问题
Trying to get selected filename with path from the JTree - TreeSelectionListener, I got stuck on this! Please give me direction to get the filename with path, have copied the complete code so far I tried.
EDIT:1
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Font;
import java.io.File;
import java.util.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
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;
import javax.swing.tree.TreeNode;
import javax.swing.tree.TreePath;
import javax.swing.tree.TreeSelectionModel;
public class FileTreePanel extends JPanel {
/**
* File system view.
*/
protected static FileSystemView fsv = FileSystemView.getFileSystemView();
/**
* Renderer for the file tree.
*
*/
private static class FileTreeCellRenderer extends DefaultTreeCellRenderer {
/**
* Icon cache to speed the rendering.
*/
private Map<String, Icon> iconCache = new HashMap<String, Icon>();
/**
* Root name cache to speed the rendering.
*/
private Map<File, String> rootNameCache = new HashMap<File, String>();
/*
* (non-Javadoc)
*
* @see javax.swing.tree.DefaultTreeCellRenderer#getTreeCellRendererComponent(javax.swing.JTree,
* java.lang.Object, boolean, boolean, boolean, int, boolean)
*/
@Override
public Component getTreeCellRendererComponent(JTree tree, Object value,
boolean sel, boolean expanded, boolean leaf, int row,
boolean hasFocus) {
FileTreeNode ftn = (FileTreeNode) value;
File file = ftn.file;
String filename = "";
if (file != null) {
if (ftn.isFileSystemRoot) {
filename = this.rootNameCache.get(file);
if (filename == null) {
filename = fsv.getSystemDisplayName(file);
this.rootNameCache.put(file, filename);
}
} else {
filename = file.getName();
}
}
JLabel result = (JLabel) super.getTreeCellRendererComponent(tree,
filename, sel, expanded, leaf, row, hasFocus);
if (file != null) {
Icon icon = this.iconCache.get(filename);
if (icon == null) {
icon = fsv.getSystemIcon(file);
this.iconCache.put(filename, icon);
}
result.setIcon(icon);
}
return result;
}
}
/**
* A node in the file tree.
*
*/
private static class FileTreeNode implements TreeNode {
/**
* Node file.
*/
private File file;
/**
* Children of the node file.
*/
private File[] children;
/**
* Parent node.
*/
private TreeNode parent;
/**
* Indication whether this node corresponds to a file system root.
*/
private boolean isFileSystemRoot;
/**
* Creates a new file tree node.
*
* @param file
* Node file
* @param isFileSystemRoot
* Indicates whether the file is a file system root.
* @param parent
* Parent node.
*/
public FileTreeNode(File file, boolean isFileSystemRoot, TreeNode parent) {
this.file = file;
this.isFileSystemRoot = isFileSystemRoot;
this.parent = parent;
this.children = this.file.listFiles();
if (this.children == null)
this.children = new File[0];
//System.out.println(children);
}
/**
* Creates a new file tree node.
*
* @param children
* Children files.
*/
public FileTreeNode(File[] children) {
this.file = null;
this.parent = null;
this.children = children;
}
public Enumeration<?> children() {
final int elementCount = this.children.length;
return new Enumeration<File>() {
int count = 0;
public boolean hasMoreElements() {
return this.count < elementCount;
}
public File nextElement() {
if (this.count < elementCount) {
return FileTreeNode.this.children[this.count++];
}
throw new NoSuchElementException("Vector Enumeration");
}
};
}
public boolean getAllowsChildren() {
return true;
}
public TreeNode getChildAt(int childIndex) {
return new FileTreeNode(this.children[childIndex],
this.parent == null, this);
}
public int getChildCount() {
return this.children.length;
}
public int getIndex(TreeNode node) {
FileTreeNode ftn = (FileTreeNode) node;
for (int i = 0; i < this.children.length; i++) {
if (ftn.file.equals(this.children[i]))
return i;
}
return -1;
}
public TreeNode getParent() {
return this.parent;
}
public boolean isLeaf() {
return (this.getChildCount() == 0);
}
}
/**
* The file tree.
*/
private JTree tree;
/**
* Creates the file tree panel.
*/
public FileTreePanel() {
//@trashgod's hint
this.setLayout(new BorderLayout());
//
File[] roots = File.listRoots();
FileTreeNode rootTreeNode = new FileTreeNode(roots);
this.tree = new JTree(rootTreeNode);
this.tree.setCellRenderer(new FileTreeCellRenderer());
this.tree.setRootVisible(false);
final JScrollPane jsp = new JScrollPane(this.tree);
tree.setVisibleRowCount(15);
Dimension preferredSize = jsp.getPreferredSize();
Dimension widePreferred = new Dimension(300,(int)preferredSize.getHeight());
jsp.setPreferredSize( widePreferred );
jsp.setBorder(new EmptyBorder(0, 0, 50, 0));
this.add(jsp, BorderLayout.WEST);
this.tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);
this.tree.setShowsRootHandles(true);
tree.addTreeSelectionListener(new TreeSelectionListener() {
public void valueChanged(TreeSelectionEvent e) {
TreePath tp = tree.getLeadSelectionPath();
if (tp!= null){
// Trying to get selected filename with path
Object filePathToAdd = tp.getPath()[tp.getPathCount()-1];
String objToStr = filePathToAdd.toString();
System.out.println("You selected " + filePathToAdd );
//http://stackoverflow.com/questions/4123299/how-to-get-datas-from-listobject-java
/*List<Object> list = (List<Object>) filePathToAdd;
for (int i=0; i<list.size(); i++){
Object[] row = (Object[]) list.get(i);
System.out.println("Element "+i+Arrays.toString(row));
}*/
}
}
});
JLabel lblNewLabel = new JLabel("Version 0.1.0 ");
lblNewLabel.setForeground(Color.GRAY);
lblNewLabel.setFont(new Font("Calibri", Font.BOLD, 12));
lblNewLabel.setBorder(new EmptyBorder(-740, 0, 0, 0));
this.add(lblNewLabel, BorderLayout.EAST);
}
/**
* @author Kirill Grouchnikov @http://www.pushing-pixels.org/
*/
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JFrame frame = new JFrame("Student Record Book");
frame.setSize(1200, 800);
frame.setLocationRelativeTo(null);
frame.add(new FileTreePanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
});
}
}
Getting the value from the object filePathToAdd like
You selected viewgui.FileTreePanel$FileTreeNode@68556f62
Edit:2
Expected output -> G:\java_code\Temp\tempfile.txt
Trying to loop thro' to get value but wasn't successful! please give me directions, Thx
回答1:
The first thing you need to do, is update FileTreeNode to provide a getter to return the File which this node represents...
private static class FileTreeNode implements TreeNode {
//...
public File getFile() {
return file;
}
Next, in your TreeSelectionListener, you need to get the selectionPath, get the lastPathComponent, test to see if it is a FileTreeNode and get the File it represents, for example...
tree.addTreeSelectionListener(new TreeSelectionListener() {
public void valueChanged(TreeSelectionEvent e) {
TreePath tp = tree.getSelectionPath();
if (tp != null) {
Object filePathToAdd = tp.getLastPathComponent();
System.out.println(filePathToAdd);
if (filePathToAdd instanceof FileTreeNode) {
FileTreeNode node = (FileTreeNode) filePathToAdd;
File file = node.getFile();
System.out.println(file);
}
}
}
});
来源：https://stackoverflow.com/questions/34270563/get-selected-filename-and-path-from-jtree