Js解析Json数据获取元素JsonPath与深度

原文出处：
http://www.yund.tech/zdetail.html?type=1&id=c2b21696839eccdef2e9b085b9e064f6

作者: jstarseven

JsonPath 是一种信息抽取类库，是从JSON文档中抽取指定信息的工具，提供多种语言实现版本，包括：Javascript, Python， PHP 和 Java，JsonPath 对于 JSON 来说，相当于 XPATH 对于 XML。

JsonPath与Xpath用法对比

Java使用Jsonpath解析json数据

Js获取Json每个节点的JsonPath

将输出结果转换成树形结构

1.JsonPath与Xpath用法对比

XPath	JSONPath	描述
/	$	根节点
.	@	现行节点
/	.or[]	取子节点
…	n/a	取父节点，Jsonpath未支持
//	…	就是不管位置，选择所有符合条件的条件
*	*	匹配所有元素节点
@	n/a	根据属性访问，Json不支持，因为Json是个Key-value递归结构，不需要。
[]	[]	迭代器标示（可以在里边做简单的迭代操作，如数组下标，根据内容选值等）
\|	[,]	支持迭代器中做多选。
[]	?()	支持过滤操作.
n/a	()	支持表达式计算
()	n/a	分组，JsonPath不支持

2.Java使用Jsonpath解析json数据 1）引入fastjson依赖


 com.alibaba
 fastjson
 1.2.6


2）java简单的解析案例
public class JsonPath {
    public static void main(String[] args) {
 String jsonStr = "{n" +
  "  "store": {n" +
  "    "book": [n" +
  "      {n" +
  " "category": "reference",n" +
  " "author": "Nigel Rees",n" +
  " "title": "Sayings of the Century",n" +
  " "price": 8.95n" +
  "      },n" +
  "      {n" +
  " "category": "fiction",n" +
  " "author": "Evelyn Waugh",n" +
  " "title": "Sword of Honour",n" +
  " "price": 12.99,n" +
  " "isbn": "0-553-21311-3"n" +
  "      }n" +
  "      {n" +
  " "category": "fiction",n" +
  " "author": "Evelyn Waugh",n" +
  " "title": "Sword of Honour two",n" +
  " "price": 12.99,n" +
  " "isbn": "0-553-21311-3"n" +
  "      }n" +
  "    ],n" +
  "    "bicycle": {n" +
  "      "color": "red",n" +
  "      "price": 19.95n" +
  "    }n" +
  "  }n" +
  "}";
 JSonObject jsonObject = JSON.parseObject(jsonStr);
 System.out.println("Book：" + JSONPath.eval(jsonObject, "$.store.book"));
 System.out.println("Book数目：" + JSONPath.eval(jsonObject, "$.store.book.size()"));
 System.out.println("第一本书title：" + JSONPath.eval(jsonObject, "$.store.book[0].title"));
 System.out.println("price大于10元的book：" + JSONPath.eval(jsonObject, "$.store.book[price > 10]"));
 System.out.println("price大于10元的title：" + JSONPath.eval(jsonObject, "$.store.book[price > 10][0].title"));
 System.out.println("price大于10元的title：" + JSONPath.eval(jsonObject, "$.store.book[price > 10][1].title"));
 System.out.println("category(类别)为fiction(小说)的book：" + JSONPath.eval(jsonObject, "$.store.book[category = 'fiction']"));
 System.out.println("bicycle的所有属性值" + JSONPath.eval(jsonObject, "$.store.bicycle.*"));
 System.out.println("bicycle的color和price属性值" + JSONPath.eval(jsonObject, "$.store.bicycle['color','price']"));
    }

3.Js获取Json每个节点的JsonPath
1）准备json测试数据
var root = {
 name: '测试节点',
 doms: {
     name: "dom测试",
     children: [
  {
      name: '茶馆',
      val: 'demo',
      child: [
   {"name": "李四", "cal": "ceshi"}, {"name": "王五", "cal": "ceshi"}
      ]
  },
  {
      name: '红与黑',
      val: 'demo',
      child: [
   {"name": "张三", "cal": "ceshi"}, {"name": "张三", "cal": "ceshi"}
      ]
  }
     ]
 },
 children: [
     {
  name: '学习',
  children: []
     },
     {
  name: '电影',
  children: [
      {
   name: '喜剧电影'
      },
      {
   name: '动作电影'
      }
  ]
     }
 ]
    }

