jsp中下拉列表框的一种实现思路

SelBoxManager.java
import java.util.ArrayList;
import java.util.List;

import javax.servlet.jsp.PageContext;

import org.apache.struts.util.LabelValueBean;

public class SelBoxManager {

 public static void prepareSelBoxCommon(PageContext page, String typeCode, int pos, String key) {
  List mList = prepareSelBox(page, typeCode, pos);
  page.setAttribute(key, mList);
 }
 
 public static void prepareSelBoxCommonNoSel(PageContext page, String typeCode, int pos, String key) {
  List mList = prepareSelBox(page, typeCode, pos);
  addNoSelection(mList);
  page.setAttribute(key, mList);
 }

 public static void prepareSelBoxCommonWithCode(PageContext page, String typeCode, int pos, String key) {
  List mList = prepareSelBoxWithCode(page, typeCode, pos);
  page.setAttribute(key, mList);
 } 
 
 public static void prepareSelBoxCommonNoSelWithCode(PageContext page, String typeCode, int pos, String key) {
  List mList = prepareSelBoxWithCode(page, typeCode, pos);
  addNoSelection(mList);
  page.setAttribute(key, mList);
 }
 
    private static void addNoSelection(List mList) {
        LabelValueBean pData = new LabelValueBean("", "--");
        mList.add(0, pData);
    }
   
 private static List prepareSelBox(PageContext page, String typeCode, int pos) {
  List mList = (List) page.getAttribute(typeCode);
  if (mList == null) {
   // TODO 未実装
   // SELECT .....
   page.setAttribute(typeCode, mList);
  }

  return mList;
 }
 
 private static List prepareSelBoxWithCode(PageContext page, String typeCode, int pos) {
  List mList = prepareSelBox(page, typeCode, pos);

  // 表示内容[区分値 区分]
  List newList = new ArrayList();
  for (int i = 0; i < mList.size(); i++) {
   LabelValueBean pData = (LabelValueBean) mList.get(i);
   String label = pData.getLabel();
   label = label + " " + pData.getValue();
   newList.add(new LabelValueBean(pData.getValue(), label));
  }
  return newList;
 }
} 

 

jsp中通过

<%SelBoxManager.prepareSelBoxCommonNosel(pageContext, "0638",  1, "SAMPLE_LIST");  %>

<logic:notEmpty name="SAMPLE_LIST">

 <html:select property="">

<html:options collection="SAMPLE_LIST" property="value"  labelValue="label"/>

</html:select>