JAVA实现百度OCR文字识别功能
调用百度OCR文字识别接口，实现图片文字识别，需要获取百度提供的API Key (ak) 和Scerct Key (sk),下面是具体实现代码和效果图。
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";
// 本地图片路径
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");
/**
* 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。
*/
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) {
// 获取token地址
String authHost = "https://aip.baidubce.com/oauth/2.0/token?";
String getAccessTokenUrl = authHost
// 1. grant_type为固定参数
+ "grant_type=client_credentials"
// 2. 官网获取的 API Key
+ "&client_id=" + ak
// 3. 官网获取的 Secret Key
+ "&client_secret=" + sk;
try {
URL realUrl = new URL(getAccessTokenUrl);
// 打开和URL之间的连接
HttpURLConnection connection = (HttpURLConnection) realUrl.openConnection();
connection.setRequestMethod("GET");
connection.connect();
// 获取所有响应头字段
Map> map = connection.getHeaderFields();
// 遍历所有的响应头字段
for (String key : map.keySet()) {
System.err.println(key + "--->" + map.get(key));
}
// 定义 BufferedReader输入流来读取URL的响应
BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String result = "";
String line;
while ((line = in.readLine()) != null) {
result += line;
}
/**
* 返回结果示例
*/
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("获取token失败！");
e.printStackTrace(System.err);
}
return null;
}
}
需要调用的几个类：
package com.baidu.ai.aip.utils;
/**
* Base64 工具类
*/
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.*;
/**
* 文件读取工具类
*/
public class FileUtil {
/**
* 读取文件内容，作为字符串返回
*/
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()));
// 创建字节输入流
FileInputStream fis = new FileInputStream(filePath);
// 创建一个长度为10240的Buffer
byte[] bbuf = new byte[10240];
// 用于保存实际读取的字节数
int hasRead = 0;
while ( (hasRead = fis.read(bbuf)) > 0 ) {
sb.append(new String(bbuf, 0, hasRead));
}
fis.close();
return sb.toString();
}
/**
* 根据文件路径读取byte[] 数组
*/
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 工具类
*/
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);
// 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", contentType);
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.write(params.getBytes(encoding));
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.err.println(key + "--->" + headers.get(key));
}
// 定义 BufferedReader输入流来读取URL的响应
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;
}
}
识别前的图片
识别后的输出数据
{"log_id": 8037719738599397843, "words_result_num": 14, "words_result": [{"location": {"width": 1043, "top": 0, "height": 172, "left": 0}, "words": "住所:浙江省永嘉县瓯北镇报喜鸟工业区长猜业执照信息公示专用"}, {"location": {"width": 464, "top": 21, "height": 57, "left": 0}, "words": "企业名称:报喜鸟控股份有限公司"}, {"location": {"width": 400, "top": 76, "height": 39, "left": 0}, "words": "类型: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:吴志泽"}, {"location": {"width": 272, "top": 186, "height": 29, "left": 0}, "words": "成立时间:2001-06-20"}, {"location": {"width": 354, "top": 219, "height": 31, "left": 0}, "words": "注册资本:126328万人民币元"}, {"location": {"width": 303, "top": 255, "height": 32, "left": 0}, "words": "营业期限:200106-20至"}, {"location": {"width": 1121, "top": 285, "height": 38, "left": 0}, "words": "经营范围:服装、皮鞋、皮革制品的生产及销售,经营进出口业务,经济信息咨询服务,企业管理"}, {"location": {"width": 983, "top": 325, "height": 33, "left": 128}, "words": "与咨询服务,培训服务,企业营销策划,房屋租赁,实业投资,投资管理,资产管理,"}, {"location": {"width": 999, "top": 358, "height": 35, "left": 124}, "words": "投资咨询,企业管理咨询(未经金融等监管部门批准,不得从事向公众融资存款、融资"}, {"location": {"width": 999, "top": 393, "height": 33, "left": 124}, "words": "担保、代客理财等金融服务)。(依法须经批准的项目,经相关部门批准后方可开展经"}, {"location": {"width": 105, "top": 429, "height": 34, "left": 123}, "words": "营活动)"}, {"location": {"width": 393, "top": 463, "height": 34, "left": 0}, "words": "登记机关:浙江省工商行政管理局"}, {"location": {"width": 274, "top": 499, "height": 34, "left": 0}, "words": "核准时间:2017-08-15"}]}