2）遍历Json对象获取每个节点的深度与JsonPath
     function traverseTree(node, flat) {
 var stack = [], res = [];
 if (!node) return;
 stack.push({"dom": node, "dep": 0, "path": "$", "name": "根节点"});
 var tmpNode;
 while (stack.length > 0) {
     tmpNode = stack.pop();
     res.push({
  "name": tmpNode.name,
  "pid": tmpNode.pid,
  "path": tmpNode.path,
  "dep": tmpNode.dep
     });
     traverseNode2(tmpNode, tmpNode.dep);
 }

 // 遍历单个节点
 function traverseNode2(node, dep) {
     var doc = node.dom;
     if (Object.prototype.toString.call(doc) === '[object Object]') {
  for (var val in doc) {
      var cpath = (node.path + "." + val);
      stack.push({
   "dom": doc[val],
   "dep": (dep + 1),
   "path": cpath,
   "pid": node.path,
   "name": val
      });
  }
     }
     if (Object.prototype.toString.call(doc) === '[object Array]') {
  for (let i = 0; i < doc.length; i++) {
      stack.push({
   "dom": doc[i],
   "dep": (dep + 1),
   "path": (node.path + "[" + i + "]"),
   "pid": node.path,
   "name": node.name + "[" + i + "]"
      });
  }
     }
 }

 // 树形结构转换
 function flat2tree(jsonData) {
     var result = [], temp = {}, i = 0, j = 0, len = jsonData.length;
     for (; i < len; i++)
  temp[jsonData[i]['path']] = jsonData[i]
     for (; j < len; j++) {
  var cel = jsonData[j]
  var tcel = temp[cel['pid']]
  if (tcel) {
      if (!tcel['children']) {
   tcel['children'] = [];
      }
      tcel['children'].push(cel)
  } else {
      result.push(cel);
  }
     }
     return result;
 }

