solution: reorganize packages

src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumApi.kt

@@ -0,0 +1,44 @@
+/**
+ * Copyright (c) 2019 ETCDEV GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.emeraldpay.dshackle.upstream.ethereum
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import io.emeraldpay.dshackle.upstream.Upstream
+import io.infinitape.etherjar.rpc.*
+import reactor.core.publisher.Mono
+import java.io.InputStream
+
+abstract class EthereumApi(
+        objectMapper: ObjectMapper
+) {
+
+    private val jacksonRpcConverter = JacksonRpcConverter(objectMapper)
+    var upstream: Upstream? = null
+
+    abstract fun execute(id: Int, method: String, params: List<Any>): Mono<ByteArray>
+
+    fun <JS, RS> executeAndConvert(rpcCall: RpcCall<JS, RS>): Mono<RS> {
+        val convertToJS = java.util.function.Function<ByteArray, Mono<JS>> { resp ->
+            val inputStream: InputStream = resp.inputStream()
+            val jsonValue: JS? = jacksonRpcConverter.fromJson(inputStream, rpcCall.jsonType, Int::class.java)
+            if (jsonValue == null) Mono.empty<JS>()
+            else Mono.just(jsonValue)
+        }
+        return execute(0, rpcCall.method, rpcCall.params as List<Any>)
+                .flatMap(convertToJS)
+                .map(rpcCall.converter::apply)
+    }
+}