JAVA實現百度OCR文字識別功能
阿新 • • 發佈：2019-02-09
呼叫百度OCR文字識別介面，實現圖片文字識別，需要獲取百度提供的API Key (ak) 和Scerct Key (sk),下面是具體實現程式碼和效果圖。
package imageProcessing; import java.io.BufferedReader; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.URL; import java.net.URLEncoder; import java.util.List; import java.util.Map; import org.json.JSONObject; import com.baidu.ai.aip.utils.FileUtil; import com.baidu.ai.aip.utils.HttpUtil; import com.baidu.aip.util.Base64Util; public class baidu1 { public static void main(String[] args) { String otherHost = "https://aip.baidubce.com/rest/2.0/ocr/v1/general"; // 本地圖片路徑 String filePath = "E:/img/38.jpg"; try { byte[] imgData = FileUtil.readFileByBytes(filePath); String imgStr = Base64Util.encode(imgData); String params = URLEncoder.encode("image", "UTF-8") + "=" + URLEncoder.encode(imgStr, "UTF-8"); /** * 線上環境access_token有過期時間， 客戶端可自行快取，過期後重新獲取。 */ String accessToken = getAuth("你的ak值", "你的secerct key值"); String result = HttpUtil.post(otherHost, accessToken, params); System.out.println(result); } catch (Exception e) { e.printStackTrace(); } } public static String getAuth(String ak, String sk) { // 獲取token地址 String authHost = "https://aip.baidubce.com/oauth/2.0/token?"; String getAccessTokenUrl = authHost // 1. grant_type為固定引數 + "grant_type=client_credentials" // 2. 官網獲取的 API Key + "&client_id=" + ak // 3. 官網獲取的 Secret Key + "&client_secret=" + sk; try { URL realUrl = new URL(getAccessTokenUrl); // 開啟和URL之間的連線 HttpURLConnection connection = (HttpURLConnection) realUrl.openConnection(); connection.setRequestMethod("GET"); connection.connect(); // 獲取所有響應頭欄位 Map<String, List<String>> map = connection.getHeaderFields(); // 遍歷所有的響應頭欄位 for (String key : map.keySet()) { System.err.println(key + "--->" + map.get(key)); } // 定義 BufferedReader輸入流來讀取URL的響應 BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream())); String result = ""; String line; while ((line = in.readLine()) != null) { result += line; } /** * 返回結果示例 */ 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("獲取token失敗！"); e.printStackTrace(System.err); } return null; }
}
需要呼叫的幾個類：
package com.baidu.ai.aip.utils; /** * Base64 工具類 */ 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 com.baidu.ai.aip.utils; import java.io.*; /** * 檔案讀取工具類 */ public class FileUtil { /** * 讀取檔案內容，作為字串返回 */ 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())); // 建立位元組輸入流 FileInputStream fis = new FileInputStream(filePath); // 建立一個長度為10240的Buffer byte[] bbuf = new byte[10240]; // 用於儲存實際讀取的位元組數 int hasRead = 0; while ( (hasRead = fis.read(bbuf)) > 0 ) { sb.append(new String(bbuf, 0, hasRead)); } fis.close(); return sb.toString(); } /** * 根據檔案路徑讀取byte[] 陣列 */ 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(); } } } }
package com.baidu.ai.aip.utils;
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 工具類
*/
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);
// 開啟和URL之間的連線
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
// 設定通用的請求屬性
connection.setRequestProperty("Content-Type", contentType);
connection.setRequestProperty("Connection", "Keep-Alive");
connection.setUseCaches(false);
connection.setDoOutput(true);
connection.setDoInput(true);
// 得到請求的輸出流物件
DataOutputStream out = new DataOutputStream(connection.getOutputStream());
out.write(params.getBytes(encoding));
out.flush();
out.close();
// 建立實際的連線
connection.connect();
// 獲取所有響應頭欄位
Map<String, List<String>> headers = connection.getHeaderFields();
// 遍歷所有的響應頭欄位
for (String key : headers.keySet()) {
System.err.println(key + "--->" + headers.get(key));
}
// 定義 BufferedReader輸入流來讀取URL的響應
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;
}
}
識別前的圖片
識別後的輸出資料
{"log_id": 8037719738599397843, "words_result_num": 14, "words_result": [{"location": {"width": 1043, "top": 0, "height": 172, "left": 0}, "words": "住所:浙江省永嘉縣甌北鎮報喜鳥工業區長猜業執照資訊公示專用"}, {"location": {"width": 464, "top": 21, "height": 57, "left": 0}, "words": "企業名稱:報喜鳥控股份有限公司"}, {"location": {"width": 400, "top": 76, "height": 39, "left": 0}, "words": "型別:其他股份有限公司(上市)"}, {"location": {"width": 238, "top": 149, "height": 32, "left": 0}, "words": "法定代表人:吳志澤"}, {"location": {"width": 272, "top": 186, "height": 29, "left": 0}, "words": "成立時間:2001-06-20"}, {"location": {"width": 354, "top": 219, "height": 31, "left": 0}, "words": "註冊資本:126328萬人民幣元"}, {"location": {"width": 303, "top": 255, "height": 32, "left": 0}, "words": "營業期限:200106-20至"}, {"location": {"width": 1121, "top": 285, "height": 38, "left": 0}, "words": "經營範圍:服裝、皮鞋、皮革製品的生產及銷售,經營進出口業務,經濟資訊諮詢服務,企業管理"}, {"location": {"width": 983, "top": 325, "height": 33, "left": 128}, "words": "與諮詢服務,培訓服務,企業營銷策劃,房屋租賃,實業投資,投資管理,資產管理,"}, {"location": {"width": 999, "top": 358, "height": 35, "left": 124}, "words": "投資諮詢,企業管理諮詢(未經金融等監管部門批准,不得從事向公眾融資存款、融資"}, {"location": {"width": 999, "top": 393, "height": 33, "left": 124}, "words": "擔保、代客理財等金融服務)。(依法須經批准的專案,經相關部門批准後方可開展經"}, {"location": {"width": 105, "top": 429, "height": 34, "left": 123}, "words": "營活動)"}, {"location": {"width": 393, "top": 463, "height": 34, "left": 0}, "words": "登記機關:浙江省工商行政管理局"}, {"location": {"width": 274, "top": 499, "height": 34, "left": 0}, "words": "核准時間:2017-08-15"}]}