前面记得有过博客简单的介绍过JDBC和ODBC的区别，在Java开发中经常用到JDBC连接数据库，下面通过实例介绍如何实现：

连接

public class DbUtil {      public static Connection getConnection(){          Connection conn=null;          try {              Class.forName("oracle.jdbc.driver.OracleDriver");//找到oracle驱动器所在的类              String url="jdbc:oracle:thin:@localhost:1521:bjpowernode"; //URL地址              String username="drp";              String password="drp";              conn=DriverManager.getConnection(url, username, password);                        } catch (ClassNotFoundException e) {              // TODO Auto-generated catch block              e.printStackTrace();          } catch (SQLException e) {              // TODO Auto-generated catch block              e.printStackTrace();          }          return conn;      }      
          public static void close(PreparedStatement pstmt){          if(pstmt !=null){              try {                  pstmt.close();              } catch (SQLException e) {                                    e.printStackTrace();              }          }      }            public static void close(ResultSet rs){          if(rs !=null){              try {                  rs.close();              } catch (SQLException e) {                  // TODO Auto-generated catch block                  e.printStackTrace();              }          }      }  

添加

public void addUser(User user){          String sql="insert into t_user(user_id,user_name,PASSWORD,CONTACT_TEL,EMAIL,CREATE_DATE)values(?,?,?,?,?,?)"; //?为参数占位符          Connection conn=null;          PreparedStatement pstmt=null; //通常利用PreparedStatement进行操作，性能得到优化          try{              conn=DbUtil.getConnection();              pstmt=conn.prepareStatement(sql);              pstmt.setString(1, user.getUserId());              pstmt.setString(2,user.getUserName());              pstmt.setString(3, user.getPassword());              pstmt.setString(4, user.getContactTel());              pstmt.setString(5,user.getEmail());              //pstmt.setTimestamp(6,new Timestamp(System.currentTimeMillis()));              pstmt.setTimestamp(6, new Timestamp(new Date().getTime()));//获取当前系统时间              pstmt.executeUpdate();//执行增删改操作                        }catch(SQLException e){              e.printStackTrace();          }finally{              DbUtil.close(conn);              DbUtil.close(pstmt);                        }                    } 

查询

public User findUserById(String userId){          String sql = "select user_id, user_name, password, contact_tel, email, create_date from t_user where user_id=?";          Connection conn=null;          PreparedStatement pstmt=null;          ResultSet rs=null;//定义存放查询结果的结果集          User user=null;          try{              conn=DbUtil.getConnection();              pstmt=conn.prepareStatement(sql);              pstmt.setString(1,userId);              rs=pstmt.executeQuery();//执行查询操作              if(rs.next()){                                user=new User();                  user.setUserId(rs.getString("user_Id"));                  user.setUserName(rs.getString("user_name"));                  user.setPassword(rs.getString("password"));                  user.setContactTel(rs.getString("contact_Tel"));                  user.setEmail(rs.getString("email"));                  user.setCreateDate(rs.getTimestamp("create_date"));                           }          }catch(SQLException e){              e.printStackTrace();          }finally{              //按顺序进行关闭              DbUtil.close(rs);              DbUtil.close(pstmt);              DbUtil.close(conn);                        }          return user;      }  

总结

1、PreparedStatement与Statement的简单区别

2、与之前的知识进行联系