在 Jayway JSONPath 中,last() 函数用来获取数组中的最后一个元素。
注意:last() 函数并不是标准 JSONPath 规范的一部分。
假设我们有以下 JSON 数据:
{ "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 }
如果执行 $.store.book.last() 表达式将获取最后一本书,JSON 如下:
{ "category": "fiction", "author": "J. R. R. Tolkien", "title": "The Lord of the Rings", "isbn": "0-395-19395-8", "price": 22.99 }
Java 示例:
package com.hxstrive.json_path.function; import com.jayway.jsonpath.JsonPath; /** * last() 函数 * @author hxstrive.com */ public class FunctionDemo10 { public static void main(String[] args) { String json = "{" + " \"store\": {" + " \"book\": [" + " {" + " \"category\": \"reference\"," + " \"author\": \"Nigel Rees\"," + " \"title\": \"Sayings of the Century\"," + " \"price\": 8.95" + " }," + " {" + " \"category\": \"fiction\"," + " \"author\": \"Evelyn Waugh\"," + " \"title\": \"Sword of Honour\"," + " \"price\": 12.99" + " }," + " {" + " \"category\": \"fiction\"," + " \"author\": \"Herman Melville\"," + " \"title\": \"Moby Dick\"," + " \"isbn\": \"0-553-21311-3\"," + " \"price\": 8.99" + " }," + " {" + " \"category\": \"fiction\"," + " \"author\": \"J. R. R. Tolkien\"," + " \"title\": \"The Lord of the Rings\"," + " \"isbn\": \"0-395-19395-8\"," + " \"price\": 22.99" + " }" + " ]," + " \"bicycle\": {" + " \"color\": \"red\"," + " \"price\": 19.95" + " }" + " }," + " \"expensive\": 10" + "}"; Object obj = JsonPath.read(json, "$.store.book.last()"); 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}