有沒有辦法以編程方式將 JSON 轉換為 AVRO 模式？

Question

我需要創建 AVRO 文件，但為此我需要兩件事：

1) JSON

2) Avro 架構

從這兩個要求 - 我有 JSON：

{"web-app": {
  "servlet": [   
    {
      "servlet-name": "cofaxCDS",
      "servlet-class": "org.cofax.cds.CDSServlet",
      "init-param": {
        "configGlossary:installationAt": "Philadelphia, PA",
        "configGlossary:adminEmail": "ksm@pobox.com",
        "configGlossary:poweredBy": "Cofax",
        "configGlossary:poweredByIcon": "/images/cofax.gif",
        "configGlossary:staticPath": "/content/static",
        "templateProcessorClass": "org.cofax.WysiwygTemplate",
        "templateLoaderClass": "org.cofax.FilesTemplateLoader",
        "templatePath": "templates",
        "templateOverridePath": "",
        "defaultListTemplate": "listTemplate.htm",
        "defaultFileTemplate": "articleTemplate.htm",
        "useJSP": false,
        "jspListTemplate": "listTemplate.jsp",
        "jspFileTemplate": "articleTemplate.jsp",
        "cachePackageTagsTrack": 200,
        "cachePackageTagsStore": 200,
        "cachePackageTagsRefresh": 60,
        "cacheTemplatesTrack": 100,
        "cacheTemplatesStore": 50,
        "cacheTemplatesRefresh": 15,
        "cachePagesTrack": 200,
        "cachePagesStore": 100,
        "cachePagesRefresh": 10,
        "cachePagesDirtyRead": 10,
        "searchEngineListTemplate": "forSearchEnginesList.htm",
        "searchEngineFileTemplate": "forSearchEngines.htm",
        "searchEngineRobotsDb": "WEB-INF/robots.db",
        "useDataStore": true,
        "dataStoreClass": "org.cofax.SqlDataStore",
        "redirectionClass": "org.cofax.SqlRedirection",
        "dataStoreName": "cofax",
        "dataStoreDriver": "com.microsoft.jdbc.sqlserver.SQLServerDriver",
        "dataStoreUrl": "jdbc:microsoft:sqlserver://LOCALHOST:1433;DatabaseName=goon",
        "dataStoreUser": "sa",
        "dataStorePassword": "dataStoreTestQuery",
        "dataStoreTestQuery": "SET NOCOUNT ON;select test='test';",
        "dataStoreLogFile": "/usr/local/tomcat/logs/datastore.log",
        "dataStoreInitConns": 10,
        "dataStoreMaxConns": 100,
        "dataStoreConnUsageLimit": 100,
        "dataStoreLogLevel": "debug",
        "maxUrlLength": 500}},
    {
      "servlet-name": "cofaxEmail",
      "servlet-class": "org.cofax.cds.EmailServlet",
      "init-param": {
      "mailHost": "mail1",
      "mailHostOverride": "mail2"}},
    {
      "servlet-name": "cofaxAdmin",
      "servlet-class": "org.cofax.cds.AdminServlet"},

    {
      "servlet-name": "fileServlet",
      "servlet-class": "org.cofax.cds.FileServlet"},
    {
      "servlet-name": "cofaxTools",
      "servlet-class": "org.cofax.cms.CofaxToolsServlet",
      "init-param": {
        "templatePath": "toolstemplates/",
        "log": 1,
        "logLocation": "/usr/local/tomcat/logs/CofaxTools.log",
        "logMaxSize": "",
        "dataLog": 1,
        "dataLogLocation": "/usr/local/tomcat/logs/dataLog.log",
        "dataLogMaxSize": "",
        "removePageCache": "/content/admin/remove?cache=pages&id=",
        "removeTemplateCache": "/content/admin/remove?cache=templates&id=",
        "fileTransferFolder": "/usr/local/tomcat/webapps/content/fileTransferFolder",
        "lookInContext": 1,
        "adminGroupID": 4,
        "betaServer": true}}],
  "servlet-mapping": {
    "cofaxCDS": "/",
    "cofaxEmail": "/cofaxutil/aemail/*",
    "cofaxAdmin": "/admin/*",
    "fileServlet": "/static/*",
    "cofaxTools": "/tools/*"},

  "taglib": {
    "taglib-uri": "cofax.tld",
    "taglib-location": "/WEB-INF/tlds/cofax.tld"}}}

但是如何基於它創建 AVRO Schema？

尋找編程方式來做到這一點，因為將有很多架構並且不能每次都手動創建 Avro 架構。

我檢查了“avro-tools-1.8.1.jar”，但不能直接從 JSON 創建 Avro Schema。

尋找可以創建 JSON -> Avro 模式的 Jar 或 Python 代碼。 如果數據類型不完美也沒關系（字符串、整數和浮點數足以開始）。

Answer 1

您可以使用 Kite SDK util 從 json 輸入推斷 avro 模式。

https://github.com/kite-sdk/kite/blob/master/kite-data/kite-data-core/src/main/java/org/kitesdk/data/spi/JsonUtil.java#L539

示例：

    String json = "{\n" +
            "    \"id\": 1,\n" +
            "    \"name\": \"A green door\",\n" +
            "    \"price\": 12.50,\n" +
            "    \"tags\": [\"home\", \"green\"]\n" +
            "}\n"
            ;
    String avroSchema = JsonUtil.inferSchema(JsonUtil.parse(json), "myschema").toString();
    System.out.println(avroSchema);

結果：

{  
   "type":"record",
   "name":"myschema",
   "fields":[  
      {  
         "name":"id",
         "type":"int",
         "doc":"Type inferred from '1'"
      },
      {  
         "name":"name",
         "type":"string",
         "doc":"Type inferred from '\"A green door\"'"
      },
      {  
         "name":"price",
         "type":"double",
         "doc":"Type inferred from '12.5'"
      },
      {  
         "name":"tags",
         "type":{  
            "type":"array",
            "items":"string"
         },
         "doc":"Type inferred from '[\"home\",\"green\"]'"
      }
   ]
}

您可以在 此處找到 maven 依賴項

Answer 2

通過簡單的 avro 模式復制和粘貼，這個很酷。

https://toolslick.com/generation/metadata/avro-schema-from-json

Answer 3

如果您想避免為每種 JSON 格式創建專用的 AVRO 模式，您可以使用rec-avro包。

它允許您采用任何 Python 數據結構，包括解析的 XML 或 JSON，並將其存儲在 Avro 中，而無需專用架構。

我為python 3測試了它。

您可以將其安裝為 pip3 install rec-avro 或在https://github.com/bmizhen/rec-avro查看代碼和文檔

我在這里給了一個 json 給 avro 示例代碼： https ://stackoverflow.com/a/55444481/6654219

Answer 4

試一試。 http://www.dataedu.ca/avro

它基本上推斷接受 JSON 的 Avro 模式。

你甚至可以給它一個 JSON 數組。 它會做的是生成一個與數組中的所有JSON 文檔兼容的 Avro 模式。

還有其他工具可以驗證結果。