我的Java程序出错了。我认为这是因为构造函数没有正确初始化。
我的基础课程
public class Hello {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here
try
{
ScrollPaneRefresh scp=new ScrollPaneRefresh();
scp.First();
scp.createAndShowGui();
}
catch(Exception e)
{
e.printStackTrace();
}
}
}
我的衍生课程
package policyreader;
import java.sql.*;
import javax.swing.event.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import javax.swing.table.*;
import java.util.*;
import javax.swing.JComboBox;
import javax.swing.SwingUtilities;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JPanel;
import java.awt.GridLayout;
import javax.swing.JFrame;
import java.io.IOException;
public class ScrollPaneRefresh extends JPanel {
private static final int PREF_W = 600;
private static final int PREF_H = 200;
int b = 0;
private String[][] newData = {
{"", ""}
};
private String[] columnName = {"S.NO", "SOLUTIONS"};
static Vector columnNames = new Vector();
static Vector data = new Vector();
static Vector columnNames56 = new Vector();
static Vector data56 = new Vector();
public static void First() {
try {
DefaultTableCellRenderer cent = new DefaultTableCellRenderer();
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection connect = DriverManager.getConnection("jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=conflictresolve.mdb;DriverID=22}", "", "");
String sql = "Select * from geteffect";
Statement stmt = connect.createStatement();
ResultSet rs = stmt.executeQuery(sql);
ResultSetMetaData md = rs.getMetaData();
int columns = md.getColumnCount();
for (int i = 1; i <= columns; i++) {
columnNames.addElement(md.getColumnName(i));
}
while (rs.next()) {
Vector row = new Vector(columns);
for (int i = 1; i <= columns; i++) {
row.addElement(rs.getObject(i));
}
data.addElement(row);
}
rs.close();
stmt.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void Second() {
Vector columnNames = new Vector();
Vector data = new Vector();
Vector columnNames1 = new Vector();
Vector columnNames2 = new Vector();
Vector data1 = new Vector();
Vector few = new Vector();
Vector com = new Vector();
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection connect = DriverManager.getConnection("jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=conflictresolve.mdb;DriverID=22}", "", "");
String sql = "Select * from allsolutiontable";
Statement stmt = connect.createStatement();
ResultSet rs = stmt.executeQuery(sql);
ResultSetMetaData md = rs.getMetaData();
String sql2 = "Select * from allsolutiontable";
Statement stmt2 = connect.createStatement();
ResultSet rs2 = stmt2.executeQuery(sql2);
ResultSetMetaData md2 = rs2.getMetaData();
String sql1 = "Select * from seteffect";
Statement stmt1 = connect.createStatement();
ResultSet rs1 = stmt1.executeQuery(sql1);
ResultSetMetaData md1 = rs1.getMetaData();
int columns = md.getColumnCount();
for (int i = 1; i <= columns; i++) {
columnNames.addElement(md.getColumnName(i));
}
int columns1 = md1.getColumnCount();
for (int i = 1; i <= columns1; i++) {
columnNames1.addElement(md1.getColumnName(i));
}
int columns2 = md2.getColumnCount();
for (int i = 1; i <= columns2; i++) {
columnNames2.addElement(md2.getColumnName(i));
}
while (rs.next()) {
Vector row = new Vector();
for (int i = 1; i <= 2; i++) {
row.addElement(rs.getObject(i));
//System.out.println(row);
}
data.addElement(row);
}
rs.close();
stmt.close();
while (rs2.next()) {
Vector large = new Vector();
//for (int i = 1; i <=columns; i++) {
large.addElement(rs2.getObject(3));
//}
few.addElement(large);
}
while (rs1.next()) {
Vector row1 = new Vector();
for (int i = 1; i <= 2; i++) {
