Question

我正在尝试序列化加权图，我遇到了一些问题。

我有一个UndirectedGraph<T>的实例，扩展了Graph<T>。 Graph<T>中仅有的两个字段是：

private Map<T,Vertex<T>> vertices;
private int edgeCount;

所以我在课程UndirectedGraph<T>中有以下序列化：

private void readObject(ObjectInputStream inputStream) throws ClassNotFoundException, IOException{
  inputStream.defaultReadObject();
  Map<T,Vertex<T>> vertexList =(Map<T,Vertex<T>>)inputStream.readObject();
  int edgeCount=(Integer)inputStream.readObject();
  super.init(vertexList,edgeCount);
}

private void writeObject(ObjectOutputStream outputStream) throws IOException{
  outputStream.defaultWriteObject();
  outputStream.writeObject(super.getVertexList());
  outputStream.writeObject(super.getNumberOfEdges());
}

在Graph<T>中，相应的方法getVertexList，getNumberOfEdges和init如下：

public int getNumberOfEdges(){
  return edgeCount;
}

protected Map<T,Vertex<T>> getVertexList(){
  return vertices;
}

protected void init(Map<T,Vertex<T>> newVertexList, int newEdgeCount){
  if (vertices==null){
     vertices=newVertexList;
     edgeCount=newEdgeCount;
  }
  else{
     throw new IllegalStateException("The graph is already initialized");
  }
}

当我在main方法中运行它时出现异常：

try(
     OutputStream file=new FileOutputStream("globalgraph.ser");
     OutputStream buffer=new BufferedOutputStream(file);
     ObjectOutput output=new ObjectOutputStream(buffer);
  )
  {
     output.writeObject(globalGraph);
  }
  catch(IOException e){
     System.err.println("IOException: " + e.getMessage());
  }

我得到的例外是＆＃34; IOException：Vertex $ Edge＆＃34;，我发现它来自行outputStream.writeObject(super.getVertexList());。除此之外，我不知道它来自哪里。 Edge是Vertex<T>和Vertex<T>次要Serializable的内部类，只是使用方法

private void readObject(ObjectInputStream inputStream) throws ClassNotFoundException, IOException{
  inputStream.defaultReadObject();
}

private void writeObject(ObjectOutputStream outputStream) throws IOException{
  outputStream.defaultWriteObject();
}

序列化。我已经看了一段时间，并且不知道是什么原因导致了这个例外。任何帮助表示赞赏。

编辑：添加顶点和边缘类

public class Vertex<T> implements Serializable{

  private T label;                 //The data within the node
  private ArrayList<Edge> edgeList;//List of edges leaving node
  private boolean visited;          //Denoting whether traversal algorithms have accessed
  private Vertex<T> previousVertex; //Previous vertex for traversal algorithms 
  private double cost;             //cost to get to this vertex from some origin vertex
  private boolean userVisited;


  public Vertex(T vertexLabel){
     label=vertexLabel;
     edgeList=new ArrayList<>();
     visited=false;
     previousVertex=null;
     cost=0;
     userVisited=false;
  }

  //Vertex methods

  protected class Edge{
     //the vertex the edge points to
     private Vertex<T> endVertex;
     //the weight of the edge from the vertex to endVertex
     private double weight;

     private int numberOfEdits;

     protected Edge(Vertex<T> vertex, double edgeWeight){
        endVertex=vertex;
        weight=edgeWeight;
        numberOfEdits=1;
     }

     //Edge methods


   }

  //Iterator inner classes, don't need to serialize these

  //***********Serialization Methods************
  private static final long serialVersionUID = 9993882109871L;

  private void readObject(ObjectInputStream inputStream) throws ClassNotFoundException, IOException{
     inputStream.defaultReadObject();
  }

  private void writeObject(ObjectOutputStream outputStream) throws IOException{
     outputStream.defaultWriteObject();
  }

}

加权图的序列化

0 个答案: