几个文件操作的小例子

最近一直在学习java web方面的东西，本来想完整的写一篇java web方面的文章，但是那一块太杂了，自己现在也不是很清晰，主要是myeclipse+Tomcat，每次启动tomcat都要花很长的时间，所以java web方面的文章目前还没有写，今天就先将自己之前的东西贴出来吧、

【案例1】获取文件的属性

运行结果：



代码如下：

/**
* 获取文件属性
* */

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.util.Date;

import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class MdifyfileAttribute extends JFrame implements ActionListener{
JButton chooseButton = new JButton("浏览...");
JLabel nameLabel = new JLabel();
JLabel sizelabel = new JLabel("文件大小");
JLabel pathLabel = new JLabel("文件路径");
JLabel uriLabel = new JLabel("URI路径");
JLabel datelabel = new JLabel("最后修改日期");

JTextField sizeField = new JTextField(30);
JTextField pathField = new JTextField(30);
JTextField uriField = new JTextField(30);
JTextField dateField = new JTextField(30);

JCheckBox readCheckBox = new JCheckBox("可读");
JCheckBox writeCheckBox = new JCheckBox("可写");
JCheckBox hideCheckBox = new JCheckBox("隐藏");

JPanel panel = new JPanel();

public MdifyfileAttribute(){
panel.setLayout(new FlowLayout());
panel.add(chooseButton);
panel.add(nameLabel);
panel.add(sizelabel);
panel.add(sizeField);
panel.add(pathLabel);
panel.add(pathField);
panel.add(uriLabel);
panel.add(uriField);
panel.add(datelabel);
panel.add(dateField);
JPanel checkPanel = new JPanel();
checkPanel.add(readCheckBox);
checkPanel.add(writeCheckBox);
checkPanel.add(hideCheckBox);
panel.add(checkPanel);
setContentPane(panel);

chooseButton.addActionListener(new ActionListener(){

@Override
public void actionPerformed(ActionEvent e){
JFileChooser chooser = new JFileChooser();
// 显示文件选择对话框
chooser.showOpenDialog(MdifyfileAttribute.this);
File file = chooser.getSelectedFile();
if(file != null){
nameLabel.setText(file.getName());
sizeField.setText(file.length() + "");
pathField.setText(file.getPath());
uriField.setText(file.toURI() + "");
dateField.setText(new Date(file.lastModified()) + "");
readCheckBox.setSelected(file.canRead());
writeCheckBox.setSelected(file.canWrite());
hideCheckBox.setSelected(file.isHidden());
}
}
});
setSize(400, 400);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

public static void main(String[] args){
new MdifyfileAttribute();
}
}

显示指定类型的文件

运行结果：



代码如下：

package File;

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileFilter;
import java.util.Date;

import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;

public class ListCustomTypeFile extends JFrame implements ActionListener{
JPanel panel = new JPanel();
JButton chooseButton = new JButton("选择文件夹");
JLabel pathLabel = new JLabel();
JLabel textLabel = new JLabel("请输入指定的文件扩展名");
JTextField textField = new JTextField(20);
JTextArea area = new JTextArea(5, 30);
File dir = null;

ListCustomTypeFile(){
panel.setLayout(new FlowLayout());
panel.add(chooseButton);
panel.add(pathLabel);
panel.add(textLabel);
panel.add(textField);
panel.add(area);
setContentPane(panel);
chooseButton.addActionListener(this);

setSize(400, 400);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

@Override
public void actionPerformed(ActionEvent e){
JFileChooser chooser = new JFileChooser();
chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
chooser.showDialog(this, null);
dir = chooser.getSelectedFile();
pathLabel.setText(dir.toString());
listFiles();
}

public void listFiles(){
if(dir == null){
return;
}
// 获取符合条件的文件数组
File[] files = dir.listFiles(new CustomFilter());
String str = "文件名" + "\t\t" + "文件大小" + "\t\t" + "最后修改日期\n";
area.setText(str);
for(File temp : files){
str += temp.getName() + "\t\t" + temp.length() + "\t\t"
+ new Date(temp.lastModified()) + "\n";
area.setText(str);
}
}

public final class CustomFilter implements FileFilter{
@Override
public boolean accept(File pathname){
// 获取用户设定的指定扩展名
String name = textField.getText();
if(name == null || name.isEmpty()){
return false;
}
if(!name.startsWith(".")){
name = "." + name;
}
name = name.toLowerCase();
if(pathname.getName().toLowerCase().endsWith(name)){
return true;
}else{
return false;
}
}
}// end inner class

public static void main(String[] args){
new ListCustomTypeFile();
}
}

下面打算以树结构显示文件目录：

先来个热身吧，先实现下面的图像再说，回忆一下Jtree的用法。其实主要是我对swing不熟悉，哈哈。

代码



代码如下：

package File;

import java.awt.FlowLayout;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTextArea;
import javax.swing.JTree;

