cuserdao.java

自己写的一个网络日志(BLOG)系统

package blog;
import java.sql.*;
import java.util.ArrayList;
/**
 * 
 * <p>Title: CUserDAO</p>
 * <p>Description:用户管理类 </p>
 * <p>Copyright: copyright (c) 2005-2005</p>
 * <p>Company: </p>
 * @author Administrator
 * @version 1.0.00_01
 */
public class CUserDAO {
	private Connection conn = null;
	private Statement stmt = null;
	private CallableStatement cstmt = null;
	private ResultSet rs = null;
	
	private static CUserDAO userDAO = null;
	
	
	public static CUserDAO newInstance(){
		if(userDAO == null){
			userDAO = new CUserDAO();
		}
		return userDAO;
	}
	private CUserDAO(){
		try {
			Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
			conn = DriverManager.getConnection("jdbc:microsoft:sqlserver://localhost:1433;databasename=blogdata",
	        		"sa",
					"sa");
		} catch (Exception e) {
			System.err.println("blog.CUserDAO.CUserDAO()"+e.getMessage());
		}

	}
	
	public  boolean  queryByUser(CUser user){
	        boolean b = false;
	        try {
	            cstmt = conn.prepareCall("{call ? = proc_queryUser(?,?)}");
	            cstmt.registerOutParameter(1,Types.INTEGER);
	            cstmt.setString(2,user.getUserName());
	            cstmt.setString(3,user.getUserPwd());
	            cstmt.execute();
	            int i = cstmt.getInt(1);
	            if(i == 0){
	            	b = false;
	            }else{
	            	b = true;
	            }
	            return b;
	        } catch (Exception e) {
	        	System.err.println("blog.CUserDAO.queryByUser()"+e.getMessage());
	            return b ;
	        }
		
	}
	
	public String queryByID(int userID){
		String userName = null;
		String sql =  "select userName from Tusers where userID="+userID;
		try{
			stmt = conn.createStatement();
			rs = stmt.executeQuery(sql);
			if(rs.next()){
				do{
					userName = rs.getString(1);
				}while(rs.next());
			}
			
		}catch(Exception e){
			System.err.println("blog.CUserDAO.queryByID()"+e.getMessage());
		}
		return userName;
	}
	
	public ArrayList executeQuery(){
		ArrayList userList = null;
		String sql = "select * from Tusers";
		try{
			stmt = conn.createStatement();
			rs = stmt.executeQuery(sql);
			if(rs.next()){
				userList = new ArrayList();
				do{
					CUser user = new CUser();
					user.setUserID(rs.getInt(1));
					user.setUserName(rs.getString(2));
					userList.add(user);
				}while(rs.next());
			}
		}catch(Exception e ){
			System.err.println("blog.CCataDAO.executeQuery()"+e.getMessage());
		}
		return userList;
	}
	
	public void close(){
		try{
			if(rs != null){
				rs = null;
				rs.close();
			}
			if(cstmt != null){
				cstmt = null;
				cstmt.close();
			}
			if(stmt != null){
				stmt = null;
				stmt.close();
			}
			if(conn != null){
				conn = null;
				conn.close();
			}
		}catch(Exception e){
			System.err.println("blog.CUserDAO.close()"+e.getMessage());
		}
	}

}