 return flat ? flat2tree(res) : res;
    }

3）测试输出
console.log("res-tree:n" + JSON.stringify(traverseTree(root, false)));
res-tree:
[
    {
 "name":"根节点",
 "path":"$",
 "dep":0
    },
    {
 "name":"children",
 "pid":"$",
 "path":"$.children",
 "dep":1
    },
    {
 "name":"children[1]",
 "pid":"$.children",
 "path":"$.children[1]",
 "dep":2
    },
    {
 "name":"children",
 "pid":"$.children[1]",
 "path":"$.children[1].children",
 "dep":3
    },
    {
 "name":"children[1]",
 "pid":"$.children[1].children",
 "path":"$.children[1].children[1]",
 "dep":4
    },
    {
 "name":"name",
 "pid":"$.children[1].children[1]",
 "path":"$.children[1].children[1].name",
 "dep":5
    },
    {
 "name":"children[0]",
 "pid":"$.children[1].children",
 "path":"$.children[1].children[0]",
 "dep":4
    },
    {
 "name":"name",
 "pid":"$.children[1].children[0]",
 "path":"$.children[1].children[0].name",
 "dep":5
    },
    {
 "name":"name",
 "pid":"$.children[1]",
 "path":"$.children[1].name",
 "dep":3
    },
    {
 "name":"children[0]",
 "pid":"$.children",
 "path":"$.children[0]",
 "dep":2
    },
    {
 "name":"children",
 "pid":"$.children[0]",
 "path":"$.children[0].children",
 "dep":3
    },
    {
 "name":"name",
 "pid":"$.children[0]",
 "path":"$.children[0].name",
 "dep":3
    },
    {
 "name":"doms",
 "pid":"$",
 "path":"$.doms",
 "dep":1
    },
    {
 "name":"children",
 "pid":"$.doms",
 "path":"$.doms.children",
 "dep":2
    },
    {
 "name":"children[1]",
 "pid":"$.doms.children",
 "path":"$.doms.children[1]",
 "dep":3
    },
    {
 "name":"child",
 "pid":"$.doms.children[1]",
 "path":"$.doms.children[1].child",
 "dep":4
    },
    {
 "name":"child[1]",
 "pid":"$.doms.children[1].child",
 "path":"$.doms.children[1].child[1]",
 "dep":5
    },
    {
 "name":"cal",
 "pid":"$.doms.children[1].child[1]",
 "path":"$.doms.children[1].child[1].cal",
 "dep":6
    },
    {
 "name":"name",
 "pid":"$.doms.children[1].child[1]",
 "path":"$.doms.children[1].child[1].name",
 "dep":6
    },
    {
 "name":"child[0]",
 "pid":"$.doms.children[1].child",
 "path":"$.doms.children[1].child[0]",
 "dep":5
    },
    {
 "name":"cal",
 "pid":"$.doms.children[1].child[0]",
 "path":"$.doms.children[1].child[0].cal",
 "dep":6
    },
    {
 "name":"name",
 "pid":"$.doms.children[1].child[0]",
 "path":"$.doms.children[1].child[0].name",
 "dep":6
    },
    {
 "name":"val",
 "pid":"$.doms.children[1]",
 "path":"$.doms.children[1].val",
 "dep":4
    },
    {
 "name":"name",
 "pid":"$.doms.children[1]",
 "path":"$.doms.children[1].name",
 "dep":4
    },
    {
 "name":"children[0]",
 "pid":"$.doms.children",
 "path":"$.doms.children[0]",
 "dep":3
    },
    {
 "name":"child",
 "pid":"$.doms.children[0]",
 "path":"$.doms.children[0].child",
 "dep":4
    },
    {
 "name":"child[1]",
 "pid":"$.doms.children[0].child",
 "path":"$.doms.children[0].child[1]",
 "dep":5
    },
    {
 "name":"cal",
 "pid":"$.doms.children[0].child[1]",
 "path":"$.doms.children[0].child[1].cal",
 "dep":6
    },
    {
 "name":"name",
 "pid":"$.doms.children[0].child[1]",
 "path":"$.doms.children[0].child[1].name",
 "dep":6
    },
    {
 "name":"child[0]",
 "pid":"$.doms.children[0].child",
 "path":"$.doms.children[0].child[0]",
 "dep":5
    },
    {
 "name":"cal",
 "pid":"$.doms.children[0].child[0]",
 "path":"$.doms.children[0].child[0].cal",
 "dep":6
    },
    {
 "name":"name",
 "pid":"$.doms.children[0].child[0]",
 "path":"$.doms.children[0].child[0].name",
 "dep":6
    },
    {
 "name":"val",
 "pid":"$.doms.children[0]",
 "path":"$.doms.children[0].val",
 "dep":4
    },
    {
 "name":"name",
 "pid":"$.doms.children[0]",
 "path":"$.doms.children[0].name",
 "dep":4
    },
    {
 "name":"name",
 "pid":"$.doms",
 "path":"$.doms.name",
 "dep":2
    },
    {
 "name":"name",
 "pid":"$",
 "path":"$.name",
 "dep":1
    }
]

