[Java] Java文本编辑器实现方法详解

• 界面布局 ： editframe
  
• main方法所在： edittext
  
• 打开功能实现：  filereadthread
  
• 保存跟能实现：  save
  

public class editframe extends jframe {
 // todo 自动生成的构造函数存根
 boolean saveflag = false;
 file savefileroot = null;
 jframe jframe;
 jpanel jpanelsouth;
 jmenubar jmenubar1;
 jmenu jmenu1;
 jmenuitem jmenuitem1;
 jmenuitem jmenuitem2;
 jmenuitem jmenuitem3;
 jmenuitem jmenuitem4;
 jseparator jseparator1;
 jtextarea jtextarea;
 jscrollpane scrollpane;// 滚动条
 public editframe() {
 // todo 自动生成的构造函数存根
 jframe = new jframe("水中鱼之1999-文本编辑器");
 jpanelsouth = new jpanel();
 jmenubar1 = new jmenubar();
 jmenu1 = new jmenu("文件");
 jmenuitem1 = new jmenuitem("打开");
 jmenuitem2 = new jmenuitem("保存");
 jmenuitem3 = new jmenuitem("另存为");
 jmenuitem4 = new jmenuitem("退出");
 jseparator1 = new jseparator();
 jtextarea = new jtextarea();
 scrollpane = new jscrollpane(jtextarea);
 jframe.setsize(800, 500);
 jframe.setlocationrelativeto(null);
 jframe.setvisible(false);
 
 setlayout();
 setsouthpanel();
 // set relationship for your component
 setrelationship();
 // 设置 scrollpane for textarea
 setscscrollpane();
 iniclick();
 }
 private void setrelationship() {
 jframe.add(borderlayout.center, scrollpane);
 jframe.add(borderlayout.south, jpanelsouth);
 jmenu1.add(jmenuitem1);
 jmenu1.add(jmenuitem2);
 jmenu1.add(jmenuitem3);
 jmenu1.add(jseparator1);
 jmenu1.add(jmenuitem4);
 jmenubar1.add(jmenu1);
 jframe.setjmenubar(jmenubar1);
 }
 private void setlayout() {
 gridlayout gridlayout = new gridlayout(1, 2);
 jpanelsouth.setlayout(gridlayout);
 }
 private void setscscrollpane() {
// jtextarea.setlinewrap(true);// 设置满一行自动换行
 scrollpane.sethorizontalscrollbarpolicy(jscrollpane.horizontal_scrollbar_as_needed);
 scrollpane.setverticalscrollbarpolicy(jscrollpane.vertical_scrollbar_as_needed);
 }
 private void setsouthpanel() {
 // add time for southpanel
 jlabel jlabeldate = new jlabel("date");
 jlabel jlabeltime = new jlabel("time");
 timer timeaction = new timer(1000, new actionlistener() {
  public void actionperformed(actionevent e) {
  long timemillis = system.currenttimemillis();
  // 转换日期显示格式
  simpledateformat date = new simpledateformat("yyyy 年 mm 月 dd 日 ");
  jlabeldate.settext("  当前日期： " + date.format(new date(timemillis)));
  simpledateformat time = new simpledateformat("hh:mm:ss ");
  jlabeltime.settext("  当前时间： " + time.format(new date(timemillis)));
  }
 });
 jpanelsouth.add(jlabeldate);
 jpanelsouth.add(jlabeltime);
 timeaction.start();
 }
 private void iniclick() {
 jframe.addwindowlistener(new windowlistener() {
  @override
  public void windowopened(windowevent e) {
  // todo auto-generated method stub
  }
  @override
  public void windowiconified(windowevent e) {
  // todo auto-generated method stub
  }
  @override
  public void windowdeiconified(windowevent e) {
  // todo auto-generated method stub
  }
  @override
  public void windowdeactivated(windowevent e) {
  // todo auto-generated method stub
  }
  @override
  public void windowclosing(windowevent e) {
  // todo auto-generated method stub
  int x = joptionpane.showconfirmdialog(null, "确认退出么？", "友情提示", joptionpane.ok_cancel_option,
   joptionpane.warning_message);
  if (x == 0) {
   system.exit(0);
  }
  }
  @override
  public void windowclosed(windowevent e) {
  // todo auto-generated method stub
  }
  @override
  public void windowactivated(windowevent e) {
  // todo auto-generated method stub
  }
 });
 jmenuitem4.addactionlistener(new actionlistener() {
  @override
  public void actionperformed(actionevent e) {
  // todo auto-generated method stub
  int x = joptionpane.showconfirmdialog(null, "确认退出么？", "友情提示", joptionpane.ok_cancel_option,
   joptionpane.warning_message);
  if (x == 0) {
   system.exit(0);
  }
  }
 });
 jmenuitem1.addactionlistener(new actionlistener() {
  @override
  public void actionperformed(actionevent e) {
  // todo auto-generated method stub
  filereadthread filereadthread = new filereadthread(editframe.this);// 开启文件读取线程
  filereadthread.start();
  system.out.println(savefileroot);
  saveflag = true;
  jtextarea.settext("");
  }
 });
 jmenuitem3.addactionlistener(new actionlistener() {
  @override
  public void actionperformed(actionevent e) {
  // todo auto-generated method stub
  save save = new save(editframe.this);
  save.start();
  saveflag = true;
  }
 });
 jmenuitem2.addactionlistener(new actionlistener() {
  @override
  public void actionperformed(actionevent e) {
  // todo auto-generated method stub
  if (!saveflag) {
   save save = new save(editframe.this);
   save.start();
   saveflag = true;
  } else {
   new save(editframe.this, savefileroot);
  }
  }
 });
 }
 public jtextarea getjtextarea() {
 return jtextarea;
 }
 public void setjtextarea(jtextarea jtextarea) {
 this.jtextarea = jtextarea;
 }
 public file getsavefileroot() {
 return savefileroot;
 }
 public void setsavefileroot(file savefileroot) {
 this.savefileroot = savefileroot;
 }
 public jframe getjframe() {
 return jframe;
 }
 public void setjframe(jframe jframe) {
 this.jframe = jframe;
 }
}

