点击(此处)折叠或打开

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class TestTree {
public static void main(String[] args) {
TestData data = new TestData();
Map<String, TreeNode> midStr = new HashMap<String, TreeNode>();
/**把list中的数据放到 map中，方便后续的查找*/
for (int n = 0; n < data.listTreeNode.size(); n++) {
midStr.put(data.listTreeNode.get(n).getId(),
data.listTreeNode.get(n));
}
String root = null; //用来保存根节点的id
/*关键操作
* 遍历 map 中的TreeNode 找到父亲节点，如果找不到父亲节点，那这个TreeNode就是根节点。
* 把自己放到父亲节点的 children 列表中
*/
for (Map.Entry<String, TreeNode> entry : midStr.entrySet()) {
TreeNode t = midStr.get(entry.getValue().getParentId());
if (t != null)
midStr.get(entry.getValue().getParentId()).getChildren()
.add(entry.getValue());
else
root = entry.getKey();
}
System.out.println(midStr.get(root));
TreeNode ret = midStr.get(root);
System.out.println(\"\");
}
}
/**
* 树形结构
* */
class TreeNode {
private String id;
private String parentId;
private List<TreeNode> children = new ArrayList<TreeNode>();;
public TreeNode(String p_id, String p_parentId) {
this.id = p_id;
this.parentId = p_parentId;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getParentId() {
return parentId;
}
public void setParentId(String parentId) {
this.parentId = parentId;
}
public List<TreeNode> getChildren() {
return children;
}
public void setChildren(List<TreeNode> children) {
this.children = children;
}
}
/**
* 模拟数据库返回数据 List <DTO>
* */
class TestData {
public List<TreeNode> listTreeNode = new ArrayList<TreeNode>();
TestData() {
listTreeNode.add(new TreeNode("1", "0"));
listTreeNode.add(new TreeNode("7", "3"));
listTreeNode.add(new TreeNode("2", "1"));
listTreeNode.add(new TreeNode("3", "1"));
listTreeNode.add(new TreeNode("4", "2"));
listTreeNode.add(new TreeNode("5", "2"));
listTreeNode.add(new TreeNode("6", "1"));
}
}

ITPub博客

如何在Java中返回树形结构最佳实践

最新文章

ITPub博客

如何在Java中返回树形结构 最佳实践

最新文章

如何在Java中返回树形结构最佳实践