Thread: java

good evening I have not received the videos in my mailbox, aufaite I have a serious problem in java that I can not solve for a week:
I create a JFrame in which I save data including choosing a PDF file that will be saved in the mysql database then retrieve the same PDF and display it in a Panel with scrollable. Please help me please

Originally Posted by Norm

If you have a java program you are having problems with, post the code (wrapped in code tags) so we can see it.

this is my CODE:

public void insertFile() {

filename = LabelNomFichier.getText();
InputStream stream = new ByteArrayInputStream(filename.getBytes(StandardCha rsets.UTF_8));
nom = txtNom.getText();

try {

String querySetLimit = "SET GLOBAL max_allowed_packet=904857600;"; // 10 MB
Statement stSetLimit = cnx.createStatement();
stSetLimit.execute(querySetLimit);

String sql = "INSERT INTO person (first_name, photo) values (?, ?)";
PreparedStatement statement = cnx.prepareStatement(sql);
statement.setString(1, nom);
statement.setBlob(2, stream);
int row = statement.executeUpdate();
if (row > 0) {
System.out.println("A contact was inserted with photo image.");

}
// cnx.close();
stream.close();
} catch (SQLException ex) {
ex.printStackTrace();
} catch (IOException ex) {
ex.printStackTrace();
}
}

private void getPDF() throws SQLException {
String SQL = "SELECT DISTINCT photo FROM person WHERE person_id='" + Classe.idPersonn + "'";
try {
PreparedStatement ps = cnx.prepareStatement(SQL);
ResultSet rs = ps.executeQuery();
System.out.println("Following flies are downloaded from database..");
while (rs.next()) {
int fileId = rs.getInt("person_id");
JOptionPane.showMessageDialog(this, Classe.idPersonn);
// Blob fileName;
// fileName = rs.getBlob("photo");
// long fileSizeInKb = rs.getLong("file_size_in_kb");
// String fileExtension = rs.getString("file_extension");
// System.out.println("File Id:" + fileId);
// System.out.println("File Name:" + fileName);
// System.out.println("File Size In KB:" + fileSizeInKb);
// System.out.println("File Extension:" + fileExtension);

Blob blob = rs.getBlob("photo");
InputStream inputStream = blob.getBinaryStream();
JOptionPane.showMessageDialog(this,Classe.idPerson n);

// ----
// InputStream stream = new ByteArrayInputStream(blob.getBytes(StandardCharset s.UTF_8));
// ----
readFile((File) blob);
System.out.println("--------------- AAAAAAA --------------------");
Files.copy(inputStream, Paths.get(LabelPDF.getText() + fileId));
}
} catch (IOException e) {
e.printStackTrace();
}
}

public String readFile(File file) {
StringBuffer fileBuffer = null;
String fileString = null;
String line = null;

try {
// String SQL = "SELECT DISTINCT photo FROM person WHERE person_id='" + Classe.idPersonn + "'";
// PreparedStatement ps = cnx.prepareStatement(SQL);
// ResultSet rs = ps.executeQuery();
System.out.println("Affichage du PDF..");

FileReader in = new FileReader(file);
BufferedReader brd= new BufferedReader(in);
fileBuffer=new StringBuffer();
while ((line = brd.readLine()) !=null ) {
fileBuffer.append(line).append(System.getProperty( "line.separator"));
}
in.close();
fileString =fileBuffer.toString();
} catch (IOException e) {
return null;
}
return fileString;
}

}

One pitfall you're going to run into is the use of BufferedReader. That class is no good for reading binary files (such as PDF), it's only good for reading plain ASCII text files. So you'll want to use FileInputStream instead and read the bytes into a buffer array instead of reading line-by-line.

As for displaying the PDF contents in a JPanel, Java doesn't have a built-in way of doing that. You'll probably want to look around for the right library for your purposes:

https://stackoverflow.com/questions/...xisting-jpanel