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POautorefreshing jtable extracting collection data
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  1. POautorefreshing jtable extracting collection data
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    copied!<p>I am a begginer with java programming.</p> <p>I am trying to make a JTable that reads collection set hashSet, and refreshes eachtime set is changed, also want to make autorefresh every 3 sec repaint on JPanel where table will be on (which works in original program). Also Class Mats changes Boolean take over time, i want to change color its writhing Mats.name in JTable depending on the value Mats.take in that mat in set which is the reason for autorefresh.</p> <p>This is a sample for table its remakeing table from scrach with each time new line is added throws java.lang.NullPointerException. I simply do not see why? Thx for the help in advance</p> <pre><code>public class Table extends JFrame { private static JTable table; private static JButton addbuttin; private static TableModel model; private static Set&lt;Mats&gt; set = null; public static String colorString(String str, Mats a) { if (a.getTake().equals(new Boolean(true))) { return "&lt;html&gt;&lt;body&gt;&lt;font color=red&gt;" + str + "&lt;/font&gt;&lt;/body&gt;&lt;/html&gt;"; } else { return "&lt;html&gt;&lt;body&gt;&lt;font color=blue&gt;" + str + "&lt;/font&gt;&lt;/body&gt;&lt;/html&gt;"; } } public static void main(String[] argv) { JFrame frame = new JFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); addbuttin = new JButton("Dodaj"); Mats a = new Mats(10, 10, 5, "WOOD", true); Mats b = new Mats(10, 12, 5, "WOOD", false); set = new HashSet&lt;Mats&gt;(); set.add(a); set.add(b); addbuttin.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent arg0) { Mats c = new Mats(10, 12, 6, "WOOD", true); set.add(c); } }); JPanel p = new JPanel(); model = new DefaultTableModel() { public boolean isCellEditable(int rowIndex, int vColIndex) { return false; } }; /**here is java.lang.NullPointerException*/ table.getModel().addTableModelListener(new TableModelListener() { @Override public void tableChanged(TableModelEvent e) { if (e.equals(TableModelEvent.INSERT)) { model = new DefaultTableModel(); addColumns(); adddata(set); } } }); addColumns(); adddata(set); table = new JTable(model); JScrollPane scrollPane = new JScrollPane(table, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER); p.add(scrollPane, BorderLayout.CENTER); p.add(addbuttin, BorderLayout.EAST); p.setSize(500, 400); frame.add(p); frame.setSize(600, 600); frame.setVisible(true); } private static void addColumns() { ((DefaultTableModel) model).addColumn("NAME"); } private static void adddata(Set&lt;Mats&gt; set) { for (Iterator iterator = set.iterator(); iterator.hasNext();) { Mats mats = (Mats) iterator.next(); String n = colorString(mats.getName(), mats); ((DefaultTableModel) model).insertRow(model.getRowCount(), new Object[] { n }); } } } </code></pre> <p>This is Class Mats simplified</p> <pre><code>public class Mats implements Comparable&lt;Mats&gt; { private String name; private Boolean take; /** * */ public Mats() { } /** * * @param name * @param uzet */ public Mats(String name, boolean take) { this.name = name.toUpperCase(); this.take = take; taken(); } /** * * @param Material */ public Mats(Mats Material) { this.name = Material.getName().toUpperCase(); this.take = Material.getTake(); Material.taken(); } /** * @return the name */ public String getName() { return name; } /** * @param name * the name to set */ public void setName(String name) { this.name = name.toUpperCase(); } /** * @param take * the take to set */ public void setTake(Boolean take) { this.take = take; } /** * @return the take */ public Boolean getTake() { return take; } /** * * @return */ @Override public String toString() { return "Material: ".toUpperCase() + getName() + "\n"; } /** * * @param obj * @return */ @Override public boolean equals(Object obj) { Mats a = (Mats) obj; if (obj == null) { return false; } if (a.getName() == this.getName()) { return true; } return false; } /** * * @return */ @Override public int hashCode() { int hash = 3; hash = 83 * hash + this.getX(); hash = 83 * hash + this.getY(); hash = 83 * hash + (this.getName() != null ? this.getName().hashCode() : 0); return hash; } /** * */ public void taken() { MatRespawn s = new MatRespawn(1000, take); s.start(); } @Override public int compareTo(Mats o) { Integer a = this.getName(); if (a.compareTo(o.getName()) != 0) return a.compareTo(o.getName()); return 0; } } </code></pre> <p>Class MatRespawn which changes Mats.take</p> <pre><code>public class MatRespawn extends Thread { private int time; private Boolean taken; public MatRespawn(int time, Boolean take) { this.time = time; this.taken = take; } public int getTime() { return time; } public void setTime(int time) { this.time = time; } public Boolean getTaken() { return taken; } public void setTaken(Boolean taken) { this.taken = taken; } @Override public void run() { try { while (true) { if (taken.equals(new Boolean(true))) { sleep(time * 10); //JOptionPane.showMessageDialog(null, "dostupnost: " + taken); taken = false; } sleep(time); //JOptionPane.showMessageDialog(null, "dostupnost: " + taken); taken = true; } } catch (InterruptedException e) { e.printStackTrace(); } } } </code></pre>
 

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