在使用keycloak集成springboot的过程中，对于需要授权访问的接口，它会跳到keycloak里进行登录，之前有个redirect_uri,登录成功后会跳回本客户端，而这个地址默认没有修改的地方，需要我们手动开发，这块不是很方便。

自定义redirect_uri

一 重写BeanPostProcessor来实现

@Component
public class KeycloackAuthenticationProcessingFilterPostProcessor implements BeanPostProcessor {

    private static final Logger logger = LoggerFactory.getLogger(KeycloackAuthenticationProcessingFilterPostProcessor.class);

    private void process(KeycloakAuthenticationProcessingFilter filter) {
        filter.setRequestAuthenticatorFactory(new SpringSecurityRequestAuthenticatorFactory() {
            @Override
            public RequestAuthenticator createRequestAuthenticator(HttpFacade facade, HttpServletRequest request, KeycloakDeployment deployment, AdapterTokenStore tokenStore, int sslRedirectPort) {
                return new SpringSecurityRequestAuthenticator(facade, request, deployment, tokenStore, sslRedirectPort) {

                    @Override
                    protected OAuthRequestAuthenticator createOAuthAuthenticator() {
                        return new OAuthRequestAuthenticator(this, facade, deployment, sslRedirectPort, tokenStore) {

                            @Override
                            protected String getRequestUrl() {
                                return "http://localhost:8081/callback";
                            }
                        };
                    }

                };
            }
        });
    }

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        if (bean instanceof KeycloakAuthenticationProcessingFilter) {
            logger.info("Injecting Custom handler...");
            process(((KeycloakAuthenticationProcessingFilter) bean));
        }
        return bean;
    }

二 在没有授权时，直接跳到 授权系统，然后观察地址上redirect_uri已经发生变化了

参考文档：https://stackoverflow.com/questions/54163924/how-to-set-redirect-uri-in-keycloak-with-spring-boot