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java.lang.Objectorg.apache.commons.net.ftp.FTPListParseEngine
public class FTPListParseEngine
This class handles the entire process of parsing a listing of file entries from the server.
This object defines a two-part parsing mechanism.
 The first part is comprised of reading the raw input into an internal
 list of strings.  Every item in this list corresponds to an actual
 file.  All extraneous matter emitted by the server will have been
 removed by the end of this phase.  This is accomplished in conjunction
 with the FTPFileEntryParser associated with this engine, by calling
 its methods readNextEntry() - which handles the issue of
 what delimits one entry from another, usually but not always a line
 feed and preParse() - which handles removal of
 extraneous matter such as the preliminary lines of a listing, removal
 of duplicates on versioning systems, etc.
 
 The second part is composed of the actual parsing, again in conjunction
 with the particular parser used by this engine.  This is controlled
 by an iterator over the internal list of strings.  This may be done
 either in block mode, by calling the getNext() and
 getPrevious() methods to provide "paged" output of less
 than the whole list at one time, or by calling the
 getFiles() method to return the entire list.
 
Examples:
Paged access:
    FTPClient f=FTPClient();
    f.connect(server);
    f.login(username, password);
    FTPListParseEngine engine = f.initiateListParsing(directory);
    while (engine.hasNext()) {
       FTPFile[] files = engine.getNext(25);  // "page size" you want
       //do whatever you want with these files, display them, etc.
       //expensive FTPFile objects not created until needed.
    }
 
 For unpaged access, simply use FTPClient.listFiles(). That method uses this class transparently.
| Constructor Summary | |
|---|---|
| FTPListParseEngine(FTPFileEntryParser parser) | |
| Method Summary | |
|---|---|
|  FTPFile[] | getFiles()Returns an array of FTPFile objects containing the whole list of files returned by the server as read by this object's parser. | 
|  FTPFile[] | getNext(int quantityRequested)Returns an array of at most quantityRequestedFTPFile
 objects starting at this object's internal iterator's current position. | 
|  FTPFile[] | getPrevious(int quantityRequested)Returns an array of at most quantityRequestedFTPFile
 objects starting at this object's internal iterator's current position,
 and working back toward the beginning. | 
|  boolean | hasNext()convenience method to allow clients to know whether this object's internal iterator's current position is at the end of the list. | 
|  boolean | hasPrevious()convenience method to allow clients to know whether this object's internal iterator's current position is at the beginning of the list. | 
|  void | readServerList(InputStream stream)Deprecated. The version of this method which takes an encoding should be used. | 
|  void | readServerList(InputStream stream,
                             String encoding)handle the iniitial reading and preparsing of the list returned by the server. | 
|  void | resetIterator()resets this object's internal iterator to the beginning of the list. | 
| Methods inherited from class java.lang.Object | 
|---|
| clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait | 
| Constructor Detail | 
|---|
public FTPListParseEngine(FTPFileEntryParser parser)
| Method Detail | 
|---|
public void readServerList(InputStream stream,
                           String encoding)
                    throws IOException
stream - input stream provided by the server socket.
IOException - thrown on any failure to read from the sever.
public void readServerList(InputStream stream)
                    throws IOException
stream - input stream provided by the server socket.
IOException - thrown on any failure to read from the sever.public FTPFile[] getNext(int quantityRequested)
quantityRequested FTPFile
 objects starting at this object's internal iterator's current position.
 If fewer than quantityRequested such
 elements are available, the returned array will have a length equal
 to the number of entries at and after after the current position.
 If no such entries are found, this array will have a length of 0.
 After this method is called this object's internal iterator is advanced
 by a number of positions equal to the size of the array returned.
quantityRequested - the maximum number of entries we want to get.
quantityRequested FTPFile
 objects starting at the current position of this iterator within its
 list and at least the number of elements which  exist in the list at
 and after its current position.
 NOTE: This array may contain null members if any of the individual file listings failed to parse. The caller should check each entry for null before referencing it.
public FTPFile[] getPrevious(int quantityRequested)
quantityRequested FTPFile
 objects starting at this object's internal iterator's current position,
 and working back toward the beginning.
 If fewer than quantityRequested such
 elements are available, the returned array will have a length equal
 to the number of entries at and after after the current position.
 If no such entries are found, this array will have a length of 0.
 After this method is called this object's internal iterator is moved
 back by a number of positions equal to the size of the array returned.
quantityRequested - the maximum number of entries we want to get.
quantityRequested FTPFile
 objects starting at the current position of this iterator within its
 list and at least the number of elements which  exist in the list at
 and after its current position.  This array will be in the same order
 as the underlying list (not reversed).
 NOTE: This array may contain null members if any of the individual file listings failed to parse. The caller should check each entry for null before referencing it.
public FTPFile[] getFiles()
                   throws IOException
NOTE: This array may contain null members if any of the individual file listings failed to parse. The caller should check each entry for null before referencing it.
IOExceptionpublic boolean hasNext()
public boolean hasPrevious()
public void resetIterator()
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