Upper underscore to lower underscore

This example will convert the field names of a schema from upper underscore to lower underscore.

Configuration
{
  "transforms" : "changeCase",
  "transforms.changeCase.type" : "com.github.jcustenborder.kafka.connect.transform.common.ChangeCase$Value",
  "transforms.changeCase.from" : "UPPER_UNDERSCORE",
  "transforms.changeCase.to" : "LOWER_UNDERSCORE"
}
Input
{
  "topic" : "topic",
  "kafkaPartition" : 1,
  "valueSchema" : {
    "type" : "STRUCT",
    "isOptional" : false,
    "fieldSchemas" : {
      "FIRST_NAME" : {
        "type" : "STRING",
        "isOptional" : false
      },
      "LAST_NAME" : {
        "type" : "STRING",
        "isOptional" : false
      }
    }
  },
  "value" : {
    "schema" : {
      "type" : "STRUCT",
      "isOptional" : false,
      "fieldSchemas" : {
        "FIRST_NAME" : {
          "type" : "STRING",
          "isOptional" : false
        },
        "LAST_NAME" : {
          "type" : "STRING",
          "isOptional" : false
        }
      }
    },
    "fieldValues" : [ {
      "name" : "FIRST_NAME",
      "schema" : {
        "type" : "STRING",
        "isOptional" : false
      },
      "storage" : "test"
    }, {
      "name" : "LAST_NAME",
      "schema" : {
        "type" : "STRING",
        "isOptional" : false
      },
      "storage" : "user"
    } ]
  },
  "timestampType" : "NO_TIMESTAMP_TYPE",
  "offset" : 1,
  "headers" : [ ]
}

Change(s) in the output are emphasized if delta(s) are detected.

Output
{
  "topic" : "topic",
  "kafkaPartition" : 1,
  "valueSchema" : {
    "type" : "STRUCT",
    "isOptional" : false,
    "fieldSchemas" : {
      "first_name" : {
        "type" : "STRING",
        "isOptional" : false
      },
      "last_name" : {
        "type" : "STRING",
        "isOptional" : false
      }
    }
  },
  "value" : {
    "schema" : {
      "type" : "STRUCT",
      "isOptional" : false,
      "fieldSchemas" : {
        "first_name" : {
          "type" : "STRING",
          "isOptional" : false
        },
        "last_name" : {
          "type" : "STRING",
          "isOptional" : false
        }
      }
    },
    "fieldValues" : [ {
      "name" : "first_name",
      "schema" : {
        "type" : "STRING",
        "isOptional" : false
      },
      "storage" : "test"
    }, {
      "name" : "last_name",
      "schema" : {
        "type" : "STRING",
        "isOptional" : false
      },
      "storage" : "user"
    } ]
  },
  "timestampType" : "NO_TIMESTAMP_TYPE",
  "offset" : 1,
  "headers" : [ ]
}