[英]How does JTree display file name?
在我的項目中,我正在嘗試添加文件資源管理器,以便用戶可以從給定目錄中選擇文件。 我想將此視圖限制為項目的根文件夾(由用戶確定)。 這與Eclipses Package Explorer非常相似,因為“工作區”由用戶決定。
目前文件不顯示完整路徑(從C :)這是我想要的,但所有文件夾顯示完整路徑(我不想要,我只想要文件夾名稱)。
那么JTree如何顯示這些名稱?
我已經看到JTree使用File.tostring()方法,但是當我實現自己的文件並覆蓋toString方法時,沒有任何改變。
這是我的代碼:
import java.awt.BorderLayout;
import java.io.File;
import javax.swing.JFileChooser;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.event.TreeModelListener;
import javax.swing.tree.TreeModel;
import javax.swing.tree.TreePath;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.util.Collections;
import java.util.Vector;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
public class pnl_fileView extends JPanel {
/**
* Display a file system in a JTree view
*
* @version $Id: FileTree.java,v 1.9 2004/02/23 03:39:22 ian Exp $
* @author Ian Darwin
*/
/** Construct a FileTree */
// public pnl_fileView(){
private myFile projectFile;
public pnl_fileView(myFile dir) {
//Create file explorer
//Need to add setup for root folder change.
//Config.getProject(); //This gets the current file from the config file.
//Begin choose File
if(projectFile == null){
JFileChooser chooser;
String choosertitle = "Please Choose a Root Folder";
chooser = new JFileChooser();
chooser.setCurrentDirectory(new java.io.File("."));
chooser.setDialogTitle(choosertitle);
chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
//
// disable the "All files" option.
//
chooser.setAcceptAllFileFilterUsed(false);
//
if (chooser.showOpenDialog(this) == JFileChooser.APPROVE_OPTION) {
System.out.println("getCurrentDirectory(): " + chooser.getCurrentDirectory());
System.out.println("getSelectedFile() : " + chooser.getSelectedFile());
projectFile = new myFile(chooser.getSelectedFile().getAbsolutePath());
//projectFile = chooser.getSelectedFile();
}
else {
System.out.println("No Selection ");
}
}
else {
// Figure out where in the filesystem to start displaying
}
//End choose file
setLayout(new BorderLayout());
// Make a tree list with all the nodes, and make it a JTree
JTree tree = new JTree(addNodes(null, projectFile));
// Add a listener
tree.addTreeSelectionListener(new TreeSelectionListener() {
public void valueChanged(TreeSelectionEvent e) {
DefaultMutableTreeNode node = (DefaultMutableTreeNode) e
.getPath().getLastPathComponent();
System.out.println("You selected " + node);
}
});
// Lastly, put the JTree into a JScrollPane.
JScrollPane scrollpane = new JScrollPane();
scrollpane.getViewport().add(tree);
add(BorderLayout.CENTER, scrollpane);
}
/** Add nodes from under "dir" into curTop. Highly recursive. */
DefaultMutableTreeNode addNodes(DefaultMutableTreeNode curTop, myFile dir) {
String curPath = dir.getPath();
System.out.println(curPath);
DefaultMutableTreeNode curDir = new DefaultMutableTreeNode(curPath);
if (curTop != null) { // should only be null at root
curTop.add(curDir);
}
Vector<String> ol = new Vector<String>();
String[] tmp = dir.list();
for (int i = 0; i < tmp.length; i++)
ol.addElement(tmp[i]);
Collections.sort(ol, String.CASE_INSENSITIVE_ORDER);
myFile f;
Vector<String> files = new Vector<String>();
// Make two passes, one for Dirs and one for Files. This is #1.
for (int i = 0; i < ol.size(); i++) {
String thisObject = (String) ol.elementAt(i);
String newPath;
if (curPath.equals("."))
newPath = thisObject;
else
newPath = curPath + myFile.separator + thisObject;
System.out.println("this is the path: " + newPath);
if ((f = new myFile(newPath)).isDirectory())
addNodes(curDir, f);
else
files.addElement(thisObject);
}
// Pass two: for files.
for (int fnum = 0; fnum < files.size(); fnum++)
curDir.add(new DefaultMutableTreeNode(files.elementAt(fnum)));
return curDir;
}
public Dimension getMinimumSize() {
return new Dimension(200, 400);
}
public Dimension getPreferredSize() {
return new Dimension(200, 400);
}
/** Main: make a Frame, add a FileTree */
public static void main(String[] av) {
JFrame frame = new JFrame("FileTree");
frame.setForeground(Color.black);
frame.setBackground(Color.lightGray);
Container cp = frame.getContentPane();
if (av.length == 0) {
cp.add(new pnl_fileView(new myFile(".")));
} else {
cp.setLayout(new BoxLayout(cp, BoxLayout.X_AXIS));
for (int i = 0; i < av.length; i++)
cp.add(new pnl_fileView(new myFile(av[i])));
}
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
class myFile extends File{
public myFile(String pathname) {
super(pathname);
}
public String toString() {
return "Hello World!";
}
public String getAbsolutePath(){
return "hi";
}
}
除了JFileChooser
,自定義Java文件瀏覽器的其他示例包括:
org.netbeans.swing.outline.Outline
與FileTreeModel
。 JTree
與FileTreeModel
, 在這里描述。 就個人而言,我不會嘗試通過使用其他對象來設置節點顯示值,我會將其留給TreeCellRenderer
來決定。 其主要原因是程序的某些其他部分可能需要節點包含的數據。
import java.io.File;
import javax.swing.JFileChooser;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.event.TreeModelListener;
import javax.swing.tree.TreeModel;
import javax.swing.tree.TreePath;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Vector;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.filechooser.FileSystemView;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
public class TestFileTree extends JPanel {
private File projectFile;
public TestFileTree(File dir) {
//Create file explorer
//Need to add setup for root folder change.
