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POArrayList Wont Add To JTable
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been searching around but didnt find my solution to my ptoblem , I'm trying to display an ArrayList of Student enrolled in a course, in which I make use of a JTable and display it through a JOptionPane, My problem is, I'm not able to display the ArrayList of Students, here is my code: <pre><code> public static void showStudentsEnrolled(int indx) { for(int x = 0; x<Course.get(indx).getEnrollees().size(); x++){ System.out.println(Course.get(indx).getEnrollees().get(x).toString()); //display enrolled students } ArrayList<Student> enrolled = Course.get(indx).getEnrollees(); StudentsTableModel model = new StudentsTableModel(enrolled); JTable table = new JTable(model); JScrollPane pane = new JScrollPane(table); JPanel panel = new JPanel(new GridLayout()); panel.add(pane); panel.setPreferredSize(new Dimension(600,400)); JOptionPane.showMessageDialog(null,panel, "Students Enrolled", JOptionPane.INFORMATION_MESSAGE); } </code></pre> You see, I have a custom table model that accepts an ArrayList as a parameter and use that as the data, I tried using another list that is present in my class which goes like this: <pre><code> ArrayList<Student> enrolled = Student; // Student is an ArrayList of Student StudentsTableModel model = new StudentsTableModel(enrolled); </code></pre> and it successfully populated the data in the table but when i try to get my real target which is: <pre><code> ArrayList<Student> enrolled = Course.get(indx).getEnrollees(); StudentsTableModel model = new StudentsTableModel(enrolled); </code></pre> the out come is an empty table, What could have caused this problem? Sorry, I have many classes involved here , so it took me some time get the necessary Codes, Here's the runnable code: <pre><code> import javax.swing.*; import javax.swing.table.AbstractTableModel; import javax.swing.table.DefaultTableCellRenderer; import java.io.Serializable; import java.util.*; import java.awt.*; public class Testy { Student stud1 = new Student(2137019,1,"Havard","Jhon",'M',"BSCS"); Student stud2 = new Student(2137019,1,"Havard","Jhon",'M',"BSCS"); Student stud3 = new Student(2137019,1,"Havard","Jhon",'M',"BSCS"); Student stud4 = new Student(2137019,1,"Havard","Jhon",'M',"BSCS"); Student stud5 = new Student(2137019,1,"Havard","Jhon",'M',"BSCS"); Student stud6 = new Student(2137019,1,"Havard","Jhon",'M',"BSCS"); Student stud7 = new Student(2137019,1,"Havard","Jhon",'M',"BSCS"); Course course1 = new Course(9003,"ICS 112","Programming Fundamentals",2,"2:30","4:00","MTH","S521"); Course course2 = new Course(9003,"ICS 112","Programming Fundamentals",2,"2:30","4:00","MTH","S521"); Course course3 = new Course(9003,"ICS 112","Programming Fundamentals",2,"2:30","4:00","MTH","S521"); static ArrayList<Student> student = new ArrayList<Student>(); static ArrayList<Course> course = new ArrayList<Course>(); public Testy(){ student.add(stud1); student.add(stud2); student.add(stud3); student.add(stud4); student.add(stud5); student.add(stud6); student.add(stud7); course.add(course1); course.add(course2); course.add(course3); //Enroll a student for(int x = 0; x < 5; x++){ course.get(0).enroll(student.get(x));} // I want to show the enrolled students in course index 0; showStudentsEnrolled(0); } public static void main (String args[]){ new Testy(); } public static void showStudentsEnrolled(int indx) { ArrayList<Student> enrolled = course.get(indx).getEnrollees(); for(int x = 0; x<enrolled.size(); x++){ System.out.println(enrolled.get(x).toString()); //display enrolled students } StudentsTableModel model = new StudentsTableModel(enrolled); JTable table = new JTable(model); JScrollPane pane = new JScrollPane(table); JPanel panel = new JPanel(new GridLayout()); panel.add(pane); panel.setPreferredSize(new Dimension(600,400)); JOptionPane.showMessageDialog(null,panel, "Students Enrolled", JOptionPane.INFORMATION_MESSAGE); } class Student { private int id ; private int yr ; private String fname; private String gname; private char mname; private String course; private boolean isEnrolled ; private ArrayList<Course> eCourse = new ArrayList<Course>(); public Student(int id,int yr, String f, String g, char m, String c){ this.id = id; this.yr = yr; fname = f; gname = g; mname = m; course = c; isEnrolled = false; } //GET THE ID NUMBER OF A STUDENT public int getId(){ return id; } //GET THE YEAR LEVEL OF A STUDENT public int getYr(){ return yr; } //GET THE FAMILY NAME OF A STUDENT public String getFname(){ return fname; } //GET THE GIVEN NAME OF A STUDENT public String getGname(){ return gname; } //GET THE MIDDILE INITIAL OF A STUDENT public char