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java树形页面代码 java 树状结构
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树形界面用Java怎样做
Java提供的DefaultMutableTreeNode类是实现了MutableTreeNode接口的类，可以使用这个类为要创建的树准备节点。DefaultMutableTreeNode类的两个常用的构造方法是：
DefaultMutableTreeNode（Object userObject）
DefaultMutableTreeNode（Object userObject， boolean allowChildren）。第一个构造方法创建的节点默认可以有子节点，第二个构造方法创建的节点有无子节点要根据参数allowChildren的真假来判断， allowChildren为true时有子节点，为假时无子节点。
树上的TreeSelectionEvent事件
树组件可以触发TreeSelectionEvent事件，树使用
addTreeSelectionListener（TreeSelectionListener listener）
方法获得一个监视器。此接口中的方法是：
public void valueChanged(TreeSelectionEvent e)
树通过使用getLastSelectedPathComponent()方法获取选中的节点，使用getUserObject()方法得到与节点相关的信息
像下面这样用，假定一定义了student类了,
DefaultMutableTreeNode root=new DefaultMutableTreeNode("大学"); //根节点
DefaultMutableTreeNode node=new DefaultMutableTreeNode("学生"); //节点
DefaultMutableTreeNode nodeson1=
new DefaultMutableTreeNode(new Student("张三",99)); //节点
DefaultMutableTreeNode nodeson2=
new DefaultMutableTreeNode(new Student("李四",88)); //节点
DefaultMutableTreeNode nodeson3=
new DefaultMutableTreeNode(new Student("刘五",77)); //节点
root.add(node); //确定节点之间的关系
node.add(nodeson1); //确定节点之间的关系
node.add(nodeson2);
node.add(nodeson3);
tree=new JTree(root); //用root做根的树组件
tree.addTreeSelectionListener(this); //
自己去实现public void valueChanged(TreeSelectionEvent e)方法
相关问答
Q1: java界面编程实现展开树
使用JTree 给你个例子import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;public class TreeDemo1{
public TreeDemo1(){
JFrame f=new JFrame("TreeDemo1");
Container contentPane=f.getContentPane();
String[] s1={"公司文件","个人信件","私人文件"};
String[] s2={"本机磁盘(C:)","本机磁盘(D:)","本机磁盘(E:)"};
String[] s3={"奇摩站","职棒消息","网络书店"};
Hashtable hashtable1=new Hashtable();
Hashtable hashtable2=new Hashtable();
hashtable1.put("我的公文包",s1);
hashtable1.put("我的电脑",s2);
hashtable1.put("收藏夹",hashtable2);
hashtable2.put("网站列表",s3);
Font font = new Font("Dialog", Font.PLAIN, 12);
Enumeration keys = UIManager.getLookAndFeelDefaults().keys();
/**定义widnows界面**/
while (keys.hasMoreElements()) {
Object key = keys.nextElement();
if (UIManager.get(key) instanceof Font) {
UIManager.put(key, font);
}
}
try{
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
}catch(Exception el){
System.exit(0);
}
/**定义widnows界面**/
JTree tree=new JTree(hashtable1);
JScrollPane scrollPane=new JScrollPane();
scrollPane.setViewportView(tree);
contentPane.add(scrollPane);
f.pack();
f.setVisible(true);
f.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(0);
}
});
}
public static void main(String[] args){
new TreeDemo1();
}
}
Q2: 求java树形目录代码范例
给java树形页面代码你一个。一共三个类。是个资源管理器java树形页面代码的代码
// FileList.java
package tl.exercise.swing;
import java.awt.Color;
import java.awt.Component;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.ListCellRenderer;
import javax.swing.ListModel;
import javax.swing.event.ListDataListener;
public class FileList
extends JList {
// PathNode theNode;
FileListModel dataModel;
static final long serialVersionUID = 10;
public FileList() {
dataModel = new FileListModel();
setModel(dataModel);
this.setCellRenderer(new MyCellRenderer());
}
public void fireTreeSelectionChanged(I_fileSystem node) {
// Vector files = node.getFiles();
// theNode = node;
dataModel.setNode(node);
updateUI();
}
}
class FileListModel implements ListModel {
FileList theList;
I_fileSystem node;
char fileType = I_fileSystem.ALL;
public void setNode(I_fileSystem node) {
this.node = node;
}
public Object getElementAt(int index) {
if (node != null) {
return ((I_fileSystem) node).getChild(fileType, index);
} else {
return null;
}
}
public int getSize() {
if (node != null) {
return ((I_fileSystem) node).getChildCount(fileType);
} else {
return 0;
}
}
public void addListDataListener(ListDataListener l) {
}
public void removeListDataListener(ListDataListener l) {
}
}
class MyCellRenderer extends JLabel implements ListCellRenderer {
public MyCellRenderer() {
setOpaque(true);
}
public Component getListCellRendererComponent(
JList list,
Object value,
int index,
boolean isSelected,
boolean cellHasFocus)
{
FolderNode node = (FolderNode) value;
setIcon(node.getIcon());
setText(value.toString());
setBackground(isSelected ? Color.BLUE.darker().darker() : Color.WHITE);
setForeground(isSelected ? Color.WHITE : Color.BLACK);
return this;
}
}
package tl.exercise.swing;
//JExplorer.java
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Toolkit;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.border.BevelBorder;
public class JExplorer {
public static void main(String[] args) {
// JFrame.setDefaultLookAndFeelDecorated(true);
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new UI(frame));
frame.pack();
Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
int left = (screen.width - frame.getWidth()) / 2;
int top = (screen.height - frame.getHeight()) / 2;
frame.setLocation(left, top);
frame.setVisible(true);
}
}
class UI extends JPanel {
// implements I_menuHandler{
static final long serialVersionUID = 0l;
static int LEFT_WIDTH = 200;
static int RIGHT_WIDTH = 300;
static int WINDOW_HEIGHT = 300;
JFrame frame = null;
public UI(JFrame frame) {
// EmptyBorder eb = new EmptyBorder(1,1,1,1);
this.frame = frame;
setPreferredSize(new Dimension(800, 600));
setBorder(new BevelBorder(BevelBorder.LOWERED));
setLayout(new BorderLayout());
FileList list = new FileList();
FileTree tree = new FileTree(list);
tree.setDoubleBuffered(true);
list.setDoubleBuffered(true);
JScrollPane treeView = new JScrollPane(tree);
treeView.setPreferredSize(
new Dimension(LEFT_WIDTH, WINDOW_HEIGHT));
JScrollPane listView = new JScrollPane(list);
listView.setPreferredSize(
new Dimension(RIGHT_WIDTH, WINDOW_HEIGHT));
JSplitPane pane =
new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, treeView,
listView);
pane.setDividerLocation(300);
pane.setDividerSize(4);
// pane.setDoubleBuffered(true);
add(pane);
}
}
package tl.exercise.swing;
//FileTree.java
/***********************************************************
* Author: Jason
* email: tl21cen@hotmail.com
* CSDN blog:
***********************************************************/
import java.awt.Component;
import java.io.File;
import java.util.Vector;
import javax.swing.Icon;
import javax.swing.JTree;
import javax.swing.event.TreeExpansionEvent;
import javax.swing.event.TreeExpansionListener;
import javax.swing.event.TreeModelListener;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.filechooser.FileSystemView;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreeModel;
import javax.swing.tree.TreePath;
public class FileTree extends JTree {
static final long serialVersionUID = 0;
private FileList theList;
public FileTree(FileList list) {
theList = list;
setModel(new FileSystemModel(new FolderNode()));
this.setCellRenderer(new FolderRenderer());
addTreeSelectionListener(new TreeSelectionListener() {
public void valueChanged(TreeSelectionEvent tse) {
}
});
this.setSelectionRow(0);
}
public void fireValueChanged(TreeSelectionEvent tse) {
TreePath tp = tse.getNewLeadSelectionPath();
Object o = tp.getLastPathComponent();
// theList.fireTreeSelectionChanged((PathNode)o);
theList.fireTreeSelectionChanged((FolderNode) o);
}
public void fireTreeCollapsed(TreePath path) {
super.fireTreeCollapsed(path);
TreePath curpath = getSelectionPath();
if (path.isDescendant(curpath)) {
setSelectionPath(path);
}
}
public void fireTreeWillExpand(TreePath path) {
System.out.println("Path will expand is " + path);
}
public void fireTreeWillCollapse(TreePath path) {
System.out.println("Path will collapse is " + path);
}
class ExpansionListener implements TreeExpansionListener {
FileTree tree;
public ExpansionListener(FileTree ft) {
tree = ft;
}
public void treeCollapsed(TreeExpansionEvent tee) {
}
public void treeExpanded(TreeExpansionEvent tee) {
}
}
}
class FileSystemModel implements TreeModel {
I_fileSystem theRoot;
char fileType = I_fileSystem.DIRECTORY;
public FileSystemModel(I_fileSystem fs) {
theRoot = fs;
}
public Object getRoot() {
return theRoot;
}
public Object getChild(Object parent, int index) {
return ((I_fileSystem) parent).getChild(fileType, index);
}
public int getChildCount(Object parent) {
return ((I_fileSystem) parent).getChildCount(fileType);
}
public boolean isLeaf(Object node) {
return ((I_fileSystem) node).isLeaf(fileType);
}
public int getIndexOfChild(Object parent, Object child) {
return ((I_fileSystem) parent).getIndexOfChild(fileType, child);
}
public void valueForPathChanged(TreePath path, Object newValue) {
}
public void addTreeModelListener(TreeModelListener l) {
}
public void removeTreeModelListener(TreeModelListener l) {
}
}
interface I_fileSystem {
final public static char DIRECTORY = 'D';
final public static char FILE = 'F';
final public static char ALL = 'A';
public Icon getIcon();
public I_fileSystem getChild(char fileType, int index);
public int getChildCount(char fileType);
public boolean isLeaf(char fileType);
public int getIndexOfChild(char fileType, Object child);
}
/**
* A data model for a JTree. This model explorer windows file system directly.
