swing·通讯录项目预备知识之JTree__数据库构建节点树[二]

上篇本来就算是结束JTree的，但今天考虑到通讯录项目的体验效果，还是没忍住稍微深研究了一点。。。

 

今天要让初始话JTree的时候，从数据库读取子节点，形成每一个组别各有一个叶子节点的初始化状态

看数据库

然后是NodeDao.java

 1 package com.java1234.dao;
 2 
 3 import java.sql.Connection;
 4 import java.sql.PreparedStatement;
 5 import java.sql.ResultSet;
 6 import java.sql.SQLException;
 7 
 8 import com.java1234.model.Group;
 9 
10 public class NodeDao {
11     public ResultSet initData(Connection conn) throws Exception{
12         String sql = "select * from list_group";
13         PreparedStatement pst = conn.prepareStatement(sql);
14         ResultSet rs = pst.executeQuery();
15         return rs;
16     }
17     public ResultSet initChild(Connection conn, Group group) throws Exception{
18         StringBuffer sql = new StringBuffer("select * from link_man m,list_group g where m.groupId = g.id");
19         sql.append(" and g.groupName = '" + group.getGroupName() + "'");
20         PreparedStatement pst = conn.prepareStatement(sql.toString());
21         
22         return pst.executeQuery();
23     }
24 }

Group.java

 1 package com.java1234.model;
 2 
 3 public class Group {
 4     int id;
 5     String groupName;
 6 
 7     public Group() {
 8         super();
 9         // TODO Auto-generated constructor stub
10     }
11     public int getId() {
12         return id;
13     }
14     public void setId(int id) {
15         this.id = id;
16     }
17     public String getGroupName() {
18         return groupName;
19     }
20     public void setGroupName(String groupName) {
21         this.groupName = groupName;
22     }
23     public Group(String groupName) {
24         super();
25         this.groupName = groupName;
26     }
27     
28 }

主界面类initTree方法更改为

 1 private void initTree() {
 2         Connection conn = null;
 3         try {
 4             conn = dbUtil.getCon();
 5             ResultSet rs = nodeDao.initData(conn);
 6             while (rs.next()) {
 7                 String groupName = rs.getString("groupName");
 8                 Group newGroup = new Group(groupName);
 9                 ResultSet rst = nodeDao.initChild(conn, newGroup);
10                 DefaultMutableTreeNode newChild = new DefaultMutableTreeNode(groupName);
11                 DefaultTreeModel model = (DefaultTreeModel) jtree_group.getModel();
12                 while(rst.next()){
13                     newSon = new DefaultMutableTreeNode(rst.getString("linkManName"));
14                     newChild.add(newSon);
15                 }
16                 rootNode.add(newChild);
17                 model.nodeStructureChanged(rootNode);
18             }
19         } catch (Exception e) {
20             // TODO Auto-generated catch block
21             JOptionPane.showMessageDialog(null, "初始化失败");
22             e.printStackTrace();
23             System.exit(0);
24         } finally {
25             try {
26                 dbUtil.conClose(conn);
27             } catch (Exception e) {
28                 // TODO Auto-generated catch block
29                 e.printStackTrace();
30             }
31         }
32     }

效果图

 

这回就真的是终章了。。。。。到此为止

 

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