Remove Authenticator generic parameter from AuthFilterBuilder

Generic parameter that controls a type of a passed authenticator
to the `AuthFilterBuilder` is not actually needed. Type-safety is already
forced by the generic parameters C(credentials) and P(principal).
The user has to provide a class that implements interface
`Authenticator<C,P>`, and we don't care about concrete type of
this implementation, because it doesn't affect the auth filter.

This commit also moves the common logic of building auth filters to
the `AuthFilterBuilder` and adds some comments for the public API.

docs/source/manual/auth.rst

@@ -100,7 +100,7 @@ takes instances of ``BasicCredentials``:
     public void run(ExampleConfiguration configuration,
                     Environment environment) {
         environment.jersey().register(new AuthDynamicFeature(
-                new BasicCredentialAuthFilter.Builder<User, ExampleAuthenticator>()
+                new BasicCredentialAuthFilter.Builder<User>()
                     .setAuthenticator(new ExampleAuthenticator())
                     .setAuthorizer(new ExampleAuthorizer())
                     .setRealm("SUPER SECRET STUFF")
@@ -125,7 +125,7 @@ takes instances of ``String``:
     public void run(ExampleConfiguration configuration,
                     Environment environment) {
         environment.jersey().register(new AuthDynamicFeature(
-            new OAuthCredentialAuthFilter.Builder<User, ExampleOAuthAuthenticator>()
+            new OAuthCredentialAuthFilter.Builder<User>()
                 .setAuthenticator(new ExampleOAuthAuthenticator())
                 .setAuthorizer(new ExampleAuthorizer())
                 .setPrefix("Bearer")

dropwizard-auth/src/main/java/io/dropwizard/auth/AuthFilter.java

@@ -1,60 +1,98 @@
 package io.dropwizard.auth;
 
+import com.google.common.base.Preconditions;
+
 import javax.annotation.Priority;
 import javax.ws.rs.Priorities;
 import javax.ws.rs.container.ContainerRequestFilter;
 import java.security.Principal;
 
 @Priority(Priorities.AUTHENTICATION)
 public abstract class AuthFilter<C, P extends Principal> implements ContainerRequestFilter {
+
     protected String prefix;
     protected String realm;
     protected Authenticator<C, P> authenticator;
     protected Authorizer<P> authorizer;
     protected UnauthorizedHandler unauthorizedHandler = new DefaultUnauthorizedHandler();
 
-    protected void setPrefix(String prefix) {
-        this.prefix = prefix;
-    }
-
-    protected void setRealm(String realm) {
-        this.realm = realm;
-    }
-
-    protected void setAuthenticator(Authenticator<C, P> authenticator) {
-        this.authenticator = authenticator;
-    }
-
-    protected void setAuthorizer(Authorizer<P> authorizer) {
-        this.authorizer = authorizer;
-    }
+    /**
+     * Abstract builder for auth filters.
+     *
+     * @param <C> the type of credentials that the filter accepts
+     * @param <P> the type of the principal that the filter accepts
+     */
+    public abstract static class AuthFilterBuilder<C, P extends Principal, T extends AuthFilter<C, P>> {
 
-    public abstract static class AuthFilterBuilder<C, P extends Principal, T extends AuthFilter<C, P>, A extends Authenticator<C, P>> {
-        protected String realm = "realm";
-        protected String prefix = "Basic";
-        protected Authenticator<C, P> authenticator;
-        protected Authorizer<P> authorizer;
+        private String realm = "realm";
+        private String prefix = "Basic";
+        private Authenticator<C, P> authenticator;
+        private Authorizer<P> authorizer;
 
-        public AuthFilterBuilder<C, P, T, A>  setRealm(String realm) {
+        /**
+         * Sets the given realm
+         *
+         * @param realm a realm
+         * @return the current builder
+         */
+        public AuthFilterBuilder<C, P, T> setRealm(String realm) {
             this.realm = realm;
             return this;
         }
 
-        public AuthFilterBuilder<C, P, T, A>  setPrefix(String prefix) {
+        /**
+         * Sets the given prefix
+         *
+         * @param prefix a prefix
+         * @return the current builder
+         */
+        public AuthFilterBuilder<C, P, T> setPrefix(String prefix) {
             this.prefix = prefix;
             return this;
         }
 
-        public AuthFilterBuilder<C, P, T, A>  setAuthorizer(Authorizer<P> authorizer) {
+        /**
+         * Sets the given authorizer
+         *
+         * @param authorizer an {@link Authorizer}
+         * @return the current builder
+         */
+        public AuthFilterBuilder<C, P, T> setAuthorizer(Authorizer<P> authorizer) {
             this.authorizer = authorizer;
             return this;
         }
 
