In the program.cs the user is asked if he wanna read the data, if he types y then the method Doc.ReadDoc starts is there any proper way:
class Program
{
static void Main(string[] args)
{
do
{
var path = "C:\\Users\\ks\\Desktop\\C#";
string fileName = path + #"\TestFile.txt";
Console.WriteLine("Do you want to read it? y/n");
string yesorno = Console.ReadLine();
if (yesorno=="y")
{
Console.Clear();
Doc.ReadDoc();
}
Console.WriteLine("Which type of vehicle");
string type = Console.ReadLine();
Console.WriteLine("how many tires");
int raeder = Convert.ToInt32( Console.ReadLine());
var Vehicle = new Used_Cars(type, raeder);
Doc.Write(Vehicle);
} while (true);
}
}
The Class with the methods (Read, Write):
public static List<string> ReadDoc()
{
var list = new List<string>();
var pfad = "C:\\Users\\ks\\Desktop\\C#";
string fileName = path+ #"\TestFile.txt";
try
{
using (StreamReader sr = new StreamReader(fileName))
{
Console.WriteLine("Data found");
string line;
Console.WriteLine(sr.ReadToEnd());
}
}
catch (Exception e)
{
// Let the user know what went wrong.
Console.WriteLine("Data not found");
Console.WriteLine(e.Message);
list = null;
}
return list;
}
And the last Method is the Write method, is this a good code to save properties in a file? How could i stop the program with ESC or smth like that, so if the user presses ESC it should stop.
public static void Write(Used_Cars vehicle)
{
var pfad = "C:\\Users\\ks\\Desktop\\C#";
string fileName = path+ #"\TestFile.txt";
Console.WriteLine("Is it correct?");
Console.WriteLine("y/n");
string yeahorno= Console.ReadLine();
if (jaodernein == "y")
{
try
{
using (StreamWriter writer = new StreamWriter(fileName))
{
writer.WriteLine(vehicle.Vehicle);
writer.WriteLine(vehicle.Wheels);
Console.WriteLine();
}
}
catch (Exception exp)
{
Console.Write(exp.Message);
}
}
}
Hi I am trying to create a method to be used in the TextArea setText method for javafx.
I am trying to get a method that does this:
public static void setTextArea(String fileName) {
String line;
try {
FileReader fileReader = new FileReader(fileName);
BufferedReader buffer = new BufferedReader(fileReader);
while ((line = buffer.readLine()) != null) {
out.println(line);
}
buffer.close();
} catch //etc etc
but I can't use it in the setText method because it is a void method.
Can anyone help translate this method so it could work in the TextArea setText method?
-Thanks!
You just pring out the lines to System.out I guess. You have to add up the content of the text file by doing something like this
public static void setTextArea(String fileName) {
String line;
String content;
try {
FileReader fileReader = new FileReader(fileName);
BufferedReader buffer = new BufferedReader(fileReader);
while ((line = buffer.readLine()) != null) {
out.println(line);
content += line;
}
buffer.close();
} catch //etc etc
Then you can either return content or call setText(content) from the TextArea class. If it's a big file, then using StringBuilder would probably be a better idea instead of concatenating each line.
You will have to get the data from the file and and set the data to textArea..
TextArea txtArea = new TextArea();
String data = getDataForTextArea(String fileLocation);
txtArea.setText(data);
public String getDataForTextArea(String fileLocation) {
InputStream inputStream = new FileInputStream(fileLocation);
if (inputStream != null) {
int b;
String txtData = "";
try {
while ((b = inputStream.read()) != -1) {
txtData += (char) b;
}
} catch (IOException e) {
e.printStackTrace();
} finally {
inputStream.close();
}
return txtData;
}
Make sure to check for nullpointerException.
How to save a file using FileChooser from JavaFX,
here's my sample:
public static void clickDownloadButton(String filename,Stage window){
File file = new File(filename);
FileChooser fileChooser = new FileChooser();
fileChooser.setTitle("Save file");
fileChooser.showSaveDialog(window);
}
Use java.nio.file.Files -
File dest = fileChooser.showSaveDialog(window);
if (dest != null) {
try {
Files.copy(file.toPath(), dest.toPath());
} catch (IOException ex) {
// handle exception...
}
}
I have a pre-initialized realm. I am going to copy into where it should be on device using snip of code below.
