网页获取数据内容中字符串为问号"?"

爬取网页时，获取的json数据中，字符串都是问号，如下图

尝试修改编码格式为utf-8,gbk等，都不行，后来给header加accept后编码格式正确，问号转换字符串成功

Request request = new Request.Builder()
   .url(url)
   .header("Accept", "application/json, text/javascript, */*; q=0.01")
   .build();

主要代码如下

package com.msun.util.webConnect;


import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import com.msun.util.FileUtil;


public class CreditchinaUtil {

public static void main(String[] args)  {

String url="http://www.baidu.com"
//获取信息
getCreditInfo(url);

}

private static void getCreditInfo(String url) {
// TODO Auto-generated method stub
OkHttpClient okHttpClient = new OkHttpClient(); 
Request request = new Request.Builder()
   .url(url)
   .header("Accept", "application/json, text/javascript, */*; q=0.01")
   .build();
try {  
Response response = okHttpClient.newCall(request).execute();  
if (response.isSuccessful()) {  
String json = response.body().string();  
    JSONArray jsonArray = JSONArray.fromObject(json);
    System.out.println(jsonArray.size());
    for (Object object : jsonArray) {
    String number = (String) JSONObject.fromObject(object).get("CARDNUMBER");
   
}
}  
} catch (IOException e) {  
e.printStackTrace();  
} 
}

}


}