百度文字识别SDK进行身份证识别以及车牌识别
首先我们得在百度智能云上开发者平台上申请一个应用，得到其AK及SK
之后参考官方文档链接：https://ai.baidu.com/ai-doc/OCR/zk3h7xw5e
整体实现效果如下：
工程目录如下：
代码如下：
AuthService.java
1 package text;
2
3 import org.json.JSONObject;
4
5 import java.io.BufferedReader;
6 import java.io.InputStreamReader;
7 import java.net.HttpURLConnection;
8 import java.net.URL;
9 import java.util.List;
10 import java.util.Map;
11
12 /**
13 * 获取token类
14 */
15 public class AuthService {
16
17 /**
18 * 获取权限token
19 * @return 返回示例：
20 * {
21 * "access_token": "24.460da4889caad24cccdb1fea17221975.2592000.1491995545.282335-1234567",
22 * "expires_in": 2592000
23 * }
24 */
25 public static String getAuth() {
26 // 官网获取的 API Key 更新为你注册的
27 String clientId = "AK";
28 // 官网获取的 Secret Key 更新为你注册的
29 String clientSecret = "SK";
30 return getAuth(clientId, clientSecret);
31 }
32
33 /**
34 * 获取API访问token
35 * 该token有一定的有效期，需要自行管理，当失效时需重新获取.
36 * @param ak - 百度云官网获取的 API Key
37 * @param sk - 百度云官网获取的 Securet Key
38 * @return assess_token 示例：
39 * "24.460da4889caad24cccdb1fea17221975.2592000.1491995545.282335-1234567"
40 */
41 public static String getAuth(String ak, String sk) {
42 // 获取token地址
43 String authHost = "https://aip.baidubce.com/oauth/2.0/token?";
44 String getAccessTokenUrl = authHost
45 // 1. grant_type为固定参数
46 + "grant_type=client_credentials"
47 // 2. 官网获取的 API Key
48 + "&client_id=" + ak
49 // 3. 官网获取的 Secret Key
50 + "&client_secret=" + sk;
51 try {
52 URL realUrl = new URL(getAccessTokenUrl);
53 // 打开和URL之间的连接
54 HttpURLConnection connection = (HttpURLConnection) realUrl.openConnection();
55 connection.setRequestMethod("GET");
56 connection.connect();
57 // 获取所有响应头字段
58 Map<String, List<String>> map = connection.getHeaderFields();
59 // 遍历所有的响应头字段
60 for (String key : map.keySet()) {
61 System.err.println(key + "--->" + map.get(key));
62 }
63 // 定义 BufferedReader输入流来读取URL的响应
64 BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
65 String result = "";
66 String line;
67 while ((line = in.readLine()) != null) {
68 result += line;
69 }
70 /**
71 * 返回结果示例
72 */
73 System.err.println("result:" + result);
74 JSONObject jsonObject = new JSONObject(result);
75 String access_token = jsonObject.getString("access_token");
76 return access_token;
77 } catch (Exception e) {
78 System.err.printf("获取token失败！");
79 e.printStackTrace(System.err);
80 }
81 return null;
82 }
83
84 }Base64Util.java
1 package text;
2
3 /**
4 * Base64 工具类
5 */
6 public class Base64Util {
7 private static final char last2byte = (char) Integer.parseInt("00000011", 2);
8 private static final char last4byte = (char) Integer.parseInt("00001111", 2);
9 private static final char last6byte = (char) Integer.parseInt("00111111", 2);
10 private static final char lead6byte = (char) Integer.parseInt("11111100", 2);
11 private static final char lead4byte = (char) Integer.parseInt("11110000", 2);
12 private static final char lead2byte = (char) Integer.parseInt("11000000", 2);
13 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', '+', '/'};
14
15 public Base64Util() {
16 }
17
18 public static String encode(byte[] from) {
19 StringBuilder to = new StringBuilder((int) ((double) from.length * 1.34D) + 3);
20 int num = 0;
21 char currentByte = 0;
22
23 int i;
24 for (i = 0; i < from.length; ++i) {
25 for (num %= 8; num < 8; num += 6) {
26 switch (num) {
27 case 0:
28 currentByte = (char) (from[i] & lead6byte);
29 currentByte = (char) (currentByte >>> 2);
30 case 1:
31 case 3:
32 case 5:
33 default:
34 break;
35 case 2:
36 currentByte = (char) (from[i] & last6byte);
37 break;
38 case 4:
39 currentByte = (char) (from[i] & last4byte);
