如何从.txt文件创建Java图形文件 [英] How To Create A Java Graph File from .txt file

问题描述

我试图创建一个图形文件，我必须从.gra文件（我认为它是一个.txt文件）读取值。我们被告知以<格式<顶点> <名称> < X-坐标> < y-coord> ，与边缘相同

我看了一些相关的问题，但仍无法找到答案。

下面是我给出的代码：

  public EdgeListVertex（V元素）{
 this.element = element; 
} 
 
 @Override 
 public V element（）{
 return element; 
 
 
 public String toString（）{
 return element.toString（）; 
} 
} 
 
 private class EdgeListEdge实现Edge< E> {
位置< EdgeListEdge>位置; 
 E元素; 
 EdgeListVertex开始，结束; 
 
 
 public EdgeListEdge（EdgeListVertex start，EdgeListVertex end，E element）{
 this.start = start; 
 this.end = end; 
 this.element = element; 
} 
 
 @Override 
 public E element（）{
 return element; 
 
 
 public String toString（）{
 return element.toString（）; 
} 
} 
 
 private List< EdgeListVertex>顶点; 
私人列表< EdgeListEdge>边缘; 
 
 $ b public EdgeListGraph（）{
 vertices = new LinkedList< EdgeListVertex>（）; 
 edges = new LinkedList< EdgeListEdge>（）; 
 
} 
 
 @SuppressWarnings（unchecked）
 @Override 
 public Vertex< V> [] endVertices（Edge< E> e）{ 
 EdgeListEdge edge =（EdgeListEdge）e; 
 Vertex [V] [] endpoints =（Vertex V []] new Vertex [2]; 
 endpoints [0] = edge.start; 
 endpoints [1] = edge.end; 
返回终点; 
} 
 
 @覆盖
公共顶点< V>相反（Vertex V V，Edge E）{
 Vertex V []] endpoints = endVertices（e）; 
 if（endpoints [0] .equals（v））{
 return endpoints [1]; 
} else if（endpoints [1] .equals（v））{
 return endpoints [0]; 
} 
抛出新的InvalidVertexException（）; （EdgeListEdge edge：edges）{
 
 $ b @Override 
 public boolean areAdjacent（Vertex V v，Vertex V w）{
 （（edge.start.equals（v））&&（edge.end.equals（w）））返回true; （（edge.end.equals（v））&&（edge.start.equals（w）））返回true; 
 if 
} 
返回false; 
} 
 
 @Override 
 public V replace（Vertex V v，V x）{
 EdgeListVertex vertex =（EdgeListVertex）v; 
 V temp = vertex.element; 
 vertex.element = x; 
 return temp; 
} 
 
 @Override 
 public E替换（Edge E，e x）{
 EdgeListEdge edge =（EdgeListEdge）e; 
 E temp = edge.element; 
 edge.element = x; 
 return temp; 
} 
 
 @覆盖
公共顶点< V> insertVertex（V v）{
 EdgeListVertex vertex = new EdgeListVertex（v）; 
位置< EdgeListVertex> position = vertices.insertLast（vertex）; 
 vertex.position = position; 
返回顶点; 
} 
 
 @Override 
 public Edge< E> （EdgeListVertex）v，（EdgeListVertex）w，o）;其中，EdgeEdgeEdge（Vertex V，v Vertex V w，E o） 
位置< EdgeListEdge> position = edges.insertLast（edge）; 
 edge.position = position; 
返回边缘; 
} 
 
 @Override 
 public V removeVertex（Vertex V）{
 Iterator< Edge< E>> it = incidentEdges（v）.iterator（）; 
 while（it.hasNext（））it.remove（）; 
 
 EdgeListVertex vertex =（EdgeListVertex）v; 
 vertices.remove（vertex.position）; 
返回vertex.element; 
} 
 
 @Override 
 public E removeEdge（Edge< E> e）{
 EdgeListEdge edge =（EdgeListEdge）e; 
 edges.remove（edge.position）; 
返回edge.element; 
} 
 
 @Override 
 public List< Edge< E>> incidentEdges（Vertex V）{
 LinkedList< Edge< E>> list = new LinkedList< Edge< E>>（）; （EdgeListEdge edge：edges）{
 if（edge.start.equals（v））list.insertLast（edge）; 
 
 
 if（edge.end.equals（v））list.insertLast（edge）; 
} 
 
返回列表; 
} 
 
 @Override 
 public List< Vertex< V>>顶点（）​​{
 LinkedList< Vertex< V>> list = new LinkedList< Vertex< V>>（）; 
 for（EdgeListVertex vertex：vertices）{
 list.insertLast（vertex）; 
} 
返回列表; 
} 
 
 @Override 
 public List< Edge< E>>边（）{
 LinkedList< Edge< E>> list = new LinkedList< Edge< E>>（）; 
（EdgeListEdge edge：edges）{
 list.insertLast（edge）; 
} 
返回列表; 
} 
 
} 
  

任何提示？

解决方案

好的方法可能是创建一个新的顶点，名称和坐标的类。然后将扫描仪中的数据读入 ArrayList 你刚创建的类的一个>。在这之后，您可以将ArrayList传递到您正在用于绘图的任何东西（这可能需要一些调整）。
$ b

示例扫描程序代码（未经测试强大>）：

 文件graphFile = new File（filepath）; 
扫描仪graphScanner =新扫描仪（graphFile）; 
  

然后，从扫描仪（未经测试）读取：

  ArrayList< graphClass> dataPoints = new ArrayList< graphClass>（）; （graphScanner.hasNextLine（））{
 dataPoints.add（new graphClass（graphScanner.nextDouble（），graphScanner.next（），graphScanner.nextDouble（））时，您必须创建graphClass 
。 graphScanner.nextDouble（））; //假定graphClass的构造函数按照该顺序获取顶点，名称，x，y 
  

我希望这有助于。

I am trying to create a graph file .I have to read in values from a .gra file(which I think is a .txt file).We were told to tokenise lines based on a space in the format <vertex> <name> <x-coord> <y-coord>,same for edge

I had a look at a couple of related questions,but still cant find the answer.

