< html:errors /> html tag

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This Tag displays a set of error messages prepared by a business logic component and stored in the ActionErrors object, a String, or a String array . you must have defined an application scope MessageResources bean under the default attribute name.

 The message keys specified in the following attributes :-errors.header :- This message text will end with <ul> to start the error messages list. Text will be rendered before the error messages list.
errors.footer :- This message text will begin with </ul> to end the error messages list .Text that will be rendered after the error messages list

errors.prefix :- Text that will be rendered before each individual error in the list

errors.suffix :- First Each individual error in the list after that text will be rendered.

The struts Errors tag have following attributes:-
1.bundle :-The servlet context attribute key for the MessageResources instance to use. if this is not specified than defaults to the application resources configured for our action 
servlet.
2.name :-Error messages can be stored in this bean. If not present than it specified 
by the Globals.ERROR_KEY constant string will be used.

The Following are many other attributes which we can use :footer header locale prefix suffix property


Directory Structure of ErrorsTagExample in Struts 1.3 Using MyEclipse IDE



index.jsp

<%@taglib uri="http://struts.apache.org/tags-html" prefix="html"%>
<%@taglib uri="http://struts.apache.org/tags-bean" prefix="bean"%>
<html>
<head>
<title>Struts html:errors tag example</title>
</head>
<body>
<h3>Struts html:errors tag example</h3>
<div style="color: red;">
<html:errors/>
</div>
<html:form action="/errorsAction">
<bean:message key="label.name"/>:
<html:text property="name" name="errorsForm"/><br/>
<bean:message key="label.password"/>:
<html:text property="password" name="errorsForm"/><br/>
<br/>
<html:submit><bean:message key="label.submit" /></html:submit>
<html:reset><bean:message key="label.reset" /></html:reset>
</html:form>
</body>
</html>

web.xml

<!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>

struts-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts-config PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 1.3//EN" 
"http://struts.apache.org/dtds/struts-config_1_3.dtd">
<struts-config>
<form-beans>
<form-bean name="errorsForm" type="org.r4r.struts.ErrorsForm"/>
</form-beans>
<global-exceptions />
<global-forwards />
<action-mappings >
<action path="/errors" type="org.apache.struts.actions.ForwardAction" parameter="/index.jsp"/>
<action path="/errorsAction" type="org.r4r.struts.ErrorsAction" name="errorsForm" input="/index.jsp">	
<forward name="success" path="/success.jsp"/>
</action>
</action-mappings>
<message-resources parameter="org.r4r.struts.ApplicationResources" />
</struts-config>

ErrorsForm.java

package org.r4r.struts;

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;

@SuppressWarnings("serial")
public class ErrorsForm extends ActionForm {
	private String name;
	private String password;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public ActionErrors validate(ActionMapping mapping, HttpServletRequest request) {
		ActionErrors errors = new ActionErrors();
		if (name == null || name.length() < 1) {
		errors.add("name", new ActionMessage("error.name.required"));
		}
		if (password == null || password.length() < 1) {
		errors.add("password", new ActionMessage("error.password.required"));
		}
		return errors;
		}
}

ErrorsAction.java

package org.r4r.struts;

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;

public class ErrorsAction extends Action {
	public ActionForward execute(ActionMapping mapping,ActionForm form,
	HttpServletRequest request,HttpServletResponse response) 
	throws Exception{
		@SuppressWarnings("unused")
		ErrorsForm passwordForm=(ErrorsForm)form;
		return mapping.findForward("success");
	}
}

ApplicationResources.properties

#label message
label.name = User Name 
label.password = Password
label.submit = Submit
label.reset = Reset
error.name.required= Name is required<br/>
error.password.required= Password is required

success.jsp

<%@taglib uri="http://struts.apache.org/tags-bean" prefix="bean"%>
 <html>
<head>
<title>Struts html:errors tag example</title>
</head>
<body>
<h3>Struts html:errors tag Example</h3>
<h4>Welcome , <bean:write name="errorsForm" property="name" /></h4>
</body>
</html>

Output





Struts 2.0 Tutorial and Example
Spring 2.5 Tutorial and Example
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Spring 2.5 MVC Example