Java继承错误
以下是我的例子: 在接口一节中,注意到实现接口的类必须实现接口的所有方法。但是,如果类被声明为抽象类,则可以定义一个不实现所有接口方法的类。比如说,Java继承错误,java,inheritance,abstract,extends,Java,Inheritance,Abstract,Extends,以下是我的例子: 在接口一节中,注意到实现接口的类必须实现接口的所有方法。但是,如果类被声明为抽象类,则可以定义一个不实现所有接口方法的类。比如说, abstract class X implements Y { // implements all but one method of Y } class XX extends X { // implements the remaining method in Y } 在这种情况下,类X必须是抽象的,因为它没有完全实现Y,但类XX实际上
abstract class X implements Y {
// implements all but one method of Y
}
class XX extends X {
// implements the remaining method in Y
}
在这种情况下,类X必须是抽象的,因为它没有完全实现Y,但类XX实际上实现了Y
这是我的密码:
public interface IRunnable {
public Object[] run(Graph<Object, ?> graph, HashMap<Object, Point> positions, int numIter);
public Object[] runSet(Graph<Object, ?> graph, HashMap<Object, Point> positions, int numIter, int [] itr);
public HashMap<Object, Point> runHelper(Graph<Object, ?> graph,HashMap<Object, Point> positions, int numIter);
public Force calculateForces(Graph<Object, ?> graph, HashMap<Object, Point> positions, Object mainVertex);
}
public abstract class Runnable implements IRunnable {
public Object[] run(Graph<Object, ?> graph, HashMap<Object, Point> positions, int numIter){
Object[] res = new Object[2];
long startTime = System.currentTimeMillis();
res[0] = runHelper(graph, new HashMap<Object, Point>(positions), numIter);
long endTime = System.currentTimeMillis();
res[1] = endTime - startTime;
return res;
}
public Object[] runSet(Graph<Object, ?> graph, HashMap<Object, Point> positions, int numIter, int [] itr){
System.out.println(itr.length);
Object[] res = new Object[itr.length];
for ( int i = 0; i < itr.length; i++){
res[i] = run(graph, new HashMap<Object, Point>(positions), itr[i]);
}
return res;
}
public HashMap<Object, Point> runHelper(Graph<Object, ?> graph,HashMap<Object, Point> positions, int numIter){
Collection<Object> vertices = graph.getVertices();
HashMap<Object, Force> forces = new HashMap<Object, Force>();
for ( int i = 0; i < numIter; i++){
for ( Object vertex : vertices ){
forces.put(vertex, calculateForces(graph, positions, vertex));
}
for ( Object vertex : vertices ){
positions.put(vertex, ForceFunctions.calculateShift(positions.get(vertex), forces.get(vertex)));
}
}
return positions;
}
}
public class Eades extends Runnable {
public static Force calculateForces(Graph<Object, ?> graph, HashMap<Object, Point> positions, Object mainVertex){
ArrayList<Object> vertices = new ArrayList<Object>(graph.getVertices());
Force totalForce = new Force(0,0);
Force neighborForce = new Force(0,0);
Object neighborVertex = null;
for ( int i = 0; i < vertices.size(); i++){
neighborForce = null;
neighborVertex = vertices.get(i);
if ( mainVertex != neighborVertex ){
if ( graph.getNeighbors(mainVertex).contains(neighborVertex) ){
neighborForce = ForceFunctions.attractive(positions.get(mainVertex),positions.get(neighborVertex));
}
else
neighborForce = ForceFunctions.repulsive(positions.get(mainVertex), positions.get(neighborVertex) );
totalForce.add(neighborForce);
}
}
return totalForce;
}
我做错了什么?Java在Java.lang
包中有一个接口,它与您的类冲突。编译器认为您希望在Eades
声明中从该接口进行扩展
将您的类重命名为其他(
MyRunnable
或更有意义的东西),这将处理错误。不,它在java.lang
中有Runnable
——这与“默认包”不同。@JonSkeet:Yep,编辑了我的答案。谢谢你指出这一点。
The type Runnable cannot be the superclass of Eades; a superclass must be a class