com.github.stefanbirkner.filtertools.filter

Class OptionalFilter

java.lang.Object

com.github.stefanbirkner.filtertools.filter.OptionalFilter

All Implemented Interfaces:

javax.servlet.Filter

public class OptionalFilter
extends Object
implements javax.servlet.Filter

Combine a filter and a Predicate or Hamcrest Matcher. The filter is executed if the predicate or the matchers matches and skipped otherwise.

Example

Define a predicate and wrap the base filter.

 public class FrenchSomethingFilter extends OptionalFilter {
   public FrenchSomethingFilter() {
     super(new HasLocale(Locale.FRENCH), new SomethingFilter());
   }
 }
 

Add the filter to your web.xml.

 <filter>
   <filter-name>FrenchSomethingFilter</filter-name>
   <filter-class>your.package.FrenchSomethingFilter</filter-class>
 </filter>
 <filter-mapping>
   <filter-name>FrenchSomethingFilter</filter-name>
   <url-pattern>/*</url-pattern>
 </filter-mapping>
 

You can provide init-params that will be dispatched to the base filter.

Lambda Support

You can use Lambda expressions as predicates if you're using Java 8.

 public class FrenchSomethingFilter extends OptionalFilter {
   public FrenchSomethingFilter() {
     super(
       (request) -> request.getLocale().equals(Locale.FRENCH),
       new SomethingFilter());
   }
 }
 

Hamcrest Support

You can use Hamcrest Matchers as predicates.

 public class FrenchSomethingFilter extends OptionalFilter {
   public FrenchSomethingFilter() {
     super(
       hasProperty("locale", equalTo(Locale.FRENCH)),
       new SomethingFilter());
   }
 }
 

Constructor Summary

Constructors

Constructor and Description
OptionalFilter(org.hamcrest.Matcher<? super javax.servlet.ServletRequest> matcher, javax.servlet.Filter baseFilter)
OptionalFilter(Predicate<? super javax.servlet.ServletRequest> predicate, javax.servlet.Filter baseFilter)

Method Summary

Modifier and Type	Method and Description
void	destroy()
void	doFilter(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain filterChain)
void	init(javax.servlet.FilterConfig filterConfig)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

OptionalFilter

public OptionalFilter(Predicate<? super javax.servlet.ServletRequest> predicate,
                      javax.servlet.Filter baseFilter)

OptionalFilter

public OptionalFilter(org.hamcrest.Matcher<? super javax.servlet.ServletRequest> matcher,
                      javax.servlet.Filter baseFilter)

Method Detail

init

public void init(javax.servlet.FilterConfig filterConfig)
          throws javax.servlet.ServletException

Specified by:

init in interface javax.servlet.Filter

Throws:

javax.servlet.ServletException

doFilter

public void doFilter(javax.servlet.ServletRequest request,
                     javax.servlet.ServletResponse response,
                     javax.servlet.FilterChain filterChain)
              throws IOException,
                     javax.servlet.ServletException

Specified by:

doFilter in interface javax.servlet.Filter

Throws:

IOException

javax.servlet.ServletException

destroy

public void destroy()

Specified by:

destroy in interface javax.servlet.Filter