Question

我有一个使用Gson在下面使用

创建的Json

val gson = new Gson
val jsonString = gson.toJson(mydata).
println(jsonString)

这是输出

  {"mydata":{"date":["2008-06-04T22:47:36Z"],
  "pdf:PDFVersion":["1.6"],
  "pdf:docinfo:title":[" PDF Test Page"],
  "xmp:CreatorTool":["Acrobat PDFMaker 7.0.7 for Word"],
  "Company":["Government of Yukon"],
  "access_permission:modify_annotations":["false"],
  "access_permission:can_print_degraded":["true"],
  "dc:creator":["Yukon","Canada","Yukon Department of Education"],
  "language":["EN-US"],
  "dcterms:created":["2008-06-04T22:44:00Z"],
  "Last-Modified":["2008-06-04T22:47:36Z"],
  "dcterms:modified":["2008-06-04T22:47:36Z"],
  "dc:format":["application/pdf; version\u003d1.6"],
  "title":[" PDF Test Page"],
   }
   }

所需的输出

  {"date":["2008-06-04T22:47:36Z"],
  "pdf:PDFVersion":["1.6"],
  "pdf:docinfo:title":[" PDF Test Page"],
  "xmp:CreatorTool":["Acrobat PDFMaker 7.0.7 for Word"],
  "Company":["Government of Yukon"],
  "access_permission:modify_annotations":["false"],
  "access_permission:can_print_degraded":["true"],
  "dc:creator":["Yukon","Canada","Yukon Department of Education"],
  "language":["EN-US"],
  "dcterms:created":["2008-06-04T22:44:00Z"],
  "Last-Modified":["2008-06-04T22:47:36Z"],
  "dcterms:modified":["2008-06-04T22:47:36Z"],
  "dc:format":["application/pdf; version\u003d1.6"],
  "title":[" PDF Test Page"],
   }

我想知道我如何能够删除上述json中的标头（{“ mydata” :)和页脚（}），以便我可以用来向Solr添加记录

Answer 1

可以通过以下方式使用Gson的API移除包装器mydata：将初始对象转换为JSON树（而不是问题中尝试的字符串），然后将mydata节点的内容转换为JSON字符串。这很容易：

val jsonTree = gson.toJsonTree(mydata)
val mydataNode = jsonTree.getAsJsonObject().getAsJsonObject("mydata")
val jsonString = gson.toJson(mydataNode) // jsonString contains the desired output

P.S。应该删除原始json中,之后的逗号"title":[" PDF Test Page"],，否则无效。

Gson从Json删除标头

1 个答案: