简单记事本java源码实例

本文实例讲述了简单记事本java实现代码。分享给大家供大家参考。具体如下：

完整代码如下：

import java.awt.*;
import java.io.*;
import java.awt.datatransfer.*;
import java.awt.event.*;
 
public class main extends frame implements actionlistener {
        private static final long serialversionuid = 1l;
textarea textarea = new textarea();
   menubar menubar = new menubar();
   menu filemenu = new menu("file");
   menuitem newitem = new menuitem("new");
   menuitem openitem = new menuitem("open");
   menuitem saveitem = new menuitem("save");
   menuitem saveasitem = new menuitem("save as");
   menuitem exititem = new menuitem("exit");
   menu editmenu = new menu("edit");
   menuitem selectitem = new menuitem("select all");
   menuitem copyitem = new menuitem("copy");
   menuitem cutitem = new menuitem("cut");
   menuitem pasteitem = new menuitem("paste");
   string filename = null;
   toolkit toolkit=toolkit.getdefaulttoolkit();
   clipboard clipboard=toolkit.getsystemclipboard();
   
    private filedialog openfiledialog = new filedialog(this,"open file",filedialog.load);
    private filedialog saveasfiledialog = new filedialog(this,"save file as",filedialog.save);
 
  public main(){
    settitle("记事本程序-by jackbase");
    setfont(new font("times new roman",font.plain,12));
    setbackground(color.white);
    setsize(400,300);
    filemenu.add(newitem);
    filemenu.add(openitem);
    filemenu.addseparator();
    filemenu.add(saveitem);
    filemenu.add(saveasitem);
    filemenu.addseparator();
    filemenu.add(exititem);
    editmenu.add(selectitem);
    editmenu.addseparator();
    editmenu.add(copyitem);
    editmenu.add(cutitem);
    editmenu.add(pasteitem);
    menubar.add(filemenu);
    menubar.add(editmenu);
    setmenubar(menubar);
    add(textarea);
    addwindowlistener(new windowadapter(){
                      public void windowclosing(windowevent e){
                          system.exit(0);
                        }
                      });
    newitem.addactionlistener(this);
    openitem.addactionlistener(this);
    saveitem.addactionlistener(this);
    saveasitem.addactionlistener(this);
    exititem.addactionlistener(this);
    selectitem.addactionlistener(this);
    copyitem.addactionlistener(this);
    cutitem.addactionlistener(this);
    pasteitem.addactionlistener(this);
  }
 
  public void actionperformed(actionevent e) {  //监听事件
    object eventsource = e.getsource();
    if(eventsource == newitem){
      textarea.settext("");
    }else if(eventsource == openitem){
      openfiledialog.show();
      filename = openfiledialog.getdirectory()+openfiledialog.getfile();
      if(filename != null)
        readfile(filename);
    }else if (eventsource == saveitem){
      if(filename != null)
        writefile(filename);
    }else if(eventsource == saveasitem){
      saveasfiledialog.show();
      filename = saveasfiledialog.getdirectory()+saveasfiledialog.getfile();
      if (filename!= null)
        writefile(filename);
    }else if(eventsource == selectitem){
       textarea.selectall();
    }else if(eventsource == copyitem){
       string text=textarea.getselectedtext();
       stringselection selection=new stringselection(text);
       clipboard.setcontents(selection,null);
    }else if(eventsource == cutitem){
       string text=textarea.getselectedtext();
       stringselection selection=new stringselection(text);
       clipboard.setcontents(selection,null);
       textarea.replacerange("",textarea.getselectionstart(),textarea.getselectionend());
    }else if(eventsource == pasteitem){
       transferable contents=clipboard.getcontents(this);
       if(contents==null) return;
       string text;
       text="";
       try{
            text=(string)contents.gettransferdata(dataflavor.stringflavor);
        }catch(exception exception){
        }
       textarea.replacerange(text,textarea.getselectionstart(),textarea.getselectionend());
    }else if(eventsource == exititem){
      system.exit(0);
    }
  }
 
  public void readfile(string filename){ //读取文件处理
    try{
      file file = new file(filename);
      filereader readin = new filereader(file);
      int size = (int)file.length();
      int charsread = 0;
      char[] content = new char[size];
      while(readin.ready())
        charsread += readin.read(content, charsread, size - charsread);
      readin.close();
      textarea.settext(new string(content, 0, charsread));
    }
    catch(ioexception e){
      system.out.println("error opening file");
    }
  }
 
  public void writefile(string filename){  //写入文件处理
    try{
      file file = new file (filename);
      filewriter writeout = new filewriter(file);
      writeout.write(textarea.gettext());
      writeout.close();
    }
    catch(ioexception e){
      system.out.println("error writing file");
    }
  }
 
    @suppresswarnings("deprecation")
        public static void main(string[] args){
      frame frame = new main(); //创建对象
      frame.show();   //是对象显示
   }
}

运行结果如下图所示：

希望本文所述对大家的java程序设计有所帮助。