Question

如何从corda自定义表中获取数据？我的示例代码如下： -

Api layer -- getIous() method 
{
    Field attributeValue=IOUSchemaV1.PersistentIOU.class.getDeclaredField("value");
    CriteriaExpression currencyIndex = Builder.equal(attributeValue, "12");
    QueryCriteria.VaultCustomQueryCriteria criteria = new 
    QueryCriteria.VaultCustomQueryCriteria(currencyIndex);
    vaultStates = services.vaultQueryByCriteria(criteria,IOUState.class);
}

在ExamplePlugin中，我添加了以下代码进行架构注册

public class ExamplePlugin extends CordaPluginRegistry implements 
WebServerPluginRegistry
{
@NotNull
@Override
public Set<MappedSchema> getRequiredSchemas()
{
    Set<MappedSchema> requiredSchemas = new HashSet<>();
    requiredSchemas.add(new IOUSchemaV1());
    return requiredSchemas;
}

}

我的架构类是---

public final class IOUSchema {

}


@CordaSerializable
public class IOUSchemaV1 extends MappedSchema 
{
public IOUSchemaV1() {
    super(IOUSchema.class, 1, ImmutableList.of(PersistentIOU.class));
}

@Entity
@Table(name = "iou_states")
public static class PersistentIOU extends PersistentState {
@Column(name = "sender_name") private final String senderName;
@Column(name = "recipient_name") private final String recipientName;
@Column(name = "value") private final int value;


public PersistentIOU(String senderName, String recipientName, int value) {
    this.senderName = senderName;
    this.recipientName = recipientName;
    this.value = value;
}

public String getSenderName() {
    return senderName;
}

public String getRecipientName() {
    return recipientName;
}

public int getValue() {
    return value;
}

} }

我的州有： -

public class IOUState implements LinearState, QueryableState 
{

--- some code goes here and below methods as well.---
@Override
public PersistentState generateMappedObject(MappedSchema schema) {
if (schema instanceof IOUSchemaV1) {
    return new IOUSchemaV1.PersistentIOU(
            this.sender.getName().toString(),
            this.recipient.getName().toString(),
            this.iou.getValue());
} else {
    throw new IllegalArgumentException("Unrecognised schema $schema");
}
}

@Override
public Iterable<MappedSchema> supportedSchemas() {
return ImmutableList.of(new IOUSchemaV1());
}
}

但是我一直在低于例外。

引起：net.corda.core.node.services.VaultQueryException：

请在CorDapp的CordaPluginRegistry配置中注册实体'com.example.schema.IOUSchemaV1'（requiredSchemas属性）并确保已声明（在supportedSchemas（）中）并映射（在generateMappedObject（）中）相关合同状态的QueryableState接口实现中的模式。

任何人都可以帮忙解决这个问题。

Answer 1

尝试从插件声明中删除implements WebServerPluginRegistry。

从Corda自定义表中获取数据时出错

1 个答案: