书接上文和上上文：
今天分享的内容是JSonpath过滤数据的API。这部分API分成两类：一类是运算符，例如：==、>、=~这些，一类是方法或者函数，例如：in、nin、anyof等等。
第一类实在没啥可分享的写法都是按照语言使用习惯，然后之前的文章也都介绍过了，下面主要分享一下方法函数的使用。
在原来的数据基础上增加了page和pages两个字段。
JSONObject json = JSON.parseObject("{" +
" \"store\": {" +
" \"book\": [" +
" {" +
" \"category\": \"reference\"," +
" \"author\": \"Nigel Rees\"," +
" \"title\": \"Sayings of the Century\"," +
" \"page\": \"D\"," +
" \"pages\": [\"S\",\"X\",\"G\"]," +
" \"price\": 8.95" +
" }," +
" {" +
" \"category\": \"fiction\"," +
" \"author\": \"Evelyn Waugh\"," +
" \"title\": \"Sword of Honour\"," +
" \"page\": \"A\"," +
" \"pages\": [\"A\",\"B\"]," +
" \"price\": 12.99" +
" }," +
" {" +
" \"category\": \"fiction\"," +
" \"author\": \"Herman Melville\"," +
" \"title\": \"Moby Dick\"," +
" \"isbn\": \"0-553-21311-3\"," +
" \"page\": \"B\"," +
" \"pages\": [\"E\",\"F\"]," +
" \"price\": 8.99" +
" }," +
" {" +
" \"category\": \"fiction\"," +
" \"author\": \"J. R. R. Tolkien\"," +
" \"title\": \"The Lord of the Rings\"," +
" \"isbn\": \"0-395-19395-8\"," +
" \"page\": \"C\"," +
" \"pages\": [\"C\",\"D\"]," +
" \"price\": 22.99" +
" }" +
" ]," +
" \"bicycle\": {" +
" \"color\": \"red\"," +
" \"price\": 19.95" +
" }" +
" }," +
" \"expensive\": 10," +
" \"ss\": [32,32,4,23]" +
"}");
这里的数组的写法跟语言一样。
jsonpath：$.store.book[?(@.page in ['A','C'])]
代码：
Object read = JsonPath.read(json, "$.store.book[?(@.page in ['A','C'])]");
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 . "pages":[
＞ ② . . . "A",
＞ ② . . . "B"
＞ ① . ],
＞ ① . "author":"Evelyn Waugh",
＞ ① . "price":12.99,
＞ ① . "page":"A",
＞ ① . "category":"fiction",
＞ ① . "title":"Sword of Honour"
＞ }
~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~ JSON ~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~
INFO->
~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~ JSON ~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~
＞ {
＞ ① . "pages":[
＞ ② . . . "C",
＞ ② . . . "D"
＞ ① . ],
＞ ① . "author":"J. R. R. Tolkien",
＞ ① . "price":22.99,
＞ ① . "isbn":"0-395-19395-8",
＞ ① . "page":"C",
＞ ① . "category":"fiction",
＞ ① . "title":"The Lord of the Rings"
＞ }
~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~ JSON ~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~
Process finished with exit code 0
这个跟上面的一模一样，只是函数变成了nin，应该是no in的缩写吧。
jsonpath：$.store.book[?(@.page nin ['A','C'])]
代码：
Object read = JsonPath.read(json, "$.store.book[?(@.page nin ['A','C'])]");
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 . "pages":[
＞ ② . . . "S",
＞ ② . . . "X"，
＞ ② . . . "G"
＞ ① . ],
＞ ① . "author":"Nigel Rees",
＞ ① . "price":8.95,
＞ ① . "page":"D",
＞ ① . "category":"reference",
＞ ① . "title":"Sayings of the Century"
＞ }
~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~ JSON ~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~
INFO->
~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~ JSON ~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~
＞ {
＞ ① . "pages":[
＞ ② . . . "E",
＞ ② . . . "F"
＞ ① . ],
＞ ① . "author":"Herman Melville",
＞ ① . "price":8.99,
＞ ① . "isbn":"0-553-21311-3",
＞ ① . "page":"B",
＞ ① . "category":"fiction",
＞ ① . "title":"Moby Dick"
＞ }
~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~ JSON ~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~
Process finished with exit code 0
这个校验的是数组之间的关系，value的值必需是数组才行，如果不是，会返回空值，但不会报错。
jsonpath：$.store.book[?(@.pages subsetof ['A','B','C'])]
代码：
Object read = JsonPath.read(json, "$.store.book[?(@.pages subsetof ['A','B','C'])]");
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 . "pages":[
＞ ② . . . "A",
＞ ② . . . "B"
＞ ① . ],
＞ ① . "author":"Evelyn Waugh",
＞ ① . "price":12.99,
＞ ① . "page":"A",
＞ ① . "category":"fiction",
＞ ① . "title":"Sword of Honour"
＞ }
~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~ JSON ~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~
Process finished with exit code 0
国外的月亮也不一定是真的圆，这个据说在 19 年初被支持了，但是最后一个发行版本是在 17 年，已经三年没有发行版本了。我改天研究一下，自己弄个最新的版本版本吧。
size可以验证数组长度也可以验证字符串长度。
jsonpath：$.store.book[?(@.pages size 3)]
字符串长度：
jsonpath：$.store.book[?(@.author size 16)]
代码：
Object read = JsonPath.read(json, "$.store.book[?(@.pages size 3)]");
output(JSONArray.parseArray(read.toString()));
Object read = JsonPath.read(json, "$.store.book[?(@.author size 16)]");
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 . "pages":[
＞ ② . . . "S",
＞ ② . . . "X",
＞ ② . . . "G"
＞ ① . ],
＞ ① . "author":"Nigel Rees",
＞ ① . "price":8.95,
＞ ① . "page":"D",
＞ ① . "category":"reference",
＞ ① . "title":"Sayings of the Century"
＞ }
~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~ JSON ~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~
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 . "pages":[
＞ ② . . . "C",
＞ ② . . . "D"
＞ ① . ],
＞ ① . "author":"J. R. R. Tolkien",
＞ ① . "price":22.99,
＞ ① . "isbn":"0-395-19395-8",
＞ ① . "page":"C",
＞ ① . "category":"fiction",
＞ ① . "title":"The Lord of the Rings"
＞ }
~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~ JSON ~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~~☢~
Process finished with exit code 0
事实证明这也是一个坑，不过可以使用size 0这个API替换一下。