我是java的初学者。我正在创建一个文件选择器，它可以一次选择多个驱动器、文件夹或文件以进行蠕虫扫描。我编写的代码可以在单个驱动器上正常工作（例如 c:\ 或 e:\ 等）。我正在尝试为系统中的所有驱动器创建一棵树。请告诉我如何做到这一点。
代码
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.tree.*;
import java.io.File;
import java.util.Collections;
import java.util.Vector;
public class FileTreeDemo {
public static void main(String[] args) {
try{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
}catch(Exception e){
System.out.println("cant done");
}
// Create a JTree and tell it to display our model
JTree tree = new JTree();
// The JTree can get big, so allow it to scroll
JScrollPane scrollpane = new JScrollPane(tree);
// Figure out where in the filesystem to start displaying
File[] roots = File.listRoots();
FileTreeModel model = new FileTreeModel(null);
model = new FileTreeModel(roots[0]);
tree.setModel(model);
CheckTreeManager checkTreeManager = new CheckTreeManager(tree);
TreePath checkedPaths[]=checkTreeManager.getSelectionModel().getSelectionPaths();
int j = checkedPaths.length;
System.out.println("Tree Path :"+j);
for(int i=0; i<checkedPaths.length;i++){
System.out.println("Tree Path :"+checkedPaths[i]);
}
// Display it all in a window and make the window appear
JFrame frame = new JFrame("FileTreeDemo");
frame.getContentPane().add(scrollpane, "Center");
frame.setSize(400,600);
frame.setVisible(true);
}
}
import java.io.File;
import javax.swing.event.TreeModelListener;
import javax.swing.tree.DefaultTreeSelectionModel;
import javax.swing.tree.TreeModel;
import javax.swing.tree.TreePath;
import javax.swing.tree.TreeSelectionModel;
public class FileTreeModel extends DefaultTreeSelectionModel implements TreeModel{
// We specify the root directory when we create the model.
protected File root;
public FileTreeModel(File root) { this.root = root;
//setSelectionMode(TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION);
}
// The model knows how to return the root object of the tree
public Object getRoot() { return root; }
// Tell JTree whether an object in the tree is a leaf
public boolean isLeaf(Object node) { return ((File)node).isFile(); }
// Tell JTree how many children a node has
public int getChildCount(Object parent) {
String[] children = ((File)parent).list();
if (children == null) return 0;
return children.length;
}
// Fetch any numbered child of a node for the JTree.
// Our model returns File objects for all nodes in the tree. The
// JTree displays these by calling the File.toString() method.
public Object getChild(Object parent, int index) {
String[] children = ((File)parent).list();
if ((children == null) || (index >= children.length)) return null;
return new File((File) parent, children[index]);
}
// Figure out a child's position in its parent node.
public int getIndexOfChild(Object parent, Object child) {
String[] children = ((File)parent).list();
if (children == null) return -1;
String childname = ((File)child).getName();
for(int i = 0; i < children.length; i++) {
if (childname.equals(children[i])) return i;
}
return -1;
}
// This method is invoked by the JTree only for editable trees.
// This TreeModel does not allow editing, so we do not implement
// this method. The JTree editable property is false by default.
public void valueForPathChanged(TreePath path, Object newvalue) {}
// Since this is not an editable tree model, we never fire any events,
// so we don't actually have to keep track of interested listeners*/
public void addTreeModelListener(TreeModelListener l) {}
public void removeTreeModelListener(TreeModelListener l) {}
}
import javax.swing.*;
import javax.swing.event.ChangeListener;
import javax.swing.plaf.ActionMapUIResource;
import java.awt.event.*;
import java.awt.*;
/**
* Maintenance tip - There were some tricks to getting this code
* working:
*
* 1. You have to overwite addMouseListener() to do nothing
* 2. You have to add a mouse event on mousePressed by calling
* super.addMouseListener()
* 3. You have to replace the UIActionMap for the keyboard event
* "pressed" with your own one.
* 4. You have to remove the UIActionMap for the keyboard event
* "released".
* 5. You have to grab focus when the next state is entered,
* otherwise clicking on the component won't get the focus.
* 6. You have to make a TristateDecorator as a button model that
* wraps the original button model and does state management.
