Java Breakpoint Continuation function instance (Java Fetch remote file) _java

Copy Code code as follows:

Import Java.io.BufferedInputStream;
Import Java.io.DataOutputStream;
Import Java.io.File;
Import Java.io.FileOutputStream;

Import java.io.IOException;

Import Java.io.RandomAccessFile;

Import java.net. * ;

/**
* File transfer client: Get remote Files
*/
public class Getremotefile_client_goon {public Getremotefile_client_goon ()
{
}

Private Boolean fileexist (String pathandfile)//Determine if the file has been downloaded but not downloaded
{
File File = new file (pathandfile);
if (File.exists ())
return true;
Else
return false;
}

Private Long FileSize (String pathandfile)//Determine the size of the file that has been downloaded
{
File File = new file (pathandfile);
return File.length ();
}
private void Filerename (String fname,string nname)//Rename the downloaded full file and remove the. TP Name
{
File File = new file (fName);
File.renameto (New File (Nname));
File.delete ();
}
public static void Main (string[] args)
{
URL url = null;
HttpURLConnection URLC = null;
DataOutputStream dos = null;
Bufferedinputstream bis = null;
FileOutputStream fos = null;
String LocalFile = "d:////x.x"; The location of the file and file name, the specific circumstances can be changed
String Localfile_bak = LocalFile + ". TP"; The file PLUS. tp extension was not downloaded to make the difference
Getremotefile_client_goon GCO = new Getremotefile_client_goon ();
Long fileSize = 0;
Long start = System.currenttimemillis ();
int len = 0;
byte [] bt = new byte [1024];
Byte[] Buffer=new byte[50*1024];
Randomaccessfile rafile = null;
Long totalsize = 0; Total size of files to download
Try
{
url = new URL ("Http://www.netbox.cn/download/nbsetup.EXE");
URLC = (httpurlconnection) url.openconnection ();
TotalSize = Long.parselong (Urlc.getheaderfield ("content-length"));
System.out.println ("Download file size is:" + totalsize);
Urlc.disconnect (); Disconnect first, and then connect, or the following will report the error that has been connected
URLC = (httpurlconnection) url.openconnection ();
Determine if a file exists
if (GCO. FileExist (Localfile_bak))//Use breakpoints to continue the transmission, here based on whether the download file is local. TP has file with the same name as the extension
{
SYSTEM.OUT.PRINTLN ("file continued) ... " );
FileSize = Gco. FileSize (Localfile_bak); Get files in small to determine where random writes are
System.out.println ("fileSize:" + fileSize);
Set User-agent
Urlc.setrequestproperty ("User-agent", "Netfox");
Set the starting position of a breakpoint continuation
Urlc.setrequestproperty ("RANGE", "bytes=" + fileSize + "-");
Urlc.setrequestproperty ("RANGE", "bytes=" +filesize); This can not be written, not less this "-".
Setting Up Acceptance information
Urlc.setrequestproperty ("Accept", "image/gif,image/x-xbitmap,application/msword,*/*");
Rafile = new Randomaccessfile (Localfile_bak, "RW"); Random Azimuth Reading
Rafile.seek (fileSize); Position pointer to filesize location
bis = new Bufferedinputstream (Urlc.getinputstream ());
while (len = Bis.read (BT)) > 0)//Loop Get file
{
Rafile.write (BT, 0, Len);
BUFFER=BUFFER+BT;
System.
}
SYSTEM.OUT.PRINTLN ("file continued to receive!" " );
}
else//Use original download
{
FOS = new FileOutputStream (Localfile_bak); Name the file's extension without downloading it. bak
DOS = new DataOutputStream (FOS);
bis = new Bufferedinputstream (Urlc.getinputstream ());
System.out.println ("Receiving files ...") " );
int test = 0;
while (len = Bis.read (BT)) > 0)//Loop Get file
{
Dos.write (BT, 0, Len);
Test + +;
if (test = = 50)//Here is the test, you can delete here, you can download the normal
break;
}
System.out.println ("File received properly!") ");
}
System.out.println ("Shared:" +
(System.currenttimemillis ()-start)/1000);
if (bis!= null)
Bis.close ();
if (Dos!= null)
Dos.close ();
if (FOS!= null)
Fos.close ();
if (rafile!= null)
Rafile.close ();
System.out.println ("Localfile_bak:" + GCO.) FileSize (Localfile_bak));
if (GCO. FileSize (localfile_bak) = = totalsize)//After downloading, rename the file
{
Gco. Filerename (Localfile_bak,localfile);
}
System.exit (0);
}
catch (Exception e)
{
Try
{
if (bis!= null)
Bis.close ();
if (Dos!= null)
Dos.close ();
if (FOS!= null)
Fos.close ();
if (rafile!= null)
Rafile.close ();
}
catch (IOException f)
{
F.printstacktrace ();
}
E.printstacktrace ();
}
System.exit (0);
}
}