row1.addElement(rs1.getObject(i));
}
data1.addElement(row1);
}
rs1.close();
stmt1.close();
rs2.close();
stmt2.close();
} catch (Exception e) {
e.printStackTrace();
}
//System.out.println(columnNames);
//System.out.println(columnNames1);
System.out.println(data);
System.out.println(data1);
System.out.println(few);
for (int i = 0; i < data.size(); i++) {
for (int j = 0; j < data1.size(); j++) {
if (data.get(i).toString().compareTo(data1.get(j).toString()) == 0) {
com.addElement(few.get(i));
System.out.println("Solution" + few.get(i).toString());
}
}
}
Connection co;
Statement st1, st2;
ResultSet rs1;
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
co = DriverManager.getConnection("jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=conflictresolve.mdb;DriverID=22}", "", "");
st1 = co.createStatement();
rs1 = st1.executeQuery("select * from conflictsolution");
//st1=co.createStatement();
for (int i = 0; i < com.size(); i++) {
String rr = "insert into conflictsolution values('" + com.get(i) + "')";
st1.executeUpdate(rr);
}
st1.close();
} catch (Exception e) {
System.out.println("there was some error in establishing connection : " + e);
}
try {
DefaultTableCellRenderer cent = new DefaultTableCellRenderer();
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection connect = DriverManager.getConnection("jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=conflictresolve.mdb;DriverID=22}", "", "");
String sql = "Select * from conflictsolution";
Statement stmt = connect.createStatement();
ResultSet rs = stmt.executeQuery(sql);
ResultSetMetaData md = rs.getMetaData();
int columns = md.getColumnCount();
for (int i = 1; i <= columns; i++) {
columnNames56.addElement(md.getColumnName(i));
}
while (rs.next()) {
Vector row = new Vector(columns);
for (int i = 1; i <= columns; i++) {
row.addElement(rs.getObject(i));
}
data56.addElement(row);
}
rs.close();
stmt.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public TablePanel gregsPanel = new TablePanel("SET THE EFFECTS FOR THE RULES", data, columnNames); // line 208
private TablePanel myPanel = new TablePanel("SOLUTIONS", data56, columnNames56, b);
public ScrollPaneRefresh() {
gregsPanel.setButtonAction(new AbstractAction("SUBMIT") {
@Override
public void actionPerformed(ActionEvent evt) {
gregsPanel.store();
Second();
myPanel.setTableModelDataVector(data56, columnNames56);
}
});
setLayout(new GridLayout(0, 1));
add(gregsPanel.getMainPanel());
add(myPanel.getMainPanel());
}
@Override // so scrollbars will show
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
public static void createAndShowGui() {
ScrollPaneRefresh mainPanel = new ScrollPaneRefresh();
try {
JFrame frame = new JFrame("CONFLICT RESOLUTION FOR POLICYSET LEVEL");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setBounds(10, 10, 1200, 600);
frame.setLocationByPlatform(true);
frame.setVisible(true);
} catch (Exception ex) {
ex.printStackTrace();
}
}
public static void main(String[] args) throws Exception {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
First();
createAndShowGui();
}
});
}
}
class TablePanel {
private JPanel mainPanel = new JPanel();
private DefaultTableModel dm;
private JTable table = new JTable();
private JTable table1 = new JTable();
private JButton changeTableBtn = new JButton();
private JScrollPane scrollpane = new JScrollPane(table);
private JScrollPane scrollpane1 = new JScrollPane(table1);
public TablePanel(String title, Vector data, Vector columnNames) {
try {
dm = new DefaultTableModel(data, columnNames);
table.setModel(dm);
table.setRowHeight(30);