*/
public class TristateCheckBox extends JCheckBox{
private final TristateDecorator model;
public TristateCheckBox(String text, Icon icon, Boolean initial){
super(text, icon);
// Add a listener for when the mouse is pressed
super.addMouseListener(new MouseAdapter(){
public void mousePressed(MouseEvent e){
grabFocus();
model.nextState();
}
});
import java.awt.BorderLayout;
import java.awt.Component;
import javax.swing.JCheckBox;
import javax.swing.JPanel;
import javax.swing.JTree;
import javax.swing.tree.TreeCellRenderer;
import javax.swing.tree.TreePath;
public class CheckTreeCellRenderer extends JPanel implements TreeCellRenderer{
private CheckTreeSelectionModel selectionModel;
private TreeCellRenderer delegate;
private TristateCheckBox checkBox = new TristateCheckBox();
public CheckTreeCellRenderer(TreeCellRenderer delegate, CheckTreeSelectionModel selectionModel){
this.delegate = delegate;
this.selectionModel = selectionModel;
setLayout(new BorderLayout());
setOpaque(false);
checkBox.setOpaque(false);
}
public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus){
Component renderer = delegate.getTreeCellRendererComponent(tree, value, selected, expanded, leaf, row, hasFocus);
TreePath path = tree.getPathForRow(row);
if(path!=null){
if(selectionModel.isPathSelected(path, true))
checkBox.setState(Boolean.TRUE);
else
checkBox.setState(selectionModel.isPartiallySelected(path) ? null : Boolean.FALSE);
}
removeAll();
add(checkBox, BorderLayout.WEST);
add(renderer, BorderLayout.CENTER);
return this;
![enter image description here][1]}
}
// Reset the keyboard action map
ActionMap map = new ActionMapUIResource();
map.put("pressed", new AbstractAction(){ //NOI18N
public void actionPerformed(ActionEvent e){
grabFocus();
model.nextState();
}
});
map.put("released", null); //NOI18N
SwingUtilities.replaceUIActionMap(this, map);
// set the model to the adapted model
model = new TristateDecorator(getModel());
setModel(model);
setState(initial);
}
public TristateCheckBox(String text, Boolean initial){
this(text, null, initial);
}
public TristateCheckBox(String text){
this(text, null);
}
public TristateCheckBox(){
this(null);
}
/** No one may add mouse listeners, not even Swing! */
public void addMouseListener(MouseListener l){}
/**
* Set the new state to either SELECTED, NOT_SELECTED or
* DONT_CARE. If state == null, it is treated as DONT_CARE.
*/
public void setState(Boolean state){
model.setState(state);
}
/** Return the current state, which is determined by the
* selection status of the model. */
public Boolean getState(){
return model.getState();
}
/**
* Exactly which Design Pattern is this? Is it an Adapter,
* a Proxy or a Decorator? In this case, my vote lies with the
* Decorator, because we are extending functionality and
* "decorating" the original model with a more powerful model.
*/
private class TristateDecorator implements ButtonModel{
private final ButtonModel other;
private TristateDecorator(ButtonModel other){
this.other = other;
}
private void setState(Boolean state){
if(state==Boolean.FALSE){
other.setArmed(false);
setPressed(false);
setSelected(false);
} else if(state==Boolean.TRUE){
other.setArmed(false);
setPressed(false);
setSelected(true);
}
else{
other.setArmed(true);
setPressed(true);
setSelected(true);
}
}
/**
* The current state is embedded in the selection / armed
* state of the model.
*
* We return the SELECTED state when the checkbox is selected
* but not armed, DONT_CARE state when the checkbox is
* selected and armed (grey) and NOT_SELECTED when the
* checkbox is deselected.