//import from assets
public static RealmConfiguration importDatabase(Context context, String realm_file_name){
RealmConfiguration defaultRealm = new RealmConfiguration.Builder(context).build();
String dir = defaultRealm.getPath();
AssetManager assetManager = context.getAssets();
try {
InputStream is;
is = assetManager.open(realm_file_name);
File dest = new File(dir);
if (dest.exists())
dest.delete();
copy(is,dest);
}catch (IOException e){
Log.e(LOG_TAG,"import database error");
}
return defaultRealm;
}
public static void copy(File src, File dst) throws IOException {
InputStream in = new FileInputStream(src);
OutputStream out = new FileOutputStream(dst);
// Transfer bytes from in to out
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
in.close();
out.close();
}
public static void copy(InputStream in, File dst) throws IOException {
OutputStream out = new FileOutputStream(dst);
// Transfer bytes from in to out
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
in.close();
out.close();
}
So it will overwrite old realm file them write new realm file in same place.
Is it right ways to import database.
If not, how can I make it better ?
To accomplish:
Upload a file from my local to server using an applet and servlet using apache fileupload jar.
Tried:
I have used a simple jsp, with a browse button and posted the action to my servlet (where I used apache fileupload). I was successful in uploading the file to the server.
Issue:
I am trying to upload a file, from my local machine, using an applet. I do not want to manually select files, instead upload files that are present in a specific folder. For now I have hardcoded the folder. I am able to look at the folder and get the list of files I want to upload.
Also, I have successfully established a connection from my applet to servlet.
Issue arises at the upload.parseRequest(request) in the servlet. I'm thinking its because the applet cannot post to servlet's request object.
Also, I have set the request type to multipart/form-data in my applet.
Right now, I am trying to pass the absolute path of the file to servlet and upload.
I have seen other posts where byte stream data is passed from applet to servlet, but the servlet uses the traditional File.write.
For me, it is mandatory to achieve this using apache fileupload.
Please suggest on how to pass a file/file path from applet to servlet, where the upload is handled by apache fileupload.
Below are my FileUploadHandler (where the HTTP requests are handled) and FileUpload(which is my applet)
Below is my FileUpload Handler:
#WebServlet(name = "FileUploadHandler", urlPatterns = { "/upload" })
#MultipartConfig
public class FileUploadHandler extends HttpServlet {
String uploadFolder ="";
#Override
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
System.out.println("doPost-servlet URL is: "
+ request.getRequestURL());
try {
uploadFolder = fileToUpload(request);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
uploadFolder = getServletContext().getRealPath("")+ File.separator;
// Create a factory for disk-based file items
DiskFileItemFactory factory = new DiskFileItemFactory();
// Create a new file upload handler
ServletFileUpload upload = new ServletFileUpload(factory);
// process only if its multipart content
if (ServletFileUpload.isMultipartContent(request)) {
System.out.println("Yes, it is a multipart request...");
try {
List<FileItem> multiparts = upload.parseRequest(request);
System.out.println("Upload.parseRequest success !");
for (FileItem item : multiparts) {
if (!item.isFormField()) {
String name = new File(item.getName()).getName();
item.write(new File(uploadFolder + File.separator
+ name));
}
}
System.out.println("File uploaded to server !");
// File uploaded successfully
request.setAttribute("message", "File Uploaded Successfully");
} catch (Exception ex) {
request.setAttribute("message", "File Upload Failed due to "
+ ex);
}
} if(!ServletFileUpload.isMultipartContent(request)){
throw new ServletException("Content type is not multipart/form-data");
}
doGet(request, response);
//request.getRequestDispatcher("/result.jsp").forward(request, response);
OutputStream outputStream = response.getOutputStream();
ObjectOutputStream objectOutputStream = new ObjectOutputStream(outputStream);
objectOutputStream.writeObject("Success !");
objectOutputStream.flush();
objectOutputStream.close();
}
private String fileToUpload(HttpServletRequest request) throws IOException,
ClassNotFoundException {
ServletInputStream servletIn = request.getInputStream();
ObjectInputStream in = new ObjectInputStream(servletIn);
String uploadFile = (String) in.readObject();
System.out.println("Value in uploadFolder is: " + uploadFile);
return uploadFile;
}
Below is the fileupload applet:
public class FileUpload extends Applet {
private JButton capture;
private JTextField textField;