40 currentByte = (char) (currentByte << 2);
41 if (i + 1 < from.length) {
42 currentByte = (char) (currentByte | (from[i + 1] & lead2byte) >>> 6);
43 }
44 break;
45 case 6:
46 currentByte = (char) (from[i] & last2byte);
47 currentByte = (char) (currentByte << 4);
48 if (i + 1 < from.length) {
49 currentByte = (char) (currentByte | (from[i + 1] & lead4byte) >>> 4);
50 }
51 }
52
53 to.append(encodeTable[currentByte]);
54 }
55 }
56
57 if (to.length() % 4 != 0) {
58 for (i = 4 - to.length() % 4; i > 0; --i) {
59 to.append("=");
60 }
61 }
62
63 return to.toString();
64 }
65 }FileUtil.java
1 package text;
2
3 import java.io.*;
4
5 /**
6 * 文件读取工具类
7 */
8 public class FileUtil {
9
10 /**
11 * 读取文件内容，作为字符串返回
12 */
13 public static String readFileAsString(String filePath) throws IOException {
14 File file = new File(filePath);
15 if (!file.exists()) {
16 throw new FileNotFoundException(filePath);
17 }
18
19 if (file.length() > 1024 * 1024 * 1024) {
20 throw new IOException("File is too large");
21 }
22
23 StringBuilder sb = new StringBuilder((int) (file.length()));
24 // 创建字节输入流
25 FileInputStream fis = new FileInputStream(filePath);
26 // 创建一个长度为10240的Buffer
27 byte[] bbuf = new byte[10240];
28 // 用于保存实际读取的字节数
29 int hasRead = 0;
30 while ( (hasRead = fis.read(bbuf)) > 0 ) {
31 sb.append(new String(bbuf, 0, hasRead));
32 }
33 fis.close();
34 return sb.toString();
35 }
36
37 /**
38 * 根据文件路径读取byte[] 数组
39 */
40 public static byte[] readFileByBytes(String filePath) throws IOException {
41 File file = new File(filePath);
42 if (!file.exists()) {
43 throw new FileNotFoundException(filePath);
44 } else {
45 ByteArrayOutputStream bos = new ByteArrayOutputStream((int) file.length());
46 BufferedInputStream in = null;
47
48 try {
49 in = new BufferedInputStream(new FileInputStream(file));
50 short bufSize = 1024;
51 byte[] buffer = new byte[bufSize];
52 int len1;
53 while (-1 != (len1 = in.read(buffer, 0, bufSize))) {
54 bos.write(buffer, 0, len1);
55 }
56
57 byte[] var7 = bos.toByteArray();
58 return var7;
59 } finally {
60 try {
61 if (in != null) {
62 in.close();
63 }
64 } catch (IOException var14) {
65 var14.printStackTrace();
66 }
67
68 bos.close();
69 }
70 }
71 }
72 }HttpUtil.java
1 package text;
2
3 import java.io.BufferedReader;
4 import java.io.DataOutputStream;
5 import java.io.InputStreamReader;
6 import java.net.HttpURLConnection;
7 import java.net.URL;
8 import java.util.List;
9 import java.util.Map;
10
11 /**
12 * http 工具类
13 */
14 public class HttpUtil {
15
16 public static String post(String requestUrl, String accessToken, String params)
17 throws Exception {
18 String contentType = "application/x-www-form-urlencoded";
19 return HttpUtil.post(requestUrl, accessToken, contentType, params);
20 }
21
22 public static String post(String requestUrl, String accessToken, String contentType, String params)
23 throws Exception {
24 String encoding = "UTF-8";
25 if (requestUrl.contains("nlp")) {
26 encoding = "GBK";
27 }
28 return HttpUtil.post(requestUrl, accessToken, contentType, params, encoding);
29 }
30
31 public static String post(String requestUrl, String accessToken, String contentType, String params, String encoding)
32 throws Exception {
33 String url = requestUrl + "?access_token=" + accessToken;
34 return HttpUtil.postGeneralUrl(url, contentType, params, encoding);
35 }
36
37 public static String postGeneralUrl(String generalUrl, String contentType, String params, String encoding)
38 throws Exception {
39 URL url = new URL(generalUrl);
40 // 打开和URL之间的连接
41 HttpURLConnection connection = (HttpURLConnection) url.openConnection();