public class TreeSimple extends JFrame{
public TreeSimple(){
JPanel panel = new JPanel();
JTextArea area = new JTextArea(5, 30);
JTree tree = new JTree();
JScrollPane js1 = new JScrollPane(tree,
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
panel.setLayout(new FlowLayout());
JScrollPane js = new JScrollPane(area);
JSplitPane jsplit = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, true,
js1, js);
panel.add(jsplit);
setContentPane(panel);
setSize(400, 400);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

public static void main(String[] args){
new TreeSimple();
}
}

下面获取文件文件目录树

运行结果如下：

package File;

import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.File;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreePath;

public class Disktree extends JFrame implements TreeSelectionListener{
DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode();
JTree tree = new JTree(rootNode);
JPanel panel = new JPanel();

public Disktree(){
tree.addTreeSelectionListener(this);
JScrollPane js = new JScrollPane(tree,
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
panel.add(tree);
setContentPane(panel);

addWindowListener(new WindowAdapter(){
@Override
public void windowActivated(WindowEvent e){
File[] files = File.listRoots();
for(File file : files){
DefaultMutableTreeNode node = new DefaultMutableTreeNode(
file);
rootNode.add(node);
}
tree.expandPath(new TreePath(rootNode));
}
});

setSize(500, 500);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

public static void main(String[] args){
new Disktree();
}

@Override
public void valueChanged(TreeSelectionEvent e){
TreePath path = e.getPath();
DefaultMutableTreeNode node = (DefaultMutableTreeNode) path
.getLastPathComponent();

Object userObject = node.getUserObject();
if(!(userObject instanceof File)){
return;
}
File folder = (File) userObject;
if(!folder.isDirectory()){
return;
}
File[] files = folder.listFiles();
for(File file : files){
node.add(new DefaultMutableTreeNode(file));
}

}
}

查找替换文本文件内容

运行结果

package File;

import java.awt.Desktop;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.filechooser.FileNameExtensionFilter;

/**
* 查找替换文本文件的内容
* */
public class ReplaceFileText extends JFrame{
JPanel panel = new JPanel();
JButton chooseButton = new JButton("浏览文件");
JTextField pathField = new JTextField(20);
JLabel searchlabel = new JLabel("搜索文本:");
JTextField searchField = new JTextField(20);
JLabel replaceLabel = new JLabel("替换为:");
JTextField replaceField = new JTextField(20);
JButton replaceButton = new JButton("替换");
JButton openButton = new JButton("打开查看文件");
File file = null; // 保存选择的文件

public ReplaceFileText(){
init();
setSize(400, 400);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

private void init(){
panel.setLayout(new GridLayout(4, 2));
panel.add(chooseButton);
panel.add(pathField);
panel.add(searchlabel);
panel.add(searchField);
panel.add(replaceLabel);
panel.add(replaceField);
panel.add(replaceButton);
panel.add(openButton);
setContentPane(panel);

chooseButton.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e){
chooseButton_event();
}
});
replaceButton.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e){
replaceButton_event();
}
});

openButton.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e){
openButton_event();
}
});

}

/**
* 选择文件按钮事件处理
* */
public void chooseButton_event(){
JFileChooser chooser = new JFileChooser();
// 设置文件扩展名过滤器
chooser.setFileFilter(new FileNameExtensionFilter("文本文件", "txt",
"java", "py", "html"));
// 设置文件选择模式
chooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
// 显示文件选择对话框
int option = chooser.showOpenDialog(this);
// 确定用户按下打开按钮，而不是取消按钮
if(option != JFileChooser.APPROVE_OPTION){
return;
}
// 获取用户选择的文件
file = chooser.getSelectedFile();
// 设置文件路径
pathField.setText(file.getPath());
}

/**
* 替换按钮事件处理
* */
public void replaceButton_event(){
String searchStr = searchField.getText();
String replaceStr = replaceField.getText();
if(searchStr == null || replaceStr == null){
return;
}
try{
FileReader reader = new FileReader(file);
char[] dates = new char[1024];
int count = 0;
StringBuilder sb = new StringBuilder();
while((count = reader.read(dates)) > 0){
String str = String.valueOf(dates, 0, count);
sb.append(str);
}
reader.close();
// 从构造器中生成字符串，并替换搜索文本
String str = sb.toString().replace(searchStr, replaceStr);
FileWriter writer = new FileWriter(file);
writer.write(str.toCharArray());
writer.close();
}catch(Exception e){
e.printStackTrace();
}
JOptionPane.showMessageDialog(null, "替换完成");
}

/**
* 打开文件按钮事件处理
* */
public void openButton_event(){
Desktop desktop = Desktop.getDesktop();
if(desktop.isDesktopSupported()){
try{
desktop.open(file);
}catch(IOException e){
e.printStackTrace();
}
}
}

public static void main(String[] args){
new ReplaceFileText();
}
}