使用之前需要获取对应的项目API_KEY，SECRET_KEY，这些参数在使用API的时候必须用到，用于生成access_token。
如何获取这些参数：在百度开发者中心申请一个“通用文字识别”项目，然后就可以获取到这些参数。
十分钟快速教程
1、pom文件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>cn.within</groupId>
<artifactId>baiduSearch</artifactId>
<version>1.0-SNAPSHOT</version>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.46</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.5</version>
</dependency>
<dependency>
<groupId>com.vaadin.external.google</groupId>
<artifactId>android-json</artifactId>
<version>0.0.20131108.vaadin1</version>
</dependency>
</dependencies>
</project>
2、获取access_token
package search;
/**
* Created by within on 2018/10/9.
*/
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.List;
import java.util.Map;
/**
* 获取token类
*
* @Author : within
*/
public class AuthService {
/**
* 获取权限token
* @return 返回示例：
* {
* "access_token": "24.460da4889caad24cccdb1fea17221975.2592000.1491995545.282335-1234567",
* "expires_in": 2592000
* }
*/
public static String getAuth() {
// 官网获取的 API Key 更新为你注册的
String clientId = "0ddYMfgtVSqcE9qMQxHhZ4Yc";
// 官网获取的 Secret Key 更新为你注册的
String clientSecret = "XXXNKZlv1gi60a04pzABadI9KgDbfkRM";
return getAuth(clientId, clientSecret);
}
/**
* 获取API访问token
* 该token有一定的有效期，需要自行管理，当失效时需重新获取.
* @param ak - 百度云官网获取的 API Key
* @param sk - 百度云官网获取的 Securet Key
* @return assess_token 示例：
* "24.460da4889caad24cccdb1fea17221975.2592000.1491995545.282335-1234567"
*/
private 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<String, List<String>> 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()));
StringBuilder result = new StringBuilder();
String line;
while ((line = in.readLine()) != null) {
result.append(line);
}
/**
* 返回结果示例
*/
System.err.println("result:" + result);
JSONObject jsonObject = new JSONObject(result.toString());
return jsonObject.getString("access_token");
} catch (Exception e) {
System.err.printf("获取token失败！");
e.printStackTrace(System.err);
}
return null;
}
public static void main(String[] args) {
getAuth();
}
}
3、编写将图片转化成base64后再转化成urlencode的工具类
package search;
/**
* Created by within on 2018/10/9.
*/
import sun.misc.BASE64Encoder;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URLEncoder;
/**
* 图片转化base64后再UrlEncode结果
* @Author : within
*/
class BaseImg64 {
/**
* 将一张本地图片转化成Base64字符串
* @param imgPath 本地图片地址
* @return 图片转化base64后再UrlEncode结果
*/
public static String getImageStrFromPath(String imgPath) {
InputStream in;
byte[] data = null;
// 读取图片字节数组
try {
in = new FileInputStream(imgPath);
data = new byte[in.available()];
in.read(data);
in.close();
} catch (IOException e) {
e.printStackTrace();
}
// 对字节数组Base64编码
BASE64Encoder encoder = new BASE64Encoder();
// 返回Base64编码过再URLEncode的字节数组字符串
return URLEncoder.encode(encoder.encode(data));
}
}
4、编写调用百度API接口的方法，获取识别结果
package search;
/**
* Created by within on 2018/10/9.
*/
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import java.io.File;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
/**
* 图像文字识别
*
* @Author : within
*/
public class check {
private static final String POST_URL = "https://aip.baidubce.com/rest/2.0/ocr/v1/general_basic?access_token=" + AuthService.getAuth();
/**
* 识别本地图片的文字
*
* @param path 本地图片地址
* @return 识别结果，为json格式
* @throws URISyntaxException URI打开异常
* @throws IOException io流异常
*/
public static String checkFile(String path) throws URISyntaxException, IOException {
File file = new File(path);
if (!file.exists()) {
throw new NullPointerException("图片不存在");
}
String image = BaseImg64.getImageStrFromPath(path);
String param = "image=" + image;
return post(param);
}
/**
* @param url 图片url
* @return 识别结果，为json格式
*/
public static String checkUrl(String url) throws IOException, URISyntaxException {
String param = "url=" + url;
return post(param);
}
/**
* 通过传递参数：url和image进行文字识别
*
* @param param 区分是url还是image识别
* @return 识别结果
* @throws URISyntaxException URI打开异常
* @throws IOException IO流异常
*/
private static String post(String param) throws URISyntaxException, IOException {
//开始搭建post请求
HttpClient httpClient = new DefaultHttpClient();
HttpPost post = new HttpPost();
URI url = new URI(POST_URL);
post.setURI(url);
//设置请求头，请求头必须为application/x-www-form-urlencoded，因为是传递一个很长的字符串，不能分段发送
post.setHeader("Content-Type", "application/x-www-form-urlencoded");
StringEntity entity = new StringEntity(param);
post.setEntity(entity);
HttpResponse response = httpClient.execute(post);
System.out.println(response.toString());
if (response.getStatusLine().getStatusCode() == 200) {
String str;
try {
/*读取服务器返回过来的json字符串数据*/
str = EntityUtils.toString(response.getEntity());
System.out.println(str);
return str;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
return null;
}
public static void main(String[] args) {
String path = "D:\\ddd\\b.jpg";
try {
long now = System.currentTimeMillis();
checkFile(path);
checkUrl("https://gss3.bdstatic.com/-Po3dSag_xI4khGkpoWK1HF6hhy/baike/c0%3Dbaike80%2C5%2C5%2C80%2C26/sign=08c05c0e8444ebf8797c6c6db890bc4f/fc1f4134970a304e46bfc5f7d2c8a786c9175c19.jpg");
System.out.println("耗时：" + (System.currentTimeMillis() - now) / 1000 + "s");
} catch (URISyntaxException | IOException e) {
e.printStackTrace();
}
}
}
5、结果对比：
HTTP/1.1 200 OK [Appid: 14374247, Connection: keep-alive, Content-Type: application/json, Date: Tue, 09 Oct 2018 02:33:39 GMT, P3p: CP=" OTI DSP COR IVA OUR IND COM ", P3p: CP=" OTI DSP COR IVA OUR IND COM ", P3p: CP=" OTI DSP COR IVA OUR IND COM ", Server: Apache, Set-Cookie: BAIDUID=85ED51BC904917BC65233AB4200AD43E:FG=1; expires=Wed, 09-Oct-19 02:33:39 GMT; max-age=31536000; path=/; domain=.baidu.com; version=1, Set-Cookie: BAIDUID=90083625BD94E791CA9F2204797662B5:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2145916555; path=/; domain=.baidu.com; version=1, Set-Cookie: BAIDUID=08654EC80A32DEBA38E50B18A85EDC5D:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2145916555; path=/; domain=.baidu.com; version=1, Tracecode: 20198605130249338634100910, Vary: Accept-Encoding, Vary: Accept-Encoding, Content-Length: 317] org.apache.http.conn.BasicManagedEntity@4461c7e3
{"log_id": 597441327730160468, "words_result_num": 5, "words_result": [{"words": "你想過普通的生活就會遇到普通的挫折"}, {"words": "你想過上最好的生活②"}, {"words": "就一定會遇上最强的傷害"}, {"words": "這世界很公平"}, {"words": "你想要最好就一定會給你最痛"}]}
十月 09, 2018 10:33:39 上午 org.apache.http.client.protocol.ResponseProcessCookies processCookies
---------------------
作者：@Within
来源：CSDN
原文：https://blog.csdn.net/qq_41264674/article/details/82979029
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