File Download

CHANGELOG.md

@@ -3,6 +3,7 @@
 - Change Transfer mode (default is binary)
 - Set Remote file name
 - Small performance optimization
+- Download Files
 
 ## 0.1.0
 

lib/src/commands/filedownload.dart

@@ -0,0 +1,75 @@
+import 'dart:io';
+
+import '../ftpexceptions.dart';
+import '../ftpsocket.dart';
+import '../transfermode.dart';
+import '../debug/debuglog.dart';
+import '../util/transferutil.dart';
+
+class FileDownload {
+  final FTPSocket _socket;
+  final TransferMode _mode;
+  final DebugLog _log;
+
+  /// File Download Command
+  FileDownload(this._socket, this._mode, this._log);
+
+  void downloadFile(String sRemoteName, File fLocalFile) {
+    _log.log('Download $sRemoteName to ${fLocalFile.path}');
+
+    // Transfer Mode
+    TransferUtil.setTransferMode(_socket, _mode);
+
+    // Enter passive mode
+    _socket.sendCommand('PASV');
+
+    String sResponse = _socket.readResponse();
+    if (!sResponse.startsWith('227 ')) {
+      throw FTPException('Could not start Passive Mode', sResponse);
+    }
+
+    int iPort = TransferUtil.parsePort(sResponse);
+
+    _socket.sendCommand('RETR $sRemoteName');
+    sResponse = _socket.readResponse(true);
+    if (sResponse.startsWith('550 ')) {
+      throw FTPException('Remote File $sRemoteName does not exist!', sResponse);
+    }
+
+    // Transfer file
+    RandomAccessFile fRAFile = fLocalFile.openSync(mode: FileMode.writeOnly);
+
+    // Data Transfer Socket
+    _log.log('Opening DataSocket to Port $iPort');
+    RawSynchronousSocket dataSocket = RawSynchronousSocket.connectSync(_socket.host, iPort);
+
+    int iToRead = 0;
+    int iRead = 0;
+
+    do {
+      if (iToRead > 0) {
+        List<int> buffer = List<int>(iToRead);
+        dataSocket.readIntoSync(buffer);
+        fRAFile.writeFromSync(buffer);
+        iRead += iToRead;
+      }
+
+      iToRead = dataSocket.available();
+
+      if (iToRead == 0 || iRead == 0) {
+        sleep(Duration(milliseconds: 500));
+        iToRead = dataSocket.available();
+      }
+    } while(iToRead > 0 || iRead == 0);
+
+    _log.log('Downloaded: $iRead B');
+
+    dataSocket.closeSync();
+    fRAFile.flushSync();
+    fRAFile.closeSync();
+
+    _socket.readResponse();
+
+    _log.log('File Downloaded!');
+  }
+}

lib/src/commands/fileupload.dart

@@ -1,11 +1,12 @@
 import 'dart:io';
 
-import 'package:ftpclient/src/debug/debuglog.dart';
 import 'package:path/path.dart';
 
 import '../ftpexceptions.dart';
 import '../ftpsocket.dart';
 import '../transfermode.dart';
+import '../debug/debuglog.dart';
+import '../util/transferutil.dart';
 
 class FileUpload {
   static const int _BUFFER_SIZE = 1024 * 1024;
@@ -21,20 +22,7 @@ class FileUpload {
     _log.log('Upload File: ${fFile.path}');
 
     // Transfer Mode
-    switch(_mode) {
-      case TransferMode.ascii:
-        // Set to ASCII mode
-        _socket.sendCommand('TYPE A');
-        _socket.readResponse();
-        break;
-      case TransferMode.binary:
-        // Set to BINARY mode
-        _socket.sendCommand('TYPE I');
-        _socket.readResponse();
-        break;
-      default:
-        break;
-    }
+    TransferUtil.setTransferMode(_socket, _mode);
 
     // Enter passive mode
     _socket.sendCommand('PASV');
@@ -44,7 +32,7 @@ class FileUpload {
       throw FTPException('Could not start Passive Mode', sResponse);
     }
 
-    int iPort = _parsePort(sResponse);
+    int iPort = TransferUtil.parsePort(sResponse);
 
     // Store File
     String sFilename = sRemoteName;
@@ -61,7 +49,7 @@ class FileUpload {
     RandomAccessFile fRAFile = fFile.openSync(mode: FileMode.read);
     int iRead = 0;
     final int iSize = fRAFile.lengthSync();
-    _log.log('File Size: $iSize');
+    _log.log('File Size: $iSize B');
 
     while (iRead < iSize) {
       int iEnd = _BUFFER_SIZE;
@@ -76,7 +64,7 @@ class FileUpload {
       iRead += iEnd;
     }
 
-    _log.log('Uploaded: $iRead');
+    _log.log('Uploaded: $iRead B');
 
     dataSocket.closeSync();
     fRAFile.closeSync();
@@ -85,18 +73,4 @@ class FileUpload {
 
     _log.log('File Uploaded!');
   }
-
-  /// Parse the Passive Mode Port from the Servers [sResponse]
-  int _parsePort(String sResponse) {
-    int iParOpen = sResponse.indexOf('(');
-    int iParClose = sResponse.indexOf(')');
-
-    String sParameters = sResponse.substring(iParOpen + 1, iParClose);
-    List<String> lstParameters = sParameters.split(',');
-
-    int iPort1 = int.parse(lstParameters[lstParameters.length - 2]);
-    int iPort2 = int.parse(lstParameters[lstParameters.length - 1]);
-
-    return (iPort1 * 256) + iPort2;
-  }
 }

lib/src/ftpclient_base.dart

@@ -1,5 +1,6 @@
 import 'dart:io';
 
+import 'package:ftpclient/src/commands/filedownload.dart';
 import 'package:ftpclient/src/commands/fileupload.dart';
 import 'package:ftpclient/src/debug/debuglog.dart';
 import 'package:ftpclient/src/debug/nooplog.dart';
@@ -50,6 +51,11 @@ class FTPClient {
     FileUpload(_socket, mode, _log).uploadFile(fFile, sRemoteName);
   }
 
+  /// Download the Remote File [sRemoteName] to the local File [fFile]
+  void downloadFile(String sRemoteName, File fFile, {TransferMode mode = TransferMode.binary}) {
+    FileDownload(_socket, mode, _log).downloadFile(sRemoteName, fFile);
+  }
+
   /// Create a new Directory with the Name of [sDirectory] in the current directory
   /// Returns `true` if the directory was created successfully
   /// Returns `false` if the directory could not be created or already exists

lib/src/ftpexceptions.dart

@@ -3,4 +3,9 @@ class FTPException implements Exception {
   final String response;
 
   FTPException(this.message, [this.response]);
+
+  @override
+  String toString() {
+    return 'FTPException: $message (Response: $response)';
+  }
 }

lib/src/ftpsocket.dart

@@ -42,10 +42,11 @@ class FTPSocket {
 
   /// Send a command to the FTP Server
   void sendCommand(String sCommand) {
-    _log.log('> $sCommand');
     if (_socket.available() > 0) {
       readResponse();
     }
+
+    _log.log('> $sCommand');
     _socket.writeFromSync(_codec.encode('$sCommand\r\n'));
   }
 

lib/src/util/transferutil.dart

@@ -0,0 +1,36 @@
+import '../ftpsocket.dart';
+import '../transfermode.dart';
+
+class TransferUtil {
+  /// Set the Transfer mode on [socket] to [mode]
+  static void setTransferMode(FTPSocket socket, TransferMode mode) {
+    switch(mode) {
+      case TransferMode.ascii:
+        // Set to ASCII mode
+        socket.sendCommand('TYPE A');
+        socket.readResponse();
+        break;
+      case TransferMode.binary:
+        // Set to BINARY mode
+        socket.sendCommand('TYPE I');
+        socket.readResponse();
+        break;
+      default:
+        break;
+    }
+  }
+
+  /// Parse the Passive Mode Port from the Servers [sResponse]
+  static int parsePort(String sResponse) {
+    int iParOpen = sResponse.indexOf('(');
+    int iParClose = sResponse.indexOf(')');
+
+    String sParameters = sResponse.substring(iParOpen + 1, iParClose);
+    List<String> lstParameters = sParameters.split(',');
+
+    int iPort1 = int.parse(lstParameters[lstParameters.length - 2]);
+    int iPort2 = int.parse(lstParameters[lstParameters.length - 1]);
+
+    return (iPort1 * 256) + iPort2;
+  }
+}