对象反序列化图形在java中生成异常

z9zf31ra  于 2021-07-12  发布在  Java
关注(0)|答案(1)|浏览(399)

我创建了一个由节点和边组成的图,如下所示:

public class Edge implements Serializable {
    private final Node neighbor;
    private final double weight;

    public Edge(Node neighbor, double weight) {
        this.neighbor = neighbor;
        this.weight = weight;
    }

    public Node getNeighbor() {
        return neighbor;
    }

    public double getWeight() {
        return weight;
    }
}

public class Node implements Serializable {
    private final String name;
    private final ArrayList<Edge> edges;

    public Node(String name) {
        this.name = name;
        this.edges = new ArrayList<>();
    }

    public String getName() {
        return name;
    }

    public ArrayList<Edge> getEdges() {
        return edges;
    }

    public void addEdge(Edge edge) {
        this.edges.add(edge);
    }
}

public class Graph implements Serializable {
    private final ArrayList<Node> nodes;

    public Graph() {
        nodes = new ArrayList<>();
    }

    public Graph(ArrayList<Node> nodes) {
        this.nodes = nodes;
    }

    public ArrayList<Node> getNodes() {
        return new ArrayList<>(nodes);
    }
}

我正在尝试序列化和反序列化图形,如下所示:

public Graph deSerialize() {
        Graph graph = new Graph();
        try {
            FileInputStream inStream = new FileInputStream(aFile);
            ObjectInputStream oIS = new ObjectInputStream(inStream);
            graph = (Graph) oIS.readObject();
            oIS.close();
            inStream.close();
        } catch (IOException | ClassNotFoundException e) {
            e.printStackTrace();
        }
        return graph;
    }

    private void serialize(Graph graph) {
        try {
            FileOutputStream outStream = new FileOutputStream(aFile);
            ObjectOutputStream oOS = new ObjectOutputStream(outStream);
            oOS.writeObject(graph);
            oOS.close();
            outStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

序列化工作正常(据我所知),但在反序列化过程中,会打印以下stacktrace,我无法找出原因:[updated]:(序列化时发生)

Exception in thread "main" java.lang.StackOverflowError
    at java.base/java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:936)
    at java.base/java.io.ObjectStreamClass.lookup(ObjectStreamClass.java:339)
    at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1135)
    at java.base/java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1553)
    at java.base/java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1510)
    at java.base/java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1433)
    at java.base/java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1179)
    at java.base/java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:349)
    at java.base/java.util.ArrayList.writeObject(ArrayList.java:897)
    at java.base/jdk.internal.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)

[添加]:(反序列化时发生)

Exception in thread "main" java.lang.StackOverflowError
    at java.base/java.io.ObjectInputStream$BlockDataInputStream.peekByte(ObjectInputStream.java:3169)
    at java.base/java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1847)
    at java.base/java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2169)
    at java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1679)
    at java.base/java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2464)
    at java.base/java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2358)
    at java.base/java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2196)
    at java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1679)
    at java.base/java.io.ObjectInputStream.readObject(ObjectInputStream.java:493)
    at java.base/java.io.ObjectInputStream.readObject(ObjectInputStream.java:451)
    at java.base/java.util.ArrayList.readObject(ArrayList.java:929)
    at java.base/jdk.internal.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)

我尝试了一些不同的方法,包括序列化节点本身的arraylist以及其他方法,但我无法深入了解它的本质。有人能帮我修一下吗?谢谢您!

ruoxqz4g

ruoxqz4g1#

“就是这样。”
也许这不是很有帮助。
当你连载 Node , Edge s将被递归序列化。一 Edge 包含 Node 这样就可以递归地序列化。即使是一个适度的图,也可以得到一个公平的递归深度,并且每一级递归都会占用相当大的堆栈空间块。
链表就是这种错误的典型例子。标准技术是对整个图形使用自定义的序列形式。例如,每当你遇到 Edge 你可以给它一个序列号(在一个 Map<Edge,Node> . 序列化 Node s与
edges transient 后面是一组 Edge 身份证。跟着这个 Edge 对象按顺序排列。反序列化时,添加 Edge 我们回到 Node s。

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