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[Java] 如何用ObjectMapper将复杂Map转换为实体类

编程语言 编程语言 发布于:2021-11-27 15:28 | 阅读数:328 | 评论:0

这篇文章主要介绍了如何用ObjectMapper将复杂Map转换为实体类的操作,具有很好的参考价值,希望对大家有所帮助。如有错误或未考虑完全的地方,望不吝赐教
目录

  • ObjectMapper将复杂Map转为实体类

    • 背景
    • 1.使用ObjectMapper要添加的依赖是
    • 2.将复杂Map开始转换

  • objectMapper 解析复杂json toMap

ObjectMapper将复杂Map转为实体类

背景
用fastjson转换复杂Map是浅层的可以转 深层的转换为null.,这时候可以用jackson来转。

1.使用ObjectMapper要添加的依赖是
<!--添加jackson包-->
 <dependency>
   <groupId>com.fasterxml.jackson.core</groupId>
   <artifactId>jackson-databind</artifactId>
   <version>2.8.3</version>
 </dependency>
2.将复杂Map开始转换
ObjectMapper mapper = new ObjectMapper();
Resource resource = mapper.convertValue(Map, Resource.class);
注意的点:实体类中的字段是驼峰的 首字母不能大写。

objectMapper 解析复杂json toMap
public void parseSettings(){
    
    String settings = "{\"基本设置\":{\"name\":\"基本设置\",\"entries\":[{\"name\":\"站号\",\"type\":\"number\",\"description\":\"\",\"value\":\"1\"},{\"name\":\"AppEUI\",\"type\":\"string\",\"description\":\"\",\"value\":\"2C26C503A0010006\"},{\"name\":\"DevEUI\",\"type\":\"string\",\"description\":\"\",\"value\":\"4A7703A000FC09\"},{\"name\":\"命令次数\",\"type\":\"number\",\"description\":\"\",\"value\":\"2\"},{\"name\":\"父井号\",\"type\":\"string\",\"description\":\"\",\"value\":\"test11\"}]},\"油阀间\":{\"name\":\"油阀间\",\"entries\":[{\"name\":\"上传间隔时间\",\"type\":\"number\",\"description\":\"\",\"value\":\"2\"},{\"name\":\"设定值\",\"type\":\"number\",\"description\":\"\",\"value\":\"10\"},{\"name\":\"波动值\",\"type\":\"number\",\"description\":\"\",\"value\":\"1\"},{\"name\":\"控制模式\",\"type\":\"number\",\"description\":\"\",\"value\":\"0\"},{\"name\":\"调节上限\",\"type\":\"number\",\"description\":\"\",\"value\":\"15\"},{\"name\":\"调节下限\",\"type\":\"number\",\"description\":\"\",\"value\":\"5\"},{\"name\":\"调节时间\",\"type\":\"number\",\"description\":\"\",\"value\":\"10\"}]},\"采集调度\":{\"name\":\"采集调度\",\"entries\":[{\"name\":\"interval\",\"type\":\"number\",\"description\":\"\",\"value\":\"2\"}]}}";
    ObjectMapper objectMapper = new ObjectMapper();
    javaType javaType = objectMapper.getTypeFactory().constructMapType(HashMap.class, String.class, SettingGroup.class);
    try {
      Map<String,SettingGroup>  mapSettings =  objectMapper.readValue(settings, javaType);
       SettingGroup group = mapSettings.get("基本设置");
       for (SettingEntry entry : group.getEntries()) {
         System.out.println(entry.getName());          
       }
      
       group = mapSettings.get("油阀间");
       for (SettingEntry entry : group.getEntries()) {
         System.out.println("entry.Name:"+entry.getName()+" entry.getValue:"+entry.getValue());
       }
    } catch (JsonParseException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (JsonMappingException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }    
  }
以上为个人经验,希望能给大家一个参考,也希望大家多多支持OPEN开发家园。
原文链接:https://blog.csdn.net/qq_31442649/article/details/108844155

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