private final String pathDirectory = "C:\\";
private final String captureConfirmMessage = "Are you sure you want to continue?";
private final String confirmDialogTitle = "Confirm upload";
final File folder = new File(pathDirectory);
public void init() {
upload= new JButton("Upload");
textField = new JTextField();
capture.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
int selection = JOptionPane.showConfirmDialog(upload,
uploadConfirmMessage, confirmDialogTitle,
JOptionPane.YES_NO_OPTION);
if (selection == JOptionPane.OK_OPTION) {
listFilesForFolder(folder);
} else if (selection == JOptionPane.CANCEL_OPTION) {
JOptionPane.showMessageDialog(upload,
"You have aborted upload", "Upload Cancelled", 2);
}
}
});
add(upload);
add(textField);
}
public void listFilesForFolder(final File folder) {
for (final File fileEntry : folder.listFiles()) {
if (fileEntry.isDirectory()) {
listFilesForFolder(fileEntry);
} else {
try {
onSendData(fileEntry.getAbsolutePath());
System.out.println(fileEntry.getAbsolutePath());
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
private URLConnection getServletConnection() throws MalformedURLException,
IOException {
// Open the servlet connection
URL urlServlet = new URL("http://localhost:8081/UploadFile/upload");
HttpURLConnection servletConnection = (HttpURLConnection) urlServlet
.openConnection();
// Config
servletConnection.setDoInput(true);
servletConnection.setDoOutput(true);
servletConnection.setUseCaches(false);
servletConnection.setDefaultUseCaches(false);
servletConnection.setRequestProperty("Content-Type", "multipart/form-data;");
servletConnection.connect();
return servletConnection;
}
private void onSendData(String fileEntry) {
try {
// Send data to the servlet
HttpURLConnection servletConnection = (HttpURLConnection) getServletConnection();
OutputStream outstream = servletConnection.getOutputStream();
ObjectOutputStream objectOutputStream= new ObjectOutputStream(
outstream);
objectOutputStream.writeObject(fileEntry);
// Receive result from servlet
InputStream inputStream = servletconnection.getInputStream();
ObjectInputStream objectInputStream = new ObjectInputStream(
inputStream);
String result = (String) objectInputStream.readObject();
objectInputStream.close();
inputStream.close();
out.flush();
out.close();
// Display result on the applet
textField.setText(result);
} catch (java.net.MalformedURLException mue) {
mue.printStackTrace();
textField.setText("Invalid serlvetUrl, error: " + mue.getMessage());
} catch (java.io.IOException ioe) {
ioe.printStackTrace();
textField.setText("Couldn't open a URLConnection, error: "
+ ioe.getMessage());
} catch (Exception e) {
e.printStackTrace();
textField.setText("Exception caught, error: " + e.getMessage());
}
}
public void paint(Graphics g) {
g.drawString("Click the button above to capture", 5, 50);
}
I could finally succeed posting the request to the servlet from the applet.
It was a simple logic that I was missing. I did not add the header and trailer while posting to the servlet, which was the key, in the servlet to identify the incoming request as a multipart data.
FileInputStream fileInputStream = new FileInputStream(new File(
fileEntry));
dataOutputStream.writeBytes(twoHyphens + boundary + lineEnd);
dataOutputStream
.writeBytes("Content-Disposition: form-data; name=\"upload\";"
+ " filename=\"" + fileEntry + "\"" + lineEnd);
dataOutputStream.writeBytes(lineEnd);
// create a buffer of maximum size
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
buffer = new byte[bufferSize];
// read file and write it into form
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
while (bytesRead > 0) {
dataOutputStream.write(buffer, 0, bufferSize);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
System.out.println(fileEntry + " uploaded.");
}
// send multipart form data necesssary after file data
dataOutputStream.writeBytes(lineEnd);
dataOutputStream.writeBytes(twoHyphens + boundary + twoHyphens
+ lineEnd);
I added the header and trailer and also used this to create the URL connection.
private URLConnection getServletConnection() throws MalformedURLException,
IOException {
// Open the servlet connection
URL urlServlet = new URL("http://localhost:8083/UploadFile/upload");
HttpURLConnection servletConnection = (HttpURLConnection) urlServlet
.openConnection();
// Config
servletConnection.setDoInput(true);
servletConnection.setDoOutput(true);
servletConnection.setUseCaches(false);
servletConnection.setDefaultUseCaches(false);
servletConnection.setRequestMethod("POST");
servletConnection.setRequestProperty("Content-Type",
"multipart/form-data;boundary=" + this.boundary);
servletConnection.setRequestProperty("Connection", "Keep-Alive");
servletConnection.connect();
return servletConnection;
}
Then, in the servlet, I was just reading the data using upload.ParseRequest(request).
Thank you for the help.