Snakeyaml似乎不必要地在列表中包装简单的值 [英] Snakeyaml appears to unnecessarily wrap simple values in lists

问题描述

我试图用Groovy和Snakeyaml解析下面的YAML文件（显然我已经清理了数据，但它足以证明这个问题）：

  --- 
 info：
汇总：Snakeyaml发行
示例：
  - 第一个示例：
名称：示例1 
 sublist：
  -  0.1：
 foo：bar 
  

我期望以下语句：

  println resource.info.summary 
 println resource.examples。1st example.name 
 println resource.examples。1st example.sublist。0.1
  

p>

  Snakeyaml发行
示例1 
 [foo：bar] 
  

和：

  println resource.examples。第一个例子.sublist。0.1.foo 
  

得到：

  bar 
  

然而， 来自：

的输出>

  println resource.info.summary 
 println resource.examples。1st example.name 
 println resource.examples 。1st example.sublist。0.1
 println resource.examples。1st example.sublist。0.1.foo 
  

是：

  Snakeyaml发行
 [示例1] 
 [[[foo：bar]]] 
 [[bar]] 
  

我可以通过包含列表标记来获得期望的输出：

  println resource.info.summary 
 println resource.examples [ 0]1st example.name 
 println resource.examples [0]。1st example.sublist [0]。0.1
 println resource.examples [0]。1st example .sublist [0]。0.1.foo 
  

这似乎不必要。也许我误解了数据的结构？为了完整起见，我用来说明这个问题的groovy代码如下所示（我从客户的代码中取出CustomerResolver代码以便它将浮动字符串）：

  import org.yaml.snakeyaml.DumperOptions 
导入组织。 yaml.snakeyaml.Yaml 
 import org.yaml.snakeyaml.constructor.Constructor 
 import org.yaml.snakeyaml.nodes.Tag 
 import org.yaml.snakeyaml.representer.Representer 
 import org.yaml.snakeyaml.resolver.Resolver 
 $ b def fileName =example.yaml
 def Yaml yaml = new Yaml（new Constructor（），new Representer（），new DumperOptions （），
 new CustomResolver（））
 def resource = yaml.load（new File（fileName）.newInputStream（））
 
 println resource.info.summary 
 println resource.examples。1st example.name 
 println resource.examples。1st example.sublist。0.1
 println resource.examples。1st example.sublist。0.1 .foo 
 
类CustomResolver扩展解析器{
 
 / * 
 *不解析浮点数和时间戳
 * / 
 
 protected void addImplicitResolvers （）{
 addImplicitResolver（Tag.BOOL，BOOL，yYnNtTfFoO）; 
 addImplicitResolver（Tag.INT，INT， -  + 0123456789）; 
 addImplicitResolver（Tag.MERGE，MERGE，<）; 
 addImplicitResolver（Tag.NULL，NULL，〜nN\0）; 
 addImplicitResolver（Tag.NULL，EMPTY，null）; 
 
 
 $ b $ / code> 

任何想法？

解决方案

问题在于如何访问yaml

例子首先包含 list ，然后只包含 object 与键第一个示例

您的情况请尝试以下访问：

  println resource.info.summary 
 println resource.examples [0]。1st example
 println resource.examples [0]。1st example .name 
 println resource.examples [0]。1st example.sublist [0] 
 println resource.examples [0]。1st example.sublist [0]。0.1
 println resource.examples [0]。1st example.sublist [0]。0.1.foo 
  

了解list访问器如何工作检查这个例子：

  @Grab（group ='org.yaml'，module ='snakeyaml'，version ='1.18'）
 import org.yaml.snakeyaml.Yaml 
 $ b $ def Yaml yaml = new Yaml（）
 def resource = yaml.load新的StringReader（'''--- 
 info：
总结ry：Snakeyaml发行
示例：
  - 第一个示例：
名称：示例1 
  - 第一个示例：
名称：示例2 
  - 第一个示例： 
 xname：示例3 
  - 第二个示例：
名称：示例4 
'''））
 
 println resource.examples。1st example 
 //打印> [[name：Example 1]，[name：Example 2]，[xname：Example 3]，null] 
 
 println resource.examples。1st example.name 
 //打印> ; [例1，例2，空] 
  