public class edittext {
 public static void main(string[] args) {
 new thread() {
  @override
  public void run() {
  // todo auto-generated method stub
  editframe editframe = new editframe();
  
  jframe jframe = new jframe();
  jpanel jpanel = new javax.swing.jpanel(){
  protected void paintcomponent(java.awt.graphics g){
    super.paintcomponent(g);
    g.drawimage(new imageicon("experiment_bac.jpg").getimage(),0,0,400,250,null);
  }
  };
  jframe.add(jpanel);
  jframe.setvisible(true);
  jframe.setsize(400, 300);
  jframe.setlocationrelativeto(null);
  
  try {
   sleep(1500);
  } catch (interruptedexception e) {
   // todo auto-generated catch block
   e.printstacktrace();
  }
  jframe.dispose();
  editframe.getjframe().setvisible(true);
  }
 }.start();
 }
}

class filereadthread extends thread {
 private editframe test;
 public filereadthread(editframe test ) {
 this.test = test;
 }
 @override
 public void run() {
 jfilechooser chooser = new jfilechooser("d:/");
 chooser.setfilefilter(new filefilter() {// 定义文件过滤器,仅显示文件夹和txt文本
  @override
  public string getdescription() {
  return null;
  }
  @override
  public boolean accept(file file) {
  if (file.isdirectory() || file.getname().endswith(".txt"))
   return true;
  return false;
  }
 });
 int option = chooser.showopendialog(test);
 if (option == jfilechooser.approve_option) {
  file selfile = chooser.getselectedfile();
  try {
  bufferedreader reader = new bufferedreader(new inputstreamreader(new fileinputstream(selfile), "gbk"));
  test.setsavefileroot(selfile);
  string line = null;
  while ((line = reader.readline()) != null) {
   test.getjtextarea().append(line + "\n");
   thread.sleep(30);// 线程暂停,以看到读取过程效果
  }
  } catch (exception e1) {
  e1.printstacktrace();
  }
  joptionpane.showmessagedialog(test, "读取完毕");
 }
 }
}

• 如果该文件是打开的 那么保存到打开文件中
  
• 如果该文件还未保存 这调用：进行保存
  
• 如果该文件已经另存为，则直接保存到另存为得的目录下
  

public class save extends thread {
 private editframe area;
 private file savefileroot = null;
 public save(editframe area, file savefileroot) {
 system.out.println(savefileroot + "123");
 string text = area.getjtextarea().gettext();
 string[] lines = text.trim().split("\n");
 try {
  printwriter out = new printwriter(new fileoutputstream(savefileroot), true);
  for (string line : lines)
  out.println(line);
 } catch (filenotfoundexception e) {
  // todo auto-generated catch block
  e.printstacktrace();
 }
 }
 public save(editframe area) {
 this.area = area;
 jfilechooser chooser = new jfilechooser();
 chooser.setcurrentdirectory(new file("."));
 chooser.setfilefilter(new filefilter() {
  @override
  public boolean accept(file f) {
  return f.getname().tolowercase().endswith(".txt");
  }
  @override
  public string getdescription() {
  return "save to";
  }
 });
 int r = chooser.showsavedialog(area);
 if (r != jfilechooser.approve_option)
  return;
 file f = chooser.getselectedfile();
 area.setsavefileroot(f);
 string text = area.getjtextarea().gettext();
 string[] lines = text.trim().split("\n");
 try {
  printwriter out = new printwriter(new fileoutputstream(f), true);
  for (string line : lines)
  out.println(line);
 } catch (filenotfoundexception e) {
  // todo auto-generated catch block
  e.printstacktrace();
 }
 }
 public file getsavefileroot() {
 return savefileroot;
 }
 public void setsavefileroot(file savefileroot) {
 this.savefileroot = savefileroot;
 }
}