42 connection.setRequestMethod("POST");
43 // 设置通用的请求属性
44 connection.setRequestProperty("Content-Type", contentType);
45 connection.setRequestProperty("Connection", "Keep-Alive");
46 connection.setUseCaches(false);
47 connection.setDoOutput(true);
48 connection.setDoInput(true);
49
50 // 得到请求的输出流对象
51 DataOutputStream out = new DataOutputStream(connection.getOutputStream());
52 out.write(params.getBytes(encoding));
53 out.flush();
54 out.close();
55
56 // 建立实际的连接
57 connection.connect();
58 // 获取所有响应头字段
59 Map<String, List<String>> headers = connection.getHeaderFields();
60 // 遍历所有的响应头字段
61 for (String key : headers.keySet()) {
62 System.err.println(key + "--->" + headers.get(key));
63 }
64 // 定义 BufferedReader输入流来读取URL的响应
65 BufferedReader in = null;
66 in = new BufferedReader(
67 new InputStreamReader(connection.getInputStream(), encoding));
68 String result = "";
69 String getLine;
70 while ((getLine = in.readLine()) != null) {
71 result += getLine;
72 }
73 in.close();
74 System.err.println("result:" + result);
75 return result;
76 }
77 }Identity.java
1 package text;
2
3 import java.net.URLEncoder;
4
5 public class Identity {
6 /**
7 * 重要提示代码中所需工具类
8 * FileUtil,Base64Util,HttpUtil,GsonUtils请从
9 * https://ai.baidu.com/file/658A35ABAB2D404FBF903F64D47C1F72
10 * https://ai.baidu.com/file/C8D81F3301E24D2892968F09AE1AD6E2
11 * https://ai.baidu.com/file/544D677F5D4E4F17B4122FBD60DB82B3
12 * https://ai.baidu.com/file/470B3ACCA3FE43788B5A963BF0B625F3
13 * 下载
14 */
15 public static String idcard() {
16 // 请求url
17 String url = "https://aip.baidubce.com/rest/2.0/ocr/v1/idcard";
18 try {
19 // 本地文件路径
20 String filePath = "image/identity.png";
21 byte[] imgData = FileUtil.readFileByBytes(filePath);
22 String imgStr = Base64Util.encode(imgData);
23 String imgParam = URLEncoder.encode(imgStr, "UTF-8");
24
25 String param = "id_card_side=" + "front" + "&image=" + imgParam;
26
27 // 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。
28 String accessToken = AuthService.getAuth();
29
30 String result = HttpUtil.post(url, accessToken, param);
31 System.out.println(result);
32 return result;
33 } catch (Exception e) {
34 e.printStackTrace();
35 }
36 return null;
37 }
38
39 public static void main(String[] args) {
40 Identity.idcard();
41 }
42 }LicensePlate.java
1 package text;
2
3 import java.net.URLEncoder;
4
5 /**
6 * 车牌识别
7 */
8 public class LicensePlate {
9
10 /**
11 * 重要提示代码中所需工具类
12 * FileUtil,Base64Util,HttpUtil,GsonUtils请从
13 * https://ai.baidu.com/file/658A35ABAB2D404FBF903F64D47C1F72
14 * https://ai.baidu.com/file/C8D81F3301E24D2892968F09AE1AD6E2
15 * https://ai.baidu.com/file/544D677F5D4E4F17B4122FBD60DB82B3
16 * https://ai.baidu.com/file/470B3ACCA3FE43788B5A963BF0B625F3
17 * 下载
18 */
19 public static String licensePlate() {
20 // 请求url
21 String url = "https://aip.baidubce.com/rest/2.0/ocr/v1/license_plate";
22 try {
23 // 本地文件路径
24 String filePath = "image/car.jpg";
25 byte[] imgData = FileUtil.readFileByBytes(filePath);
26 String imgStr = Base64Util.encode(imgData);
27 String imgParam = URLEncoder.encode(imgStr, "UTF-8");
28
29 String param = "image=" + imgParam;
30
31 // 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。
32 String accessToken = AuthService.getAuth();
33
34 String result = HttpUtil.post(url, accessToken, param);
35 System.out.println(result);
36 return result;
37 } catch (Exception e) {
38 e.printStackTrace();
39 }
40 return null;
41 }
42
43 public static void main(String[] args) {
44 LicensePlate.licensePlate();
45 }
46 }以上参考于 文字识别OCR
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