//Config.getProject(); //This gets the current file from the config file.
//Begin choose File
if (projectFile == null) {
JFileChooser chooser;
String choosertitle = "Please Choose a Root Folder";
chooser = new JFileChooser();
chooser.setCurrentDirectory(new java.io.File("."));
chooser.setDialogTitle(choosertitle);
chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
//
// disable the "All files" option.
//
chooser.setAcceptAllFileFilterUsed(false);
//
if (chooser.showOpenDialog(this) == JFileChooser.APPROVE_OPTION) {
System.out.println("getCurrentDirectory(): " + chooser.getCurrentDirectory());
System.out.println("getSelectedFile() : " + chooser.getSelectedFile());
projectFile = new File(chooser.getSelectedFile().getAbsolutePath());
//projectFile = chooser.getSelectedFile();
} else {
System.out.println("No Selection ");
}
} else {
// Figure out where in the filesystem to start displaying
}
//End choose file
setLayout(new BorderLayout());
// Make a tree list with all the nodes, and make it a JTree
JTree tree = new JTree(addNodes(null, projectFile));
tree.setCellRenderer(new MyTreeCellRenderer());
// Add a listener
tree.addTreeSelectionListener(new TreeSelectionListener() {
public void valueChanged(TreeSelectionEvent e) {
DefaultMutableTreeNode node = (DefaultMutableTreeNode) e
.getPath().getLastPathComponent();
System.out.println("You selected " + node);
}
});
// Lastly, put the JTree into a JScrollPane.
JScrollPane scrollpane = new JScrollPane();
scrollpane.getViewport().add(tree);
add(BorderLayout.CENTER, scrollpane);
}
/**
* Add nodes from under "dir" into curTop. Highly recursive.
*/
DefaultMutableTreeNode addNodes(DefaultMutableTreeNode curTop, File dir) {
DefaultMutableTreeNode curDir = new DefaultMutableTreeNode(dir);
if (curTop != null) { // should only be null at root
curTop.add(curDir);
}
File[] tmp = dir.listFiles();
Vector<File> ol = new Vector<File>();
ol.addAll(Arrays.asList(tmp));
Collections.sort(ol, new Comparator<File>() {
@Override
public int compare(File o1, File o2) {
int result = o1.getName().compareTo(o2.getName());
if (o1.isDirectory() && o2.isFile()) {
result = -1;
} else if (o2.isDirectory() && o1.isFile()) {
result = 1;
}
return result;
}
});
// Pass two: for files.
for (int fnum = 0; fnum < ol.size(); fnum++) {
File file = ol.elementAt(fnum);
DefaultMutableTreeNode node = new DefaultMutableTreeNode(file);
if (file.isDirectory()) {
addNodes(node, file);
}
curDir.add(node);
}
return curDir;
}
public Dimension getMinimumSize() {
return new Dimension(200, 400);
}
public Dimension getPreferredSize() {
return new Dimension(200, 400);
}
public static void main(String[] av) {
JFrame frame = new JFrame("FileTree");
frame.setForeground(Color.black);
frame.setBackground(Color.lightGray);
Container cp = frame.getContentPane();
if (av.length == 0) {
cp.add(new TestFileTree(new File(".")));
} else {
cp.setLayout(new BoxLayout(cp, BoxLayout.X_AXIS));
for (int i = 0; i < av.length; i++) {
cp.add(new TestFileTree(new File(av[i])));
}
}
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public class MyTreeCellRenderer extends DefaultTreeCellRenderer {
private FileSystemView fsv = FileSystemView.getFileSystemView();
@Override
public Component getTreeCellRendererComponent(JTree tree, Object value, boolean sel, boolean expanded, boolean leaf, int row, boolean hasFocus) {
System.out.println(value);
super.getTreeCellRendererComponent(tree, value, sel, expanded, leaf, row, hasFocus);
if (value instanceof DefaultMutableTreeNode) {
value = ((DefaultMutableTreeNode)value).getUserObject();
if (value instanceof File) {
File file = (File) value;
if (file.isFile()) {
setIcon(fsv.getSystemIcon(file));
setText(file.getPath());
} else {
setIcon(fsv.getSystemIcon(file));
setText(file.getName());
}
}
}
return this;
}
}
}
您的代碼中有一些“有趣”的部分。
雖然Vector
不是一個糟糕的選擇,但List
(或者在這種情況下,特別是ArrayList
)更快,因為它沒有同步。
而不是使用循環將元素添加到列表中,使用Arrays.asList(...)
將數組轉換為列表並使用List#addAll
方法(它也在Vector
中)
我不確定你正在使用什么版本的Java,但是你現在可以使用for-each
Java 6(我認為),這意味着代替for (int i = 0; i < ol.size(); i++)
你可以做for (String thisObject : ol)
。
因為您在列表中使用泛型,所以不需要轉換對象;)
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