Java 数据库操作类

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

/**********
 * 
 * @author aq
 * 
 */
public class DBOper {
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;

    public Connection getConn(String server, String dbname, String user, String pwd)
            throws ClassNotFoundException, SQLException, InstantiationException, IllegalAccessException {
        String DRIVER = "com.mysql.jdbc.Driver";
        String URL = "jdbc:mysql://" + server + ":3306/" + dbname + "?user=" + user + "&password=" + pwd
                + "&useUnicode=true&characterEncoding=utf8";
        Class.forName(DRIVER).newInstance();
        conn = DriverManager.getConnection(URL);
        return conn;
    }

    public void closeAll() {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (pstmt != null) {
            try {
                pstmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    public ResultSet executeQuery(String preparedSql, String[] param) {
        try {
            pstmt = conn.prepareStatement(preparedSql);
            if (param != null) {
                for (int i = 0; i < param.length; i++) {
                    pstmt.setString(i + 1, param[i]);
                }
            }
            rs = pstmt.executeQuery();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return rs;
    }

    public int executeUpdate(String preparedSql, String[] param) {
        int num = 0;
        try {
            pstmt = conn.prepareStatement(preparedSql);
            if (param != null) {
                for (int i = 0; i < param.length; i++) {
                    pstmt.setString(i + 1, param[i]);
                }
            }
            num = pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return num;
    }

}