struts2的select标签用法实例分析

<%
java.util.HashMap map = new java.util.LinkedHashMap();
map.put(1,"aaa");
map.put(2,"bbb");
map.put(3,"c");
request.setAttribute("map",map);
request.setAttribute("aa","2");
%>
<s:select list="#request.map" label="abc" listKey="key" listValue="value"
 value="#request.aa" headerKey="0" headerValue="aabb"></
s:select
>

public class Program implements Serializable {
  /  serialVersionUID /
  private static final long serialVersionUID = 1L;
  private int programid;
  private String programName;
  public int getProgramid() {
    return programid;
  }
  public void setProgramid(int programid) {
    this.programid = programid;
  }
    public String getProgramName() {
    return programName;
  }
  public void setProgramName(String programName) {
    this.programName = programName;
  }
}

 xxxextends extends ActionSupport {
  private List<Program> programs ;
    public List<Program> getPrograms() {
    return programs;
  }
  public void setPrograms(List<Program> programs) {
      this.programs = programs;
  }
}

<s:select list="programs" listValue="programName" listKey="programid" name="program" id="program"
headerKey="0l" headerValue="" value="bean.programid "></s:select>