如何创建动态树? [英] How to create a dynamic tree?

问题描述

我在使用primefaces树实现实现动态树结构时遇到了一些麻烦.在primeface提供的展示柜中，代码的结构如下所示.但是，这是非常静态的.我试图弄清楚如何处理从数据库中获取的数据，在编译时树的深度是未知的.

I´m having some trouble implementing a dynamic tree structure using the primefaces tree implementation. In the showcase provided by primeface, the structure of the code is like below. This is however very static. I´m trying to figure out how I could do this with data fetched from a database, where the depth of the tree would be unknown at compile time.

我认为我可能需要某种递归方法来实现此目的，但我无法完全理解实现的样子.

I`m thinking that I probabply need some recursive method to implement this, but I cannot quite get my head around what the implementation would look like.

有什么想法吗?

下面是Primefaces中的示例代码

Below is the example code from primefaces

private TreeNode root;
private TreeNode selectedNode;

public TreeBean() {
    root = new DefaultTreeNode("Root", null);
    TreeNode node0 = new DefaultTreeNode("Node 0", root);
    TreeNode node1 = new DefaultTreeNode("Node 1", root);
    TreeNode node2 = new DefaultTreeNode("Node 2", root);

    TreeNode node00 = new DefaultTreeNode("Node 0.0", node0);
    TreeNode node01 = new DefaultTreeNode("Node 0.1", node0);

    TreeNode node10 = new DefaultTreeNode("Node 1.0", node1);
    TreeNode node11 = new DefaultTreeNode("Node 1.1", node1);

    TreeNode node000 = new DefaultTreeNode("Node 0.0.0", node00);
    TreeNode node001 = new DefaultTreeNode("Node 0.0.1", node00);
    TreeNode node010 = new DefaultTreeNode("Node 0.1.0", node01);

    TreeNode node100 = new DefaultTreeNode("Node 1.0.0", node10);
}

推荐答案

private TreeNode root;

private TreeNode selectedNode;

public TreeBean() {
root = new DefaultTreeNode("Root", null);
List rootNodes<Employee> = SearchDao.getRootNodes();

Iterator it = rootNodes.iterator();
while (it.hasNext()) {

TreeNode node1 = new DefaultTreeNode(**it.next()**, root);
    **/* in place of it.next() I need to display empName. When I click on empName, I need to get the Id(Pkey). */**

}

}

public TreeNode getRoot() {
return root;
}

public TreeNode getSelectedNode() {
return selectedNode;
}

public void setSelectedNode(TreeNode selectedNode) {
this.selectedNode = selectedNode;
}



public void addChildNode(ActionEvent actionEvent) {
System.out.println("Selected Node: "+getSelectedNode().toString());
TreeNode newNode = new DefaultTreeNode("Node New", getSelectedNode());
getSelectedNode().setExpanded(true);
}
public void addTopicBelow(ActionEvent actionEvent){
TreeNode newNode = new DefaultTreeNode("Node New", getSelectedNode().getParent());
}
public void deleteNode(ActionEvent actionEvent){
 System.out.println("Node to be deleted: "+getSelectedNode().toString());
 //getSelectedNode().
}

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