treedatapro.java

用ExtJS做的一个网页聊天工具

package com.shyhao.qq.service;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;

import net.sf.json.JSONArray;

import com.shyhao.qq.jobo.TreeNode;

public class TreeDataPro {

	private String ParentId;
	//数据库连接参数
	private String DRIVER = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
	private String URL = "jdbc:sqlserver://localhost:1433;   DatabaseName=shyhao";
	private String NAME = "songyinghao";
	private String PASSWORD = "159";

	public TreeDataPro() {

		try {
			Class.forName(DRIVER);
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}

	}

	public String getParentId() {
		return ParentId;
	}

	public void setParentId(String parentId) {
		ParentId = parentId;
	}

	/**
	 * 方法： getJsonString()
	 * 作用：从数据库中提取所需的节点信息
	 * 并转化成json类型
	 * 返回
	 */
	public String getJsonString() {
		Connection conn = null;
		Statement stmt = null;
		ResultSet rs = null;
		ArrayList<TreeNode> TreeNodeArray = null;

		String SQLString = "select * from QQUser where ParentId="
				+ this.ParentId +"and OnLine='1'"+ " order by NodeId";

		try {
			conn = DriverManager.getConnection(URL, NAME, PASSWORD);
			stmt = conn.createStatement();

			rs = stmt
					.executeQuery("select ParentId from QQUser where ParentId>0 group by ParentId order by ParentId");

			StringBuffer parentIdBuffer = new StringBuffer();
			parentIdBuffer.append("|");
			// 得到所有的parentDID
			while (rs.next()) {
				parentIdBuffer.append(rs.getString("ParentId"));
				parentIdBuffer.append("|");
			}
			// 转化为字符串
			String parentIdString = parentIdBuffer.toString();
            //查询父节点为ParentId时所包含的信息
			rs = stmt.executeQuery(SQLString);
			TreeNodeArray = new ArrayList<TreeNode>();

			while (rs.next()) {
				TreeNode TreeNode = new TreeNode();
				TreeNode.setId(rs.getString("NodeId"));
				TreeNode.setText(rs.getString("UserName"));
				TreeNode.setDescription(rs.getString("UserName"));
				if (parentIdString.indexOf("|" + rs.getString("NodeId") + "|") >= 0) {
					//父节点
					TreeNode.setCls("folder");
					TreeNode.setLeaf(false);
					TreeNode.setExpandable(false);
				} else {
					//子节点
					TreeNode.setCls("file");
					TreeNode.setLeaf(true);
					TreeNode.setExpandable(false);
				}
				TreeNodeArray.add(TreeNode);
			}

			 // 得到JSON数组
			JSONArray jsonArr = JSONArray.fromObject(TreeNodeArray);
			// 把JSON数组转化为String类型并返回
			return jsonArr.toString();
		} catch (Exception e) {
			e.printStackTrace();
			System.out.println("TreeDataPro.java is in "+e);
			return "";
			
		} finally {
			try {
				//关闭连接
				conn.close();
			} catch (SQLException e) {

				e.printStackTrace();
			}
		}
	}
}