动态加载树(tree)和动态加载表格(table)

package com.dao; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; public class DaoTest { Connection con = null; public Connection getConnection() { Connection conn = null; String url = "jdbc:mysql://localhost/test?useUnicode=true&amp;characterEncoding=gbk"; String user = "root"; String password = "mytopicforever"; try { if (conn == null) { Class.forName("com.mysql.jdbc.Driver").newInstance(); conn = DriverManager.getConnection(url, user, password); } } catch (Exception e) { System.out.println("连接失败"); return null; } finally { url = null; user = null; password = null; } return conn; } public ArrayList<Nodes> getNodeInfo() { String sql = "select nodeId ,parentId ,hrefAddress ,nodeName from tree_table order by id "; PreparedStatement pre = null; Connection conn = null; conn = getConnection(); ResultSet rs = null; ArrayList<Nodes> list = new ArrayList<Nodes>(); try { pre = conn.prepareStatement(sql); rs =pre.executeQuery(); while (rs.next()){ Nodes node = new Nodes(); node.setHrefAddress(rs.getString("hrefAddress")); node.setNodeId(rs.getString("nodeId")); node.setParentId(rs.getString("parentId")); node.setNodeName(rs.getString("nodeName")); list.add(node); } rs.close(); pre.close(); conn.close(); } catch (SQLException e) { e.printStackTrace(); }finally{ pre = null; conn = null; rs = null; } return list; } }