//自定义目录树类
@Data
@ApiModel(value = "目录树节点", description = "目录树节点")
public class TreeNode{
   
    private Parent parent;

    private List<TreeNode> childrenList;

}
@Data
class  Parent{
   
    private Integer id;
    private String name;
    private Integer parentId;
}

json 数据

{
   
	"parent": {
   
		"id": 1,
		"name": "root/",
		"parentId": 0
	},
	"childrenList": [{
   
		"parent": {
   
			"id": 2,
			"name": "app/",
			"parentId": 1
		},
		"childrenList": [{
   

			"parent": {
   
				"id": 4,
				"name": "sys/",
				"parentId": 2
			},
			"childrenList": []
		}]
	}]
}

fastjson解析json数据到java对象中

TreeNode treeNode = JSON.parseObject(userDir.getMemDir(),new TypeReference<TreeNode>(){
   });

TypeReferences是fastjson的一个内置类

自定义的类属性名称需要和json数据格式的key相同才能进行解析