JsonPath实践（四）

书接上文和上上文以及上上上文：

JsonPath实践（一）
JsonPath实践（二）
JsonPath实践（三）

本期继续将如何处理json数组，主要内容是通过正则过滤json数组中的数据，以及通过正则校验json节点值。

JSonpath中的正则语法是通用的，但是使用方法跟Groovy非常类似。有兴趣的同学参考：Java和Groovy正则使用。使用=~这个标记语法表示正则匹配，然后用前后两个/符号表示正则的内容，这一点跟Groovy一模一样，还有多了一种忽略大小写的语法，就是在正则语句后面的/加上i这个字母（暂时没发现其他字母的标记功能）。

json数据

首先看官方给的json数据的Demo（我做了一点点修改）：

JSONObject json = JSON.parseObject("{" +
                "    "store": {" +
                "        "book": [" +
                "            {" +
                "                "category": "reference"," +
                "                "author": "Nigel Rees"," +
                "                "title": "Sayings of the Century"," +
                "                "price": 8.95" +
                "            }," +
                "            {" +
                "                "category": "fiction"," +
                "                "author": "Evelyn Waugh"," +
                "                "title": "Sword of Honour"," +
                "                "price": 12.99" +
                "            }," +
                "            {" +
                "                "category": "fiction"," +
                "                "author": "Herman Melville"," +
                "                "title": "Moby Dick"," +
                "                "isbn": "0-553-21311-3"," +
                "                "price": 8.99" +
                "            }," +
                "            {" +
                "                "category": "fiction"," +
                "                "author": "J. R. R. Tolkien"," +
                "                "title": "The Lord of the Rings"," +
                "                "isbn": "0-395-19395-8"," +
                "                "price": 22.99" +
                "            }" +
                "        ]," +
                "        "bicycle": {" +
                "            "color": "red"," +
                "            "price": 19.95" +
                "        }" +
                "    }," +
                "    "expensive": 10," +
                "    "ss": [32,32,4,23]" +
                "}");

通过正则过滤数组

jsonpath：$..book[?(@.author =~ /.*Rees/)]

或者使用路径表示：

jsonpath：$.store.book[?(@.author =~ /.*Rees/)]

这里表示倒数第一个对象

代码：

        Object read = JsonPath.read(json, "$.store.book[?(@.author =~ /.*Rees/)]");
        output(JSONArray.parseArray(read.toString()));

等效写法继续省略……

控制台输出：

INFO-> 当前用户：fv，IP：10.60.192.21，工作目录：/Users/fv/Documents/workspace/fun/,系统编码格式:UTF-8,系统Mac OS X版本:10.15.6
INFO-> 
~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~ JSON ~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~
＞  {
＞  ① . "author":"Nigel Rees",
＞  ① . "price":8.95,
＞  ① . "category":"reference",
＞  ① . "title":"Sayings of the Century"
＞  }
~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~ JSON ~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~

Process finished with exit code 0

忽略大小写

jsonpath：$..book[?(@.author =~ /.*REES/)]

或者使用忽略大小写语法：

jsonpath：$.store.book[?(@.author =~ /.*REES/i)]

这里表示倒数第一个对象

代码：

        Object read = JsonPath.read(json, "$.store.book[?(@.author =~ /.*REES/)]");
        output(JSONArray.parseArray(read.toString()).isEmpty());

        Object read = JsonPath.read(json, "$.store.book[?(@.author =~ /.*Rees/i)]");
        output(JSONArray.parseArray(read.toString()));

等效写法继续省略……

控制台输出：

INFO-> 当前用户：fv，IP：10.60.192.21，工作目录：/Users/fv/Documents/workspace/fun/,系统编码格式:UTF-8,系统Mac OS X版本:10.15.6
INFO-> true

Process finished with exit code 0

INFO-> 当前用户：fv，IP：10.60.192.21，工作目录：/Users/fv/Documents/workspace/fun/,系统编码格式:UTF-8,系统Mac OS X版本:10.15.6
INFO-> 
~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~ JSON ~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~
＞  {
＞  ① . "author":"Nigel Rees",
＞  ① . "price":8.95,
＞  ① . "category":"reference",
＞  ① . "title":"Sayings of the Century"
＞  }
~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~ JSON ~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~

Process finished with exit code 0

正则验证节点值

这个不支持，哈哈，我会封装一下，让它支持。