我想将 YAML 文档读取到自定义对象的映射(而不是映射,snakeYaml 默认会这样做).所以这个:
I want to read a YAML document to a map of custom objects (instead of maps, which snakeYaml does by default). So this:
19:
typeID: 2
limit: 300
20:
typeID: 8
limit: 100
将加载到如下所示的地图:
Would be loaded to a map which looks like this:
Map<Integer, Item>
项目在哪里:
class Item {
private Integer typeId;
private Integer limit;
}
我找不到使用snakeYaml 的方法,也找不到更好的库来完成这项任务.
I could not find a way to do this with snakeYaml, and I couldn't find a better library for the task either.
文档仅包含嵌套在其他对象中的地图/集合的示例,因此您可以执行以下操作:
The documentation only has examples with maps/collections nested inside other objects, so that you can do the following:
TypeDescription typeDescription = new TypeDescription(ClassContainingAMap.class);
typeDescription.putMapPropertyType("propertyNameOfNestedMap", Integer.class, Item.class);
Constructor constructor = new Constructor(typeDescription);
Yaml yaml = new Yaml(constructor);
/* creating an input stream (is) */
ClassContainingAMap obj = (ClassContainingAMap) yaml.load(is);
但是当 Map 格式位于文档的根目录时,我该如何定义它呢?
But how do I go about defining the Map format when it is at the root of the document?
你需要添加一个自定义构造函数.但是,在您的情况下,您不想注册项目"或项目列表"标签.
You need to add a custom Constructor. However, in your case you don't want register an "item" or "item-list" tag.
实际上,您希望将 Duck Typing 应用于您的 Yaml.这不是超级高效,但有一种相对简单的方法可以做到这一点.
In effect, you want to apply Duck Typing to your Yaml. It's not super efficient, but there is a relatively easy way to do this.
class YamlConstructor extends Constructor {
@Override
protected Object constructObject(Node node) {
if (node.getTag() == Tag.MAP) {
LinkedHashMap<String, Object> map = (LinkedHashMap<String, Object>) super
.constructObject(node);
// If the map has the typeId and limit attributes
// return a new Item object using the values from the map
...
}
// In all other cases, use the default constructObject.
return super.constructObject(node);
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