通过Java Applet实现上传功能调试总结，Jre和linux下FTP开启调试总结。

通过Java Applet实现上传功能调试总结，Jre和linux下FTP开启调试总结。

最近通过做的项目中修改个bug，在jsp页面中潜入applet，通过applet来上传5-10G之间的文件。
修改过程记录如下：
JSP页面中

                <div id="appletTemp">   
                       <applet code = "org/apache/commons/yp/MyApplet.class"  name="test" archive="applet.jar"
                             height="32" width="260" mayscript>
                        <s:text name="image.add.installJdk"></s:text>
                         </applet>
                  </div>   

以下为Java Applet结合commons-net-2.0.jar包实现上传文件的功能代码：

package  org.apache.commons.yp;

import  java.applet.Applet;
import  java.awt.BorderLayout;
import  java.awt.Font;
import  java.awt.HeadlessException;
import  java.awt.event.ActionEvent;
import  java.awt.event.ActionListener;
import  java.io.File;
import  java.io.IOException;
import  javax.swing.JButton;
import  javax.swing.JFileChooser;
import  javax.swing.JTextField;
import  javax.swing.filechooser.FileFilter;
import  netscape.javascript.JSObject;

public   class  MyApplet  extends  Applet  implements  ActionListener {
     public   void  destroy() {
    }

     public  String getAppletInfo() {
         return   " This is my default applet created by Eclipse " ;
    }

     public   void  init() {
    }

     public   void  start() {
    }

     public   void  stop() {
    }

     private   static   final   long  serialVersionUID  =   1L ;

     private  MyApplet jFrame  =   null ;

     private  JButton jFileButton  =   null ;
     private  JButton onClickButton  =   null ;
    JTextField jtf  =   new  JTextField( 10 );
    File fileIn  =   null ;
    FileFtpApplet myFtp  =   new  FileFtpApplet();
     public   int  totalSize  =   0 ;
     public   int  nowSize  =   0 ;
     public  String hostName;
     public  Integer port;
     public  String user;
     public  String password; 
    
     public  String getHostName() {
         return  hostName;
    }

     public   void  setHostName(String hostName) {
         this .hostName  =  hostName;
    }

     public  Integer getPort() {
         return  port;
    }

     public   void  setPort(Integer port) {
         this .port  =  port;
    }

     public  String getUser() {
         return  user;
    }

     public   void  setUser(String user) {
         this .user  =  user;
    }

     public  String getPassword() {
         return  password;
    }

     public   void  setPassword(String password) {
         this .password  =  password;
    }

     public  MyApplet() {
        System.out.println( "  MyApplet start  " );
        jFrame  =   this ;
        jFrame.setSize( 50 ,  10 );
        jFileButton  =   new  JButton( " 浏览 " );
        jFileButton.setFont( new  Font( " system " , Font.PLAIN,  12 ));
        jFileButton.setSize( 2 ,  2 );
        onClickButton  =   new  JButton( " 上传 " );
        onClickButton.setFont( new  Font( " system " , Font.PLAIN,  12 ));
        jFrame.add(jtf, BorderLayout.NORTH);
        jFrame.add(jFileButton);
        jFrame.add(onClickButton);
        jtf.setEditable( true );
        onClickButton.addActionListener((ActionListener)  this );
        jFileButton.addActionListener((ActionListener)  this );
        onClickButton.setSize( 2 ,  20 );
        System.out.println( "  MyApplet end  " );
         this .start();
    }

     public   void  actionPerformed(ActionEvent e) {
        System.out.println( "  actionPerformed(ActionEvent e)   " );
        String comm  =  e.getActionCommand();
         try  {
             if  ( " 浏览 " .equals(comm)) {
                JFileChooser jfChooser  =   new  JFileChooser( "" );
                jfChooser.setDialogTitle( " 打开并上传文件 " );
                jfChooser.setFileFilter( new  FileFilter() {
                    @Override
                     public   boolean  accept(File f) {
                         if  (f.getName().endsWith( " img " )  ||  f.isDirectory())
                             return   true ;
                         return   false ;
                    }