4.将输出结果转换成树形结构
console.log("res-tree:n" + JSON.stringify(traverseTree(root, true)));
res-tree:
[
    {
 "name":"根节点",
 "path":"$",
 "dep":0,
 "children":[
     {
  "name":"children",
  "pid":"$",
  "path":"$.children",
  "dep":1,
  "children":[
      {
   "name":"children[1]",
   "pid":"$.children",
   "path":"$.children[1]",
   "dep":2,
   "children":[
{
    "name":"children",
    "pid":"$.children[1]",
    "path":"$.children[1].children",
    "dep":3,
    "children":[
 {
     "name":"children[1]",
     "pid":"$.children[1].children",
     "path":"$.children[1].children[1]",
     "dep":4,
     "children":[
  {
      "name":"name",
      "pid":"$.children[1].children[1]",
      "path":"$.children[1].children[1].name",
      "dep":5
  }
     ]
 },
 {
     "name":"children[0]",
     "pid":"$.children[1].children",
     "path":"$.children[1].children[0]",
     "dep":4,
     "children":[
  {
      "name":"name",
      "pid":"$.children[1].children[0]",
      "path":"$.children[1].children[0].name",
      "dep":5
  }
     ]
 }
    ]
},
{
    "name":"name",
    "pid":"$.children[1]",
    "path":"$.children[1].name",
    "dep":3
}
   ]
      },
      {
   "name":"children[0]",
   "pid":"$.children",
   "path":"$.children[0]",
   "dep":2,
   "children":[
{
    "name":"children",
    "pid":"$.children[0]",
    "path":"$.children[0].children",
    "dep":3
},
{
    "name":"name",
    "pid":"$.children[0]",
    "path":"$.children[0].name",
    "dep":3
}
   ]
      }
  ]
     },
     {
  "name":"doms",
  "pid":"$",
  "path":"$.doms",
  "dep":1,
  "children":[
      {
   "name":"children",
   "pid":"$.doms",
   "path":"$.doms.children",
   "dep":2,
   "children":[
{
    "name":"children[1]",
    "pid":"$.doms.children",
    "path":"$.doms.children[1]",
    "dep":3,
    "children":[
 {
     "name":"child",
     "pid":"$.doms.children[1]",
     "path":"$.doms.children[1].child",
     "dep":4,
     "children":[
  {
      "name":"child[1]",
      "pid":"$.doms.children[1].child",
      "path":"$.doms.children[1].child[1]",
      "dep":5,
      "children":[
   {
"name":"cal",
"pid":"$.doms.children[1].child[1]",
"path":"$.doms.children[1].child[1].cal",
"dep":6
   },
   {
"name":"name",
"pid":"$.doms.children[1].child[1]",
"path":"$.doms.children[1].child[1].name",
"dep":6
   }
      ]
  },
  {
      "name":"child[0]",
      "pid":"$.doms.children[1].child",
      "path":"$.doms.children[1].child[0]",
      "dep":5,
      "children":[
   {
"name":"cal",
"pid":"$.doms.children[1].child[0]",
"path":"$.doms.children[1].child[0].cal",
"dep":6
   },
   {
"name":"name",
"pid":"$.doms.children[1].child[0]",
"path":"$.doms.children[1].child[0].name",
"dep":6
   }
      ]
  }
     ]
 },
 {
     "name":"val",
     "pid":"$.doms.children[1]",
     "path":"$.doms.children[1].val",
     "dep":4
 },
 {
     "name":"name",
     "pid":"$.doms.children[1]",
     "path":"$.doms.children[1].name",
     "dep":4
 }
    ]
},
{
    "name":"children[0]",
    "pid":"$.doms.children",
    "path":"$.doms.children[0]",
    "dep":3,
    "children":[
 {
     "name":"child",
     "pid":"$.doms.children[0]",
     "path":"$.doms.children[0].child",
     "dep":4,
     "children":[
  {
      "name":"child[1]",
      "pid":"$.doms.children[0].child",
      "path":"$.doms.children[0].child[1]",
      "dep":5,
      "children":[
   {
"name":"cal",
"pid":"$.doms.children[0].child[1]",
"path":"$.doms.children[0].child[1].cal",
"dep":6
   },
   {
"name":"name",
"pid":"$.doms.children[0].child[1]",
"path":"$.doms.children[0].child[1].name",
"dep":6
   }
      ]
  },
  {
      "name":"child[0]",
      "pid":"$.doms.children[0].child",
      "path":"$.doms.children[0].child[0]",
      "dep":5,
      "children":[
   {
"name":"cal",
"pid":"$.doms.children[0].child[0]",
"path":"$.doms.children[0].child[0].cal",
"dep":6
   },
   {
"name":"name",
"pid":"$.doms.children[0].child[0]",
"path":"$.doms.children[0].child[0].name",
"dep":6
   }
      ]
  }
     ]
 },
 {
     "name":"val",
     "pid":"$.doms.children[0]",
     "path":"$.doms.children[0].val",
     "dep":4
 },
 {
     "name":"name",
     "pid":"$.doms.children[0]",
     "path":"$.doms.children[0].name",
     "dep":4
 }
    ]
}
   ]
      },
      {
   "name":"name",
   "pid":"$.doms",
   "path":"$.doms.name",
   "dep":2
      }
  ]
     },
     {
  "name":"name",
  "pid":"$",
  "path":"$.name",
  "dep":1
     }
 ]
    }
]

Js解析Json数据获取元素JsonPath与深度

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