TableColumn column = table.getColumnModel().getColumn(1); // line 279
//TableColumnModel tcm = table.getColumnModel();
//tcm.getColumn(1).setPreferredWidth(10);
column.setCellRenderer(new ComboBoxCellRenderer());
column.setCellEditor(new ComboBoxCellEditor());
// cent.setHorizontalAlignment(JLabel.CENTER);
JPanel btnPanel = new JPanel();
btnPanel.add(changeTableBtn);
mainPanel.setBorder(BorderFactory.createTitledBorder(title));
mainPanel.setLayout(new BorderLayout(5, 5));
mainPanel.add(scrollpane, BorderLayout.CENTER);
mainPanel.add(btnPanel, BorderLayout.PAGE_END);
} catch (Exception e) {
e.printStackTrace();
}
}
public TablePanel(String title, Vector data, Vector columnNames, int a) {
dm = new DefaultTableModel(data, columnNames);
table1.setModel(dm);
JPanel btnPanel = new JPanel();
//btnPanel.add(changeTableBtn);
mainPanel.setBorder(BorderFactory.createTitledBorder(title));
mainPanel.setLayout(new BorderLayout(5, 5));
mainPanel.add(scrollpane1, BorderLayout.CENTER);
mainPanel.add(btnPanel, BorderLayout.PAGE_END);
}
public void store() {
Connection conn;
Statement s;
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); // Establish a connection
conn = DriverManager.getConnection("jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=conflictresolve.mdb;DriverID=22}", "", "");
System.out.println("Databse Connected");
s = conn.createStatement();
String sql = "INSERT INTO seteffect VALUES (?, ?)";
PreparedStatement ps = conn.prepareStatement(sql);
TableModel tm = table.getModel();
int nRow = tm.getRowCount(), nCol = tm.getColumnCount();
System.out.println(" rows:" + nRow + "columns:" + nCol);
for (int r = 0; r < nRow; r++) {
for (int c = 1; c <= nCol; c++) {
//ps.setObject(c, tm.getValueAt(r, (nCol-1)));
if (c == 1) {
ps.setString(c, tm.getValueAt(r, c - 1).toString());
} /* else if(c==2)
{
ps.setString(c, tm.getValueAt(r, c-1).toString());
}*/ else {
ps.setString(c, tm.getValueAt(r, nCol - 1).toString());
}
}
ps.executeUpdate();
}
conn.close();
} catch (Exception ex) {
ex.printStackTrace();
}
}
public void setButtonAction(Action action) {
changeTableBtn.setAction(action);
}
public void setTableModelDataVector(Vector data, Vector columnNames) {
dm.setDataVector(data, columnNames);
}
public void fireTableDataChanged() {
dm.fireTableDataChanged();
}
public JScrollPane getScrollPane() {
return scrollpane;
}
public JComponent getMainPanel() {
return mainPanel;
}
}
class ComboBoxPanel extends JPanel {
private String[] m = new String[]{"Permit", "Deny"};
protected JComboBox<String> comboBox = new JComboBox<String>(m) {
@Override
public Dimension getPreferredSize() {
Dimension d = super.getPreferredSize();
return new Dimension(70, d.height);
}
};
public ComboBoxPanel() {
super();
setOpaque(true);
comboBox.setEditable(true);
add(comboBox);
}
}
class ComboBoxCellRenderer extends ComboBoxPanel
implements TableCellRenderer {
public ComboBoxCellRenderer() {
super();
setName("Table.cellRenderer");
}
@Override
public Component getTableCellRendererComponent(
JTable table, Object value, boolean isSelected,
boolean hasFocus, int row, int column) {
setBackground(isSelected ? table.getSelectionBackground()
: table.getBackground());
if (value != null) {
comboBox.setSelectedItem(value);
}
return this;
}
}
class ComboBoxCellEditor extends ComboBoxPanel
implements TableCellEditor {
public ComboBoxCellEditor() {
super();
comboBox.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
fireEditingStopped();
}
});
addMouseListener(new MouseAdapter() {
@Override
public void mousePressed(MouseEvent e) {
fireEditingStopped();
}
});
}
@Override
public Component getTableCellEditorComponent(