*
* p
* Perhaps there is a fatal bug with this design. For speed, each of instances
* of this model contains file objects of subdirectory, up to now, there isn't
* any method to release them until program be end. I'm afraid that the memory
* would be full of if the file system is large enough and JVM memery size
* setted too small.
*
* p
* I won't pay more attention to solve it. it isn't goal of current a exercise.
*
* @author Jason
*/
class FolderNode implements I_fileSystem {
// private static FolderNode theRoot;
private static FileSystemView fsView;
private static boolean showHiden = true;;
private File theFile;
private VectorFile all = new VectorFile();
private VectorFile folder = new VectorFile();
/**
* set that whether apply hiden file.
*
* @param ifshow
*/
public void setShowHiden(boolean ifshow) {
showHiden = ifshow;
}
public Icon getIcon() {
return fsView.getSystemIcon(theFile);
}
public String toString() {
// return fsView.
return fsView.getSystemDisplayName(theFile);
}
/**
* create a root node. by default, it should be the DeskTop in window file
* system.
*
*/
public FolderNode() {
fsView = FileSystemView.getFileSystemView();
theFile = fsView.getHomeDirectory();
prepareChildren();
}
private void prepareChildren() {
File[] files = fsView.getFiles(theFile, showHiden);
for (int i = 0; i files.length; i++) {
all.add(files[i]);
if (files[i].isDirectory()
!files[i].toString().toLowerCase().endsWith(".lnk")) {
folder.add(files[i]);
}
}
}
private FolderNode(File file) {
theFile = file;
prepareChildren();
}
public FolderNode getChild(char fileType, int index) {
if (I_fileSystem.DIRECTORY == fileType) {
return new FolderNode(folder.get(index));
} else if (I_fileSystem.ALL == fileType) {
return new FolderNode(all.get(index));
} else if (I_fileSystem.FILE == fileType) {
return null;
} else {
return null;
}
}
public int getChildCount(char fileType) {
if (I_fileSystem.DIRECTORY == fileType) {
return folder.size();
} else if (I_fileSystem.ALL == fileType) {
return all.size();
} else if (I_fileSystem.FILE == fileType) {
return -1;
} else {
return -1;
}
}
public boolean isLeaf(char fileType) {
if (I_fileSystem.DIRECTORY == fileType) {
return folder.size() == 0;
} else if (I_fileSystem.ALL == fileType) {
return all.size() == 0;
} else if (I_fileSystem.FILE == fileType) {
return true;
} else {
return true;
}
}
public int getIndexOfChild(char fileType, Object child) {
if (child instanceof FolderNode) {
if (I_fileSystem.DIRECTORY == fileType) {
return folder.indexOf(((FolderNode) child).theFile);
} else if (I_fileSystem.ALL == fileType) {
return all.indexOf(((FolderNode) child).theFile);
} else if (I_fileSystem.FILE == fileType) {
return -1;
} else {
return -1;
}
} else {
return -1;
}
}
}
class FolderRenderer extends DefaultTreeCellRenderer {
private static final long serialVersionUID = 1L;
public Component getTreeCellRendererComponent(JTree tree, Object value,
boolean sel, boolean expanded, boolean leaf, int row,
boolean hasFocus) {
I_fileSystem node = (I_fileSystem) value;
Icon icon = node.getIcon();
setLeafIcon(icon);
setOpenIcon(icon);
setClosedIcon(icon);
return super.getTreeCellRendererComponent(tree, value, sel, expanded,
leaf, row, hasFocus);
}
}
Q3: 怎样利用java在页面实现树形结构图
你针对这个表写个实体类，写出它的dao，然后取出所有数据放到List，把list放到request.setAttribute("all");在请求到的页面中用getAttribute取出，然后用js写DOM模型表示出来，js中的引用可以直接使用java的数据，例如：%
List l = (List)request.getAttribute("all");
for(int i==0;il.size();i++){
实体类 a = ( 实体类)l.get(i);
%
var url = %=a.get属性()%
%
}
%
DOM模型可以使js更好的控制我们想要实现的效果
java树形页面代码的介绍就聊到这里吧，感谢你花时间阅读本站内容，更多关于java 树状结构、java树形页面代码的信息别忘了在本站进行查找喔。
