用CashFilter实现页面级缓存实践

1.mysql在本地localhost的test数据库 建person表,暂以字段id,name,passWord ,表中可输入一行值.

2.建类 DAOUtil

import  Java.sql.Connection;
import  java.sql.DriverManager;

public class DAOUtil {
    public DAOUtil() {
    }

   public static Connection getConn() {
        Connection conn = null;
        String db_url = "jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=gb2312";
        String db_user = "root";
        String db_password= "admin";
        String db_driver = "com.mysql.jdbc.Driver";

        try {
            Class.forName(db_driver);
            conn = DriverManager.getConnection(db_url, db_user, db_password);
             } catch (Exception ex) {
             ex.printStackTrace();
        }
        return conn;
    }

  /**
  * dbclose
  * 关闭Connection，Statement
  * @param conn Connection
  * @param stmt Statement
  */
 public static void dbclose(Connection conn, Statement stmt) {
       try {
           if (stmt != null)
               stmt.close();
       } catch (Exception e) {
         e.printStackTrace();
       }
       try {
           if (conn != null)
               conn.close();
       } catch (Exception e) {
          e.printStackTrace();
       }
   }

}

3.建类 PersonDAO

import java.util.*;
import java.sql.Connection;
import java.sql.Statement;
import java.sql.ResultSet;

public class PersonDAO {
    static PersonDAO pdao;
    public static PersonDAO getInstance() {
        if (pdao == null) {
            synchronized (PersonDAO.class) {
                pdao = new PersonDAO();
            }
        }
        return pdao;
    }