dtree_JQuery　增加删除修改功能

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; import java.util.List; public class DaoTest { Connection con = null; public Connection getConnection() { Connection conn=null; String driverClassName = "com.mysql.jdbc.Driver"; String url = "jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8"; String username = "root"; String password = "123456"; try { if (conn == null) { Class.forName(driverClassName).newInstance(); conn = DriverManager.getConnection(url, username, password); } } catch (Exception e) { System.out.println("数据库连接有误！"); return null; } finally { url = null; username = 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 { System.err.println(sql); pre = conn.prepareStatement(sql); rs =pre.executeQuery(); while (rs.next()){ Nodes node = new Nodes(); node.setHrefAddress(rs.getString("hrefAddress")); node.setNodeId(rs.getInt("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; } public void updatenote(Nodes nodes){ String sql="update tree_table set nodename='"+nodes.getNodeName()+"'where nodeid="+nodes.getNodeId()+""; Connection conn=null; PreparedStatement pre = null; try{ conn=getConnection(); pre=conn.prepareStatement(sql); pre.executeUpdate(); }catch(Exception e){ e.printStackTrace(); } } public void delete(Nodes nodes){ String sql="delete from tree_table where nodeid="+nodes.getNodeId()+""; Connection conn=null;System.err.println(sql); PreparedStatement pre = null; try{ conn=getConnection(); pre=conn.prepareStatement(sql); pre.execute(); }catch(Exception e){ e.printStackTrace(); } } public void add(Nodes nodes){ int nodeid=nodes.getNodeId(); String parentid=nodes.getParentId(); String hs=nodes.getHrefAddress(); String nodename=nodes.getNodeName(); String sql="insert into tree_table values("+null+","+nodeid+",'"+parentid+"','"+hs+"','"+nodename+"')"; Connection conn=null; PreparedStatement pre = null; try{ conn=getConnection(); pre=conn.prepareStatement(sql); pre.execute(); }catch(Exception e){ e.printStackTrace(); } } public Nodes findMaxNode(){ System.out.println("%%%%%%%%%%%%%%%%%%%%"); String sql = "select max(nodeid) from tree_table order by nodeid"; PreparedStatement pre = null; Connection conn = null;System.err.println(sql); ResultSet rs=null; Nodes nodes=new Nodes(); try{ conn=getConnection(); pre=conn.prepareStatement(sql); rs=pre.executeQuery(); while(rs.next()){ int nodeid=rs.getInt(1); System.out.println(nodeid); nodes.setNodeId(nodeid); } }catch(Exception e){ e.printStackTrace(); } return nodes; } }