GUI树组件，表格

树组件首先要new一个JTree，再加结点，然后添加到 JScrollPane

JTree tree1=new JTree();
//.......添加节点
add(new ScrollPane(tree1)

添加节点

DefaultMutableTreeNode root=new DefaultMutableTreeNode("dongxi")//后面的是备注
DefaultMutableTreeNode root=new DefaultMutableTreeNode(new Good("aa",11));//还可以作为叶子new 对象

添加监视器（由树来添加

addTreeSelectionListener(TreeSelectionListener listener)

TreeSelectionListener接口的方法

public void valueChanged(TreeSelectionEvent e)

在上面的接口方法中，返回树的结点，再返回结点中的对象

DefaultMutableTreeNode node1=(DefaultMutableTreeNode)tree.getLastSelectedPathComponent();//只有树Tree才能用的方法
if(node.isLeaf())//判断是否叶子节点
Obeject a=(Obeject)node.getUserObject()//返回叶子里面的对象

完整的测试代码

public class test{

    public static void main(String args[]){
        MyWin window1=new MyWin();
        window1.setBounds(12,12,400,300);
    }
}

class MyWin extends JFrame implements TreeSelectionListener{
    JTextField text1;
    JButton button1,button2;
    JTextArea textArea1,textArea2;
    JLabel label1;
    JTree tree1;
    MyWin(){
        init();
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    void init(){
        DefaultMutableTreeNode root=new DefaultMutableTreeNode("Goods");
        DefaultMutableTreeNode nodeTV=new DefaultMutableTreeNode("TV");        
        DefaultMutableTreeNode nodePhone=new DefaultMutableTreeNode("phone");    
        DefaultMutableTreeNode tv1=new DefaultMutableTreeNode(new Goods("huangTV",11));
        DefaultMutableTreeNode tv2=new DefaultMutableTreeNode(new Goods("yuTV",21));
        DefaultMutableTreeNode phone1=new DefaultMutableTreeNode(new Goods("ga",31));
        DefaultMutableTreeNode phone2=new DefaultMutableTreeNode(new Goods("bing",11));
        root.add(nodeTV);
        root.add(nodePhone);
        nodeTV.add(tv1);
        nodeTV.add(tv2);
        nodePhone.add(phone1);
        nodePhone.add(phone2);
        tree1=new JTree(root);
        tree1.addTreeSelectionListener(this);
        setLayout(new GridLayout(1,2));
        add(new JScrollPane(tree1));
        textArea2=new JTextArea(15,15);
        add(new JScrollPane(textArea2));
    }
    public void valueChanged(TreeSelectionEvent e){
        DefaultMutableTreeNode a=(DefaultMutableTreeNode)tree1.getLastSelectedPathComponent();
        if(a.isLeaf()){//是叶子节点？
            Goods b=(Goods)a.getUserObject();
            textArea2.append(b.name+": "+b.price+"
");
        }
        else
            textArea2.setText(null);
    }
}

class Goods{
    String name;
    double price;
    Goods(String name,double price){
        this.name=name;
        this.price=price;
    }
}

---

表格组件

Jtable默认的构造方法有7个，这里说常用的3个

JTable()
JTable(int a,int b)//几行几列
JTable(Object data[][],Object columnName[])//data为数据数组，columnName为列名数组

如果表格data[][]是 数字类型，可以用 Double.parseDouble 或者Integer.parseInt(s);

调用repaint来刷新表格

计算成绩代码测试

class MyWin extends JFrame implements ActionListener{
    JTable table1;
    JButton button1;
    Object a[][];
    Object name[]={"姓名","英语成绩","数学成绩","总成绩"};
    MyWin(){
        init();
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    void init(){
        a=new Object[8][4];
        for(int i=0;i<8;i++){
            for(int j=0;j<4;j++){
                if(j!=0)
                    a[i][j]=0;
                else
                    a[i][j]="姓名";
            }
        }
        button1=new JButton("click");
        table1=new JTable(a,name);
        Container con1=this.getContentPane();//获得一个容器,不用add
        getContentPane().add(new JScrollPane(table1), BorderLayout.CENTER);
        con1.add(new JLabel("update the data and click the button"),BorderLayout.NORTH);
        con1.add(button1,BorderLayout.SOUTH);
        button1.addActionListener(this);
//        validate();//验证组件
        
    }
    public void actionPerformed(ActionEvent e) {
        double sum=0;
        boolean boo=true;
        for(int i=0;i<8;i++){
            sum=0;
            for(int j=1;j<3;j++){
                try{sum+=Double.parseDouble(a[i][j].toString());
                }
                catch(Exception ee){
                    boo=false;
                    table1.repaint();
                }
            }
            if(boo==true){
                a[i][3]=sum+"";//把他改为String
                table1.repaint();
            }
            
        }
    }

}