带有Servlet过滤器的JSF 2.2

Question

I use jsf 2.2 and i want to redirect jsf pages to login page without session i didn't use http session here.iam trying to use session scoped variable and check whelther variable is null or not and redirect it to login page because session scoped is enough instead of http session right??

my filter class is

package com.invoice;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet Filter implementation class sessionfilter
 */


public class sessionfilter implements Filter {

    /**
     * Default constructor. 
     */
    public sessionfilter() {
        // TODO Auto-generated constructor stub
    }

    /**
     * @see Filter#destroy()
     */
    public void destroy() {
        // TODO Auto-generated method stub
    }

    /**
     * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
     */
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        // TODO Auto-generated method stub
        // place your code here

        // pass the request along the filter chain
        HttpServletResponse httpResponse = (HttpServletResponse) response;
        login b=new login();
        if(b.username=="")
        {

            httpResponse.sendRedirect("Login.xhtml");   

        }
        else{
        chain.doFilter(request, response);
        }
    }

    /**
     * @see Filter#init(FilterConfig)
     */
    public void init(FilterConfig fConfig) throws ServletException {
        // TODO Auto-generated method stub
    }

}

my bean class is here

package com.invoice;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

import javax.faces.bean.SessionScoped;
import javax.faces.context.FacesContext;


public class login {

    String username,userpassword,errormess,navipg;



    public String getNavipg() {
        return navipg;
    }

    public void setNavipg(String navipg) {
        this.navipg = navipg;
    }

    public String getErrormess() {
        return errormess;
    }

    public void setErrormess(String errormess) {
        this.errormess = errormess;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getUserpassword() {
        return userpassword;
    }

    public void setUserpassword(String userpassword) {
        this.userpassword = userpassword;
    }
    public String navigate()
    {
        try
        {

            Class.forName("oracle.jdbc.driver.OracleDriver");
            Connection con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:XE","invoice","google");
            Statement stmt=con.createStatement(); 
            ResultSet rs=stmt.executeQuery("select username,password from usertable where username='"+username+"' and password='"+userpassword+"' ");
            if(rs.next())
            {

                setErrormess("");
                navipg="invoiceinfo";


            }
            else

            {

                setErrormess("Invalid Login credentials");
                username="";
                navipg="Login";


            }

        }
        catch(Exception e)
        {

            e.printStackTrace();

        }
        return navipg;

    }
    public String logout()
    {

         FacesContext.getCurrentInstance().getExternalContext().invalidateSession();
            return "Login";

    }




}

my web.xml filter tag is

<filter>
   <filter-name>sessionfilter</filter-name>
   <filter-class>com.invoice.sessionfilter</filter-class>

</filter>
<filter-mapping>
   <filter-name>sessionfilter</filter-name>
   <url-pattern>/Jsf Invoice System/*</url-pattern>
</filter-mapping>

but page is not getting redirected

Answer 1

b.username=="" will NEVER be true .

Required Reading

• How do I compare strings in Java?
• Basic String comparison in Java