使用列表的列表递归填充 JTree

Question

这道题在

中有相反的过程

我想实现流程的方法优化，我将这个流程简化（乘法和除法），就像所示的树一样。

底部和粗体矩形（在线工具不要让我更改颜色）表示 N 分子和 D[=40 之间的总乘法=] 每个列表的分母。

现在，我正在 Java 中创建列表列表，以计算每个列表（过程）的总成本。

我的第一步是创建一个 class...

public class Pair { private int num; private int den; public Pair(int num, int den) { this.num = num; this.den = den; } public int getNum() { return num; } public void setNum(int num) { this.num = num; } public int getDen() { return den; } public void setDen(int den) { this.den = den; } @Override public String toString() { return "Pair{" + "num=" + num + ", den=" + den + '}'; } }

第二步是...

public class 测试对 {

public static void main(String... args) { ArrayList<ArrayList<Pair>> listOfListPair = new ArrayList<>(); listOfListPair.add((ArrayList<Pair>) Arrays.asList( new Pair[]{new Pair(1, 1), new Pair(3, 1), new Pair(1, 2)})); listOfListPair.add((ArrayList<Pair>) Arrays.asList( new Pair[]{new Pair(1, 1), new Pair(3, 1), new Pair(3, 1)})); listOfListPair.add((ArrayList<Pair>) Arrays.asList( new Pair[]{new Pair(1, 1), new Pair(3, 1), new Pair(2, 1)})); listOfListPair.add((ArrayList<Pair>) Arrays.asList( new Pair[]{new Pair(1, 1), new Pair(11, 2), new Pair(1, 2)})); listOfListPair.add((ArrayList<Pair>) Arrays.asList( new Pair[]{new Pair(1, 1), new Pair(11, 2), new Pair(13, 3)})); listOfListPair.add((ArrayList<Pair>) Arrays.asList( new Pair[]{new Pair(1, 1), new Pair(1, 7), new Pair(1, 2)})); listOfListPair.add((ArrayList<Pair>) Arrays.asList( new Pair[]{new Pair(1, 1), new Pair(1, 7), new Pair(2, 1), new Pair(2, 1)})); listOfListPair.add((ArrayList<Pair>) Arrays.asList( new Pair[]{new Pair(1, 1), new Pair(1, 7), new Pair(2, 1), new Pair(3, 1)})); listOfListPair.add((ArrayList<Pair>) Arrays.asList( new Pair[]{new Pair(1, 1), new Pair(1, 7), new Pair(2, 1), new Pair(5, 1)})); listOfListPair.add((ArrayList<Pair>) Arrays.asList( new Pair[]{new Pair(1, 1), new Pair(1, 7), new Pair(2, 1), new Pair(2, 7)})); javax.swing.JTree myTree = new javax.swing.JTree(); listOfListPair.stream().forEachOrdered(listPair -> { //HOW POPULATE THE myTree? }); }

}

对我来说重要的问题：JTree, Optimization algorithm, Java

关于递归填充我的树的一些线索？、

Answer 1

我的答案稍作改动...

public class TestPair {

  public static void main(String... args) {
    List<List<Pair>> listOfListPair = new ArrayList<>();

    listOfListPair.add((List<Pair>) Arrays.asList(
        new Pair[]{new Pair(1, 1), new Pair(3, 1), new Pair(1, 2)}));
    listOfListPair.add((List<Pair>) Arrays.asList(
        new Pair[]{new Pair(1, 1), new Pair(3, 1), new Pair(3, 1)}));
    listOfListPair.add((List<Pair>) Arrays.asList(
        new Pair[]{new Pair(1, 1), new Pair(3, 1), new Pair(2, 1)}));

    listOfListPair.add((List<Pair>) Arrays.asList(
        new Pair[]{new Pair(1, 1), new Pair(11, 2), new Pair(1, 2)}));
    listOfListPair.add((List<Pair>) Arrays.asList(
        new Pair[]{new Pair(1, 1), new Pair(11, 2), new Pair(13, 3)}));

