如何实例化课程

Question

我的应用程序有问题，我无法实例化一个类

这是我的java.lang.ClassCastException

eclipse.emf.editeurgraphique.risque.features.StartEventFeature$CreateStartEventFeature cannot be cast to org.eclipse.graphiti.features.ICreateFeature 
at eclipse.emf.editeurgraphique.risque.features.StartEventFeature.getCreateFeature(StartEventFeature.java:43)

这是我的方法：

 public ICreateFeature getCreateFeature(IFeatureProvider fp) {
    return (ICreateFeature) new CreateStartEventFeature(fp);
}

我的界面：

public interface ICreateFeature extends ICreate, IFeature {
 }

还有我的课

 public CreateStartEventFeature(IFeatureProvider fp) {
        super(fp, "Start Event", "Indicates the start of a process or    choreography");
    }

Answer 1

您的CreateStartEventFeature不会扩展您定义的任何类，因此通过调用超级构造函数

super(fp, "Start Event", "Indicates the start of a process or    choreography");

您尝试从Object类运行参数化的构造函数。

Answer 2

CreateStartEventFeature需要实现接口：

public class CreateStartEventFeature extends MyBaseClass implements ICreateFeature 
{...}

Answer 3

这个问题有点令人困惑，因为它没有显示出整个问题，但是我假设CreateStartEventFeature实现了ICreateFeature，因此请尝试省略显式的强制转换：

public ICreateFeature getCreateFeature(IFeatureProvider fp) {
    return new CreateStartEventFeature(fp);
}