KafkaTopology.kt 2.18 KB
Newer Older
Jonas Waeber's avatar
Jonas Waeber committed
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
/*
 * Table Data Import Service
 * Copyright (C) 2020 Memoriav
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

package org.memobase

import com.beust.klaxon.JsonObject
import com.beust.klaxon.Klaxon
import com.beust.klaxon.KlaxonException
import org.apache.kafka.streams.StreamsBuilder
import org.apache.kafka.streams.Topology
import org.apache.logging.log4j.LogManager
import org.memobase.settings.SettingsLoader
Jonas Waeber's avatar
Jonas Waeber committed
28
import java.io.StringReader
Jonas Waeber's avatar
Jonas Waeber committed
29
30
31
32

class KafkaTopology(private val settings: SettingsLoader) {
    private val log = LogManager.getLogger("StreamsProcessing")

Jonas Waeber's avatar
Jonas Waeber committed
33
    private val municipalities = MunicipalitiesLoader.getMunicipalities()
Jonas Waeber's avatar
Jonas Waeber committed
34

Jonas Waeber's avatar
Jonas Waeber committed
35
36
37
38
39
    fun build(): Topology {
        val builder = StreamsBuilder()
        val stream = builder.stream<String, String>(settings.inputTopic)
        stream
            .flatMapValues { value -> parseJson(value) }
Jonas Waeber's avatar
Jonas Waeber committed
40
41
            .flatMapValues { value -> value.keys.map { key -> Pair(value[key] as JsonObject, key) } }
            .mapValues { value -> transformJson(value.first, value.second) }
Jonas Waeber's avatar
Jonas Waeber committed
42
            .map { _, value -> value.write() }
Jonas Waeber's avatar
Jonas Waeber committed
43
44
45
46
47
48
49
50
51
52
53
54
55
56
            .to(settings.outputTopic)

        return builder.build()
    }

    private fun parseJson(data: String): List<JsonObject> {
        return try {
            listOf(Klaxon().parseJsonObject(StringReader(data)))
        } catch (ex: KlaxonException) {
            log.error("Failed to parse source: $data.")
            emptyList()
        }
    }

Jonas Waeber's avatar
Jonas Waeber committed
57
58
    private fun transformJson(input: JsonObject, language: String): Transform {
        return Transform(municipalities).createInstitution(input, language)
Jonas Waeber's avatar
Jonas Waeber committed
59
60
    }
}