    listOfListPair.add((List<Pair>) Arrays.asList(
        new Pair[]{new Pair(1, 1), new Pair(1, 7), new Pair(1, 2)}));
    listOfListPair.add((List<Pair>) Arrays.asList(
        new Pair[]{new Pair(1, 1), new Pair(1, 7), new Pair(2, 1), new Pair(2, 1)}));
    listOfListPair.add((List<Pair>) Arrays.asList(
        new Pair[]{new Pair(1, 1), new Pair(1, 7), new Pair(2, 1), new Pair(3, 1)}));
    listOfListPair.add((List<Pair>) Arrays.asList(
        new Pair[]{new Pair(1, 1), new Pair(1, 7), new Pair(2, 1), new Pair(5, 1)}));
    listOfListPair.add((List<Pair>) Arrays.asList(
        new Pair[]{new Pair(1, 1), new Pair(1, 7), new Pair(2, 1), new Pair(2, 7)}));

    final JTree tree = new JTree();
    tree.setRootVisible(false);
    removeAllTreeNodes(tree);
    listOfListPair.stream().forEachOrdered(listPair -> {
      addPairToTree(tree, listPair);
    });

    JFrame frame = new JFrame("Optimization Pair");
    JScrollPane scrollPane = new JScrollPane();
    scrollPane.setViewportView(tree);
    frame.add("Center", scrollPane);
    frame.pack();
    frame.setSize(new Dimension(600, 600));
    frame.setVisible(true);
  }

  private static void addPairToTree(JTree tree, List<Pair> listPair) {
    try {
      DefaultTreeModel treeModel = ((DefaultTreeModel) tree.getModel());
      DefaultMutableTreeNode rootTreeNode = (DefaultMutableTreeNode) treeModel.getRoot();
      DefaultMutableTreeNode pairTreeNode = rootTreeNode;
      final Pair leafPair = new Pair(1, 1);
      for (Pair pair : listPair) {
        pairTreeNode = getDefaultMutableTreeNode(pairTreeNode, pair, true);
        leafPair.setDen(leafPair.getDen() * ((Pair) pairTreeNode.getUserObject()).getDen());
        leafPair.setNum(leafPair.getNum() * ((Pair) pairTreeNode.getUserObject()).getNum());
      }
      getDefaultMutableTreeNode(pairTreeNode, leafPair, false);
      treeModel.reload(rootTreeNode);
    } catch (Exception e) {
      throw e;
    }
  }

  private static DefaultMutableTreeNode getDefaultMutableTreeNode(DefaultMutableTreeNode parent, Pair newChild, Boolean isLeaf) {
    if (parent != null) {
      DefaultMutableTreeNode child;
      for (int i = 0; i < parent.getChildCount(); i++) {
        child = (DefaultMutableTreeNode) parent.getChildAt(i);
        if (child.toString().equals(newChild.toString())) {
          return child;
        }
      }
      child = new DefaultMutableTreeNode(newChild, isLeaf);
      parent.add(child);
      return child;
    } else {
      return null;
    }
  }

  private static void removeAllTreeNodes(JTree tree) {
    DefaultMutableTreeNode rootTreeNode = (DefaultMutableTreeNode) tree.getModel().getRoot();
    if (rootTreeNode != null) {
      rootTreeNode.removeAllChildren();
    }
    reloadTree(tree);
  }

  private static void reloadTree(JTree tree) {
    DefaultTreeModel treeModel = ((DefaultTreeModel) tree.getModel());
    DefaultMutableTreeNode rootTreeNode = (DefaultMutableTreeNode) treeModel.getRoot();
    treeModel.reload(rootTreeNode);
  }

}

使用列表的列表递归填充 JTree

Recursively populate JTree, using list of list

java

list

swing

java-stream

jtree