userinfodao.java

JAVA聊天室servlet实现 纯servlet实现的聊天系统 注释清楚 易于理解

package com.bean;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
  /**
   * 验证并保存用户
   * @author Administrator
   *
   */

public class UserInfoDao {
	private Connection con=null;
	private Statement s=null;
	private ResultSet rs =null;
	
	public static final String URL="jdbc:sqlserver://127.0.0.1:1433;databaseName=PersonRegister";
	public static final String USER="sa";
	public static final String PWD="";
	
	
	
	/**
	 * 获取连接数据库的方法
	 */
	
	public Connection conn(){
		try {
			Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
			con =DriverManager.getConnection(URL,USER,PWD);
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return con;
	}
	
	/**
	 * 验证用户
	 */
	public boolean  YanZhen(UserInfoBean uib) {
		boolean flag =false;		
		String sql ="select * from Registered";
		try {
			s=conn().createStatement();
			rs =s.executeQuery(sql);
			ResultSetMetaData rsm =rs.getMetaData();
			
			while (rs.next()) {				
					String str1=rs.getString((rsm.getColumnName(2)));
					String str2=rs.getString((rsm.getColumnName(3)));
					if (uib.getUserName().equals(str1)&&uib.getPwd().equals(str2)){
						flag =true;
					}				
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}finally {
			closeRs();
			closeStmt();
			closeConn();
		}
		return flag;
	}
	/**
	 * 关闭连接
	 *
	 */
	public  void closeConn() {
		if (con!=null) {
			try {
				con.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}finally {
				
				con=null;
			}
			
		}
	}
	
	
	/**
	 * 关闭结果集
	 *
	 */
	public void closeRs () {
		if (rs!=null) {
			try {
				rs.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}finally {
				rs=null;
			}
		}
	}
	
	
	/**
	 * 
	 * 关闭语句集方法
	 */
	
	public void closeStmt() {
		if (s!=null) {
			try {
				s.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}finally {
				s=null;
			}
		}
	}
	
	

}