Java/struts/servlet file Download and ftp file download

1. Front-end Code

Action or servlet using hyperlinks to struts

<a target= "_blank" href= "ftpfileaction!downloadfile.action? transurl=ftp://10.0.2.1/tazi/a.xml "> click Download </a>

2. Background Code Action or servlet

String S1=transurl;//Transurl is a parameter accepted by the foregroundS1=s1.substring (6); S1=s1.substring (S1.indexof ("/")); STRING fn=s1.substring (S1.lastindexof ("/") +1); String filepath=s1.substring (0,s1.lastindexof ("/")); Response.setcharacterencoding ("GBK"); Response.setcontenttype ("Application/octet-stream"); Response.AddHeader ("Content-disposition", "attachment;filename=\" "+ fn+" \ "");//The filename that is defined in the response file header contains the Chinese must be the original ISO-8859-1 encoding. String filename=NewString (Fn.getbytes ("iso-8859-1"), "GBK");//the file name to be used in the program must be converted to GBK encodingBooleanSuc=false; suc=downfilestream ("10.0.2.1", "MyUser", "MyPwd", filepath, filename, OS);//Downfilestream is a way to download FTP files to a file streamif(!suc)    {Response.reset (); Response.setcharacterencoding ("GBK"); PrintWriter writer=Newprintwriter (OS); Writer.write ("The specified file does not exist!"); Writer.close ();}Else{os.close ();}; 

3.ftp File Download processing

Note that the package introduced here is

org.apache.commons.net.ftp.*

(1). Download to Local

ImportOrg.apache.commons.net.ftp.FTP;Importorg.apache.commons.net.ftp.FTPClient;ImportOrg.apache.commons.net.ftp.FTPFile;Importorg.apache.commons.net.ftp.FTPReply; Public Static BooleanDownfile (String URL,//FTP server hostname        intPort//FTP Server PortString username,//FTP login AccountString Password,//FTP Login PasswordString RemotePath,//relative paths on the FTP serverString FileName,//the file name to downloadString LocalPath//save to Local path after download) {    BooleanSuccess =false; FtpClient FTP=Newftpclient (); Try {        intreply;        Ftp.connect (URL, port); //If you use the default port, you can connect directly to the FTP server using Ftp.connect (URL)Ftp.login (username, password);//LoginReply =Ftp.getreplycode (); if(!ftpreply.ispositivecompletion (Reply))            {Ftp.disconnect (); returnsuccess; } ftp.changeworkingdirectory (RemotePath);//Transfer to FTP server directoryftpfile[] fs =Ftp.listfiles (); Booleanftpfileexist=false;  for(Ftpfile ff:fs) {if(Ff.getname (). Equals (FileName)) {ftpfileexist=true; File dir=NewFile (LocalPath); if(!dir.exists ())                {Dir.mkdirs (); } File LocalFile=NewFile (LocalPath + file.separator +ff.getname ()); OutputStream is=NewFileOutputStream (LocalFile,true); Ftp.setbuffersize (1024); if(Ftp.setfiletype (Ftp.binary_file_type)) {Ftp.retrievefile (Ff.getname (), is);                Is.close ();        }}} ftp.logout (); if(ftpfileexist) {Success=true; }    } Catch(IOException e) {e.printstacktrace (); } finally {        if(ftp.isconnected ()) {Try{ftp.disconnect (); } Catch(IOException IoE) {}}} returnsuccess;}

(2). Download to file output stream OutputStream

 Public Static BooleanDownfilestream (String URL,//FTP server hostname        intPort//FTP Server PortString username,//FTP login AccountString Password,//FTP Login PasswordString RemotePath,//relative paths on the FTP serverString FileName,//the file name to downloadoutputstream OS) {    BooleanSuccess =false; FtpClient FTP=Newftpclient (); Try {        intreply;        Ftp.connect (URL, port); //If you use the default port, you can connect directly to the FTP server using Ftp.connect (URL)Ftp.login (username, password);//LoginReply =Ftp.getreplycode (); if(!ftpreply.ispositivecompletion (Reply))            {Ftp.disconnect (); return false; } ftp.changeworkingdirectory (RemotePath);//Transfer to FTP server directoryftpfile[] fs =Ftp.listfiles (); Booleanftpfileexist=false;  for(Ftpfile ff:fs) {String ffname=NewString (Ff.getname (). GetBytes ("Iso-8859-1"), "GBK"); if(Ffname.equals (fileName)) {ftpfileexist=true; Ftp.setbuffersize (1024); if(Ftp.setfiletype (Ftp.binary_file_type)) {Ftp.retrievefile (Ff.getname (), OS);        }}} ftp.logout (); if(ftpfileexist) {Success=true; }    } Catch(IOException e) {e.printstacktrace (); } finally {        if(ftp.isconnected ()) {Try{ftp.disconnect (); } Catch(IOException IoE) {}}} returnsuccess;}

Java/struts/servlet file Download and ftp file download