Struts <html:select> drop down box example

Download this Struts select option (drop down box) example – Struts-Select-Option-Example.zip

In this Struts example, you will learn how to create a HTML select option (drop down box) with Struts <html:select> and <html:option> tag. The <select> tag is used to create a select list (drop-down list); while <option> tags inside the select element define the available options in the list.

1. Folder Structure

This is the final project structure created by Maven. Please create the corresponding folders.

2. Action class

Create an Action class, do nothing but forward the request.

HtmlSelectOptionAction.java

package com.mkyong.common.action;
 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
 
import com.mkyong.common.form.HtmlSelectOptionForm;
 
public class HtmlSelectOptionAction extends Action{
 
	public ActionForward execute(ActionMapping mapping,ActionForm form,
			HttpServletRequest request,HttpServletResponse response) 
        throws Exception {
 
	  HtmlSelectOptionForm htmlSelectOptionForm = (HtmlSelectOptionForm)form;
 
	  return mapping.findForward("success");
	}
 
}

3. Properties file

Create a properties file, and declare the error and label messages.

Common.properties

#error message
error.common.html.select.required = Please select a year.
 
#label message
label.common.html.select.name = Select a year 
label.common.html.select.button.submit = Submit
label.common.html.select.button.reset = Reset

4. ActionForm

Create a ActionForm, contains a year variable to hold the select option value.

HtmlSelectOptionForm.java

package com.mkyong.common.form;
 
import javax.servlet.http.HttpServletRequest;
 
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionMessage;
 
public class HtmlSelectOptionForm extends ActionForm{
 
	String year;
 
	public String getYear() {
		return year;
	}
 
	public void setYear(String year) {
		this.year = year;
	}
 
	@Override
	public ActionErrors validate(ActionMapping mapping,
	  HttpServletRequest request) {
 
	    ActionErrors errors = new ActionErrors();
 
	    if( getYear() == null || ("".equals(getYear())))
	    {
	       errors.add("common.select.err",
	    	 new ActionMessage("error.common.html.select.required"));
	    }
 
	    return errors;
	}
 
	@Override
	public void reset(ActionMapping mapping, HttpServletRequest request) {
		// reset properties
		year = "";
	}
 
}

5. JSP Page

Use the Struts’s HTML tag <html:select> and <html:option> to create a HTML drop down list.

select.jsp

<%@taglib uri="http://struts.apache.org/tags-html" prefix="html"%>
<%@taglib uri="http://struts.apache.org/tags-bean" prefix="bean"%>
 
<html>
<head>
</head>
<body>
<h1>Struts html:select example</h1>
 
<html:form action="/Select">
 
<html:messages id="err_name" property="common.select.err">
<div style="color:red">
	<bean:write name="err_name" />
</div>
</html:messages>
 
<div style="padding:16px">
 
<bean:message key="label.common.html.select.name" /> :
<html:select property="year">
    <html:option value="">-- None --</html:option>
	<html:option value="1980">1980</html:option>
	<html:option value="1981">1981</html:option>
	<html:option value="1982">1982</html:option>
	<html:option value="1983">1983</html:option>
	<html:option value="1984">1984</html:option>
	<html:option value="1985">1985</html:option>
</html:select>
</div>
 
<div style="padding:16px">
	<div style="float:left;padding-right:8px;">
		<html:submit>
                   <bean:message key="label.common.html.select.button.submit" />
                </html:submit>
	</div>
	<html:reset>
           <bean:message key="label.common.html.select.button.reset" />
        </html:reset>
</div>
 
</html:form>
 
</body>
</html>

Get the selected drop down box value from htmlSelectOptionForm form and display it

display.jsp

<%@taglib uri="http://struts.apache.org/tags-bean" prefix="bean"%>
 
<html>
<head>
</head>
<body>
<h1>
	Your selected year is : 
	<bean:write name="htmlSelectOptionForm" property="year" />
</h1>
</body>
</html>

6. struts-config.xml

Create a Struts configuration file and link all together.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts-config PUBLIC 
"-//Apache Software Foundation//DTD Struts Configuration 1.3//EN" 
"http://jakarta.apache.org/struts/dtds/struts-config_1_3.dtd">
 
<struts-config>
 
	<form-beans>
		<form-bean
			name="htmlSelectOptionForm"
			type="com.mkyong.common.form.HtmlSelectOptionForm"/>
 
	</form-beans>
 
	<action-mappings>
 
	        <action
			path="/SelectPage"
			type="org.apache.struts.actions.ForwardAction"
			parameter="/pages/select.jsp"/>
 
		<action
			path="/Select"
			type="com.mkyong.common.action.HtmlSelectOptionAction"
			name="htmlSelectOptionForm"
			validate="true"
			input="/pages/select.jsp"
			>	
 
			<forward name="success" path="/pages/display.jsp"/>
		</action>
	</action-mappings>
 
	<message-resources
		parameter="com.mkyong.common.properties.Common" />
 
</struts-config>

7. web.xml

Final step, create a web.xml and integrate the Struts framework.

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >
 
<web-app>
  <display-name>Maven Struts Examples</display-name>
 
  <servlet>
    <servlet-name>action</servlet-name>
    <servlet-class>
        org.apache.struts.action.ActionServlet
    </servlet-class>
    <init-param>
        <param-name>config</param-name>
        <param-value>
         /WEB-INF/struts-config.xml
        </param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
 
  <servlet-mapping>
       <servlet-name>action</servlet-name>
       <url-pattern>*.do</url-pattern>
  </servlet-mapping>
 
</web-app>