Struts2 's Select Tag Usage example Analysis _jsp programming

The example in this article describes the Select label usage of STRUTS2. Share to everyone for your reference. Specifically as follows:

A small problem is encountered in the project, summed up.

About the use of the STRUTS2 select tag.

Struts2 the data from other tables to fill the Drop-down menu with the <s:select> tab display.

The struts2 version is 2.1.8

<s:select
List= ""
Name= ""
Value= ""
Headerkey= ""
Headervalue= ""
Listkey= ""
Listvalue= ""
/>
(1) list is a must-have property list can store the map list set type of data

List property: Usually defined in action, must be a source that can be iterated, such as a list, Map, set, and so on. If it is a map, then the key of the map corresponds to the value in the Value,map in the Select tab corresponding to option in the Select label. If it is a list or a set, it can be specified by Listkey and ListValue.

(2) If the list is empty Headkey and headvalue cannot be empty. Listkey and Listvalue:listkey correspond to the value in the Select label, and listvalue corresponds to option in the Select label

(3) Name property: That is, the names of the select in the form.

The following details explain the meaning of each property.

Headervalue: Default Value
Headerkey: Default name
List: source data (You can get the list from the database in the action method)
Name: location where the selected data is stored (here we < define the object > in the action in the attribute value username of object obj)
Listkey: Name of the dropdown option
ListValue: Value of the dropdown option
Value: Default value

1. First example:

Copy Code code as follows:

<s:select list= "{' AA ', ' BB ', ' cc '}" theme= "simple" headerkey= "headervalue=" ></s:select>

2. Second example:

Copy Code code as follows:

<s:select list= "#{1: ' AA ', 2: ' BB ', 3: ' CC '}" label= "abc" listkey= "Key" listvalue= "value" headerkey= "0" headervalue= " Aabb ">

3. A third example:

<%
Java.util.HashMap map = new Java.util.LinkedHashMap ();
Map.put (1, "AAA");
Map.put (2, "BBB");
Map.put (3, "CCC");
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
>

Headerkey Headervalue to set the default value
4. Fourth example

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;
  }
}

On the JSP page

<s:select list= "Programs" listvalue= "ProgramName" listkey= "ProgramID" name= "program" id= "program"
headerkey= "0l" headervalue= "" value= "Bean.programid" ></s:select> 

Among them: list= "Programs" is the List,listvalue= "ProgramName" for the action inside the <option value= "xxx" >value</option> Corresponding to the fields inside the bean programname
Listkey= "ProgramID" is <option value= "xxx", corresponding to the field in the Bean programid,value= "Bean.programid" for the set Select selected value, S:select will automatically select the value for key in the bean

I hope this article will help you with the design of struts.