*/
private Boolean getState(){
if(isSelected() && !isArmed()){
// normal black tick
return Boolean.TRUE;
} else if(isSelected() && isArmed()){
// don't care grey tick
return null;
} else{
// normal deselected
return Boolean.FALSE;
}
}
/** We rotate between NOT_SELECTED, SELECTED and DONT_CARE.*/
private void nextState(){
Boolean current = getState();
if(current == Boolean.FALSE){
setState(Boolean.TRUE);
} else if(current == Boolean.TRUE){
setState(null);
} else if(current == null){
setState(Boolean.FALSE);
}
}
/** Filter: No one may change the armed status except us. */
public void setArmed(boolean b){
}
public boolean isFocusTraversable() {
return isEnabled();
}
/** We disable focusing on the component when it is not
* enabled. */
public void setEnabled(boolean b){
// setFocusable(b);
other.setEnabled(b);
}
/** All these methods simply delegate to the "other" model
* that is being decorated. */
public boolean isArmed(){return other.isArmed();
}
public boolean isSelected(){return other.isSelected();
}
public boolean isEnabled(){return other.isEnabled();
}
public boolean isPressed(){return other.isPressed();
}
public boolean isRollover(){return other.isRollover();
}
public void setSelected(boolean b){other.setSelected(b);
}
public void setPressed(boolean b){other.setPressed(b);
}
public void setRollover(boolean b){other.setRollover(b);
}
public void setMnemonic(int key){other.setMnemonic(key);
}
public int getMnemonic(){return other.getMnemonic();
}
public void setActionCommand(String s){other.setActionCommand(s);
}
public String getActionCommand(){return other.getActionCommand();
}
public void setGroup(ButtonGroup group){other.setGroup(group);
}
public void addActionListener(ActionListener l){other.addActionListener(l);
}
public void removeActionListener(ActionListener l){other.removeActionListener(l);
}
public void addItemListener(ItemListener l){other.addItemListener(l);
}
public void removeItemListener(ItemListener l){other.removeItemListener(l);
}
public void addChangeListener(ChangeListener l){other.addChangeListener(l);
}
public void removeChangeListener(ChangeListener l){other.removeChangeListener(l);
}
public Object[] getSelectedObjects(){return other.getSelectedObjects();
}
}
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JCheckBox;
import javax.swing.JTree;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.TreePath;
public class CheckTreeManager extends MouseAdapter implements TreeSelectionListener{
private CheckTreeSelectionModel selectionModel;
private JTree tree = new JTree();
int hotspot = new JCheckBox().getPreferredSize().width;
public CheckTreeManager(JTree tree){
this.tree = tree;
selectionModel = new CheckTreeSelectionModel(tree.getModel());
tree.setCellRenderer(new CheckTreeCellRenderer(tree.getCellRenderer(), selectionModel));
tree.addMouseListener(this);
selectionModel.addTreeSelectionListener(this);
}
public void mouseClicked(MouseEvent me){
TreePath path = tree.getPathForLocation(me.getX(), me.getY());
if(path==null)
return;
if(me.getX()>tree.getPathBounds(path).x+hotspot)
return;
boolean selected = selectionModel.isPathSelected(path, true);
selectionModel.removeTreeSelectionListener(this);
try{
if(selected)
selectionModel.removeSelectionPath(path);
else
selectionModel.addSelectionPath(path);
System.out.println("Tree Path :"+path);
} finally{
selectionModel.addTreeSelectionListener(this);
tree.treeDidChange();
}
}
public CheckTreeSelectionModel getSelectionModel(){return selectionModel;
}
public void valueChanged(TreeSelectionEvent e){tree.treeDidChange();
}
}
public static void main(String args[]) throws Exception{
UIManager.setLookAndFeel(
UIManager.getSystemLookAndFeelClassName());
JFrame frame = new JFrame("TristateCheckBoxTest"); //NOI18N
frame.getContentPane().setLayout(new GridLayout(0, 1, 5, 5));
final TristateCheckBox swingBox = new TristateCheckBox(
"Testing the tristate checkbox"); //NOI18N
swingBox.setMnemonic('T');
frame.getContentPane().add(swingBox);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
}
import java.util.ArrayList;
import java.util.Stack;
import javax.swing.tree.*;
public class CheckTreeSelectionModel extends DefaultTreeSelectionModel{
private TreeModel model;
//FileTreeModel model;
public CheckTreeSelectionModel(TreeModel model){
this.model = model;
setSelectionMode(TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION);
}
// tests whether there is any unselected node in the subtree of given path
public boolean isPartiallySelected(TreePath path){
if(isPathSelected(path, true))
return false;
TreePath[] selectionPaths = getSelectionPaths();
if(selectionPaths==null)
return false;
for(int j = 0; j<selectionPaths.length; j++){
if(isDescendant(selectionPaths[j], path))
return true;
}
return false;
}
// tells whether given path is selected.
