我们任然遵循学习新知识的基本方法，先编写一个简单的“Hello World”程序。
在 maven 的 pom.xml 文件中添加如下依赖：
<dependency> <groupId>com.jayway.jsonpath</groupId> <artifactId>json-path</artifactId> <version>2.9.0</version> </dependency>
使用 JsonPath.read() 静态方法，提取指定 JSON 字符串中所有书籍（book）的作者信息，代码如下：
package com.hxstrive.json_path;
import com.jayway.jsonpath.JsonPath;
import java.util.List;
/**
* Jayway JsonPath 入门示例
* @author hxstrive.com
*/
public class Demo {
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" +
"}";
// 获取所有书籍的作者
List<String> authors = JsonPath.read(json, "$.store.book[*].author");
for(String author : authors) {
System.out.println("author: " + author);
}
}
}注意，上述示例中，“$.store.book[*].author”是一个 JsonPath 字符串，其中，$ 表示当前整个 JSON 字符串，* 是一个通配符，$.store.book[*] 表示获取所有的书籍信息。
如果读者曾经使用过 ApiFox 工具的变量提取，那么对 JsonPath 应该非常熟悉，如下图：
运行示例，输出如下：
author: Nigel Rees author: Evelyn Waugh author: Herman Melville author: J. R. R. Tolkien
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