                    @Override
                     public  String getDescription() {
                         return   " 镜像文件(*.img) " ;
                    }
                });
                 int  result  =  jfChooser.showOpenDialog(jFrame);
                 if  (result  ==  JFileChooser.APPROVE_OPTION) {
                    fileIn  =  jfChooser.getSelectedFile();
                    jtf.setText(fileIn.getPath());
                     try  {
                        JSObject.getWindow( this ).eval(
                                 " getinfo( "   +   " \ ""  + fileIn.getName() +  " \ ""
                                         +   " ) " );
                    }  catch  (Exception ea) {
                        ea.printStackTrace();
                    }
                     if  (fileIn  !=   null   &&  fileIn.exists()) {
                         try  {
                             long  l1  =  System.currentTimeMillis();
                            System.out.println(hostName + " ----hostName " );
                            System.out.println(port + " ----port " );
                            System.out.println(user + " -----user " );
                            System.out.println(password + " ---------password " );
                             if  (myFtp.connect(hostName, port, user, password)) {
                                myFtp.setLocal(fileIn.getPath());
                                myFtp.setFileName(fileIn.getName());
                                myFtp.setRemote( " ../../opt/nebula/images " );
                                 long  l2  =  System.currentTimeMillis();
                                System.out.println( " end: "   +  l2);
                                System.out.println( " remaining: "   +  (l2  -  l1));
                            }
                        }  catch  (Exception e1) {
                            System.out.println( " 连接出错  "   +  e1.getMessage());
                        }
                    }
                }
            }  else   if  ( " 上传 " .equals(comm)) {
                 try  {
                    JSObject.getWindow( this ).eval(
                             " javascript:showLoading( "   +   " \ ""  + fileIn.getName()
                                     +   " \ ""  +  " ) " );
                }  catch  (Exception ea) {
                    ea.printStackTrace();
                }
                myFtp.upload(hostName, port, user, password);
                 try  {
                    JSObject.getWindow( this ).eval(
                             " javascript:uploadEnd( "   +   " \ ""  + fileIn.getName()
                                     +   " \ ""  +  " ) " );
                }  catch  (Exception ea) {
                    ea.printStackTrace();
                }
            }
        }  catch  (HeadlessException e1) {
            e1.printStackTrace();
        }  finally  {
             try  {
                myFtp.disconnect();
            }  catch  (IOException e1) {
                e1.printStackTrace();
            }
        }
    }
}

package  org.apache.commons.yp;

import  java.io.File;
import  java.io.FileInputStream;
import  java.io.IOException;
import  java.io.OutputStream;
import  java.io.RandomAccessFile;
import  org.apache.commons.net.ftp.FTPClient;
import  org.apache.commons.net.ftp.FTPFile;
import  org.apache.commons.net.ftp.FTPReply;

/**
 * 
 * Function Description:FTP 鍔熻兘绫伙紝鍚玴ut鍜実et鏂规硶
  */

public   class  FileFtpApplet {
     public   static  FTPClient ftp  =   new  FTPClient();
     public  String remote;
     public  String fileName;
     public  String local;

     public  String getRemote() {
         return  remote;
    }

     public   void  setRemote(String remote) {
         this .remote  =  remote;
    }

     public  String getFileName() {
         return  fileName;
    }

     public   void  setFileName(String fileName) {
         this .fileName  =  fileName;
    }

     public  String getLocal() {
         return  local;
    }

     public   void  setLocal(String local) {
         this .local  =  local;
    }

     public   boolean  upload(String hostname, Integer port, String username,
            String password) {
         try  {
             this .connect(hostname, port, username, password);
        }  catch  (IOException e1) {
            e1.printStackTrace();
        }
        ftp.enterLocalPassiveMode();
         try  {
            ftp.setFileType(FTPClient.BINARY_FILE_TYPE);
        }  catch  (IOException e) {
            e.printStackTrace();
        }
         try  {
            ftp.changeWorkingDirectory( "" );
        }  catch  (IOException e) {
            e.printStackTrace();
        }
         boolean  result;
         try  {
            createDir(remote);
        }  catch  (IOException e) {
            e.printStackTrace();
        }
         boolean  isExists  =   false ;
         long  fileSize  =   0 ;
        FTPFile[] files  =   new  FTPFile[ 10 ];
         try  {
            files  =  ftp.listFiles();
        }  catch  (IOException e) {
            e.printStackTrace();
        }
         for  ( int  i  =   0 ; i  <  files.length; i ++ ) {
            FTPFile file  =  files[i];
             if  (fileName.equals(file.getName())) {
                isExists  =   true ;
                fileSize  =  file.getSize();
                 break ;
            }
        }
         if  (isExists) {
            System.out.println( " fileSize: "   +  fileSize);
            File fLocal  =   new  File(local);
            OutputStream os;
             try  {
                os  =  ftp.appendFileStream(fileName);
                RandomAccessFile randomAccessFileLocal;
                randomAccessFileLocal  =   new  RandomAccessFile(fLocal,  " r " );
                randomAccessFileLocal.seek(fileSize);
                 int  len  =   0 ;
                 byte [] bt  =   new   byte [ 1024 ];
                 while  ((len  =  randomAccessFileLocal.read(bt))  >   0 ) {
                    os.write(bt,  0 , len);
                }
                randomAccessFileLocal.close();
                os.close();
                result  =   true ;
            }  catch  (IOException e) {
                e.printStackTrace();
            }