Here's the code I was given:

        public EdgeListVertex(V element) {
            this.element = element;
        }

        @Override
        public V element() {
            return element;
        }

        public String toString() {
            return element.toString();
        }
    }

    private class EdgeListEdge implements Edge<E> {
        Position<EdgeListEdge> position;
        E element;
        EdgeListVertex start, end;


        public EdgeListEdge(EdgeListVertex start, EdgeListVertex end, E element) {
            this.start = start;
            this.end = end;
            this.element = element;
        }

        @Override
        public E element() {
            return element;
        }

        public String toString() {
            return element.toString();
        }
    }

    private List<EdgeListVertex> vertices;
    private List<EdgeListEdge> edges;


    public EdgeListGraph() {
        vertices = new LinkedList<EdgeListVertex>();
        edges = new LinkedList<EdgeListEdge>();

    }

    @SuppressWarnings("unchecked")
    @Override
    public Vertex<V>[] endVertices(Edge<E> e) {
        EdgeListEdge edge = (EdgeListEdge) e;
        Vertex<V>[] endpoints = (Vertex<V>[]) new Vertex[2];
        endpoints[0] = edge.start;
        endpoints[1] = edge.end;
        return endpoints;
    }

    @Override
    public Vertex<V> opposite(Vertex<V> v, Edge<E> e) {
        Vertex<V>[] endpoints = endVertices(e);
        if (endpoints[0].equals(v)) {
            return endpoints[1];
        } else if (endpoints[1].equals(v)) {
            return endpoints[0];
        }
        throw new InvalidVertexException();
    }

    @Override
    public boolean areAdjacent(Vertex<V> v, Vertex<V> w) {
        for (EdgeListEdge edge: edges) {
            if ((edge.start.equals(v)) && (edge.end.equals(w))) return true;
            if ((edge.end.equals(v)) && (edge.start.equals(w))) return true;
        }
        return false;
    }

    @Override
    public V replace(Vertex<V> v, V x) {
        EdgeListVertex vertex = (EdgeListVertex) v;
        V temp = vertex.element;
        vertex.element = x;
        return temp;
    }

    @Override
    public E replace(Edge<E> e, E x) {
        EdgeListEdge edge = (EdgeListEdge) e;
        E temp = edge.element;
        edge.element = x;
        return temp;
    }

    @Override
    public Vertex<V> insertVertex(V v) {
        EdgeListVertex vertex = new EdgeListVertex(v);
        Position<EdgeListVertex> position = vertices.insertLast(vertex);
        vertex.position = position;
        return vertex;
    }

    @Override
    public Edge<E> insertEdge(Vertex<V> v, Vertex<V> w, E o) {
        EdgeListEdge edge = new EdgeListEdge((EdgeListVertex) v, (EdgeListVertex) w, o);
        Position<EdgeListEdge> position = edges.insertLast(edge);
        edge.position = position;
        return edge;
    }

    @Override
    public V removeVertex(Vertex<V> v) {
        Iterator<Edge<E>> it = incidentEdges(v).iterator();
        while (it.hasNext()) it.remove();

        EdgeListVertex vertex = (EdgeListVertex) v;
        vertices.remove(vertex.position);
        return vertex.element;
    }

    @Override
    public E removeEdge(Edge<E> e) {
        EdgeListEdge edge = (EdgeListEdge) e;
        edges.remove(edge.position);
        return edge.element;
    }

    @Override
    public List<Edge<E>> incidentEdges(Vertex<V> v) {
        LinkedList<Edge<E>> list = new LinkedList<Edge<E>>();

        for (EdgeListEdge edge : edges) {
            if (edge.start.equals(v)) list.insertLast(edge);
            if (edge.end.equals(v)) list.insertLast(edge);
        }

        return list;
    }

    @Override
    public List<Vertex<V>> vertices() {
        LinkedList<Vertex<V>> list = new LinkedList<Vertex<V>>();
        for (EdgeListVertex vertex : vertices) {
            list.insertLast(vertex);
        }
        return list;
    }

    @Override
    public List<Edge<E>> edges() {
        LinkedList<Edge<E>> list = new LinkedList<Edge<E>>();
        for (EdgeListEdge edge : edges) {
            list.insertLast(edge);
        }
        return list;
    }

}

Any tips?

解决方案

A good approach might be to create a new class with fields for vertex, name and coordinates. Then read in the data from a scanner into an ArrayList of the class you just created. After this, you could just pass the ArrayList into whatever you are using for graphing (which might require a few tweaks).

Example scanner code (untested):

File graphFile = new File(filepath);
Scanner graphScanner = new Scanner(graphFile);

Then, to read from the scanner (untested):

ArrayList<graphClass> dataPoints = new ArrayList<graphClass>(); //you will have to make graphClass
while(graphScanner.hasNextLine()) {
    dataPoints.add(new graphClass(graphScanner.nextDouble(), graphScanner.next(), graphScanner.nextDouble(), graphScanner.nextDouble()); //assuming constructor of graphClass takes vertex, name, x, y in that order

I hope this helps.

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