getMname(){ return mname; } //GET THE COURSE OF A STUDENT public String getCourse(){ return course; } //SET ID NUMBER OF A STUDENT public void setId(int ids){ id = ids; } //SET YEAR LEVEL OF A STUDENT public void setYr(int yrs){ yr = yrs; } //SET THE FAMILY NAME OF A STUDENT public void setFname(String fnames){ fname = fnames; } //SET THE GIVEN NAME OF A STUDENT public void setGname(String gnames){ gname = gnames; } //SET THE MIDDILE INITIAL OF A STUDENT public void setMname(char mnames){ mname = mnames; } //SET THE COURSE OF A STUDENT public void setCourse(String courses){ course = courses; } } class Course implements Serializable { private String startTime; private String endTime; private int units; private int courseCode; private String courseNumber; private String courseDescription; private String room; private String days; private String status; private String schedule; private boolean open ; private ArrayList <Student> enrollees = new ArrayList<Student>(); /**CONSTRUCTOR FOR THE COURSE/* * accepts values to be passed on Course * @param classCode int that will serve as the class code of the class * @param courseNum string subject of the course * @param courseDes string descriptive title of the course * @param unit int units of the course * @param time1 String time in which the course begins * @param time2 String time in which the course dismiss * @param day String days abbreviation in which the course takes place * @param rooms String room in which the course takes place */ public Course(int classCode,String courseNum,String courseDes,int unit,String time1,String time2,String day,String rooms){ courseCode = classCode; courseNumber = courseNum; courseDescription = courseDes; units = unit; startTime =time1; endTime = time2; room = rooms; days = day; schedule = startTime + "-" + endTime + " " + days; open = true; status = "Open"; } public void enroll(Student student) { enrollees.add(student); } //get the students enrolled in the course public ArrayList <Student> getEnrollees(){ return enrollees; } } public static class StudentsTableModel extends AbstractTableModel { boolean DEBUG = false; private String[] columnNames = {"ID Number","Last Name","First Name","Middle Initial","Course","Year"}; private static ArrayList<Student> data ; public StudentsTableModel(ArrayList<Student> students){ data = new ArrayList<Student>(); for(int x = 0; x<students.size(); x++){ //checks if the student is available for enrollment if(students.get(x).isEnrolled() == false){ data.add(students.get(x));} else if(students.get(x).isEnrolled() == true){// Do nothing , don't add to the list } } // save changes fireTableDataChanged(); } public static void setArrayData(ArrayList<Student> student){ data = student; } public static ArrayList<Student> getCurrentArray(){ return data; } public int getColumnCount() { return columnNames.length; } public int getRowCount() { return data.size(); } public String getColumnName(int col) { return columnNames[col]; } // Customize getValueAt method public Object getValueAt(int row, int col) { Object object = null; switch (col){ case 0 : object = data.get(row).getId(); break; case 1 : object = data.get(row).getFname(); break; case 2 : object = data.get(row).getGname(); break; case 3 : object = data.get(row).getMname(); break; case 4 : object = data.get(row).getCourse(); break; case 5 : object = data.get(row).getYr(); break; } return object; } public Class<? extends Object> getColumnClass(int c) { Object a = 1; Object b = "String"; Object e = 'd'; if(c == 0 || c==5) return a.getClass(); else if(c==1 || c==2 || c==4) return b.getClass(); else if(c==3) return e.getClass(); else{ return getValueAt(0,c).getClass(); } } // Make all the fields constant public boolean isCellEditable(int row, int col) { if (col < 5) { return false; } else { return true; } } // Customize setValueAt method public void setValueAt(Object value, int row, int col) { if (DEBUG) { System.out.println("Setting value at " + row + "," + col + " to " + value + " (an instance of " + value.getClass() + ")"); } switch (col){ case 0: data.get(row).setId((Integer)value); break; case 1: data.get(row).setFname((String)value); break; case 2: data.get(row).setGname((String)value); break; case 3: data.get(row).setMname((Character)value); break; case 4: data.get(row).setCourse((String)value); break; case 5: data.get(row).setYr((Integer)value); break; } fireTableCellUpdated(row, col); } } } </code></pre> Still an empty table; Can somebody get it work for me ? it may be a simple problem but I'm so confused to figure out the cause , thanks in advance
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ArrayList Wont Add To JTable
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