运用类反射机制简化Struts应用程序的开发

Connection conn=DriverManager.getConnection("JDBC URL ");
      sql=" select *  from some tables ";
PreparedStatement stmt = conn.prepareStatement(sql);
      ResultSet rs = stmt.executeQuery();
ArrayList array=new ArrayList();
while (rs.next()) ...{
   AActionForm actionForm =new AActionForm ();
   actionForm.setId(rs.getString("Id"));
   actionForm.setName(rs.getString("Name"));
   array.add(actionForm);
}

<logic:present name=" array " scope="request">
<logic:iterate name=" array " id=" array "
type="com.bhsky.webis.Goods">
     <tr align="center">
        <td class="table2">
<bean:write name=" array " property="goodsid"/>
</td>
        <td class="table2">
<bean:write name=" array " property="goodsname"/>
</td>
      </tr>
  </logic:iterate>
</logic:present>

 package com.bhsky.webis.system;
import org.apache.struts.action.*;
import javax.servlet.http.*;

public class UsersActionForm extends ActionForm ...{
private String usr_id;
private String usr_name;
public void setUsr_id(String usr_id) ...{
    this.usr_id = usr_id;
}
public String getUsr_id() ...{
    return usr_id;
}
public String getUsr_memo() ...{
    return usr_memo;
}
public void setUsr_name(String usr_name) ...{
    this.usr_name = usr_name;
}
}

 /**//////////////////////////////////////////////////////////////////////////////
    //Function: 完成ResultSet对象向ArrayList对象为集合的对象的转化
    //Para:sql,指定的查询Sql
   //Para:className,Sql相对应得JavaBean/FormBean类的名字
   //Return:以类className为一条记录的结果集，完成ResultSet对象向ArrayList对象为集
    //合的className对象的转化
  /**///////////////////////////////////////////////////////////////////////////////
  public ArrayList Select(String sql,String className)...{
    ArrayList paraList=new ArrayList();
    try...{
      if (conn == null)...{
        Connection();
      }
      PreparedStatement stmt = conn.prepareStatement(sql);
      ResultSet rs = stmt.executeQuery();
      String recordValue="";
      Object c1=null;
      paraList=new ArrayList();
      ResultSetMetaData rsmd = rs.getMetaData();
      int columnCount = rsmd.getColumnCount();
      while (rs.next())...{
          c1=Class.forName(className).newInstance();
          for (int i=1; i<=columnCount; i++) ...{
            if(rs.getString(rsmd.getColumnName(i))!=null)...{
              recordValue=rs.getString(rsmd.getColumnName(i));
            }else...{
              recordValue="";
            }
Method
m=c1.getClass().getMethod(getSetMethodName(rsmd.getColumnName(i)),
new Class[]...{recordValue.getClass()});
            m.invoke (c1, new Object[]...{recordValue});
          }
          paraList.add(c1);
      }
    }catch(SQLException ex)...{

}catch(ClassNotFoundException e)...{
}catch(NoSuchMethodException e) ...{
}catch(InvocationTargetException e)...{
}catch (IllegalAccessException e)...{
}catch(InstantiationException e)...{
} finaly...{
        closeConnection();
return paraList;
}
  }

//Function:取得用户列表
  //Para:
  //Return:返回用户列表
  /**//////////////////////////////////////////////////////////////////////////
  public ArrayList getUsers()...{
      ArrayList ret=null;
      DatabaseManage db=new DatabaseManage();
      String sql=" select usr_id,usr_name "
          +" from users " ;
      ret=db.Select(sql," com.bhsky. webis.system.UsersActionForm");
      return ret;
  }

public ActionForward execute(ActionMapping actionMapping, ActionForm actionForm,
                   HttpServletRequest request, HttpServletResponse httpServletResponse)
   ...{
    /**//**@todo: complete the business logic here, this is just a skeleton.*/
    UsersActionForm uaf=(UsersActionForm)actionForm;
    SystemService ubb=new SystemService();
    ArrayList userList=ubb.getUsers();
    request.setAttribute("userList",userList);
    ActionForward actionForward=actionMapping.findForward(url);
    return actionForward;
  }

<table width="700" class="1" border="1" cellspacing="1" align="center">
        <tr>
          <td class="list" >用户ID</td>
          <td class="list" >姓&#160&#160名</td>
        </tr>
        <logic:present name="userList" scope="request">
          <logic:iterate name="userList" id="userList"
type="com.bhsky.webis.system.UsersActionForm">
        <tr>
          <td class="cell1"  height="22"><bean:write name="userList"
property="usr_id"/></td>
          <td class="cell1"  height="22"><bean:write name="userList"
property="usr_name"/></td>
        </tr>
        </logic:iterate>
      </logic:present>
</table>