我们如何在Kafka生产者代码中访问Avro模式中的数组字段？

huangapple
go评论105阅读模式
英文:

How can we access the array fields from Avro Schema in the Kafka producer code?

问题

我有以下的Avro模式：

  1. {
  2.   "name": "ABC",
  3.   "type": "record",
  4.   "namespace": "com.schema.avro",
  5.   "fields": [
  6.     {
  7.       "name": "str1",
  8.       "type": "string"
  9.     },
  10.     {
  11.       "name": "arrData",
  12.       "type": [
  13.         "null",
  14.         {
  15.           "type": "array",
  16.           "items": {
  17.             "name": "arrData_record",
  18.             "type": "record",
  19.             "fields": [
  20.               {
  21.                 "name": "var1",
  22.                 "type": ["null", "string"],
  23.                 "default": null
  24.               },
  25.               {
  26.                 "name": "var2",
  27.                 "type": ["null", "int"],
  28.                 "default": null
  29.               }
  30.             ]
  31.           }
  32.         }
  33.       ],
  34.       "default": null
  35.     }
  36.   ]
  37. }

我使用了POM.XML Maven插件来生成这些类。以下是从插件生成的两个类：
i) ABC
ii) arrData_record

我能够像下面这样使用ABC类中的str1字段：

  1. ABC abc = ABC.newBuilder()
  2.        .setStr1("随机值")
  3.        .build()

类似地，我也可以使用.setArrData()来使用arrData字段。

我想要以类似的方式设置数组字段，使用.setVar1()和.setVar2()。您可以提供一些关于如何使用Array类中的字段并进行类似设置的示例代码吗？谢谢。

英文:

I have the below Avro Schema:

  1.     `{
  2.       "name": "ABC",
  3.       "type": "record",
  4.       "namespace": "com.schema.avro",
  5.       "fields": [
  6.         {
  7.           "name": "str1",
  8.           "type": "string"
  9.         },
  10.         {
  11.           "name": "arrData",
  12.           "type":["null",
  13.           {
  14.             "type": "array",
  15.             "items": {
  16.               "name": "arrData_record",
  17.               "type": "record",
  18.               "fields": [
  19.                 {
  20.                   "name": "var1",
  21.                   "type": ["null","string"],
  22.                   "default": null
  23.                 },
  24.                 {
  25.                   "name": "var2",
  26.                   "type": ["null","int"],
  27.                   "default": null
  28.                 }
  29.               ]
  30.             }
  31.           }
  32.           ],
  33.           "default": null
  34.         }
  35.       ]
  36.     }`

I used the POM.XML Maven plugin to generate the classes.
Below 2 classes were generated from the plugin-
i) ABC
ii) arrData_record

I am able to use the field str1 from ABC as below:

  1.     ABC abc = ABC.newBuilder()
  2.            .setStr1("random value")
  3.            .build()

Similarly, I am also getting an option to use .setArrData().

I want to set the array fields in a similar way using .setVar1() and .setVar2().

How can I use the fields from the Array class and set it similarly? Any sample code would be of great help.

Thanks.

答案1

得分: 3

生成的Avro模式类可以像这样进行操作：

  1. ABC
  2.     .newBuilder()
  3.     .setArrData(Collections.singletonList(arrData_record
  4.         .newBuilder()
  5.         .setVar1("Var1")
  6.         .setVar2(2)
  7.         .build()))
  8.     .build();
英文:

The generated class from the Avro schema could be manipulated like this

  1. ABC
  2.     .newBuilder()
  3.     .setArrData(Collections.singletonList(arrData_record
  4.         .newBuilder()
  5.         .setVar1("Var1")
  6.         .setVar2(2)
  7.         .build()))
  8.     .build();

答案2

得分: 0

尽管我接受了尼克的答案，那个答案是正确的，但最终我使用了以下代码，因为我想在Var1和Var2中添加多个值-

使用以下代码填充了arrData_record的对象-

  1. arrData_record a1 = arrData_record.newBuilder()
  2.         .setVar1("abc")
  3.         .setVar2(1)
  4.         .build();
  6. arrData_record a2 = arrData_record.newBuilder()
  7.         .setVar1("def")
  8.         .setVar2(2)
  9.         .build();

将其添加到arrData列表中-

  1. arrData.add(a1);
  2. arrData.add(a2);

最后添加了arrData-

  1. ABC abc = ABC.newBuilder()
  2.     .setStr1("随机值")
  3.     .setarrData(arrData)
  4.     .build();
英文:

Even though I accepted Nic's answer and that answer is correct, I used the below code finally as I wanted to add multiple values in Var1 and Var2-

Populated the objects of the arrData_record using below code-

arrData_record a1 = arrData_record.newBuilder()
.setVar1("abc")
.setVar2(1)
.build();

arrData_record a2 = arrData_record.newBuilder()
.setVar1("def")
.setVar2(2)
.build();

Added it into list arrData-

arrData.add(a1);
arrData.add(a2);

Finally added arrData-

ABC abc = ABC.newBuilder()
.setStr1("random value")
.setarrData(arrData)
.build()

huangapple
  • 本文由 发表于 2020年8月25日 06:50:17
  • 转载请务必保留本文链接：https://go.coder-hub.com/63569679.html
  • apache-kafka
  • arrays
  • avro
  • java
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