards[0].address;
       document.getElementById("idcard_num").innerHTML = data.cards[0].id_card_number;
       if(data.cards[0].side == "front"){
            document.getElementById("admin_side").innerHTML = "人像面";
       }else{
             document.getElementById("admin_side").innerHTML = "国徽面";
       }
       document.getElementById("admin_time_used").innerHTML = data.time_used + "ms";
    },"json");
}

private String photoInfo;   //身份证信息
    
//根据图片URL读取图片内容信息
@RequestMapping(value="/readPhotoInfo1.do",method=RequestMethod.POST)
public  String readPhotoInfo1(HttpServletRequest request,HttpServletResponse response) throws IOException{
    response.setContentType("text/html; charset=utf-8");
    //js里通过ajax传递过来的图片URL
    String photoURL = request.getParameter("photoURL");
    URL photo_url = new URL(photoURL);    
    HttpURLConnection conn = (HttpURLConnection)photo_url.openConnection();    
    conn.setConnectTimeout(3*1000);  
    //防止屏蔽程序抓取而返回403错误  
    conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");  
    //得到输入流  
    InputStream inputStream = conn.getInputStream();    
    byte[] buff = CertificateRecognition.getBytesFromInputStream(inputStream);     
        
    //API的地址
    String url = "https://api-cn.faceplusplus.com/cardpp/v1/ocridcard";
    HashMap<String, String> map = new HashMap<>();
    HashMap<String, byte[]> byteMap = new HashMap<>();
    map.put("api_key", "你的api_key");
    map.put("api_secret", "你的api_secret");
    map.put("return_landmark", "1");
    map.put("return_attributes", "gender,age,smiling,headpose,facequality,blur,eyestatus,emotion,ethnicity,beauty,mouthstatus,eyegaze,skinstatus");
    byteMap.put("image_file", buff);
    PrintWriter out = response.getWriter();

    callPost(url, map, byteMap, out);
    out.close();
    return null;
}

//调用CertificateRecognition中的post方法
private void callPost(String url, HashMap<String, String> map, HashMap<String, byte[]> byteMap, PrintWriter pw) {
   try{
      byte[] bacd = CertificateRecognition.post(url, map, byteMap);
      this.photoInfo = new String(bacd);
      pw.println(photoInfo);
      System.out.println(photoInfo);
   }catch (Exception e) {
      e.printStackTrace();
   }
}

②通过本地上传方式

当选择本地图片，由于绑定js的change事件，首先完成修改img标签的背景图片，这里的js得到的是本地图片的base64编码，并将其传给'readPhoto2'函数。该函数将的base64编码通过AJAX异步请求传至Controller层，Controller层首先需要对图片的base64编码进行截取（前缀data：image/ jpeg; base64，为无效字符串），并调整异常数据，再将其写入本地一个规定的绝对路径。然后同理通过上述代码转为字节型数组，并将其put至HashMap中作为参数之一。这时再调用post函数，得到返回值并转为JSON格式返回至' readPhoto2'函数，该函数再取值通过id赋值给相应的标签。参考代码如下。

$("#admin_upload_photo").change(function(){    
      if(window.FileReader){       //chrome,firefox7+,opera,IE10,IE9，IE9也可以用滤镜来实现
           oFReader = new FileReader();
           oFReader.readAsDataURL(this.files[0]);
           oFReader.onload = function (oFREvent) {
               document.getElementById('bg-model4_img').src = oFREvent.target.result;
               var base64 = oFREvent.target.result;
               alert(base64);
               readPhoto2(base64);
           }; 
      }
});

/*通过绝对路径读取图片*/
function readPhoto2(base64){ 
    $.post("readPhotoInfo2.do",{base64},function(data){
        document.getElementById("name").innerHTML = data.cards[0].name;
        document.getElementById("sex").innerHTML = data.cards[0].gender;
        document.getElementById("race").innerHTML = data.cards[0].race;
        document.getElementById("birthday").innerHTML = data.cards[0].birthday;
        document.getElementById("address").innerHTML = data.cards[0].address;
        document.getElementById("idcard_num").innerHTML = data.cards[0].id_card_number;
        if(data.cards[0].side == "front"){
            document.getElementById("admin_side").innerHTML = "人像面";
        }else{
            document.getElementById("admin_side").innerHTML = "国徽面";
        }
        document.getElementById("admin_time_used").innerHTML = data.time_used + "ms";
    },"json");
}

//根据图片绝对路径读取图片内容信息
@RequestMapping(value="/readPhotoInfo2.do",method=RequestMethod.POST)
public  String readPhotoInfo2(HttpServletRequest request,HttpServletResponse response) throws IOException{
    response.setContentType("text/html; charset=utf-8");
    //js里通过ajax传递过来的图片base64编码
    String base64 = request.getParameter("base64");
    int size = base64.indexOf(",");  //截取第一个,号后面的字符串
    System.out.println(size);  //21
    
    String substr = base64.substring(22); 
    
    BASE64Decoder decoder = new BASE64Decoder();
    try 
    {           
        byte[] b = decoder.decodeBuffer(substr);
        for(int i=0;i<b.length;++i)  //调整异常数据
        {
            if(b[i]<0){
                b[i] += 256;
            }
        }            
        String imgFilePath = "e:/base.png";   //新生成的图片存放路径
        OutputStream out = new FileOutputStream(imgFilePath);    
        out.write(b);
        out.flush();
        out.close();           
        
        File file = new File(imgFilePath);
        byte[] buff = CertificateRecognition.getBytesFromFile(file);
        
        //API的地址
        String url = "https://api-cn.faceplusplus.com/cardpp/v1/ocridcard";
        HashMap<String, String> map = new HashMap<>();
        HashMap<String, byte[]> byteMap = new HashMap<>();
        map.put("api_key", "你的api_key");
        map.put("api_secret", "你的api_secret");
        map.put("return_landmark", "1");
        map.put("return_attributes", "gender,age,smiling,headpose,facequality,blur,eyestatus,emotion,ethnicity,beauty,mouthstatus,eyegaze,skinstatus");
        byteMap.put("image_file", buff);
        PrintWriter pw = response.getWriter();

        callPost(url, map, byteMap, pw);
        pw.close();
        
    } 
    catch (Exception e){
       e.printStackTrace();
    }
    return null;
}

项目效果图如下（证件图片是在网上任意找的一张图片，不针对于任何人）。

如有疏漏错误之处，还请不吝赐教！