我正在将一些XML转换为JSON，我使用Groovy的XmlSlurper来解析XML，然后构建一个具有所需结构的Groovy Map，然后我使用{{1或JsonOutput将该对象打印为JSON。这是代码：
JsonBuilder一切似乎都很好，当我打印import groovy.json.*
def X = """
<XML>
<Rules>
<Rule Alias="" EV="Height" Ht="0" InsuredId="1" Number="" QuestionTypeId="22" ResultType="None" Seq="0" Title="現在の身長・体重" Visible="false" Width="0">身長<Answer Alias="" Sev="0">170<Decision Product="">
<UnderwritingDecision Decision="ACC"/>
</Decision>
<Rule Alias="" EV="Weight" Ht="0" InsuredId="1" Number="" QuestionTypeId="21" ResultType="None" Seq="15" Visible="false" Width="0">体重<Answer Alias="" Sev="0">100<Decision Product="">
<UnderwritingDecision Decision="ACC"/>
</Decision>
<Rule Alias="NPCL" EV="Age" Ht="0" InsuredId="1" Number="" QuestionTypeId="1" ResultType="None" Seq="16" Title="NPCL" Visible="false" Width="0">年齢<Answer Alias="" Sev="0">34<Decision Product="">
<UnderwritingDecision Decision="ACC"/>
</Decision>
</Answer>
</Rule>
</Answer>
</Rule>
</Answer>
</Rule>
<Rule Alias="" ExtID="ImpairmentTag" Ht="0" InsuredId="1" Number="" QuestionTypeId="9" ResultType="None" Seq="1" Title="1項" Visible="true" Width="0">最近3ヶ月以内に、医師の診察・検査・治療・投薬を受けたことがありますか。<Answer Alias="" Sev="0">いいえ<Decision Product="">
<UnderwritingDecision Decision="ACC"/>
</Decision>
</Answer>
</Rule>
</Rules>
</XML>
"""
def xml = new XmlSlurper().parseText(X)
def nodeText = { it.nodeIterator().next().localText()[0] }
def createQuestion
createQuestion = {
[
Text: nodeText(it),
// answer could have other questions could be nested
Answer: !it.Answer.Rule.isEmpty() ? [ nodeText(it.Answer), createQuestion(it.Answer.Rule)] : [nodeText(it.Answer)],
InsuredId: it.'@InsuredId',
Visible: it.'@Visible',
CategoryText: it.'@Title',
FieldTypeId: it.'@QuestionTypeId',
ExitId: it.'@ExtID',
Alias: it.'@Alias',
Number: it.'@Number',
ResultType: it.'@ResultType'
]
}
def v = xml.Rules.Rule.collect(createQuestion)
assert v instanceof List
assert v[0] instanceof Map
assert v[0].Text instanceof String
时，它具有良好的结构。但是，当我使用v时，我会获得JsonOutput.toJson(v)。如果我使用java.lang.StackOverflowError，那么我得到如下几行：
new JsonBuilder(v) groovy.json.JsonOutput.writeIterator(JsonOutput.java:442)
at groovy.json.JsonOutput.writeObject(JsonOutput.java:272)
at groovy.json.JsonOutput.writeIterator(JsonOutput.java:442)
at groovy.json.JsonOutput.writeObject(JsonOutput.java:272)
at groovy.json.JsonOutput.writeIterator(JsonOutput.java:442)
对象潜伏着周期性结构吗？
更奇怪的是 - 如果在上面的脚本末尾添加了以下行
v你会进入控制台：
println v[0].Answer[1].Answer[1]
println JsonOutput.toJson(v[0].Answer[1].Answer[1])