I am attempting to parse the following YAML file using Groovy and Snakeyaml (clearly I have sanitised the data but it is sufficient to demonstrate the issue):

---
info:
  summary: Snakeyaml Issue
examples:
  - 1st example:
      name: Example 1
      sublist:
        - 0.1:
           foo: bar

I would expect the following statements:

println resource.info.summary
println resource.examples."1st example".name
println resource.examples."1st example".sublist."0.1"

to yield:

Snakeyaml Issue
Example 1
[foo:bar]

and:

println resource.examples."1st example".sublist."0.1".foo

to yield:

bar

However, the actual output from:

println resource.info.summary
println resource.examples."1st example".name
println resource.examples."1st example".sublist."0.1"
println resource.examples."1st example".sublist."0.1".foo

is:

Snakeyaml Issue
[Example 1]
[[[foo:bar]]]
[[bar]]

I can only get the desired output by including the list indicies:

println resource.info.summary
println resource.examples[0]."1st example".name
println resource.examples[0]."1st example".sublist[0]."0.1"
println resource.examples[0]."1st example".sublist[0]."0.1".foo

which seems unnecessary. Perhaps I am misunderstanding the structure of the data?

For completeness, the groovy code that I am using to illustrate the issue is shown below (I grabbed the CustomerResolver code off the web so that it would keep floats as strings):

import org.yaml.snakeyaml.DumperOptions
import org.yaml.snakeyaml.Yaml
import org.yaml.snakeyaml.constructor.Constructor
import org.yaml.snakeyaml.nodes.Tag
import org.yaml.snakeyaml.representer.Representer
import org.yaml.snakeyaml.resolver.Resolver

def fileName = "example.yaml"
def Yaml yaml = new Yaml(new Constructor(), new Representer(), new DumperOptions(),
    new CustomResolver())
def resource = yaml.load(new File(fileName).newInputStream())

println resource.info.summary
println resource.examples."1st example".name
println resource.examples."1st example".sublist."0.1"
println resource.examples."1st example".sublist."0.1".foo

class CustomResolver extends Resolver {

    /*
     * Do not resolve float and timestamp
     */

    protected void addImplicitResolvers() {
        addImplicitResolver(Tag.BOOL, BOOL, "yYnNtTfFoO");
        addImplicitResolver(Tag.INT, INT, "-+0123456789");
        addImplicitResolver(Tag.MERGE, MERGE, "<");
        addImplicitResolver(Tag.NULL, NULL, "~nN\0");
        addImplicitResolver(Tag.NULL, EMPTY, null);

    }
}

Any ideas?

解决方案

the problem in a way how you access the yaml

the examples first contains list and only then contains object with key 1st example

for your case try this access:

println resource.info.summary
println resource.examples[0]."1st example"
println resource.examples[0]."1st example".name
println resource.examples[0]."1st example".sublist[0]
println resource.examples[0]."1st example".sublist[0]."0.1"
println resource.examples[0]."1st example".sublist[0]."0.1".foo

to understand how list accessor works check this example:

@Grab(group='org.yaml', module='snakeyaml', version='1.18')
import org.yaml.snakeyaml.Yaml

def Yaml yaml = new Yaml()
def resource = yaml.load(new StringReader('''---
info:
  summary: Snakeyaml Issue
examples:
  - 1st example:
      name: Example 1
  - 1st example:
      name: Example 2
  - 1st example:
      xname: Example 3
  - 2nd example:
      name: Example 4
'''))

println resource.examples."1st example"
//prints>  [[name:Example 1], [name:Example 2], [xname:Example 3], null]

println resource.examples."1st example".name
//prints> [Example 1, Example 2, null]

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