【JMeter】获取json响应报文中数组长度

import com.jayway.jsonpath.JsonPath;
import com.jayway.jsonpath.Predicate;
import net.minidev.json.JSONArray;
public class Test {    
    public static String readjson(String json, String jsonPath) {        
        try
        {
            Object value = JsonPath.read(json, jsonPath, new Predicate[0]);            
            if (value instanceof Integer)
              {
                return value.toString();
              }else if (value instanceof String)
              {
                    return value.toString();
              }else if (value instanceof Boolean)
              {
                    return value.toString();
              }else if (value instanceof JSONArray)
              {
                  JSONArray arr = (JSONArray)value;
                  if(!arr.isEmpty()){return arr.toJSONString();}                  
                  return "";
              }else if (value instanceof LinkedHashMap)
              {
                    return value.toString();
              }else if (value instanceof float)
              {
                    return value.toString();
              }else{
                  return  value.toString();
              }
        }
        catch(Exception e){
            return "pathnotfound";
        }        
    }    
}
//------------------------------------------------------------------------------------------------------------------
public static void fun(){
    String response_data=prev.getResponseDataAsString();//prev为JMeter预定义变量
    String JsonPath="$.data.detail.length()";
    String result=Test.readjson(response_data,JsonPath);
    int resultToNum=Integer.parseInt(result);
    log.info("------------------------详情长度："+result+"----------------------");
}
fun();