Preparations for the :
Need to get the corresponding project before using API_KEY and SECRET_KEY, these parameters must be used when using the API, is used to generate access_token.
How to obtain these parameters?
http://ai.baidu.com/tech/ocr/general
After landing to create an application



Click the create application, fill in the corresponding information. Click on the application list can get API_KEY and SECRET_KEY


Download the Java SDK, and introducing the jar package project



call
implementation, obtain access_token

 package com. Baidu. Ai. Aip. The auth. 

The import org. Json. JSONObject; 

Import the Java. IO. BufferedReader; 
Import the Java. IO. InputStreamReader; 
The import java.net.HttpURLConnection; 
The import java.net.URL; 
import java.util.List; 
import java.util.Map; 

/* * 
* access token class 
*/
Public class AuthService {

/* * 
* get access token 
* @ return return example: 
* {
* "access_token" : "24.460 da4889caad24cccdb1fea17221975 2592000.1491995545.282335-1234567", 
* "expires_in" : 2592000 
*} 
*/
Public static String getAuth () {
//website to get the API Key update registration for you 
String clientId="baidu cloud applications AK"; 
//website to obtain the Secret Key to update for you register 
String clientSecret="baidu cloud applications SK"; 
Return getAuth (clientId, clientSecret); 
} 

/* * 
* get access token API 
* the token has certain validity, the need to manage, when failure to obtain again. 
* @ param ak - baidu cloud's official website for the API Key 
* @ param sk - baidu cloud's official website to obtain Securet Key 
* @ return assess_token example: 
"*" 24.460 da4889caad24cccdb1fea17221975 2592000.1491995545.282335-1234567 
*/
Public static String getAuth String ak, String (sk) {
//access token address 
String authHost="https://aip.baidubce.com/oauth/2.0/token?" ; 
String getAccessTokenUrl=authHost 
//1. Grant_type for fixed parameter 
+ "grant_type=client_credentials" 
//2. The official website to get the API Key 
+ "& amp; Client_id="+ ak 
//3. The website to get the Secret Key of 
+ "& amp; The client_secret="+ sk. 
Try {
RealUrl URL=new URL (getAccessTokenUrl); 
//the connection between the open and URL 
HttpURLConnection connection=(HttpURLConnection) realUrl. OpenConnection (); 
Connection. SetRequestMethod (" GET "); 
connection.connect(); 
//get all the response header fields 
Map The map=connection. GetHeaderFields (); 
//to iterate through all the response header fields 
For (String key: map. KeySet ()) {
System. Err. Println (key + "-- -- -- & gt;" + map. Get (key)); 
} 
//define BufferedReader the response of the input stream to read the URL 
BufferedReader in=new BufferedReader (new InputStreamReader (connection. The getInputStream ())); 
The String result=""; 
The String line; 
While ((line=in readLine ())!=null) {
The result +=line; 
} 
/* * 
* returns the sample 
*/
System. Err. Println (" result: "+ result); 
JSONObject JSONObject=new JSONObject (result); 
String access_token=jsonObject.getString("access_token"); 
Return access_token. 
} the catch (Exception e) {
Failed to get token System. Err. Printf ("!" ); 
E.p rintStackTrace System. (err); 
} 
return null; 
} 

} 

write into base64 before the picture into urlencode tools

 package com. Baidu. Ai. Aip. The auth. 

The import sun. Misc. BASE64Encoder; 

Import the Java. IO. FileInputStream; 
import java.io.IOException; 
Import the Java. IO. InputStream; 
The import java.net.URLEncoder; 

/* * 
* image into base64 UrlEncode again after the results 
*/

Public class BaseImg64 {
/* * 
* local photo into Base64 string 
*/
Public static String getImageStrFromPath (String imgPath) {
InputStream in; 
Byte [] data=https://bbs.csdn.net/topics/null; 
//read image byte array 
Try {
In=new FileInputStream (imgPath); 
Data=https://bbs.csdn.net/topics/new byte [in the available ()]; 
In the read (data); 
In the close (); 
} the catch (IOException e) {
e.printStackTrace(); 
} 
//to byte array Base64 encoding 
BASE64Encoder encoder=new BASE64Encoder (); 
//return Base64 encoded and then URLEncode the byte array of string 
Return URLEncoder. Encode (encoder. Encode (data)); 
} 
} 

write calls baidu API interface method, to obtain recognition results

 
Package com. Baidu. Ai. Aip. Auth. 

The import org. Apache. HTTP. HttpResponse; 
The import org. Apache. HTTP. Client. HttpClient; 
The import org. Apache. HTTP. Client. The methods. The HttpPost; 
The import org. Apache. HTTP. Entity. StringEntity; 
The import org. Apache. HTTP. Impl. Client. DefaultHttpClient; 
The import org. Apache. HTTP. Util. EntityUtils; 

Import the Java. IO. The File; 
import java.io.IOException; 
The import java.net.URI; 
The import java.net.URISyntaxException; 

/* * 
* image character recognition 
*/

Public class Check {
Private static final String POST_URL="HTTP://https://aip.baidubce.com/rest/2.0/ocr/v1/general_basic? Access_token="+ AuthService getAuth (); 

/* * 
nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull