Android™
Android™
Read Text at a 32-bit Offset from a Remote SFTP File
See more SFTP Examples
Demonstrates the Chilkat SFtp.ReadFileText32 method, which reads up to a number of bytes from a specific 32-bit byte offset of an open handle and decodes them to text. The arguments are the handle, the offset, the maximum number of bytes, and the charset.
Background: Reading from an explicit offset lets you fetch just the part of a file you need — a header, a record at a known position, a slice of a large log — without downloading everything before it. As with offset writes, the offset counts bytes rather than characters, so it must respect the encoded width of any multibyte content.
Chilkat Android™ Downloads
// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;
import android.app.Activity;
import com.chilkatsoft.*;
import android.widget.TextView;
import android.os.Bundle;
public class SimpleActivity extends Activity {
private static final String TAG = "Chilkat";
// Called when the activity is first created.
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
boolean success = false;
// Demonstrates the SFtp.ReadFileText32 method, which reads up to a number of bytes from a
// specific 32-bit byte offset of an open handle and decodes them to text. The 1st argument is
// the handle, the 2nd is the offset, the 3rd is the maximum number of bytes, and the 4th is the
// charset.
CkSFtp sftp = new CkSFtp();
// Connect, authenticate, and initialize the SFTP subsystem.
int port = 22;
success = sftp.Connect("sftp.example.com",port);
if (success == false) {
Log.i(TAG, sftp.lastErrorText());
return;
}
// Normally you would not hard-code the password in source. You should instead obtain it
// from an interactive prompt, environment variable, or a secrets vault.
String password = "mySshPassword";
success = sftp.AuthenticatePw("mySshLogin",password);
if (success == false) {
Log.i(TAG, sftp.lastErrorText());
return;
}
success = sftp.InitializeSftp();
if (success == false) {
Log.i(TAG, sftp.lastErrorText());
return;
}
String handle = sftp.openFile("subdir/record.dat","readOnly","openExisting");
if (sftp.get_LastMethodSuccess() == false) {
Log.i(TAG, sftp.lastErrorText());
return;
}
// Read 5 bytes starting at byte offset 10, without first reading the bytes before it.
int offset = 10;
int numBytes = 5;
String text = sftp.readFileText32(handle,offset,numBytes,"utf-8");
if (sftp.get_LastMethodSuccess() == false) {
Log.i(TAG, sftp.lastErrorText());
return;
}
Log.i(TAG, text);
success = sftp.CloseHandle(handle);
if (success == false) {
Log.i(TAG, sftp.lastErrorText());
return;
}
sftp.Disconnect();
}
static {
System.loadLibrary("chilkat");
// Note: If the incorrect library name is passed to System.loadLibrary,
// then you will see the following error message at application startup:
//"The application <your-application-name> has stopped unexpectedly. Please try again."
}
}