OAuth2 Access Token Nested Json Response Http Message Converter

OAuth2AccessTokenNestedJsonResponseHttpMessageConverter.java

/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package xyz.ansidev.oauth2;

import org.springframework.core.ParameterizedTypeReference;
import org.springframework.core.convert.converter.Converter;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpOutputMessage;
import org.springframework.http.MediaType;
import org.springframework.http.converter.*;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.security.oauth2.core.OAuth2AccessToken;
import org.springframework.security.oauth2.core.endpoint.OAuth2AccessTokenResponse;
import org.springframework.security.oauth2.core.endpoint.OAuth2ParameterNames;
import org.springframework.util.Assert;
import org.springframework.util.CollectionUtils;
import org.springframework.util.StringUtils;

import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.time.Instant;
import java.time.temporal.ChronoUnit;
import java.util.*;
import java.util.stream.Collectors;
import java.util.stream.Stream;

/**
 * A {@link HttpMessageConverter} for an {@link OAuth2AccessTokenResponse OAuth 2.0 Access Token Response}.
 *
 * @author Joe Grandja
 * @see AbstractHttpMessageConverter
 * @see OAuth2AccessTokenResponse
 * @since 5.1
 */
public class OAuth2AccessTokenNestedJsonResponseHttpMessageConverter
extends AbstractHttpMessageConverter<OAuth2AccessTokenResponse> {
    private static final Charset DEFAULT_CHARSET = StandardCharsets.UTF_8;

    private static final ParameterizedTypeReference<Map<String, Object>> PARAMETERIZED_RESPONSE_TYPE =
    new ParameterizedTypeReference<>() {};
    protected Converter<Map<String, Object>, OAuth2AccessTokenResponse> tokenResponseConverter =
    new OAuth2AccessTokenResponseConverter();
    protected Converter<OAuth2AccessTokenResponse, Map<String, String>> tokenResponseParametersConverter =
    new OAuth2AccessTokenResponseParametersConverter();
    private GenericHttpMessageConverter<Object> jsonMessageConverter = new MappingJackson2HttpMessageConverter();

    public OAuth2AccessTokenNestedJsonResponseHttpMessageConverter() {
        super(DEFAULT_CHARSET, MediaType.APPLICATION_JSON, new MediaType("application", "*+json"));
    }

    @Override
    protected boolean supports(Class<?> clazz) {
        return OAuth2AccessTokenResponse.class.isAssignableFrom(clazz);
    }

    @Override
    protected OAuth2AccessTokenResponse readInternal(Class<? extends OAuth2AccessTokenResponse> clazz,
                                                     HttpInputMessage inputMessage)
    throws IOException, HttpMessageNotReadableException {

        try {
            @SuppressWarnings("unchecked") Map<String, Object> tokenResponseParameters =
            (Map<String, Object>) this.jsonMessageConverter.read(PARAMETERIZED_RESPONSE_TYPE.getType(), null,
                                                                 inputMessage);
            return this.tokenResponseConverter.convert(tokenResponseParameters);
        } catch (Exception ex) {
            throw new HttpMessageNotReadableException(
            "An error occurred reading the OAuth 2.0 Access Token Response: " + ex.getMessage(), ex, inputMessage);
        }
    }

    @Override
    protected void writeInternal(OAuth2AccessTokenResponse tokenResponse, HttpOutputMessage outputMessage)
    throws IOException, HttpMessageNotWritableException {

        try {
            Map<String, String> tokenResponseParameters = this.tokenResponseParametersConverter.convert(tokenResponse);
            this.jsonMessageConverter.write(tokenResponseParameters, PARAMETERIZED_RESPONSE_TYPE.getType(),
                                            MediaType.APPLICATION_JSON, outputMessage);
        } catch (Exception ex) {
            throw new HttpMessageNotWritableException(
            "An error occurred writing the OAuth 2.0 Access Token Response: " + ex.getMessage(), ex);
        }
    }

    /**
     * Sets the {@link Converter} used for converting the OAuth 2.0 Access Token Response parameters
     * to an {@link OAuth2AccessTokenResponse}.
     *
     * @param tokenResponseConverter the {@link Converter} used for converting to an {@link OAuth2AccessTokenResponse}
     */
    public final void setTokenResponseConverter(
    Converter<Map<String, Object>, OAuth2AccessTokenResponse> tokenResponseConverter) {
        Assert.notNull(tokenResponseConverter, "tokenResponseConverter cannot be null");
        this.tokenResponseConverter = tokenResponseConverter;
    }

    /**
     * Sets the {@link Converter} used for converting the {@link OAuth2AccessTokenResponse}
     * to a {@code Map} representation of the OAuth 2.0 Access Token Response parameters.
     *
     * @param tokenResponseParametersConverter the {@link Converter} used for converting to a {@code Map} representation of the Access Token Response parameters
     */
    public final void setTokenResponseParametersConverter(
    Converter<OAuth2AccessTokenResponse, Map<String, String>> tokenResponseParametersConverter) {
        Assert.notNull(tokenResponseParametersConverter, "tokenResponseParametersConverter cannot be null");
        this.tokenResponseParametersConverter = tokenResponseParametersConverter;
    }