JTable table, Object value, boolean isSelected, int row, int column) {
this.setBackground(table.getSelectionBackground());
comboBox.setSelectedItem(value);
return this;
}
//Copid from DefaultCellEditor.EditorDelegate
@Override
public Object getCellEditorValue() {
return comboBox.getSelectedItem();
}
@Override
public boolean shouldSelectCell(EventObject anEvent) {
if (anEvent instanceof MouseEvent) {
MouseEvent e = (MouseEvent) anEvent;
return e.getID() != MouseEvent.MOUSE_DRAGGED;
}
return true;
}
@Override
public boolean stopCellEditing() {
if (comboBox.isEditable()) {
comboBox.actionPerformed(new ActionEvent(this, 0, ""));
}
fireEditingStopped();
return true;
}
//Copid from AbstractCellEditor
protected EventListenerList listenerList = new EventListenerList();
transient protected ChangeEvent changeEvent = null;
@Override
public boolean isCellEditable(EventObject e) {
return true;
}
@Override
public void cancelCellEditing() {
fireEditingCanceled();
}
@Override
public void addCellEditorListener(CellEditorListener l) {
listenerList.add(CellEditorListener.class, l);
}
@Override
public void removeCellEditorListener(CellEditorListener l) {
listenerList.remove(CellEditorListener.class, l);
System.out.println(listenerList);
}
public CellEditorListener[] getCellEditorListeners() {
return listenerList.getListeners(CellEditorListener.class);
}
protected void fireEditingStopped() {
// Guaranteed to return a non-null array
Object[] listeners = listenerList.getListenerList();
// Process the listeners last to first, notifying
// those that are interested in this event
for (int i = listeners.length - 2; i >= 0; i -= 2) {
if (listeners[i] == CellEditorListener.class) {
// Lazily create the event:
if (changeEvent == null) {
changeEvent = new ChangeEvent(this);
}
((CellEditorListener) listeners[i + 1]).editingStopped(changeEvent);
}
}
}
protected void fireEditingCanceled() {
// Guaranteed to return a non-null array
Object[] listeners = listenerList.getListenerList();
// Process the listeners last to first, notifying
// those that are interested in this event
for (int i = listeners.length - 2; i >= 0; i -= 2) {
if (listeners[i] == CellEditorListener.class) {
// Lazily create the event:
if (changeEvent == null) {
changeEvent = new ChangeEvent(this);
}
((CellEditorListener) listeners[i + 1]).editingCanceled(changeEvent);
}
}
}
}
1）当我单独运行派生类时，我没有收到任何错误。 2）当我运行我的基类时，我得到以下错误，请帮助我
java.lang.ArrayIndexOutOfBoundsException: 1 >= 0
at java.util.Vector.elementAt(Vector.java:470)
at javax.swing.table.DefaultTableColumnModel.getColumn(DefaultTableColumnModel.java:294)
at policyreader.TablePanel.<init>(ScrollPaneRefresh.java:279)
at policyreader.ScrollPaneRefresh.<init>(ScrollPaneRefresh.java:208)
at policyreader.Hello.main(Hello.java:20)
答案 0 :(得分：2)
您只需阅读堆栈跟踪即可。引发异常at ScrollPaneRefresh.java:279：
TableColumn column = table.getColumnModel().getColumn(1);
您正试图访问表格的第二列。该表的模型使用：
初始化dm = new DefaultTableModel(data, columnNames);
这是由ScrollPaneRefresh的初始化调用的：
at policyreader.ScrollPaneRefresh.<init>(ScrollPaneRefresh.java:208)
引用的行必须是以下两行之一：
public TablePanel gregsPanel = new TablePanel("SET THE EFFECTS FOR THE RULES", data, columnNames);
private TablePanel myPanel = new TablePanel("SOLUTIONS", data56, columnNames56, b);
并且columnNames或columnNames56包含0或1列，但不包含2.那么这些变量在哪里初始化？
static Vector columnNames = new Vector();
static Vector data = new Vector();
static Vector columnNames56 = new Vector();
static Vector data56 = new Vector();
所以一切都是空的。
坦率地说，你的代码很乱。它使用公共字段，应该是实例方法的静态方法，单个文件中的所有内容，与Swing代码混合的JDBC代码。在继续之前，您最好学会将单一职责分配给单个类，并了解静态方法和实例方法之间的区别，并尊重Java命名约定。