        }  else  {
             try  {
                File f  =   new  File(local);
                FileInputStream in  =   new  FileInputStream(f);
                result  =  ftp.storeFile(fileName, in);
                in.close();
                 return  result;
            }  catch  (Exception e) {
                e.printStackTrace();
            }
        }
         return   false ;
    }

     /**
     * 寤虹珛FTP杩炴帴
      */
     public   boolean  connect(String hostname,  int  port, String username,
            String password)  throws  IOException {
        ftp.connect(hostname, port);
        ftp.login(username, password);
         if  ( ! FTPReply.isPositiveCompletion(ftp.getReplyCode())) {
            disconnect();
             return   false ;
        }
         return   true ;
    }

     /**
     * 鍏抽棴FTP杩炴帴
      */
     public   void  disconnect()  throws  IOException {
         if  (ftp.isConnected()) {
            ftp.disconnect();
        }
    }

     public   void  createDir(String dir)  throws  IOException {
         if  (dir  !=   null   &&  dir.trim().length()  >   0 ) {
            String[] dirs  =  dir.split( " / " );
            String workingDir  =   "" ;
             for  ( int  i  =   0 ; i  <  dirs.length; i ++ ) {
                 if  ( ! existDirectory(workingDir, dirs[i])) {
                    ftp.makeDirectory(dirs[i]);
                    workingDir  =  dirs[i];
                    ftp.changeWorkingDirectory(dirs[i]);
                }  else  {
                    workingDir  =  dirs[i];
                    ftp.changeWorkingDirectory(dirs[i]);
                }
            }
        }
    }

     public   boolean  existDirectory(String path, String dirName)
             throws  IOException {
         boolean  flag  =   false ;
        FTPFile[] ftpFileArr  =  ftp.listFiles(path);
         for  (FTPFile ftpFile : ftpFileArr) {
             if  (ftpFile.isDirectory()
                     &&  ftpFile.getName().equalsIgnoreCase(dirName)) {
                flag  =   true ;
                 break ;
            }
        }
         return  flag;
    }
}

访问该jsp页面，第一次会提示“请安装jdk” ，那么就按照他所说的，去

http://www.java.com/下载jre进行安装。 （但是我自己服务器上已经有jdk，为什么默认找到里面的jre呢，在研究中。。。）
控制台中打印的信息：

Java Plug-in 1.6.0_26
使用 JRE 版本 1.6.0_26-b03 Java HotSpot(TM) Client VM
用户主目录 = C:\Documents and Settings\server

----------------------------------------------------
c:   清除控制台窗口
f:   终结在结束队列上的对象
g:   垃圾收集
h:   显示此帮助消息
l:   转储类载入程序列表
m:   打印内存使用
o:   触发日志记录
q:   隐藏控制台
r:   重新载入策略配置
s:   转储系统和部署属性
t:   转储线程列表
v:   转储线程堆栈
x:   清除类载入程序高速缓存
0-5: 设置跟踪级别为<n>
----------------------------------------------------

。。。。。。。。。。。。。。。。。。。。。。。。。。

安装完成jre后，报错 ClassNotFoundException找不到应用中的org/apache/commons/yp/MyApplet.class文件.
因为 archive="applet.jar"，默认找的是工程WebRoot下面的See the line -:
applet.jar，所以需要将MyApplet.java打包为applet.jar中并放到WebRoot下。
访问还是报错说找不到org/apache/commons/net/ftp/FTPClient.class类，我工程中的lib下已经存在commons-net-2.0.jar，找的应该是默认在applet.jar中类，
所以我又将

commons-net-2.0.jar

中所有的class文件放到了applet.jar中。在访问不存在找不到类的问题了。

但是又出现了新的问题，说

Caused by: java.security.AccessControlException: access denied (java.io.FilePermission <<ALL FILES>> read)等相关的异常。
解决方案如下:
Edit and append the snippet below, to the end of the policy file (The typical location of your policy file is C:\Program Files\Java\jre1.5.0_16\lib\security\java.policy). If you are running a different JRE (i.e. 1.6), then the folder name 'jre1.5.0_16' will obviously reflect your version of the java runtime environment.

