为第 3 方类扩展 Corda 序列化

Question

TL;博士；

我需要 Corda 从 JDK 序列化 JSONObject。我怀疑我可以为它添加一个自定义解析器，但我不知道怎么做。

全文：

所以我有一堆类充当 JSON api 周围的 semy 类型的安全包装器。一个例子：

@CordaSerializable
class ClaimReq(val json: JSONObject) {
    val proverDid: String = json.getString("prover_did")
    val credDefId: String = json.getString("cred_def_id")
}

当我尝试通过 Corda 频道发送这样的课程时，问题出现了。系统序列化 org.json.JSONObject 时出现问题：

java.io.NotSerializableException：找不到类 org.json.JSONObject 的反序列化构造函数。 在 net.corda.nodeapi.internal.serialization.amqp.SerializationHelperKt.constructorForDeserialization(SerializationHelper.kt:50) ~[corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SchemaKt.fingerprintForObject(Schema.kt:456) ~[corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SchemaKt.access$fingerprintForObject(Schema.kt:1) ~[corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SchemaKt$fingerprintForType$3.invoke(Schema.kt:423) ~[corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SchemaKt$fingerprintForType$3.invoke(Schema.kt) ~[corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SchemaKt.fingerprintWithCustomSerializerOrElse(Schema.kt:345) ~[corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SchemaKt.fingerprintForType(Schema.kt:417) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SchemaKt.fingerprintForObject(Schema.kt:459) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SchemaKt.access$fingerprintForObject(Schema.kt:1) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SchemaKt$fingerprintForType$3.invoke(Schema.kt:423) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SchemaKt$fingerprintForType$3.invoke(Schema.kt) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SchemaKt.fingerprintWithCustomSerializerOrElse(Schema.kt:345) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SchemaKt.fingerprintForType(Schema.kt:417) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SchemaKt.fingerprintForType$default(Schema.kt:352) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SchemaKt.fingerprintForType(Schema.kt:328) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.ObjectSerializer.(ObjectSerializer.kt:34) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SerializerFactory$makeClassSerializer$1.apply(SerializerFactory.kt:271) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SerializerFactory$makeClassSerializer$1.apply(SerializerFactory.kt:40) [corda-node-api-3.1-corda.jar:?] 在 java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1688) [?:1.8.0_171] 在 net.corda.nodeapi.internal.serialization.amqp.SerializerFactory.makeClassSerializer(SerializerFactory.kt:255) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SerializerFactory.get(SerializerFactory.kt:100) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SerializationOutput.writeObject$node_api(SerializationOutput.kt:98) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SerializationOutput.writeObject$node_api$default(SerializationOutput.kt:97) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SerializationOutput.writeObject$node_api(SerializationOutput.kt:78) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SerializationOutput$_serialize$1$1.invoke(SerializationOutput.kt:64) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SerializationOutput$_serialize$1$1.invoke(SerializationOutput.kt:22) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SerializationHelperKt.withList(SerializationHelper.kt:401) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SerializationOutput$_serialize$1.invoke(SerializationOutput.kt:63) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SerializationOutput$_serialize$1.invoke(SerializationOutput.kt:22) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SerializationHelperKt.withDescribed(SerializationHelper.kt:390) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SerializationOutput._serialize$node_api(SerializationOutput.kt:62) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.SerializationOutput.serialize(SerializationOutput.kt:36) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.amqp.AbstractAMQPSerializationScheme.serialize(AMQPSerializationScheme.kt:128) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.SerializationFactoryImpl$serialize$1$1.invoke(SerializationScheme.kt:126) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.SerializationFactoryImpl$serialize$1$1.invoke(SerializationScheme.kt:86) [corda-node-api-3.1-corda.jar:?] 在 net.corda.core.serialization.SerializationFactory.withCurrentContext(SerializationAPI.kt:66) [corda-core-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.SerializationFactoryImpl$serialize$1.invoke(SerializationScheme.kt:126) [corda-node-api-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.SerializationFactoryImpl$serialize$1.invoke(SerializationScheme.kt:86) [corda-node-api-3.1-corda.jar:?] 在 net.corda.core.serialization.SerializationFactory.asCurrent(SerializationAPI.kt:80) [corda-core-3.1-corda.jar:?] 在 net.corda.nodeapi.internal.serialization.SerializationFactoryImpl.serialize(SerializationScheme.kt:126) [corda-node-api-3.1-corda.jar:?] 在 net.corda.core.serialization.SerializationAPIKt.serialize(SerializationAPI.kt:221) [corda-core-3.1-corda.jar:?] 在 net.corda.core.serialization.SerializationAPIKt.serialize$default(SerializationAPI.kt:220) [corda-core-3.1-corda.jar:?] 在 net.corda.node.services.statemachine.FlowStateMachineImpl.createSessionData(FlowStateMachineImpl.kt:353) [corda-node-3.1-corda.jar:?] 在 net.corda.node.services.statemachine.FlowStateMachineImpl.send(FlowStateMachineImpl.kt:235) [corda-node-3.1-corda.jar:?] 在 net.corda.node.services.statemachine.FlowSessionImpl.send(FlowSessionImpl.kt:52) [corda-node-3.1-corda.jar:?] 在 net.corda.node.services.statemachine.FlowSessionImpl.send(FlowSessionImpl.kt:56) [corda-node-3.1-corda.jar:?] 在 com.luxoft.blockchainlab.corda.hyperledger.indy.flow.IssueClaimFlow$Prover.call(IssueClaimFlow.kt:85) [main/:?] 在 com.luxoft.blockchainlab.corda.hyperledger.indy.flow.IssueClaimFlow$Prover.call(IssueClaimFlow.kt:71) [main/:?] 在 net.corda.node.services.statemachine.FlowStateMachineImpl.run(FlowStateMachineImpl.kt:96) [corda-node-3.1-corda.jar:?] 在 net.corda.node.services.statemachine.FlowStateMachineImpl.run(FlowStateMachineImpl.kt:44) [corda-node-3.1-corda.jar:?] 在 co.paralleluniverse.fibers.Fiber.run1(Fiber.java:1092) [quasar-core-0.7.9-jdk8.jar:0.7.9] 在 co.paralleluniverse.fibers.Fiber.exec(Fiber.java:788) [quasar-core-0.7.9-jdk8.jar:0.7.9]

所以我用一个特定的构造函数和一个 getter 解决了这个问题：

@CordaSerializable
class ClaimReq(val json: JSONObject) {
    val proverDid: String = json.getString("prover_did")
    val credDefId: String = json.getString("cred_def_id")

    @ConstructorForDeserialization constructor(str: String) : this(JSONObject(str))
    val str = json.toString()
}

不幸的是，该解决方案需要在每个类声明中添加 2 行。有什么办法可以抽象出来，比如在超类中？或者我可以使用自定义 parcer 扩展 Corda 序列化以支持 JSONObject？

Answer 1

由 Corda 框架序列化的具有多个构造函数的任何类都需要用 @ConstructorForDeserialization 注释其中一个构造函数。显然JSONObject中没有带有这个注解的构造函数。

您需要为JSONObject 类提供自定义序列化程序。在此处查看定义自定义序列化程序的示例：https://docs.corda.net/head/cordapp-custom-serializers.html#example。

如果这个序列化器在类路径上，它将被节点在运行时使用。