スレッドから JUNG グラフのエッジを動的に削除していますが、結果はNullPointerExceptions.
私が見ているスタックトレース:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at edu.uci.ics.jung.visualization.renderers.BasicEdgeRenderer.paintEdge(BasicEdgeRenderer.java:51)
at edu.uci.ics.jung.visualization.renderers.BasicRenderer.renderEdge(BasicRenderer.java:78)
at edu.uci.ics.jung.visualization.renderers.BasicRenderer.render(BasicRenderer.java:38)
at edu.uci.ics.jung.visualization.BasicVisualizationServer.renderGraph(BasicVisualizationServer.java:346)
at edu.uci.ics.jung.visualization.BasicVisualizationServer.paintComponent(BasicVisualizationServer.java:301)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1074)
at java.desktop/javax.swing.JComponent.paintToOffscreen(JComponent.java:5255)
at java.desktop/javax.swing.RepaintManager$PaintManager.paintDoubleBufferedImpl(RepaintManager.java:1643)
at java.desktop/javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1618)
at java.desktop/javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1556)
at java.desktop/javax.swing.RepaintManager.paint(RepaintManager.java:1323)
at java.desktop/javax.swing.JComponent._paintImmediately(JComponent.java:5203)
at java.desktop/javax.swing.JComponent.paintImmediately(JComponent.java:5013)
at java.desktop/javax.swing.RepaintManager$4.run(RepaintManager.java:865)
at java.desktop/javax.swing.RepaintManager$4.run(RepaintManager.java:848)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:389)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
at java.desktop/javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:848)
at java.desktop/javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:823)
at java.desktop/javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:772)
at java.desktop/javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1884)
at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:313)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:770)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:389)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:740)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
エラーを再現するコード スニペットを次に示します。
import javax.swing.JFrame;
import edu.uci.ics.jung.algorithms.layout.AbstractLayout;
import edu.uci.ics.jung.algorithms.layout.ISOMLayout;
import edu.uci.ics.jung.graph.Graph;
import edu.uci.ics.jung.graph.SparseGraph;
import edu.uci.ics.jung.graph.util.Graphs;
import edu.uci.ics.jung.visualization.GraphZoomScrollPane;
import edu.uci.ics.jung.visualization.VisualizationViewer;
public class JungRepro {
public static void main(String[] args) throws InterruptedException {
// Create the graph with vertices and edges
Graph<Integer, Integer> graph = Graphs.synchronizedGraph(new SparseGraph<Integer, Integer> ());
final int nbrVertices = 10;
for (int i = 0; i < nbrVertices; i++)
graph.addVertex(i);
int e = 0;
for (int i = 0; i < nbrVertices; i++)
for (int j = 0; j < i; j++)
graph.addEdge(e++, i, j);
AbstractLayout<Integer, Integer> layout = new ISOMLayout<Integer, Integer> (graph);
VisualizationViewer<Integer, Integer> vv = new VisualizationViewer<Integer, Integer> (layout);
JFrame frame = new JFrame ("JungRepro");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new GraphZoomScrollPane (vv));
frame.pack();
frame.setVisible(true);
// Remove edges one by one
while (e >= 0) {
graph.removeEdge(e--);
Thread.sleep(25);
}
}
}
よろしくお願いします。
repaint()[編集: エラーが への呼び出しではなく への呼び出しによって引き起こされたという事実を反映するために、質問を部分的に書き直しましたremoveEdge()。]