Java实现树的格式化打印以及返回前端json树

本文主要讲hutool工具类打印树的用法。注意，项目需要引入hutool工具类，pom依赖：

    cn.hutool
    hutool-all
    5.7.4

step1. 首先准备数据（Test.json）:

[
  {"orgId": 1,"parentOrgId": 0,"name": "xxx科技公司","desc": "xxx科技公司是一所只有007的company"},
  {"orgId": 11,"parentOrgId": 1,"name": "研发部","desc": "研发只有996"},
  {"orgId": 111,"parentOrgId": 11,"name": "Java开发部","desc": "描述....."},
  {"orgId": 1111,"parentOrgId": 111,"name": "Java开发1组","desc": "描述....."},
  {"orgId": 1112,"parentOrgId": 111,"name": "Java开发2组","desc": "描述....."},
  {"orgId": 112,"parentOrgId": 11,"name": "Python开发部","desc": "描述....."},
  {"orgId": 113,"parentOrgId": 11,"name": "C++开发部","desc": "描述....."},
  {"orgId": 12,"parentOrgId": 1,"name": "财务部","desc": "描述....."},
  {"orgId": 13,"parentOrgId": 1,"name": "商务部","desc": "描述....."},
  {"orgId": 14,"parentOrgId": 1,"name": "销售部","desc": "描述....."},
  {"orgId": 141,"parentOrgId": 14,"name": "华南区","desc": "描述....."},
  {"orgId": 142,"parentOrgId": 14,"name": "华北区","desc": "描述....."},
  {"orgId": 143,"parentOrgId": 14,"name": "华东区","desc": "描述....."}
]

step2. 单元测试代码：

public void testTree(){
     // 读取json文件内容，转换为entity
     String resultJson = FileUtil.readString(new ClassPathResource("Test.json").getFile(), "UTF-8");
     List orgs = JSONUtil.toList(resultJson, Org.class);
     List treeNodeList = new ArrayList();

     // 设置树节点
     orgs.forEach(org -> {
         TreeNode node = new TreeNode();
         node.setId(org.getOrgId());
         node.setParentId(org.getParentOrgId());
         node.setName(org.getName());
         Map map = new HashMap();
         map.put("desc", org.getDesc());
         node.setExtra(map);
         treeNodeList.add(node);
     });

     // 设置树节点字段别名
     TreeNodeConfig treeNodeConfig = new TreeNodeConfig();
     treeNodeConfig.setIdKey("basicId");
     treeNodeConfig.setParentIdKey("parentBasicId");
     treeNodeConfig.setNameKey("lable");

     // 开始构建树
     Tree tree = TreeUtil.buildSingle(treeNodeList, 0L, treeNodeConfig, new DefaultNodeParser());
     tree.setName("机构树示例");

     // 格式化打印树
     System.out.println(tree);

     // 打印json树
     String jsonStr = JSONUtil.toJsonStr(tree);
     JSONObject jsonObject = new JSONObject(jsonStr);
     Object children = jsonObject.get("children");
     System.out.println(JSONUtil.toJsonPrettyStr(children.toString()));
}

机构树打印运行效果： 返回json格式：

[
    {
        "basicId": 1,
        "weight": 0,
        "parentBasicId": 0,
        "children": [
            {
                "basicId": 11,
                "weight": 0,
                "parentBasicId": 1,
                "children": [
                    {
                        "basicId": 111,
                        "weight": 0,
                        "parentBasicId": 11,
                        "children": [
                            {
                                "basicId": 1111,
                                "weight": 0,
                                "parentBasicId": 111,
                                "lable": "Java开发1组",
                                "desc": "描述....."
                            },
                            {
                                "basicId": 1112,
                                "weight": 0,
                                "parentBasicId": 111,
                                "lable": "Java开发2组",
                                "desc": "描述....."
                            }
                        ],
                        "lable": "Java开发部",
                        "desc": "描述....."
                    },
                    {
                        "basicId": 112,
                        "weight": 0,
                        "parentBasicId": 11,
                        "lable": "Python开发部",
                        "desc": "描述....."
                    },
                    {
                        "basicId": 113,
                        "weight": 0,
                        "parentBasicId": 11,
                        "lable": "C++开发部",
                        "desc": "描述....."
                    }
                ],
                "lable": "研发部",
                "desc": "研发只有996"
            },
            {
                "basicId": 12,
                "weight": 0,
                "parentBasicId": 1,
                "lable": "财务部",
                "desc": "描述....."
            },
            {
                "basicId": 13,
                "weight": 0,
                "parentBasicId": 1,
                "lable": "商务部",
                "desc": "描述....."
            },
            {
                "basicId": 14,
                "weight": 0,
                "parentBasicId": 1,
                "children": [
                    {
                        "basicId": 141,
                        "weight": 0,
                        "parentBasicId": 14,
                        "lable": "华南区",
                        "desc": "描述....."
                    },
                    {
                        "basicId": 142,
                        "weight": 0,
                        "parentBasicId": 14,
                        "lable": "华北区",
                        "desc": "描述....."
                    },
                    {
                        "basicId": 143,
                        "weight": 0,
                        "parentBasicId": 14,
                        "lable": "华东区",
                        "desc": "描述....."
                    }
                ],
                "lable": "销售部",
                "desc": "描述....."
            }
        ],
        "lable": "xxx科技公司",
        "desc": "xxx科技公司是一所只有007的company"
    }
]