java"类文件查看器"不能处理给定的输入

import java.awt.dialog; import java.awt.filedialog; import java.awt.gridlayout; import java.awt.event.actionevent; import java.awt.event.actionlistener; import java.io.bufferedreader; import java.io.file; import java.io.fileinputstream; import java.io.inputstreamreader; import java.io.randomaccessfile;

import javax.sound.midi.shortmessage; import javax.swing.jframe; import javax.swing.jmenu; import javax.swing.jmenubar; import javax.swing.jmenuitem; import javax.swing.joptionpane; import javax.swing.jpanel; import javax.swing.jscrollpane; import javax.swing.jtextarea; import javax.swing.border.titledborder;

public class mycompiler extends jframe implements actionlistener { private static final long serialversionuid = 1l; jpanel p; jtextarea t; jscrollpane s; filedialog fd; jmenubar menubar; jmenu file, edit; jmenuitem file1, file2, file3;

public static void main(string args[]) { mycompiler f = new mycompiler(); f.go(); }

@suppresswarnings( { "deprecation", "deprecation" }) public void go() { // fr=new jframe("mycompiler"); this.settitle("文本文件查看器"); t = new jtextarea(); p = new jpanel(); s = new jscrollpane(t); s.setverticalscrollbarpolicy(jscrollpane.vertical_scrollbar_always); s.sethorizontalscrollbarpolicy(jscrollpane.horizontal_scrollbar_always);

s.setborder(new titledborder("显示区"));

menubar = new jmenubar(); file = new jmenu("文件(f)"); edit = new jmenu("编辑(e)"); file1 = new jmenuitem("打开"); file1.addactionlistener(this); file2 = new jmenuitem("退出"); file2.addactionlistener(this); file3 = new jmenuitem("清空"); file3.addactionlistener(this); file.add(file1); file.add(file2); edit.add(file3); menubar.add(file); menubar.add(edit); p.setlayout(new gridlayout(1, 1));

file3.addactionlistener(new actionlistener(){

public void actionperformed(actionevent e) { // todo auto-generated method stub t.settext(""); }}); setjmenubar(menubar); p.add(s); add(p); setsize(500, 500); setvisible(true); show(); }

@suppresswarnings("deprecation") public void actionperformed(actionevent e) { // byte b[]=new byte[888]; if (e.getactioncommand() == "打开") { fd = new filedialog(this, "打开", filedialog.load); fd.setdirectory("."); fd.show(); file myfile = new file(fd.getdirectory(), fd.getfile()); system.out.println(myfile.getname()); string tmpname = myfile.getname().substring(myfile.getname().lastindexof(".") + 1, myfile.getname().length()); system.out.println(tmpname); if(!tmpname.equals("txt")) { joptionpane.showmessagedialog(null,"文件类型错误","错误",joptionpane.error_message); } else { try { randomaccessfile raf = new randomaccessfile(myfile, "r"); while (raf.getfilepointer() < raf.length()) { t.append(raf.readline().tostring() + "\n"); } } catch (exception ie) { system.out.println(e.tostring()); } } } if (e.getactioncommand() == "退出") { dispose(); system.exit(0); } }

} 还有个编码那个没搞好··你看看先