JackJSON的用法

String getJSON(Object obj){ 
    ObjectMapper objectMapper = new ObjectMapper();  //创建一个ObjectMapper对象
      return objectMapper.writeValueAsString(obj);  // 直接调用writeValueAsString 方法即可进行转换
    }catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

Object getObject(String str,Class<?> clazz){
    ObjectMapper objectMapper = new ObjectMapper();
    try{
      return objectMapper.readValue(str, clazz); //调用readValue方法即可
    }catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

// 1.创建一个ObjectMapper对象
ObjectMapper objectMapper = new ObjectMapper();
//2.获得一个类型工厂，然后调用constructCollectionType方法，此时需要传入两个参数，第一个是List集合对象，另一个是实际的Java对象
CollectionType listType = objectMapper.getTypeFactory().constructCollectionType(ArrayList.class, NameValuePairRequest.class);
// 3.调用readValue方法，将要转换的JSON对象和CollectionType作为参数输入进去。
List<NameValuePairRequest>  nameValuePairRequests= objectMapper.readValue(form_body, listType);

    JavaType javaType = mapper.getTypeFactory().constructParametricType(Map.class, Object.class, String.class);
      Map<String,Object> value = mapper.readValue(param, javaType);