    /**
     * A {@link Converter} that converts the provided
     * OAuth 2.0 Access Token Response parameters to an {@link OAuth2AccessTokenResponse}.
     */
    private static class OAuth2AccessTokenResponseConverter
    implements Converter<Map<String, Object>, OAuth2AccessTokenResponse> {
        private static final Set<String> TOKEN_RESPONSE_PARAMETER_NAMES = Stream.of(OAuth2ParameterNames.ACCESS_TOKEN,
                                                                                    OAuth2ParameterNames.TOKEN_TYPE,
                                                                                    OAuth2ParameterNames.EXPIRES_IN,
                                                                                    OAuth2ParameterNames.REFRESH_TOKEN,
                                                                                    OAuth2ParameterNames.SCOPE)
                                                                                .collect(Collectors.toSet());

        @Override
        public OAuth2AccessTokenResponse convert(Map<String, Object> tokenResponseParameters) {
            String accessToken = tokenResponseParameters.get(OAuth2ParameterNames.ACCESS_TOKEN)
                                                        .toString();

            OAuth2AccessToken.TokenType accessTokenType = null;
            if (OAuth2AccessToken.TokenType.BEARER.getValue()
                                                  .equalsIgnoreCase(
                                                  tokenResponseParameters.get(OAuth2ParameterNames.TOKEN_TYPE)
                                                                         .toString())) {
                accessTokenType = OAuth2AccessToken.TokenType.BEARER;
            }

            long expiresIn = 0;
            if (tokenResponseParameters.containsKey(OAuth2ParameterNames.EXPIRES_IN)) {
                try {
                    expiresIn = Long.valueOf(tokenResponseParameters.get(OAuth2ParameterNames.EXPIRES_IN)
                                                                    .toString());
                } catch (NumberFormatException ex) { }
            }

            Set<String> scopes = Collections.emptySet();
            if (tokenResponseParameters.containsKey(OAuth2ParameterNames.SCOPE)) {
                String scope = tokenResponseParameters.get(OAuth2ParameterNames.SCOPE)
                                                      .toString();
                scopes = Arrays.stream(StringUtils.delimitedListToStringArray(scope, " "))
                               .collect(Collectors.toSet());
            }

            String refreshToken = String.valueOf(tokenResponseParameters.get(OAuth2ParameterNames.REFRESH_TOKEN));

            Map<String, Object> additionalParameters = new LinkedHashMap<>();
            tokenResponseParameters.entrySet()
                                   .stream()
                                   .filter(e -> !TOKEN_RESPONSE_PARAMETER_NAMES.contains(e.getKey()))
                                   .forEach(e -> additionalParameters.put(e.getKey(), e.getValue()));

            return OAuth2AccessTokenResponse.withToken(accessToken)
                                            .tokenType(accessTokenType)
                                            .expiresIn(expiresIn)
                                            .scopes(scopes)
                                            .refreshToken(refreshToken)
                                            .additionalParameters(additionalParameters)
                                            .build();
        }
    }

    /**
     * A {@link Converter} that converts the provided {@link OAuth2AccessTokenResponse}
     * to a {@code Map} representation of the OAuth 2.0 Access Token Response parameters.
     */
    private static class OAuth2AccessTokenResponseParametersConverter
    implements Converter<OAuth2AccessTokenResponse, Map<String, String>> {

        @Override
        public Map<String, String> convert(OAuth2AccessTokenResponse tokenResponse) {
            Map<String, String> parameters = new HashMap<>();

            long expiresIn = -1;
            if (tokenResponse.getAccessToken()
                             .getExpiresAt() != null) {
                expiresIn = ChronoUnit.SECONDS.between(Instant.now(), tokenResponse.getAccessToken()
                                                                                   .getExpiresAt());
            }

            parameters.put(OAuth2ParameterNames.ACCESS_TOKEN, tokenResponse.getAccessToken()
                                                                           .getTokenValue());
            parameters.put(OAuth2ParameterNames.TOKEN_TYPE, tokenResponse.getAccessToken()
                                                                         .getTokenType()
                                                                         .getValue());
            parameters.put(OAuth2ParameterNames.EXPIRES_IN, String.valueOf(expiresIn));
            if (!CollectionUtils.isEmpty(tokenResponse.getAccessToken()
                                                      .getScopes())) {
                parameters.put(OAuth2ParameterNames.SCOPE, StringUtils.collectionToDelimitedString(
                tokenResponse.getAccessToken()
                             .getScopes(), " "));
            }
            if (tokenResponse.getRefreshToken() != null) {
                parameters.put(OAuth2ParameterNames.REFRESH_TOKEN, tokenResponse.getRefreshToken()
                                                                                .getTokenValue());
            }
            if (!CollectionUtils.isEmpty(tokenResponse.getAdditionalParameters())) {
                tokenResponse.getAdditionalParameters()
                             .entrySet()
                             .stream()
                             .forEach(e -> parameters.put(e.getKey(), e.getValue()
                                                                       .toString()));
            }

            return parameters;
        }
    }
}