在你自己的jre\lib\security\java.policy文件中增加如下配置。对于文件的访问许可。
grant codeBase "http://*/-" {
    permission java.security.AllPermission;
    permission java.io.FilePermission "<<ALL FILES>>", "read";
    permission java.io.FilePermission "<<ALL FILES>>", "write";
};
经过测试，以上配置可用。

java applet界面如下：

以上问题解决之后,点击浏览，弹出框选择文件，之后点击上传。
查看jre控制台说连接不上ftp 21端口，Connected refused Exception，
那就说明linux的ftp 21端口没有开启。看如下解决方案：

1-ssh以root用户身份登录 登录Linux系统后，

vi /etc/xinetd.d/gssftp

# default: off
# description: The kerberized FTP server accepts FTP connections \
#              that can be authenticated with Kerberos 5.
service ftp
{
        flags           = REUSE
        socket_type     = stream
        wait            = no
        user            = root
        server          = /usr/kerberos/sbin/ftpd
        server_args     = -l  -a
        log_on_failure  += USERID
        disable         = yes
}
将

server_args     = -l  -a 修改为 server_args     = -l

disable         = yes 修改 disable         = no

然后执行

[root@vm-container-16-5 sbin]# service xinetd restart
Stopping xinetd:                                           [  OK  ]
Starting xinetd:                                           [  OK  ]

OK！！！！

2- 执行service xinetd restart如果出现

xinetd: unrecognized service

则可能说明安装操作系统时默认未安装xinetd
通过yum -y install xinetd
[root@vm-container-16-5 sbin]# service xinetd restart
xinetd: unrecognized service
[root@vm-container-16-5 sbin]# yum -y install xinetd
Rocks-5.3                                                                                                                                                                          | 1.1 kB     00:00     
Setting up Install Process
Resolving Dependencies
There are unfinished transactions remaining. You might consider running yum-complete-transaction first to finish them.
The program yum-complete-transaction is found in the yum-utils package.
--> Running transaction check
---> Package xinetd.x86_64 2:2.3.14-10.el5 set to be updated
--> Finished Dependency Resolution

Dependencies Resolved

==========================================================================================================================================================================================================
 Package                                      Arch                                         Version                                                  Repository                                       Size
==========================================================================================================================================================================================================
Installing:
 xinetd                                       x86_64                                       2:2.3.14-10.el5                                          Rocks-5.3                                       125 k

Transaction Summary
==========================================================================================================================================================================================================
Install      1 Package(s)         
Update       0 Package(s)         
Remove       0 Package(s)         

Total download size: 125 k
Downloading Packages:
xinetd-2.3.14-10.el5.x86_64.rpm                                                                                                                                                    | 125 kB     00:00     
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing     : xinetd                                                                                                                                                                             1/1

Installed:
  xinetd.x86_64 2:2.3.14-10.el5                                                                                                                                                                           

Complete!
[root@vm-container-16-5 sbin]# service xinetd restart      
Stopping xinetd:                                           [FAILED]
Starting xinetd:                                           [  OK  ]
[root@vm-container-16-5 sbin]# service xinetd restart
Stopping xinetd:                                           [  OK  ]
Starting xinetd:                                           [  OK  ]

Linux下如果FTP访问不了可以进行如下设置修改：

在终端中执行 vi /etc/selinux/config，将其中的selinux=enforcing的enforcing改为disable。然后保存退出vi，执行setenforce 0 或者重启。就可以上传了。

如果，你不是上述的解决方法的话，有可能是你没有到ftp服务器下的incoming文件夹中，或者你没有把incoming文件夹的权限改为777。

ELinux是「Security-Enhanced Linux」的简称，是 美国国家安全局「NSA＝The National Security Agency」 和SCC（Secure Computing Corporation）开发的 Linux的一个扩张强制访问控制安全模块。原先是在Fluke上开发的，2000年以 GNU GPL 发布。