如何實例化課程

Question

我的應用程序有問題，我無法實例化一個類

這是我的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)

這是我的方法：

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

我的界面：

public interface ICreateFeature extends ICreate, IFeature {
 }

還有我的課

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

Answer 1

您的CreateStartEventFeature不會擴展您定義的任何類，因此通過調用超級構造函數

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

您嘗試從Object類運行參數化的構造函數。

Answer 2

CreateStartEventFeature需要實現接口：

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

Answer 3

這個問題有點令人困惑，因為它沒有顯示出整個問題，但是我假設CreateStartEventFeature實現了ICreateFeature，因此請嘗試省略顯式的強制轉換：

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