新建 文本文档.txt

一个功能强大的图书管理系统,是个人版,适合学习swing的初学者阅读.

 public void root()
    {
        //连接数据库
        //获得结果集
        //创建树的根、枝
        
        Dbcom db = new Dbcom();
        ResultSet re = null;
        DefaultMutableTreeNode bookstype[];
        int size=0;
        int j =0;
        int i=0;
        int arry[] = new int[26];
        if (db.getconn()) {
            re = db.search();
            try {
                while(re.next())
                    size++;
                bookstype = new DefaultMutableTreeNode[size];
                boolean a=re.first();
                for(i=0,j=0;a;i++)
                {
                    String booktypeNum = re.getString(2).trim();
                    String booktypeName = re.getString(3).trim();
                    if (booktypeNum.length() == 1) {
                        arry[j]=i;
                        j++;
                        bookstype[i] = new DefaultMutableTreeNode(booktypeName);                    
                    }                    
                    a=re.next();
                }
                a=re.first();
                for(i=0,j=0;a;i++)
                {
                    String booktypeNum = re.getString(2).trim();
                    String booktypeName = re.getString(3).trim();
                    if (booktypeNum.length() >1) {
                        
                        bookstype[i] = new DefaultMutableTreeNode(booktypeName);
                        bookstype[j-1].add(bookstype[i]);
                        
                    }
                    else
                        j++;

                    a=re.next();
                }

                
                for(i=0,j=0;i<bookstype.length;i++)
                {
                    if(i==arry[j])
                    {
                        books.add(bookstype[i]);
                        j++;
                    }
            
                   
                }
                

                
            } catch (SQLException ex) {
                System.out.println(ex.toString());
            }          
            jTreBooks.updateUI();
            db.myClose();
        }
        else
            JOptionPane.showMessageDialog(this,"连接数据库失败","连接错误",JOptionPane.WARNING_MESSAGE);
    }