CODEWITHSUNDEEP
javaservletsservlet-filtersjava-ee-8
Sanders Gutiérrez
Sanders Gutiérrez

Reputation: 105

How to create correctly a Filter in Java EE 8 from Java code?

I want to create programmatically a Filter in Java EE 8 from Java Code, so I did this code in my application.

Gif captures: gif capture one - gif capture two

My filter is LoginFilter.java

package afrominga.filters;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;

@WebFilter
public class LoginFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        System.out.println("Hello from LoginFilter.");
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        System.out.println("I am running the LoginFilter tasks.");
    }

    @Override
    public void destroy() {
        System.out.println("Goodbie from LoginFilter");
    }
}

I have in my web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    <display-name>Archetype Created Web Application</display-name>

    <filter>
        <filter-name>LoginFilter</filter-name>
        <filter-class>afrominga.filters.LoginFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>LoginFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <error-page>
        <error-code>404</error-code>
        <location>/error/404.jsp</location>
    </error-page>
    <error-page>
        <error-code>500</error-code>
        <location>/error/500.jsp</location>
    </error-page>
</web-app>

So, at the time of to open my browser with the root path context of my application, the filter print in the output the text of my System.out, but my page is left blank and does not show me the home page. I don't understand why this happens, this would must forward to my home page because only print a text in my console.

can would someone help me? please

Upvotes: 1

Views: 2201

Answers (1)

Anonymous Beaver
Anonymous Beaver

Reputation: 419

One problem is that your doFilter() method. Right now, your filter is just printing and not passing the request along to the next filter/your application. You just need to add one line.

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        System.out.println("I am running the LoginFilter tasks.");
        filterChain.doFilter(request, response)
    }

Upvotes: 2

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