在Struts 2中未显示有关选择下拉菜单的错误消息

Question

I have following code

Action:

private String yourSearchEngine;
private String selectedUserGroupId;   

//with both getter and setter.

public void validate(){
    if("-1".equals(getYourSearchEngine())){
        addFieldError("yourSearchEngine", getText("select search engine"));
        addressList.add("Select search engine");
    }

    if("-1".equals(getSelectedUserGroupId())){
        addFieldError("selectedUserGroupId", "select user group");
        addressList.add("Select user group");
    }

JSP page:

<s:select   label="Search engine:" 
            headerKey="-1" 
            headerValue="Select Search Engines"
            list="searchEngine" 
            name="yourSearchEngine" 
            id="yourSearchEngine"
            value="defaultSearchEngine" 
            tooltip="Select Search Engines" />

<s:select   label = "User Group:" 
            list = "userGroupList" 
            listKey = "userGroupId"
            listValue = "userGroup"
            name = "selectedUserGroupId"
            id="selectedUserGroupId"
            headerKey="-1" 
            headerValue="Select Group" 
            tooltip="Select Group" ></s:select>

when I submit the form and value is -1 , it is not display error message. I can see that addFieldError code run addressList get populated.

But is not displaying error message.

Answer 1

By default Struts2 uses xhtml theme. This theme is designed to display field errors on input elements bound to the action. If errors aren't displayed then make sure you have used xhtml theme, or you can add explicitely theme attribute to each select tag or to the form tag. You can also configure a theme to be used by default using struts constant.

<s:select   label="Search engine:" 
            headerKey="-1" 
            headerValue="Select Search Engines"
            list="searchEngine" 
            name="yourSearchEngine" 
            id="yourSearchEngine"
            value="defaultSearchEngine" 
            tooltip="Select Search Engines" 
            theme="xhtml" />

<s:select   label = "User Group:" 
            list = "userGroupList" 
            listKey = "userGroupId"
            listValue = "userGroup"
            name = "selectedUserGroupId"
            id="selectedUserGroupId"
            headerKey="-1" 
            headerValue="Select Group" 
            tooltip="Select Group" 
            theme="xhtml" />

See where you can specify a theme in struts tags. Specifying The Theme Struts 2 Should Use .

You can specify the theme on a per Struts 2 tag basis or you can use one of the following methods to specify what theme Struts 2 should use:

• The theme attribute on the specific tag
• The theme attribute on a tag's surrounding form tag
• The page-scoped attribute named "theme"
• The request-scoped attribute named "theme"
• The session-scoped attribute named "theme"
• The application-scoped attribute named "theme"
• The struts.ui.theme property in struts.properties (defaults to xhtml )

To make this effective on the page make sure the INPUT result configured to the action with defaultStack of interceptors.