Building on my previous questions. I've managed to make a GUI that queries a SQL database and displays the result in a table. Christ, it's a lot of work for such a simple activity.
The code below works. Does it adhere to MVC conventions? If I understand correctly, MainFrame and CustomTable are the "View" classes. They format and present data in the GUI. Student and its subclasses are the "Model" classes. They hold the data retrieved from the database. Misc is the "Controller" class. It queries the database, instantiates Model class objects to hold the data, then passes the Model data to the View classes. Do I have that right?
Apologies in advance for the null layout and bad error handling. They're two area I haven't studied sufficiently.
There are 4 classes I'm not posting. Student and its three subclasses Undergraduate, Graduate, and PartTime. Each class has properties that correspond to columns in a database table. And each instantiated object should correspond to a row in the table.
MainFrame class:
package kft1task4;
import javax.swing.*;
import java.awt.event.*;
import java.sql.SQLException;
import javax.swing.JScrollPane;
public class MainFrame extends JFrame implements ActionListener {
JPanel pane = new JPanel();
JButton butt = new JButton("Push Me To Update The Table");
CustomTable ct = new CustomTable();
JTable tab = new JTable(ct);
MainFrame() {
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(1000,200,1500,1000);
pane.setLayout(null);
add(pane);
butt.setBounds(20,550,200,100);
butt.addActionListener(this);
pane.add(butt);
JScrollPane jsp = new JScrollPane(tab);
jsp.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);
jsp.setBounds(20,50,1460,500);
pane.add(jsp);
}
@Override
public void actionPerformed(ActionEvent e) {
try{
ct.reQuery();
}
catch (ClassNotFoundException f){System.out.println("Exception");}
catch (InstantiationException f){System.out.println("Exception");}
catch (IllegalAccessException f){System.out.println("Exception");}
catch (SQLException f){System.out.println("Exception");}
}
}
CustomTable class:
package kft1task4;
import javax.swing.table.AbstractTableModel;
import java.util.ArrayList;
import java.sql.SQLException;
public class CustomTable extends AbstractTableModel {
String[] colName = {"Classification", "Student ID", "First Name", "Last Name", "Status", "Mentor", "GPA", "Credit Hours", "Level", "Thesis Titile", "Thesis Advisor", "Company"};
ArrayList<Student> students = new ArrayList<Student>();
public String getColumnName(int col){
return colName[col];
}
public int getColumnCount(){
return colName.length;
}
public int getRowCount(){
return students.size();
}
@Override
public String getValueAt(int row, int col){
int j = 10;
switch (col){
case 0: return students.get(row).getClass().toString().replace("class kft1task4.", "");
case 1: return Integer.toString(students.get(row).studentID);
case 2: return students.get(row).nameFirst;
case 3: return students.get(row).nameLast;
case 4: return students.get(row).status;
case 5: return students.get(row).mentor;
case 6: return Double.toString(students.get(row).gpa);
case 7: return Integer.toString(students.get(row).creditHours);
case 8: if( students.get(row) instanceof Undergraduate){Undergraduate st = (Undergraduate)students.get(row); return st.level;} else {return null;}
case 9: if( students.get(row) instanceof Graduate){Graduate st = (Graduate)students.get(row); return st.thesisTitle;} else {return null;}
case 10: if( students.get(row) instanceof Graduate){Graduate st = (Graduate)students.get(row); return st.thesisAdvisor;} else {return null;}
case 11: if( students.get(row) instanceof PartTime){PartTime st = (PartTime)students.get(row); return st.company;} else {return null;}
default: return "Default";
}
}
public boolean isCellEditable(int col, int row){
return true;
}
@Override
public void setValueAt(Object s, int row, int col){
fireTableDataChanged();
}
public void reQuery() throws ClassNotFoundException, InstantiationException, IllegalAccessException, SQLException{
try{
students.clear();
students = Misc.query();
}
catch (ClassNotFoundException f){System.out.println("Exception");}
catch (InstantiationException f){System.out.println("Exception");}
catch (IllegalAccessException f){System.out.println("Exception");}
catch (SQLException f){System.out.println("Exception");}
fireTableDataChanged();
}
CustomTable() {
//reQuery();
}
}
Misc class:
package kft1task4;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
public class Misc {
Misc(){
}
public static ArrayList<Student> query() throws ClassNotFoundException, InstantiationException, IllegalAccessException, SQLException{
ArrayList<Student> studs = new ArrayList<Student>();
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/kft1task4?" + "user=root&password=");
Statement stmt = conn.createStatement();
String cl = "";
ResultSet rs = stmt.executeQuery("Select * from students");
while(rs.next()){
cl = rs.getString("class");
if(cl.equals("Undergraduate")){
studs.add(new Undergraduate(rs.getString("nameFirst"),rs.getString("nameLast"),rs.getInt("student_id"),rs.getDouble("gpa"),rs.getString("status"),rs.getString("mentor"),rs.getInt("creditHours"),rs.getString("level")));
}
else if(cl.equals("Graduate")){
studs.add(new Graduate(rs.getString("nameFirst"),rs.getString("nameLast"),rs.getInt("student_id"),rs.getDouble("gpa"),rs.getString("status"),rs.getString("mentor"),rs.getInt("creditHours"), rs.getString("thesisTitle"),rs.getString("thesisAdvisor")));
}
else if(cl.equals("PartTime")){
studs.add(new PartTime(rs.getString("nameFirst"),rs.getString("nameLast"),rs.getInt("student_id"),rs.getDouble("gpa"),rs.getString("status"),rs.getString("mentor"),rs.getInt("creditHours"),rs.getString("Company")));
}
}
conn.close();
stmt.close();
rs.close();
return studs;
} //end query method
}
