如何在Java中获取JSON路径的所有输出路径,以便通过它们的函数替换现有值
Posted
tags:
篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了如何在Java中获取JSON路径的所有输出路径,以便通过它们的函数替换现有值相关的知识,希望对你有一定的参考价值。
假设我有这个.json巫婆我想要应用一个函数来收集这本书的价格:
{
"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
}
我这样做的想法是指定jsonpath
$.store.book[*].price
并获得输出路径列表(如本网站:qazxsw poi)
https://jsonpath.com/
甚至更好的是路径和价值之间的直接映射
[ "$.store.book[0].price", "$.store.book[1].price", "$.store.book[2].price", "$.store.book[3].price" ]
然后在列表上循环以在每个值上应用函数并使用新值设置json
但我找不到如何获得该路径列表,我该怎么做? (或者,如果你有什么东西可以通过自己的函数直接替换值,我也会接受:))
PS:我给的.json只是一个例子,我需要它.json方式比它更嵌套
答案
要列出需要使用配置对象解析文档的路径。之后,您需要再次解析它以进行更新:
[ {"$.store.book[0].price":8.95}, {"$.store.book[1].price":12.99}, {"$.store.book[2].price":8.99}, {"$.store.book[3].price":22.99} ]
上面的代码打印:
import com.jayway.jsonpath.Configuration;
import com.jayway.jsonpath.JsonPath;
import com.jayway.jsonpath.Option;
import com.jayway.jsonpath.internal.JsonContext;
import java.io.File;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.List;
import java.util.stream.Collectors;
public class JsonPathApp {
public static void main(String[] args) throws Exception {
File jsonFile = new File("./resource/test.json").getAbsoluteFile();
// read paths
List<String> paths = JsonPath
.using(Configuration.builder().options(Option.AS_PATH_LIST).build())
.parse(jsonFile)
.read("$.store.book[*].price", List.class);
// compile paths
List<JsonPath> jsonPaths = paths
.stream()
.map(p -> JsonPath.compile(p))
.collect(Collectors.toList());
// parse once for reading/updating
JsonContext document = (JsonContext) JsonPath.parse(jsonFile);
jsonPaths.forEach(path -> {
BigDecimal value = document.read(path, BigDecimal.class);
document.set(path, transform(value));
});
System.out.println(document.jsonString());
}
private static BigDecimal transform(BigDecimal value) {
return value.setScale(0, RoundingMode.HALF_UP);
}
}
也可以看看:
{ "store": { "book": [ { "category": "reference", "author": "Nigel Rees", "title": "Sayings of the Century", "price": 9 }, { "category": "fiction", "author": "Evelyn Waugh", "title": "Sword of Honour", "price": 13 }, { "category": "fiction", "author": "Herman Melville", "title": "Moby Dick", "isbn": "0-553-21311-3", "price": 9 }, { "category": "fiction", "author": "J. R. R. Tolkien", "title": "The Lord of the Rings", "isbn": "0-395-19395-8", "price": 23 } ], "bicycle": { "color": "red", "price": 19.95 } }, "expensive": 10 }
- JSONPath
以上是关于如何在Java中获取JSON路径的所有输出路径,以便通过它们的函数替换现有值的主要内容,如果未能解决你的问题,请参考以下文章