【Java】 实现一个简单文件浏览器（1）

学习Java的Swing的时候写的一个超简单文件浏览器

效果如图：

项目结构：

这里面主要用了两个控件，JTree和JTable

下面先说下左侧的文件树如何实现：

首先是FileTree类，继承于JTree类，这里实现了树节点展开，和鼠标移动事件响应

package FileTree;

import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.File;

import javax.swing.JTree;
import javax.swing.event.TreeExpansionEvent;
import javax.swing.event.TreeWillExpandListener;
import javax.swing.filechooser.FileSystemView;
import javax.swing.tree.ExpandVetoException;
import javax.swing.tree.TreePath;

/**
 * Created by Administrator on 2016/3/29.
 */
public class FileTree extends JTree {
	private static final long serialVersionUID = 1L;
	public TreePath mouseInPath;
    static protected FileSystemView fileSystemView = FileSystemView.getFileSystemView();
    public FileTree() {
        setRootVisible(false);
        addTreeWillExpandListener(new TreeWillExpandListener(){
            @Override
            public void treeWillExpand(TreeExpansionEvent event) throws ExpandVetoException {
                FileTreeNode fileNode = (FileTreeNode)event.getPath().getLastPathComponent();
                if (!fileNode.isInit()){
                    File[] files;
                    if(fileNode.isDummyRoot()) {
                        files = fileSystemView.getRoots();
                    } else {
                        files = fileSystemView.getFiles(fileNode.getFile(), false);
                    }

                    for (int i = 0; i < files.length; i++){
                        if (files[i].isDirectory())
                        {
                            FileTreeNode childFileNode = new FileTreeNode(files[i]);
                            fileNode.add(childFileNode);
                        }
                    }
                }
                fileNode.setInit(true);
            }

            @Override
            public void treeWillCollapse(TreeExpansionEvent event) throws ExpandVetoException {

            }
        });

        addMouseMotionListener(new MouseAdapter() {
            @Override
            public void mouseMoved(MouseEvent e) {
                TreePath path = getPathForLocation(e.getX(), e.getY());
                if (path != null) {
                    if (mouseInPath != null) {
                        Rectangle oldRect = getPathBounds(mouseInPath);
                        mouseInPath = path;
                        repaint(getPathBounds(path).union(oldRect));
                    } else {
                        mouseInPath = path;
                    }
                } else if (mouseInPath != null) {
                    Rectangle oldRect =getPathBounds(mouseInPath);
                    mouseInPath = null;
                    repaint(oldRect);
                }
            }
        });
    }
}

FileTreeCellRenderer继承自DefaultTreeCellRenderer， 负责树节点显示渲染，这里主要是需要重载getTreeCellRendererComponent()方法

public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus)

解释：配置基于传入组件的渲染器。使用 convertValueToText 向树传递消息，从而设置该值，最终对 value 调用 toString。基于选择设置前景色，基于 leaf 和 expanded 参数设置图标。

返回：渲染器用来绘制值的 Component

package FileTree;

import java.awt.Color;
import java.awt.Component;
import java.io.File;

import javax.swing.JLabel;
import javax.swing.JTree;
import javax.swing.plaf.ColorUIResource;
import javax.swing.tree.DefaultTreeCellRenderer;

/**
 * Created by Administrator on 2016/3/29.
 */
public class FileTreeCellRenderer extends  DefaultTreeCellRenderer {

	private static final long serialVersionUID = 1L;

	public FileTreeCellRenderer(){
    }
    @Override
    public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus) {
        FileTree fileTree = (FileTree) tree;
        FileTreeNode fileNode = (FileTreeNode) value;
        File file = (File) fileNode.getUserObject();

        JLabel label = (JLabel)super.getTreeCellRendererComponent(tree,value,selected,expanded,leaf,row,hasFocus);
        label.setText(fileNode.getFileName());

        label.setIcon(fileNode.getFileIcon());
        label.setOpaque(false);
        if (fileTree.mouseInPath != null &&
                fileTree.mouseInPath.getLastPathComponent().equals(value)) {
            label.setOpaque(true);
//            label.setBackground(new Color(255, 0, 0, 90));
            label.setBackground(Color.gray);
        }
        return label;
    }

    @Override
    public void setBackground(Color bg) {
        if (bg instanceof ColorUIResource){
            bg = null;
        }
        super.setBackground(bg);
    }
}

FileTreeNode继承DefaultMutableTreeNode类， 用于保存文件名和其他文件相关属性

package FileTree;

import java.io.File;

import javax.swing.Icon;
import javax.swing.filechooser.FileSystemView;
import javax.swing.tree.DefaultMutableTreeNode;

/**
 * Created by Administrator on 2016/3/29.
 */
public class FileTreeNode extends DefaultMutableTreeNode {

	private static final long serialVersionUID = 1L;

	static FileSystemView fileSystemView = FileSystemView.getFileSystemView();

    private boolean isInit;
    private boolean isDummyRoot;
    private String fileName;
    private Icon fileIcon;

    public File getFile() {
        return file;
    }

    private File file;

    public FileTreeNode(File file){
        this(file, false, true);
    }
    public FileTreeNode(File file, boolean isDummyRoot){
        this(file,isDummyRoot, true);
    }
    public FileTreeNode(File file, boolean isDummyRoot, boolean allowsChildren){
        super(file, allowsChildren);
        this.file = file;
        this.fileName = fileSystemView.getSystemDisplayName(file);
        this.fileIcon = fileSystemView.getSystemIcon(file);
        this.isDummyRoot = isDummyRoot;
    }

    public boolean isInit() {
        return isInit;
    }

    public void setInit(boolean init) {
        isInit = init;
    }

    public boolean isDummyRoot() {
        return isDummyRoot;
    }

    public void setDummyRoot(boolean dummyRoot) {
        isDummyRoot = dummyRoot;
    }

    public String getFileName() {
        return fileName;
    }

    public void setFileName(String fileName) {
        this.fileName = fileName;
    }

    public Icon getFileIcon() {
        return fileIcon;
    }

    public void setFileIcon(Icon fileIcon) {
        this.fileIcon = fileIcon;
    }
}

本文链接: http://www.bugcoding.com/entry/15

版权所有。转载时必须以链接形式注明作者和原始出处及本声明。