Java：JGraphT使用循環添加邊線

Question

是否可以通過使用循環將邊線添加到圖形中？我解析一個字符串來確定適當的邊和標籤。出於某種原因，它只會爲用於遍歷字符串的while循環的第一輪添加邊緣。對於所有其他消息，將出現以下消息：

警告：由於底層JGraphT圖拒絕創建邊，因此已刪除邊。當違背底層圖的約束條件時會發生這種情況，例如，嘗試向禁止它們的圖添加平行邊或自循環。爲避免此消息，請確保使用合適的底層JGraphT圖形。

import java.awt.*; 
import java.awt.geom.*; 

import javax.swing.*; 

import org.jgraph.*; 
import org.jgraph.graph.*; 

import org.jgrapht.*; 
import org.jgrapht.ext.*; 
import org.jgrapht.graph.*; 

// resolve ambiguity 
import org.jgrapht.graph.DefaultEdge; 

public class JGraphAdapterDemo 
    extends JApplet 
{ 

    private static final long serialVersionUID = 3256444702936019250L; 
    private static final Color DEFAULT_BG_COLOR = Color.decode("#FAFBFF"); 
    private static final Dimension DEFAULT_SIZE = new Dimension(530, 320); 

    static ListenableGraph<String, String> g = 
     new ListenableDirectedMultigraph<String, String>(String.class); 

    static int [] finalStates = new int[10]; 
    static int startState = 0; 
    static char tran = ' '; 
    static int endState = 0; 

    private JGraphModelAdapter<String,String> jgAdapter; 

    public static void main(String [] args) 
    { 
     JGraphAdapterDemo applet = new JGraphAdapterDemo(); 
     applet.init(); 

     JFrame frame = new JFrame(); 
     frame.getContentPane().add(applet); 
     frame.setTitle("JGraphT Adapter to JGraph Demo"); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.pack(); 
     frame.setVisible(true); 
    } 

    public void init() 
    { 
     // create a JGraphT graph 
     ListenableGraph<String, String> g = 
      new ListenableDirectedMultigraph<String, String>(String.class); 

     // create a visualization using JGraph, via an adapter 
     jgAdapter = new JGraphModelAdapter<String, String>(g); 

     JGraph jgraph = new JGraph(jgAdapter); 

     adjustDisplaySettings(jgraph); 
     getContentPane().add(jgraph); 
     resize(DEFAULT_SIZE); 

     int numStates = 4; 
     int numSymbols; 
     int currentState; 
     int i = 0; 

      String input = "4 2 0 2 -1 0 a 1 1 b 3 2 c 2 3 c 3 -1";  //place input String here 
      int readInt = 0; 
      int j = 0; 
      String str = ""; 
      int place = 0; 
      String fState; 

      //read in numStates, numSymbols, initialState 
      i=0; 

      //parse string 
      i = input.indexOf(" ",0); 

      str = input.substring(0,i); //number of states 
      numStates = Integer.parseInt(str); //convert to int 

      for(int k = 0; k< numStates; k++){ 
       g.addVertex("q"+k); 
      } 

      i++; 
      j = i; 

      i=input.indexOf(" ",j); 

      str = input.substring(j,i); //number of symbols 
      numSymbols = Integer.parseInt(str); 

      i++; 
      j = i; 

      i=input.indexOf(" ",j); 

      str = input.substring(j,i); //initial state 
      currentState = Integer.parseInt(str); 

      i++; 
      j = i;  

      //read in finalStates 
      while(readInt!=-1){ 
       i=input.indexOf(" ",j); 
       fState = input.substring(j,i); //a final state 
       readInt = Integer.parseInt(fState); 
       if(readInt!=-1){ 
        finalStates[place] = readInt; 
        i++; 
        j = i; 
        place++; 
       }//end if 
      }//end while 
      i++; 
      j = i; 

      String sState; 
      String eState; 

      while(startState!=-1&& j<(input.length()-2)){   //until end of file 
       i=input.indexOf(" ",j); 
       sState = input.substring(j,i); //start state 
       startState = Integer.parseInt(sState); //convert to int 
       if(startState!=-1){    
        i++; 
        j = i; 

        String cStr = ""; 
        tran = input.charAt(i);   //transition 
        cStr = cStr + tran; 
        i = i+2; 
        j=i;   

        i=input.indexOf(" ",j); 
        eState = input.substring(j,i);  //end state 
        endState = Integer.parseInt(eState); 

        i++; 
        j=i; 
        String one = "q"+startState; 
        String two = "q"+endState; 
        System.out.println(one+ two +" "+cStr); 
        g.addEdge(one, two, cStr); 

        //drawEdge(one, two, cStr); 

       }//end if 

      }//end while 

    } 

    public static void drawEdge(String v, String v1, String label){ 
     System.out.println(v +" "+v1+ " "+label); 
     g.addEdge(v,v1,label); 
    } 

    private void adjustDisplaySettings(JGraph jg) 
    { 
     jg.setPreferredSize(DEFAULT_SIZE); 

     Color c = DEFAULT_BG_COLOR; 
     String colorStr = null; 

     try { 
      colorStr = getParameter("bgcolor"); 
     } catch (Exception e) { 
     } 

     if (colorStr != null) { 
      c = Color.decode(colorStr); 
     } 

     jg.setBackground(c); 
    } 

    @SuppressWarnings("unchecked") // FIXME hb 28-nov-05: See FIXME below 
    private void positionVertexAt(Object vertex, int x, int y) 
    { 
     DefaultGraphCell cell = jgAdapter.getVertexCell(vertex); 
     AttributeMap attr = cell.getAttributes(); 
     Rectangle2D bounds = GraphConstants.getBounds(attr); 

     Rectangle2D newBounds = 
      new Rectangle2D.Double(
       x, 
       y, 
       bounds.getWidth(), 
       bounds.getHeight()); 

     GraphConstants.setBounds(attr, newBounds); 

     // TODO: Clean up generics once JGraph goes generic 
     AttributeMap cellAttr = new AttributeMap(); 
     cellAttr.put(cell, attr); 
     jgAdapter.edit(cellAttr, null, null, null); 
    } 

    //~ Inner Classes ---------------------------------------------------------- 

    /** 
    * a listenable directed multigraph that allows loops and parallel edges. 
    // */ 
    private static class ListenableDirectedMultigraph<V, E> 
    extends DefaultListenableGraph<V, E> 
    implements DirectedGraph<V, E> 
    { 
    private static final long serialVersionUID = 1L; 

    ListenableDirectedMultigraph(Class<E> edgeClass) 
     { 
     super(new DirectedMultigraph<V, E>(edgeClass)); 
     } 
    } 


} 

Answer 1

如果要使用允許循環的圖形，必須創建一個抽象類「AbstractBaseGraph」。出於這個原因，你必須創建另一個類來擴展你的超類。這是一個例子。

public class MiGrafo 
extends AbstractBaseGraph<String, DefaultEdge> 
implements DirectedGraph<String, DefaultEdge> { 

public MiGrafo() {// EdgeFactory<String, DefaultEdge> arg0, boolean arg1,boolean arg2 
    super(new ClassBasedEdgeFactory<String, DefaultEdge>(
      DefaultEdge.class), 
     true, 
     true); 
    // TODO Auto-generated constructor stub 
} 

}

另外，你必須執行定向或無向圖後續的你延伸。

當您創建，允許使用圈你只有寫這句話的新圖：

MiGrafo h = new MiGrafo();

最後你只需要使用圖形像一個簡單的圖表。

再見。