-        public AuthFilterBuilder<C, P, T, A> setAuthenticator(A authenticator) {
+        /**
+         * Sets the given authenticator
+         *
+         * @param authenticator an {@link Authenticator}
+         * @return the current builder
+         */
+        public AuthFilterBuilder<C, P, T> setAuthenticator(Authenticator<C, P> authenticator) {
             this.authenticator = authenticator;
             return this;
         }
 
-        public abstract T buildAuthFilter();
+        /**
+         * Builds an instance of the filter with provided an authenticator,
+         * an authorizer, a prefix, and a realm.
+         *
+         * @return a new instance of a filter
+         */
+        public T buildAuthFilter() {
+            Preconditions.checkArgument(realm != null, "Realm is not set");
+            Preconditions.checkArgument(prefix != null, "Prefix is not set");
+            Preconditions.checkArgument(authenticator != null, "Authenticator is not set");
+            Preconditions.checkArgument(authorizer != null, "Authorizer is not set");
+
+            T authFilter = newInstance();
+            authFilter.authorizer = authorizer;
+            authFilter.authenticator = authenticator;
+            authFilter.prefix = prefix;
+            authFilter.realm = realm;
+            return authFilter;
+        }
+
+        protected abstract T newInstance();
     }
 }

dropwizard-auth/src/main/java/io/dropwizard/auth/basic/BasicCredentialAuthFilter.java

@@ -5,6 +5,7 @@
 import io.dropwizard.auth.AuthenticationException;
 import io.dropwizard.auth.AuthFilter;
 import io.dropwizard.auth.Authenticator;
+import io.dropwizard.auth.Authorizer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import javax.annotation.Priority;
@@ -84,21 +85,18 @@ public String getAuthenticationScheme() {
     }
 
 
-    public static class Builder<APrincipal extends Principal, AAuthenticator extends Authenticator<BasicCredentials, APrincipal>>
-            extends AuthFilterBuilder<BasicCredentials, APrincipal, BasicCredentialAuthFilter<APrincipal>, AAuthenticator> {
+    /**
+     * Builder for {@link BasicCredentialAuthFilter}.
+     * <p>An {@link Authenticator} and an {@link Authorizer} must be provided during the building process.</p>
+     *
+     * @param <P> the principal
+     */
+    public static class Builder<P extends Principal> extends
+            AuthFilterBuilder<BasicCredentials, P, BasicCredentialAuthFilter<P>> {
 
         @Override
-        public BasicCredentialAuthFilter<APrincipal> buildAuthFilter() {
-            if (realm == null || authenticator == null || prefix == null || authorizer == null) {
-                throw new RuntimeException("Required auth filter parameters not set");
-            }
-
-            BasicCredentialAuthFilter<APrincipal> basicCredentialAuthFilter = new BasicCredentialAuthFilter<>();
-            basicCredentialAuthFilter.setRealm(realm);
-            basicCredentialAuthFilter.setAuthenticator(authenticator);
-            basicCredentialAuthFilter.setPrefix(prefix);
-            basicCredentialAuthFilter.setAuthorizer(authorizer);
-            return basicCredentialAuthFilter;
+        protected BasicCredentialAuthFilter<P> newInstance() {
+            return new BasicCredentialAuthFilter<>();
         }
     }
 }

dropwizard-auth/src/main/java/io/dropwizard/auth/oauth/OAuthCredentialAuthFilter.java

@@ -4,6 +4,7 @@
 import io.dropwizard.auth.AuthenticationException;
 import io.dropwizard.auth.AuthFilter;
 import io.dropwizard.auth.Authenticator;
+import io.dropwizard.auth.Authorizer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -69,20 +70,18 @@ public String getAuthenticationScheme() {
         throw new WebApplicationException(unauthorizedHandler.buildResponse(prefix, realm));
     }
 
-    public static class Builder<APrincipal extends Principal, AAuthenticator extends Authenticator<String, APrincipal>>
-            extends AuthFilterBuilder<String, APrincipal, OAuthCredentialAuthFilter<APrincipal>, AAuthenticator> {
-        @Override
-        public OAuthCredentialAuthFilter<APrincipal> buildAuthFilter() {
-            if (realm == null || authenticator == null || prefix == null || authorizer == null) {
-                throw new RuntimeException("Required auth filter parameters not set");
-            }
+    /**
+     * Builder for {@link OAuthCredentialAuthFilter}.
+     * <p>An {@link Authenticator} and an {@link Authorizer} must be provided during the building process.</p>
+     *
+     * @param <P> the type of the principal
+     */
+    public static class Builder<P extends Principal>
+            extends AuthFilterBuilder<String, P, OAuthCredentialAuthFilter<P>> {
 