// if dig is true, then a path is assumed to be selected, if
// one of its ancestor is selected.
public boolean isPathSelected(TreePath path, boolean dig){
if(!dig)
return super.isPathSelected(path);
while(path!=null && !super.isPathSelected(path))
path = path.getParentPath();
return path!=null;
}
// is path1 descendant of path2
private boolean isDescendant(TreePath path1, TreePath path2){
Object obj1[] = path1.getPath();
Object obj2[] = path2.getPath();
for(int i = 0; i<obj2.length; i++){
if(obj1[i]!=obj2[i])
return false;
}
return true;
}
public void setSelectionPaths(TreePath[] pPaths){
throw new UnsupportedOperationException("not implemented yet!!!");
}
public void addSelectionPaths(TreePath[] paths){
// unselect all descendants of paths[]
for(int i = 0; i<paths.length; i++){
TreePath path = paths[i];
TreePath[] selectionPaths = getSelectionPaths();
if(selectionPaths==null)
break;
ArrayList toBeRemoved = new ArrayList();
for(int j = 0; j<selectionPaths.length; j++){
if(isDescendant(selectionPaths[j], path))
toBeRemoved.add(selectionPaths[j]);
}
super.removeSelectionPaths((TreePath[])toBeRemoved.toArray(new TreePath[0]));
}
// if all siblings are selected then unselect them and select parent recursively
// otherwize just select that path.
for(int i = 0; i<paths.length; i++){
TreePath path = paths[i];
TreePath temp = null;
while(areSiblingsSelected(path)){
temp = path;
if(path.getParentPath()==null)
break;
path = path.getParentPath();
}
if(temp!=null){
if(temp.getParentPath()!=null)
addSelectionPath(temp.getParentPath());
else{
if(!isSelectionEmpty())
removeSelectionPaths(getSelectionPaths());
super.addSelectionPaths(new TreePath[]{temp});
}
}else
super.addSelectionPaths(new TreePath[]{ path});
}
}
// tells whether all siblings of given path are selected.
private boolean areSiblingsSelected(TreePath path){
TreePath parent = path.getParentPath();
if(parent==null)
return true;
Object node = path.getLastPathComponent();
Object parentNode = parent.getLastPathComponent();
int childCount = model.getChildCount(parentNode);
for(int i = 0; i<childCount; i++){
Object childNode = model.getChild(parentNode, i);
if(childNode==node)
continue;
if(!isPathSelected(parent.pathByAddingChild(childNode)))
return false;
}
return true;
}
public void removeSelectionPaths(TreePath[] paths){
for(int i = 0; i<paths.length; i++){
TreePath path = paths[i];
if(path.getPathCount()==1)
super.removeSelectionPaths(new TreePath[]{ path});
else
toggleRemoveSelection(path);
}
}
// if any ancestor node of given path is selected then unselect it
// and selection all its descendants except given path and descendants.
// otherwise just unselect the given path
private void toggleRemoveSelection(TreePath path){
Stack stack = new Stack();
TreePath parent = path.getParentPath();
while(parent!=null && !isPathSelected(parent)){
stack.push(parent);
parent = parent.getParentPath();
}
if(parent!=null)
stack.push(parent);
else{
super.removeSelectionPaths(new TreePath[]{path});
return;
}
while(!stack.isEmpty()){
TreePath temp = (TreePath)stack.pop();
TreePath peekPath = stack.isEmpty() ? path : (TreePath)stack.peek();
Object node = temp.getLastPathComponent();
Object peekNode = peekPath.getLastPathComponent();
int childCount = model.getChildCount(node);
for(int i = 0; i<childCount; i++){
Object childNode = model.getChild(node, i);
if(childNode!=peekNode)
super.addSelectionPaths(new TreePath[] {temp.pathByAddingChild(childNode)});
}
}
super.removeSelectionPaths(new TreePath[]{parent});
}
}