How can i setting the max_allowed_packet' variable?

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Java

MySQL

I have developed a code for store an image as a longblob.. so it will save small jpgs perfectly?
how can i increase the image capacity?
i have heard that i need to increase max_allowed_packet on mysql

private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        
        {
    
    String Pass_No = jTF1.getText();
    Object selectedItem1 = jCB1.getSelectedItem();
    String CntryName1 = selectedItem1.toString();
    Object selectedItem2 = jCB2.getSelectedItem();
    String CntryName2 = selectedItem2.toString();
    Object selectedItem3 = jCB3.getSelectedItem();
    String CntryName3 = selectedItem3.toString();
            java.util.Date sdate = jDC2.getDate();
            String strDate = DateFormat.getDateInstance().format(sdate);
            java.util.Date edate = jDC1.getDate();
            String etrDate = DateFormat.getDateInstance().format(edate);
            String Docs = jTF8.getText();
            
    

    Connection connect = null;
    Statement statement = null;
    PreparedStatement preSt = null;
    ResultSet resultSet = null;
    
        try{
        Class.forName("com.mysql.jdbc.Driver");
        connect=DriverManager.getConnection("jdbc:mysql://localhost:3306/userdb","root","");
        File Imagefile = new File(jTF4.getText());
        File Jpgfile = new File(jTF5.getText());
        preSt=connect.prepareStatement("insert into ppdata values(?,?,?,?,?,?,?,?,?)");
        FileInputStream fin1 = new FileInputStream(Imagefile);
        FileInputStream fin2 = new FileInputStream(Jpgfile);
        
        preSt.setString(1, Pass_No);
        preSt.setString(2, CntryName1);
        preSt.setString(3, CntryName2);
        preSt.setString(4, CntryName3);
        preSt.setString(5, strDate);
        preSt.setString(6, etrDate);
        preSt.setBinaryStream(7,(InputStream)fin1,(int)Imagefile.length());
        preSt.setBinaryStream(8,(InputStream)fin2,(int)Jpgfile.length());
        preSt.setString(9, Docs);
        
        preSt.executeUpdate();
        System.out.println("Successfully inserted the file into the database!");
        preSt.close();
        connect.close();

        }
        catch(Exception e){
            JOptionPane.showMessageDialog(null, e.getMessage());
        }

        }   
    }                     

What I have tried:

i have tried small images? that will store perfectly.
but larger files are not possible?