如何在合約中使用介面？

如何在合約中創建和使用介面？

例如，當我有以下契約時：

package com.jelurida.ardor.contracts;

import nxt.addons.AbstractContract;
import nxt.addons.JO;
import nxt.addons.RequestContext;

public class TestContract extends AbstractContract {


   public interface Test {
       String addPrefix(String text);
   }


   public class TestImpl implements Test {
       @Override
       public String addPrefix(String text) {
           return "prefix_" + text;
       }
   }


   @Override
   public JO processRequest(RequestContext context) {
       Test test = new TestImpl();
       JO resp = new JO();
       resp.put("text", test.addPrefix("some text"));
       return context.generateResponse(resp);
   }
}

執行單元測試時出現以下錯誤：

2018-12-20 17:40:09 INFO: main Loading resource from com/jelurida/ardor/contracts/TestContract.class
2018-12-20 17:40:09 INFO: main Loading resource from classpath com/jelurida/ardor/contracts/TestContract.class
2018-12-20 17:40:09 INFO: main Loading inner class com.jelurida.ardor.contracts.TestContract.TestImpl resource from com/jelurida/ardor/contracts/TestContract$TestImpl.class
2018-12-20 17:40:09 INFO: main Loading resource from classpath com/jelurida/ardor/contracts/TestContract$TestImpl.class
2018-12-20 17:40:09 INFO: main Loading inner class com.jelurida.ardor.contracts.TestContract.Test resource from com/jelurida/ardor/contracts/TestContract$Test.class
2018-12-20 17:40:09 INFO: main Loading resource from classpath com/jelurida/ardor/contracts/TestContract$Test.class

2018-12-20 17:40:09 INFO: main Shutting down...

java.lang.LinkageError: loader (instance of  nxt/addons/ContractLoader$CloudDataClassLoader): attempted  duplicate class definition for name: "com/jelurida/ardor/contracts/TestContract$Test"

   at java.lang.ClassLoader.defineClass1(Native Method)
   at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
   at nxt.addons.ContractLoader$CloudDataClassLoader.findClass(ContractLoader.java:308)
   at nxt.addons.ContractLoader.loadContractFromJar(ContractLoader.java:252)
   at nxt.addons.ContractLoader.loadContractFromJar(ContractLoader.java:210)
   at nxt.tools.ContractManager.loadContract(ContractManager.java:437)
   at nxt.tools.ContractManager.uploadImpl(ContractManager.java:327)
   at com.jelurida.ardor.contracts.ContractTestHelper.lambda$deployContract$0(ContractTestHelper.java:110)
   at java.security.AccessController.doPrivileged(Native Method)
   at com.jelurida.ardor.contracts.ContractTestHelper.deployContract(ContractTestHelper.java:107)
   at com.jelurida.ardor.contracts.ContractTestHelper.deployContract(ContractTestHelper.java:98)
   at com.jelurida.ardor.contracts.ContractTestHelper.deployContract(ContractTestHelper.java:93)
   at com.jelurida.ardor.contracts.ContractTestHelper.deployContract(ContractTestHelper.java:89)
   at com.jelurida.ardor.contracts.TestContractTest.uploadTest(TestContractTest.java:9)
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:498)
   at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
   at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
   at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
   at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
   at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
   at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
   at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
   at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
   at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
   at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
   at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
   at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
   at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
   at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
   at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
   at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
   at org.junit.runners.Suite.runChild(Suite.java:127)
   at org.junit.runners.Suite.runChild(Suite.java:26)
   at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
   at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
   at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
   at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
   at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
   at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
   at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
   at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
   at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
   at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
   at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
   at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
   at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

我該如何解決這個錯誤？我正在使用版本 2.2.1

我假設這裡的問題是Test介面被載入了兩次，首先是在掃描契約以載入內部類時，然後在載入 TestImpl 類時間接載入，這導致“名稱的嘗試重複類定義：”com/ jelurida/ardor/contracts/TestContract$Test" 錯誤。

這可能是我們可以在下一個版本中修復的問題。

引用自：https://bitcoin.stackexchange.com/questions/83066