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 . * ;
public class GetRemoteFile_Client_GoOn { public GetRemoteFile_Client_GoOn()
{
}
private boolean FileExist(String pathAndFile) //Determine if the file has been downloaded, but not completed
{
File file = new File(pathAndFile);
if (file.exists())
return true ;
else
return false ;
}
private long FileSize(String pathAndFile) //Determine the size of the downloaded file
{
File file = new File(pathAndFile);
return file.length();
}
private void FileRename(String fName,String nName) //Change the name of the downloaded 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 " ; // File saved in place and file name, specific circumstances can be changed
String localFile_bak = localFile + " .tp " ; //Do not download the file plus. Tp extension, in order to distinguish
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 file size 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 connect later, otherwise an error will be reported
urlc = (HttpURLConnection) url.openConnection();
//Determines if the file exists
if (gco.FileExist(localFile_bak)) //With breakpoint continuation, the basis here is to see whether the download file locally. Tp has an extension with the same name file
{
System.out.println( " File transfer... " );
fileSize = gco.FileSize(localFile_bak); //Get the file in small in order to determine the random write location
System.out.println( " fileSize: " + fileSize);
//Set the user-agent
// urlc.setRequestProperty("User-Agent","NetFox");
//Sets the starting position of the breakpoint continuation
urlc.setRequestProperty( " RANGE " , " bytes= " + fileSize + " - " );
// urlc.setRequestProperty("RANGE", "bytes="+fileSize); // I can't write it like this. I can't write it without this "-".
//Set accept message
urlc.setRequestProperty( " Accept " , " image/gif,image/x-xbitmap,application/msword,*/* " );
raFile = new RandomAccessFile(localFile_bak, " rw " ); //Random azimuth reading
raFile.seek(fileSize); //Locate the pointer to the fileSize position
bis = new BufferedInputStream(urlc.getInputStream());
while ((len = bis.read(bt)) > 0 ) //Loop fetch file
{
raFile.write(bt, 0 , len);
// buffer=buffer+bt;
// System.
}
System.out.println( " File continuation received! " );
}
else //Use original download
{
fos = new FileOutputStream(localFile_bak); //Name the file extension.bak without downloading it
dos = new DataOutputStream(fos);
bis = new BufferedInputStream(urlc.getInputStream());
System.out.println( " Receiving files... " );
int test = 0 ;
while ((len = bis.read(bt)) > 0 ) //Loop fetch 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 as normal!" );
}
System.out.println( " Share: " +
(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 );
}
}