Java實現目錄查找與文本閱讀

2019-11-17 04:10:12

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來源：轉載

供稿：網友

1.實現文本閱讀

package AllAboutFile;

/**
*
* @author lucifer
*/

import java.awt.*;
import java.awt.event.*;
import java.io.*;

public class FileViewer extends Frame implements ActionListener{
String directory;
TextArea textarea; //顯示文本內容的地方

     public FileViewer(){
          this(null,null);
     }
     public FileViewer(String filename){
          this(null,filename);
     }
     public FileViewer(String directory,String filename){
          super();
          addWindowListener(
               new WindowAdapter(){
                    public void WindowClosing(WindowEvent e){
                         dispose();
                    }
               }
          );
          //Create TextArea
          textarea = new TextArea("",24,80);
          textarea.setFont(new Font("Monospaced",Font.PLAIN,12));
          textarea.setEditable( false );
          this.add("Center",textarea);
          //Create Panel
          Panel p = new Panel();
          p.setLayout( new FlowLayout(FlowLayout.RIGHT,10,5) );
          this.add(p,"South");
          //Create Button
          Font font = new Font("SansSerif",Font.BOLD,14);
          Button OpenFile = new Button("Open File");
          Button Close = new Button("Close");
          OpenFile.addActionListener(this);
          OpenFile.setActionCommand("open");
          OpenFile.setFont(font);
          Close.addActionListener( this );
          Close.setActionCommand( "close" );
          Close.setFont( font );

p.add( OpenFile );
p.add( Close );

this.pack();

          if(directory == null){
               File f;
               if((filename != null)&&(f = new File(filename)).isAbsolute()){
                    directory = f.getParent();
                    filename = f.getName();
               }
               else
                    directory = System.get          }

          this.directory = directory;
          setFile(directory,filename);
     }

     public void setFile(String directory,String filename){
          if((filename == null)||(filename.length() == 0)){
               return;
          }
          File f = new File(directory,filename);
          try{
               FileReader fr = new FileReader(f);
               char buffer[] = new char[4096];
               int len;
               textarea.setText( "" );
               //show text
               while((len = fr.read(buffer)) != -1){
                    String str = new String(buffer,0,len);
                    textarea.append( str );
               }
               this.setTitle( "FileViewer:" + filename );
               textarea.setCaretPosition( 0 );

               fr.close();
          }
          catch(Exception e){
               textarea.setText( e.getMessage() );
          }
     }

     public void actionPerformed(ActionEvent e){
          String cmd = e.getActionCommand();
          if(cmd.equals( "open" )){
               FileDialog fd = new FileDialog(this,"Select File",FileDialog.LOAD);
               fd.setDirectory( directory );

fd.show();

               directory = fd.getDirectory();
               setFile(directory,fd.getFile());
               fd.dispose();
          }
          else if(cmd.equals( "close" )){
               this.dispose();
          }
     }

     static public void main(String[] args){
          Frame f = new FileViewer((args.length==1)?args[0]:null);
          f.addWindowListener(new WindowAdapter(){
               public void WindowClosed(WindowEvent e){
                    System.exit(0);
               }
            }
          );
          f.show();
     }

}

2.目錄顯示與操作

package AllAboutFile;

/**
*
* @author lucifer
*/

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.text.DateFormat;
public class FileLister extends Frame implements ActionListener,ItemListener{
     private List list;
     private TextField details;
     private Panel buttons;
     private Button up,close;
     private File currentDir;
     private FilenameFilter filter;
     private String[] files;
     private DateFormat dateFormatter =
             DateFormat.getDateTimeInstance(DateFormat.SHORT,DateFormat.SHORT);