listfiledemo.java

这是一个简单的图书管理系统,适用于教学中演示,讲解java高级编程语言

package helpfile;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreePath;

//列出目录下的文件

public class ListFileDemo extends JFrame{
	JTextField jtfPath,jtfPath2;	//路径输入文本域
	JTextArea jtfShow;	//显示目录下的内容
JLabel label,label2,label3;
	public ListFileDemo(){
		super("列出目录下的文件");
		Container container=getContentPane();	//得到容器
		container.setLayout(new GridBagLayout());
		label=new JLabel("逻辑盘符");
		label2=new JLabel("文件路径");
		label3=new JLabel("文件名称");
		jtfPath=new JTextField(16);	//实例化路径输入文本框
		jtfPath2=new JTextField(16);	//实例化路径输入文本框
		JButton jbGo=new JButton("转到");	//实例化"转到"按钮
		JButton  jstore=new JButton("存储");
		jtfShow=new JTextArea();	//实例化显示内容文本框
		jtfPath.addActionListener(new ShowDirListener());	//增加事件处理
		jbGo.addActionListener(new ShowDirListener());
		JScrollPane jsp=new JScrollPane(jtfShow);
		jsp.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));	//设置边界
		//JPanel panel=new JPanel();	//实例化面板,用于增加路径输入和按钮
		container.add(label,new GridBagConstraints(0, 0, 1, 1, 0.0, 0.0, 
			      GridBagConstraints.CENTER, GridBagConstraints.BOTH, new Insets(0, 0, 5, 0), 0, 0));
	    container.add(jtfPath , new GridBagConstraints(1, 0, 1, 1, 1.0, 0.0
	            ,GridBagConstraints.WEST, GridBagConstraints.HORIZONTAL, new Insets(5, 5, 0, 5), 0, 0));//增加组件到容器
	    container.add(jbGo,  new GridBagConstraints(5, 0, 1, 1, 0.0, 0.0
	            ,GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(5, 5, 0, 0), 0, 0));
		container.add(label2,new GridBagConstraints(0, 1, 1, 1, 0.0, 0.0
	            ,GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(0, 5, 0, 0), 0, 0));
		container.add(jsp,new GridBagConstraints(1, 1, 6, 3, 20, 20, 
			      GridBagConstraints.CENTER, GridBagConstraints.BOTH, new Insets(0, 0, 5, 0), 0, 0));
		container.add(label3,new GridBagConstraints(0, 6, 1, 1, 0.0, 0.0, 
			      GridBagConstraints.CENTER, GridBagConstraints.BOTH, new Insets(0, 0, 5, 0), 0, 0));
		container.add(jtfPath2,    new GridBagConstraints(1, 6, 3, 1, 0.0, 0.0
	            ,GridBagConstraints.NORTHWEST, GridBagConstraints.HORIZONTAL, new Insets(5, 5, 0, 5), 0, 0));
    	container.add(jstore,new GridBagConstraints(5, 6, 1, 1, 0.0, 0.0
	            ,GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(5, 5, 0, 0), 0, 0));
    	
    	
		setSize(350,300);	//设置窗口尺寸
		setVisible(true);	//设置窗口可视
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);	//关闭窗口时退出程序
	}

	class ShowDirListener implements ActionListener {	//取得目录内容的事件处理
		public void actionPerformed(ActionEvent event) {
			showDirContent(jtfPath.getText());	//调用显示目录内容方法
		}
	}

	public void showDirContent(String path){	//该方法实现取得目录内容
		
      
       
		File file=new File(path);	//用路径实例化一个文件对象
	File[] files=file.listFiles();	//重点:取得目录内所有文件列表
		StringBuffer message=new StringBuffer();	//实例化一个StringBuffer,用于处理显示的字符串
		message.append(path);	//增加信息
		message.append(" 内容如下：\n");
		for (int i=0;i<files.length;i++){
			if (files[i].isDirectory()){	//如果这是一个目录
			
				message.append("<dir>\t");	//增加目录标识
			}
			else{
				message.append("\t");
			}
		message.append(files[i].getName());	//增加文件或目录名
		message.append("\n");
		}
		jtfShow.setText(new String(message));	//显示消息
	}

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