-            OAuthCredentialAuthFilter<APrincipal> oauthCredentialAuthFilter = new OAuthCredentialAuthFilter<>();
-            oauthCredentialAuthFilter.setRealm(realm);
-            oauthCredentialAuthFilter.setAuthenticator(authenticator);
-            oauthCredentialAuthFilter.setPrefix(prefix);
-            oauthCredentialAuthFilter.setAuthorizer(authorizer);
-            return oauthCredentialAuthFilter;
+        @Override
+        protected OAuthCredentialAuthFilter<P> newInstance() {
+            return new OAuthCredentialAuthFilter<>();
         }
     }
 }

dropwizard-auth/src/test/java/io/dropwizard/auth/basic/BasicAuthProviderTest.java

@@ -3,7 +3,6 @@
 import com.codahale.metrics.MetricRegistry;
 import io.dropwizard.auth.AuthDynamicFeature;
 import io.dropwizard.auth.AuthResource;
-import io.dropwizard.auth.Authenticator;
 import io.dropwizard.auth.util.AuthUtil;
 import io.dropwizard.jersey.DropwizardResourceConfig;
 import io.dropwizard.logging.BootstrapLogging;
@@ -155,8 +154,7 @@ public BasicAuthTestResourceConfig() {
         private ContainerRequestFilter getAuthFilter() {
             final String validUser = "good-guy";
 
-            BasicCredentialAuthFilter.Builder<Principal, Authenticator<BasicCredentials, Principal>> builder
-                    = new BasicCredentialAuthFilter.Builder<>();
+            BasicCredentialAuthFilter.Builder<Principal> builder  = new BasicCredentialAuthFilter.Builder<>();
             builder.setAuthorizer(AuthUtil.getTestAuthorizer(validUser, VALID_ROLE));
             builder.setAuthenticator(AuthUtil.<BasicCredentials, Principal>getTestAuthenticatorBasicCredential(validUser));
             return builder.buildAuthFilter();

dropwizard-auth/src/test/java/io/dropwizard/auth/basic/BasicCustomAuthProviderTest.java

@@ -147,8 +147,7 @@ public BasicAuthTestResourceConfig() {
         private ContainerRequestFilter getAuthFilter() {
             final String validUser = "good-guy";
 
-            BasicCredentialAuthFilter.Builder<Principal, Authenticator<BasicCredentials, Principal>> builder
-                    = new BasicCredentialAuthFilter.Builder<>();
+            BasicCredentialAuthFilter.Builder<Principal> builder  = new BasicCredentialAuthFilter.Builder<>();
             builder.setAuthorizer(AuthUtil.getTestAuthorizer(validUser, VALID_ROLE));
             builder.setAuthenticator(AuthUtil.getTestAuthenticatorBasicCredential(validUser));
             builder.setPrefix("Custom");

dropwizard-auth/src/test/java/io/dropwizard/auth/oauth/OAuthCustomProviderTest.java

@@ -19,7 +19,7 @@
 import org.junit.Test;
 import javax.ws.rs.WebApplicationException;
 import javax.ws.rs.core.HttpHeaders;
-import javax.ws.rs.core.SecurityContext;
+
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.failBecauseExceptionWasNotThrown;
 

dropwizard-example/src/main/java/com/example/helloworld/HelloWorldApplication.java

@@ -82,7 +82,7 @@ public void run(HelloWorldConfiguration configuration, Environment environment)
 
         environment.healthChecks().register("template", new TemplateHealthCheck(template));
         environment.jersey().register(DateRequiredFeature.class);
-        environment.jersey().register(new AuthDynamicFeature(new BasicCredentialAuthFilter.Builder<User, ExampleAuthenticator>()
+        environment.jersey().register(new AuthDynamicFeature(new BasicCredentialAuthFilter.Builder<User>()
                 .setAuthenticator(new ExampleAuthenticator())
                 .setAuthorizer(new ExampleAuthorizer())
                 .setRealm("SUPER SECRET STUFF")

dropwizard-example/src/test/java/com/example/helloworld/resources/ProtectedResourceTest.java

@@ -1,7 +1,6 @@
 package com.example.helloworld.resources;
 
 import com.example.helloworld.core.User;
-import com.google.common.base.Function;
 import com.google.common.base.Optional;
 import io.dropwizard.auth.*;
 import io.dropwizard.auth.basic.BasicCredentialAuthFilter;
@@ -46,7 +45,7 @@ public boolean authorize(User user, String role) {
             }
         };
 
-        BASIC_AUTH_HANDLER = new BasicCredentialAuthFilter.Builder<User, Authenticator<BasicCredentials, User>>()
+        BASIC_AUTH_HANDLER = new BasicCredentialAuthFilter.Builder<User>()
                 .setAuthenticator(AUTHENTICATOR)
                 .setAuthorizer(AUTHORIZER)
                 .setPrefix("Basic")