SnakeYaml堆叠钥匙 [英] SnakeYaml get stacked keys

问题描述

这是我的.yml文件时:

When this is my .yml file:

test1: "string1"
test2:
  test3: "string2"

如何获取 test3 的值?

Map<String, Object> yamlFile = new Yaml().load(YamlFileInputStream);

yamlFile.get("test1"); // output: string1
yamlFile.get("test2"); // output: {test3=string2}

yamlFile.get("test2.test3"); // output: key not found

推荐答案

YAML没有„ stacked keys".它具有嵌套映射.点.不是特殊字符，通常可以在键中出现，因此您不能将其用于查询嵌套映射中的值.

YAML does not have „stacked keys". It has nested mappings. The dot . is not a special character and can occur normally in a key, therefore you cannot use it for querying values in nested mappings.

您已经展示了如何访问包含 test3 键的映射，您可以从那里简单地查询值:

You already show how to access the mapping containing the test3 key, you can simply query the value from there:

((Map<String, Object)yamlFile.get("test2")).get("test3");

但是，将YAML文件的结构定义为类要简单得多:

However, it is much simpler to define the structure of your YAML file as class:

class YamlFile {
    static class Inner {
        public String test3;
    }

    public String test1;
    public Inner test2;
}

然后您可以像这样加载它:

Then you can load it like this:

YamlFile file = new Yaml(new Constructor(YamlFile.class)).loadAs(
    input, YamlFile.class);
file.test2.test3; // this is your string

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