我想写个选课系统，很简单的那种啊，用了一个表格来包含课程信息，最后一列就是是否选择该课程的一个boolean列，在勾选完自己想选的课程之后就按提交按钮，选择的课程信息会出现在另一个面板上的JTextArea上，可是那个那个getValueAt函数总是报错，不知原因啊，我把我写的代码发一下啊
import javax.swing.*;
import javax.swing.table.AbstractTableModel;
import java.awt.*;
import java.awt.event.*;
public class test implements ActionListener{
JTable table=null;
MyTable mt=null;
JTextArea ta=null;
JFrame f=null;
Container contentPane=null;
JButton b1=null;
JButton b2=null;
public test(){
f=new JFrame();
contentPane = f.getContentPane();
contentPane.setLayout(new CardLayout());
mt=new MyTable();
table = new JTable(mt);
table.setPreferredScrollableViewportSize(new Dimension(550,90));
JScrollPane s=new JScrollPane(table);
JPanel p1=new JPanel();
p1.setLayout(new GridLayout(2,1));
JPanel p11=new JPanel();
p1.add(s);
b1=new JButton("tijiao");
b1.addActionListener(this);
p11.add(b1,BorderLayout.CENTER);
p1.add(p11);
JPanel p2=new JPanel();
ta=new JTextArea("yixuan"+"\n");
ta.setSize(550, 30);
p2.setLayout(new GridLayout(2,1));
p2.add(ta);
JPanel p21=new JPanel();
b2=new JButton("queding");
b2.addActionListener(this);
p21.add(b2,BorderLayout.CENTER);
p2.add(p21);
contentPane.add("one",p1);contentPane.add("two",p2);
((CardLayout)contentPane.getLayout()).show(contentPane, "one");
f.setTitle("bixiu");
f.pack();
f.setVisible(true);
f.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(0);
}
});
}
public void actionPerformed(ActionEvent e){
if(e.getSource()==b1){
for(int i=1;i<5;i++)
{
//boolean choice=(Boolean) mt.getValueAt(i, 3);
boolean choice=Boolean.parseBoolean(""+mt.getValueAt(i,3));
if(choice)
{
ta.append("kecheng: "+mt.getValueAt(i, 1)+"\t"+"xuefen: "+mt.getValueAt(i, 2));
}
}
((CardLayout)contentPane.getLayout()).show(contentPane,"two");
}
if(e.getSource()==b2){
}
table.revalidate();
f.validate();
}
public static void main(String args[]){
new test();
}
}
class MyTable extends AbstractTableModel{
/**
*
*/
private static final long serialVersionUID = 1L;
Object[][]p={
{"math",new Integer(6),new Boolean(false)},
{"C++",new Integer(5),new Boolean(false)},
{"Chinese",new Integer(3),new Boolean(false)},
{"English",new Integer(4),new Boolean(false)},
};
String[]n={"Name","XueFen","Choose"};
Class columnsClass[]={String.class,Integer.class,Boolean.class};
public int getColumnCount(){
return n.length;
}
public int getRowCount(){
return p.length;
}
public String getColumnName(int col){
return n[col];
}
public Object getValueAt(int row,int col){
return p[row][col];
}
public Class<?> getColumnClass(int c){
return columnsClass[c];
}
public boolean isCellEditable(int rowIndex,int columnIndex){
return true;
}
public void setValueAt(Object value,int row,int col){
p[row][col]=value;
fireTableCellUpdated(row,col);
}
}
------解决方案--------------------
已经改好了，改的地方给你标记了一下
- Java code
import javax.swing.*;import javax.swing.table.AbstractTableModel;import java.awt.*;import java.awt.event.*;public class Test implements ActionListener{ JTable table=null; MyTable mt=null; JTextArea ta=null; JFrame f=null; Container contentPane=null; JButton b1=null; JButton b2=null; public Test(){ f=new JFrame(); contentPane = f.getContentPane(); contentPane.setLayout(new CardLayout()); mt=new MyTable(); table = new JTable(mt); table.setPreferredScrollableViewportSize(new Dimension(550,90)); JScrollPane s=new JScrollPane(table); JPanel p1=new JPanel(); p1.setLayout(new GridLayout(2,1)); JPanel p11=new JPanel(); p1.add(s); b1=new JButton("提交"); b1.addActionListener(this); p11.add(b1,BorderLayout.CENTER); p1.add(p11); JPanel p2=new JPanel(); ta=new JTextArea("已选"+"\n"); ta.setSize(550, 30); p2.setLayout(new GridLayout(2,1)); p2.add(ta); JPanel p21=new JPanel(); b2=new JButton("确定"); b2.addActionListener(this); p21.add(b2,BorderLayout.CENTER); p2.add(p21); contentPane.add("one",p1);contentPane.add("two",p2); ((CardLayout)contentPane.getLayout()).show(contentPane, "one"); f.setTitle("bixiu"); f.pack(); f.setVisible(true); f.addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e){ System.exit(0); } }); } @Override public void actionPerformed(ActionEvent e){ if(e.getSource()==b1){//提交按钮 for(int i=0;i<table.getRowCount();i++){ //这里修改了 //boolean choice=(Boolean) mt.getValueAt(i, 3); boolean choice=Boolean.parseBoolean(""+mt.getValueAt(i,2)); if(choice){ //下面这行修改了 ta.append("课程: "+mt.getValueAt(i, 0)+"\t"+"学分: "+mt.getValueAt(i, 1)); } } ((CardLayout)contentPane.getLayout()).show(contentPane,"two"); } if(e.getSource()==b2){ } table.revalidate(); f.validate(); } public static void main(String args[]){ new Test(); }}class MyTable extends AbstractTableModel{ /** * */ private static final long serialVersionUID = 1L; Object[][]p={ {"math",new Integer(6),new Boolean(false)}, {"C++",new Integer(5),new Boolean(false)}, {"Chinese",new Integer(3),new Boolean(false)}, {"English",new Integer(4),new Boolean(false)}, }; String[]n={"Name","XueFen","Choose"}; Class columnsClass[]={String.class,Integer.class,Boolean.class}; public int getColumnCount(){ return n.length; } public int getRowCount(){ return p.length; } public String getColumnName(int col){ return n[col]; } public Object getValueAt(int row,int col){ return p[row][col]; } public Class<?> getColumnClass(int c){ return columnsClass[c]; } public boolean isCellEditable(int rowIndex,int columnIndex){ return true; } public void setValueAt(Object value,int row,int col){ p[row][col]=value; fireTableCellUpdated(row,col); }}