Fielderror Tag (Non-Form UI Tags) Example

In this section, we are going to describe the fielderror tags. The fielderror tag is a UI tag that renders field errors if they exists.

Add the following code snippet into the struts.xml file.
struts.xml

<action name="fieldError">
         <result>/pages/uiTags/loginFielderrorTag.jsp</result>
</action>

<action name="checkUser" class="net.roseindia.checkField">
       <result name="input">/pages/uiTags/loginFielderrorTag.jsp</result>
       <result name="error">/pages/uiTags/fielderrorTag.jsp</result>
       <result>/pages/uiTags/validUser.jsp</result>
</action>

Develop an action class using addFieldError(String fieldName, String errorMessage) method. This method adds an error message for a given field to the corresponding jsp page.
checkField.java


package net.roseindia;

import com.opensymphony.xwork2.ActionSupport;



public class checkField extends ActionSupport {

  private String username = null;

  private String password = null;

  public String execute() throws Exception{

    if ((getUsername().equals("Roseindia")) && 

           (getPassword().equals("Roseindia"))){

      addActionMessage("Valid User!");

      return SUCCESS;

    }

    if(!(getUsername().equals("Roseindia")))

    addFieldError("username","Invalid username!");



    if(!(getPassword().equals("Roseindia")))

    addFieldError("password","Invalid password!");



    return ERROR;

  }

  //Set and get the user name

  public void setUsername(String username){

    this.username = username;

  }

  public String getUsername(){

    return username;

  }

  //set and get the password

  public void setPassword(String pass){

    password = pass;

  }

  public String getPassword(){

    return password;

  }

}

Create a Login jsp page as shown:
loginFielderrorTag.jsp


<%@ taglib prefix="s" uri="/struts-tags" %>



<html>

  <head>

    <title>Fielderror Tag Example!</title>

  <body>

  <s:form action="checkUser" method="POST">

  <s:textfield label="User Name" name="username" size="20" maxlength="10" />

  <s:password label="Password" name="password" size="20" maxlength="10" />

  <s:submit value="Submit" />

  </s:form>

  

  </body>

</html>

Create a jsp page that will display your field error messages (when fails to logged-in) using the empty <s:fielderror/>tag as shown:
fielderrorTag.jsp


<%@ taglib prefix="s" uri="/struts-tags" %>



<html>

  <head>

    <title>Fielderror Tag Example!</title>

  <body>

  <h1>

  <s:fielderror />

        

  </h1>

  <a href="/struts2tags/roseindia/fieldError.action">Go Back</a>

  </body>

</html>

Create a jsp page that will display your messages (when succeed to logged-in) using the empty <s:actionmessage />tag as shown:
validUser.jsp


<%@ taglib prefix="s" uri="/struts-tags" %>



<html>

  <head>

    <title>Fielderror  Tag Example!</title>

  <body>

  <h1>

  <s:actionmessage />

  </h1>

  </body>

</html>

you will see the output of the loginFielderrorTag.jsp as shown below:

Enter the wrong user name and correct password in the login page

you will get the following output:

Enter the correct user name and wrong password in the login page

you will get the following output:

Enter incorrect values in both fields of the login page

you will get the following output:

Enter correct values in both fields of the login page

you will get the following output: