dao.java

jsp+servlet经典的登录注册

package dao;

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

import javabean.MyBean;

public class DAO {
	Connection conn = null;

	Statement st = null;

	ResultSet rs = null;

	PreparedStatement pst = null;

	String url = "jdbc:microsoft:sqlserver://127.0.0.1:1433;DatabaseName=student";

	public DAO() {
		try {
			Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	public ArrayList<MyBean> ListAllInformation(String sql) {
		ArrayList<MyBean> arrayList = new ArrayList<MyBean>();
		try {
			conn = DriverManager.getConnection(url, "sa", "sa");
			st = conn.createStatement();
			rs = st.executeQuery(sql);

			while (rs.next()) {
				MyBean myBean = new MyBean();
				myBean.setUserID(rs.getInt("userID"));
				myBean.setUserName(rs.getString("userName"));
				myBean.setPassWord(rs.getString("passWord"));
				arrayList.add(myBean);
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			try {
				if (rs != null) {
					rs.close();
				}
				if (st != null) {
					st.close();
				}
				if (conn != null) {
					conn.close();
				}
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}

		return arrayList;
	}

	public int del(String sql) {  //更新删除都可以用这个
		int n = 0;
		try {
			conn = DriverManager.getConnection(url, "sa", "sa");
			st = conn.createStatement();
			n = st.executeUpdate(sql);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			try {
				if (rs != null) {
					rs.close();
				}
				if (st != null) {
					st.close();
				}
				if (conn != null) {
					conn.close();
				}
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		return n;
	}

	public int AddPerson(String sql, String userName, String passWord) {
		int n = 0;
		try {
			conn = DriverManager.getConnection(url, "sa", "sa");
			pst = conn.prepareStatement(sql);
			//RegisterBean register = new RegisterBean();
			pst.setString(1, userName);
			pst.setString(2, passWord);
			n = pst.executeUpdate();

		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			try {
				if (st != null) {
					st.close();
				}
				if (conn != null) {
					conn.close();
				}
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
		return n;
	}

	public MyBean Modinfo(int userID) {
		MyBean myBean = new MyBean();
		String sql = "select * from login where userID=?";
		try {
			conn = DriverManager.getConnection(url, "sa", "sa");
			pst = conn.prepareStatement(sql);
			pst.setInt(1, userID);
			rs = pst.executeQuery();
			while(rs.next()){
				myBean.setUserID(rs.getInt("userID"));
				myBean.setPassWord(rs.getString("passWord"));
				myBean.setUserName(rs.getString("userName"));
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			try {
				if (rs != null) {
					rs.close();
				}
				if (st != null) {
					st.close();
				}
				if (conn != null) {
					conn.close();
				}
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		return myBean;
	}
}