Question

我正在探索Corda。我从cordapp-template-java开始。我试图添加一个流NewFlow，该流具有一个Item作为成员变量。项目的定义

@CordaSerializable
public class Item {
    private final String name;
    private final Party owner;

    public Item(String name, Party owner) {
        this.name = name;
        this.owner = owner;
    }

    public String getName() {
        return name;
    }

    public Party getOwner() {
        return owner;
    }
}

部署节点后，我无法调用此流程。这就是我调用NewFlow的方式：

start NewFlow price: 100, item: { name: Item1, owner: "O=PartyB,L=New York,C=US" }, timeFrame: "toTimeStr=12-DEC-2019 12:26:45", parties:["O=PartyB,L=New York,C=US"]

它引发错误-

No matching constructor found:
- [java.lang.Integer, com.template.states.Item, com.template.states.TimeFrame, net.corda.core.identity.Party[]]: Could not parse as a command: Cannot construct instance of `com.template.states.Item` (no Creators, like default construct, exist): cannot deserialize from Object value (no delegate- or property-based Creator)
 at [Source: UNKNOWN; line: -1, column: -1]

我需要对类Item做些什么？还是这只是一些序列化问题？

编辑：

Flow类的摘录-

public class NewFlow extends FlowLogic<Void> {

    private final int price;
    private final Item item;
    private final TimeFrame timeframe;
    private final List<Party> parties;

    /**
     * The progress tracker provides checkpoints indicating the progress of the flow to observers.
     */
    private final ProgressTracker progressTracker = new ProgressTracker();

    public PostTenderFlow(Integer price, Item item, TimeFrame timeframe, Party[] parties) {
        this.price = price;
        this.item = item;//new Item(itemName, getOurIdentity());
        this.timeframe = timeframe;
        this.parties= Arrays.asList(parties);
    }

Answer 1

您的错误提示“未找到匹配的构造函数”。问题出在您定义的Flow类上。您需要在流类中有一个构造函数，该构造函数接受您从命令行传递的参数。

例如，如果您的NewFlow类具有构造函数：

public NewFlow(int price, String someData){
   ...
}

您可以使用以下方法开始流程：

flow start NewFlow price: 100, someData: "My Data"

如何在Corda中编写作为命令参数的Java类？

1 个答案: