如何在Groovy中使用JSONObject和JSONArray类？没有得到“无法解决类JSONObject”错误在终端

Question

我试图做一个JSON对象（从根到叶节点），并使用JSONObject和JSONArray类在groovy中从我的孩子兄弟姐妹树结构递归地以json格式打印但我不断地得到这个“无法解决类JSONObject”的错误。我的代码片段如下：

void screenout(Nope roota, Map mapp) { 
    me = roota; 
    Nope temp = roota; 
    if (roota == null) 
     return; 
    def rootie = new JSONObject(); 
    def infos = new JSONArray(); 
    while (temp != null) { 
     def info = new JSONObject(); 
     info.put("category", temp.val) 
     info.put("path", mapp[temp.val]) 
     infos.add(info); 
     roota = temp; 
     temp = temp.sibling; 
     screenout(roota.child, mapp); 
    } 
    rootie.put("children", infos); 

    if (me == root) { 
     println(rootie.JSONString()); 
    } 
} 

Answer 1

因此，考虑到：

class Node { 
    String category 
    List children 
} 

def tree = new Node(category:'a', children:[ 
    new Node(category:'ab'), 
    new Node(category:'ad', children:[ 
     new Node(category:'ada') 
    ]) 
]) 

我可以这样做：

import groovy.json.* 

println new JsonBuilder(tree).toPrettyString() 

要打印出：

{ 
    "category": "a", 
    "children": [ 
     { 
      "category": "ab", 
      "children": null 
     }, 
     { 
      "category": "ad", 
      "children": [ 
       { 
        "category": "ada", 
        "children": null 
       } 
      ] 
     } 
    ] 
}