Jakarta Commons BeanUtils 学习

参考： http://www.duduwolf.com/wiki/2007/296.html
      http://www.chinaitpower.com/A/2005-07-03/150232.html
1)普通的Bean处理  不管是什么Set参数为3个 ( 对象本身, 属性名或属性内位置, 值 ) //list的 add 有点特别
                            Get参数为2个 ( 对象本身, 属性名或属性内位置 )
  

        Employee em  =   new  Employee();  //String name; String[] ss;  Map map; List list;
        BeanUtils.setProperty(em, " name " , " liukaiyi " );  //String set
        BeanUtils.setProperty(em, " ss " , new  String[]{ " 1 " , " 2 " , " 3 " }); //String[] set
           BeanUtils.setProperty(em,"ss[2]","google");  //String[2] set

        BeanUtils.setProperty(em, " map " , new  HashMap());   //Map set 
            BeanUtils.setProperty(em, " map(key) " , " value " );  //Map.put(Key,Value)
            
        BeanUtils.setProperty(em, " list " , new  ArrayList( Arrays.asList(  new  Object[ 20 ] ) )); //List有点特别
            BeanUtils.setProperty(em, " list[0] " , " list " );       //不可以直接添加？？？
            
        BeanUtils.setProperty(em, " avg " , " 23 " );       //int set
                
        
        System.out.println( BeanUtils.getSimpleProperty(em, " name " ) );   
        System.out.println( BeanUtils.getProperty(em, " ss[2] " ) );
        System.out.println( BeanUtils.getProperty(em, " map(key) " ) );
        
        System.out.println( BeanUtils.getProperty(em, " list[0].class " ) );  // 取的是 ==list.get(0).getClass()
        
        System.out.println( BeanUtils.getProperty(em, " avg " ) ); 

2)动态属性

  // 定义动态属性集
 DynaProperty[] props  =   new  DynaProperty[]{
     new  DynaProperty( " address " , java.util.Map. class ),
     new  DynaProperty( " subordinate " , mypackage.Employee[]. class ),
     new  DynaProperty( " firstName " , String. class ),
     new  DynaProperty( " lastName " ,  String. class )
      };
  // 创建动态类来设定动态属性值
    BasicDynaClass dynaClass  =   new  BasicDynaClass( " employee " ,  null , props);
    DynaBean employee  =  dynaClass.newInstance();
    employee.set( " address " ,  new  HashMap());
    employee.set( " subordinate " ,  new  mypackage.Employee[ 0 ]);
    employee.set( " firstName " ,  " Fred " );
    employee.set( " lastName " ,  " Flintstone " );

//也可以同上一样 提供统一 的Get Set 还是 字符操作 ^o^  哈哈
         BeanUtils.setProperty(bean,"address",new HashMap());
             BeanUtils.setProperty(bean,"address(ads1)","江西");
         BeanUtils.setProperty(bean,"name","liu");
         BeanUtils.setProperty(bean,"subordinate",new String[3]);
             BeanUtils.setProperty(bean,"subordinate[1]","heha");
         System.out.println(  BeanUtils.getProperty(bean,"address(ads1)") );
         System.out.println(  BeanUtils.getProperty(bean,"name") );
         System.out.println(  BeanUtils.getProperty(bean,"subordinate[1]") );

3）JDBC 扩展

 Connection conn  =  ;
    Statement stmt  =  conn.createStatement();
    ResultSet rs  =  stmt.executeQuery
    ( " select accountid, name from customers " );
    Iterator rows  =  ( new  ResultSetDynaClass(rs)).iterator();  // ResultSetDynaClass(java.sql.ResultSet resultSet)
     while  (rows.hasNext()) {
  // 利用动态bean进行输出
    DynaBean row  =  (DynaBean) rows.next();   //连实体Bean都可以不要了 
        BeanUtils.copyProperties( MyBean ,row );  //  bean<--dynaBean 就这样去得到值 ^o^ 
          MyBean.get Accountid();  ....           
    }
    rs.close();
    stmt.close();

4)HttpServletRequest 扩展

    HttpServletRequest request  =  ;
    MyBean bean  =  ;
    HashMap map  =   new  HashMap();
    Enumeration names  =  request.getParameterNames();
     while  (names.hasMoreElements()) {
      String name  =  (String) names.nextElement();
      map.put(name, request.getParameterValues(name));
    }
    BeanUtils.populate(bean, map); // bean<--map  struts好象是就用这个 Form