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;
     }

 }