最简单java 反射原理示例

package com.accp; import java.sql.*; /** * * @author Administrator * */ public class BaseDao { private Connection conn; private Statement stmt; private ResultSet rs; public static void main(String[] args) throws SQLException { BaseDao db = new BaseDao(); String sql = "select * from UserInfo"; int pageSize = 2;//每页显示将行 int pageNow = 3; //当前第二页 ResultSet rs = db.executeQuery(sql); if(!rs.next()) return; // 将光标移动到给定的游标地址 rs.absolute((pageNow-1)*pageSize+1); for (int i = 0; i < pageSize; i++) { System.out.println("编号 ： "+ rs.getString(1)+ " 用户名 ： " + rs.getString(2) + " 密码 ： " + rs.getString(3)); if(!rs.next()) break; } } public BaseDao() { try { Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); conn = DriverManager.getConnection("jdbc:odbc:test"); stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE); }catch(Exception ex) { System.out.println(ex); } } public void executeUpdate(String sql) throws SQLException { stmt.executeUpdate(sql); } public ResultSet executeQuery(String sql) throws SQLException { rs = stmt.executeQuery(sql); return rs; } public void close() { if(rs!=null) { try { rs.close(); }catch(Exception ex) {} } if(stmt!=null) { try { stmt.close(); }catch(Exception ex) {} } if(conn!=null) { try { conn.close(); }catch(Exception ex) {} } } }