Yaml文件的If条件- Java

Question

我有Yaml文件：

#Define CDN domains
---
CDN: 
 quality: 200..300
 cost: low
 Video-type: mp4

使用这个Java代码，我检索CDN的子值：

 // The path of your YAML file.

 Yaml yaml = new Yaml();

 Map<String, Map<String, String>> values =
  (Map<String, Map<String, String>>) yaml
    .load(new FileInputStream(new File("/workspace/servlet-yaml/src/test.yaml")));

for (String key : values.keySet()) {
  Map<String, String> subValues = values.get(key);
  for (String subValueKey : subValues.keySet()) {
    System.out.println(values); 
  }
}

产出如下：

{CDN={quality=200..300, cost=low, Video-type=mp4}}
{CDN={quality=200..300, cost=low, Video-type=mp4}}
{CDN={quality=200..300, cost=low, Video-type=mp4}}

• 首先，我不知道为什么会重复三次？
• 其次，我想编写一个if cost = low代码，然后做一些事情。

Answer 1

首先，我不知道它为什么收获三次？

因为你是这么说的。对于每个subValueKey，打印整个值集。有三个子键，所以完整的值集会被打印三次.

其次，我想编写一个代码，如果成本=低，那么就做一些事情。

Yaml yaml = new Yaml();

Map<String, Map<String, String>> values =
        (Map<String, Map<String, String>>) yaml.load(
        new FileInputStream(new File(
        "/workspace/servlet-yaml/src/test.yaml")));

final Map<String, String> cdn = values.get("CDN");
    // or iterate over all keys like you currently do
final String cost = cdn.get("cost");
    // or iterate over all subkeys and compare them to "cost".
    // that way, it's easier to handle missing keys.
if ("low".equals(cost)) {
    // do something
}