在 JsonPath 中,@ 操作符表示过滤谓词正在处理的当前节点。
假如我们有“$..book[?(@.price > 20)]”JsonPath 表达式,其中 @ 表示每个书籍对象,而 @.price 将获取每个书籍的 price 字段的值。
Java 示例:
package com.hxstrive.json_path.operators;
import com.jayway.jsonpath.JsonPath;
/**
* @ 符号
* @author hxstrive.com
*/
public class OperatorsDemo02 {
public static void main(String[] args) {
String json = "{" +
" \"store\": {" +
" \"book\": [" +
" {" +
" \"category\": \"reference\"," +
" \"author\": \"Nigel Rees\"," +
" \"title\": \"Sayings of the Century\"," +
" \"price\": 8.95" +
" }," +
" {" +
" \"category\": \"fiction\"," +
" \"author\": \"Evelyn Waugh\"," +
" \"title\": \"Sword of Honour\"," +
" \"price\": 12.99" +
" }," +
" {" +
" \"category\": \"fiction\"," +
" \"author\": \"Herman Melville\"," +
" \"title\": \"Moby Dick\"," +
" \"isbn\": \"0-553-21311-3\"," +
" \"price\": 8.99" +
" }," +
" {" +
" \"category\": \"fiction\"," +
" \"author\": \"J. R. R. Tolkien\"," +
" \"title\": \"The Lord of the Rings\"," +
" \"isbn\": \"0-395-19395-8\"," +
" \"price\": 22.99" +
" }" +
" ]," +
" \"bicycle\": {" +
" \"color\": \"red\"," +
" \"price\": 19.95" +
" }" +
" }," +
" \"expensive\": 10" +
"}";
Object obj = JsonPath.read(json, "$..book[?(@.price > 20)]");
System.out.println(obj);
}
}运行示例,输出如下:
[{"category":"fiction","author":"J. R. R. Tolkien","title":"The Lord of the Rings","isbn":"0-395-19395-8","price":22.99}]从上述输出可知,仅仅输出了书籍价格大于 20 的书籍。