语法及其算法检测
1. 要求做一个程序扫描指定的目录及其所有的子目录和文件，要求生成一个目录树的文本文件，格式如下，假如要求扫描的是c:\
C:\
|--test1
|--test2
| |--childt1
| | |--cct1
| | |--cct2
| | | |--ccdc1
| | | |--ccdc2
| |--childt2
|--test3
|--child3
| |--ccd3
2. 程序可以采用命令行方式，或者桌面程序方式
3. 请注意示例中的格式，仔细理解。
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileFilter;
import java.util.HashMap;
import java.util.Map;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
public class PathTree extends JPanel {
private static final long serialVersionUID = 1L;
private JButton stopButton = new JButton("停止扫描");
private JButton browseButton = new JButton("选择文件夹");
private JTextArea pathsTextArea = new JTextArea();
private JCheckBox showHiddenFilesCheckbox = new JCheckBox("显示隐藏文件", false);
private Map
private FileFilter docFilter = new DocFilter(); // 文档过滤器
private FileFilter dirFilter = new DirFilter(); // 文件夹过滤器
private boolean stopped = false; // 是否停止扫描的标志
public PathTree() {
initGui();
}
// 初始化界面
private void initGui() {
this.setLayout(new BorderLayout());
JPanel buttonsPanel = new JPanel();
buttonsPanel.setBorder(BorderFactory.createMatteBorder(0, 0, 1, 0, Color.GRAY));
buttonsPanel.add(showHiddenFilesCheckbox);
buttonsPanel.add(browseButton);
buttonsPanel.add(stopButton);
this.add(buttonsPanel, BorderLayout.NORTH);
JScrollPane scroller = new JScrollPane(pathsTextArea);
scroller.setBorder(null);
this.add(scroller, BorderLayout.CENTER);
browseButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// 选择文件夹
final JFileChooser chooser = new JFileChooser();
chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
int result = chooser.showOpenDialog(PathTree.this);
if (result == JFileChooser.APPROVE_OPTION) {
Thread t = new Thread(new Runnable() {
@Override
public void run() {
File dir = chooser.getSelectedFile();
pathsTextArea.setText("");
stopped = false;
walkTree(dir, 0);
}
});
t.start();
}
}
});
stopButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
stopped = true;
}
});
}
// 递归遍历目录树
private void walkTree(File dir, int level) {
// 1. current dir path
// 2. docs path that located in this dir
// 3. sub dirs path
if (stopped) { return; }
// 如果不显示隐藏文件，则返回
if (dir.isHidden() && !showHiddenFilesCheckbox.isSelected()) { return; }
final StringBuilder pathBuffer = new StringBuilder(1024);
// 访问当前目录
pathBuffer.append(createPath(dir, level));
// 访问文档
for (File doc : dir.listFiles(docFilter)) {
if (doc.isHidden() && !showHiddenFilesCheckbox.isSelected()) {
continue;
}
pathBuffer.append(createPath(doc, level + 1));
}
// 把当前目录下的文件更新到text area中
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
pathsTextArea.append(pathBuffer.toString());
}
});
// 递归遍历子目录
for (File subDir : dir.listFiles(dirFilter)) {
walkTree(subDir, level + 1);
}
}
// 创建文件的路径
public String createPath(File file, int level) {
StringBuilder pathBuffer = new StringBuilder(128);
pathBuffer.append(getPathIndex(level)).append(file.getName()).append("\n");
return pathBuffer.toString();
}
// 创建目录的缩进
private String getPathIndex(int level) {
// 如果不存在，则创建
if (pathIndexes.get(level) == null) {
StringBuilder indexBuffer = new StringBuilder(128);
for (int i = 0; i < level; ++i) {
indexBuffer.append("| ");
}
indexBuffer.append("|----");
pathIndexes.put(Integer.valueOf(level), indexBuffer.toString());
return indexBuffer.toString();
} else {
return pathIndexes.get(level);
}
}
// 创建主窗口
private static void createGUIAndShow() {
JFrame frame = new JFrame("目录结构树");
frame.setContentPane(new PathTree());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Dimension ss = Toolkit.getDefaultToolkit().getScreenSize();
int w = 600;
int h = 700;
int x = (ss.width - w) / 2;
int y = (ss.height - h) / 2 - 40;
x = x > 0 ? x : 0;
y = y > 0 ? y : 0;
frame.setBounds(x, y, w, h);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
createGUIAndShow();
}
});
}
}
class DocFilter implements FileFilter {
@Override
public boolean accept(File file) {
return file.isFile();
}
}
class DirFilter implements FileFilter {
@Override
public boolean accept(File file) {
return file.isDirectory();
}
}