Add support for redirection on logout (#7418)

#### What type of PR is this?

/kind improvement
/area core
/milestone 2.20.x

#### What this PR does / why we need it:

This PR adds support for redirection on logout. We can request <http://localhost:8090/logout?redirect_uri=/archives> with GET method, then click the logout to see the redirection.

#### Which issue(s) this PR fixes:

Fixes https://github.com/halo-dev/halo/issues/7401

#### Does this PR introduce a user-facing change?

```release-note
登出页面支持自定义重定向
```

application/src/main/java/run/halo/app/security/LogoutSecurityConfigurer.java

@@ -10,16 +10,22 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.core.annotation.Order;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
+import org.springframework.lang.NonNull;
 import org.springframework.security.config.web.server.ServerHttpSecurity;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.core.context.ReactiveSecurityContextHolder;
 import org.springframework.security.core.context.SecurityContext;
+import org.springframework.security.web.server.DefaultServerRedirectStrategy;
+import org.springframework.security.web.server.ServerRedirectStrategy;
 import org.springframework.security.web.server.WebFilterExchange;
 import org.springframework.security.web.server.authentication.logout.DelegatingServerLogoutHandler;
-import org.springframework.security.web.server.authentication.logout.RedirectServerLogoutSuccessHandler;
 import org.springframework.security.web.server.authentication.logout.ServerLogoutHandler;
 import org.springframework.security.web.server.authentication.logout.ServerLogoutSuccessHandler;
+import org.springframework.security.web.server.savedrequest.ServerRequestCache;
+import org.springframework.security.web.server.savedrequest.WebSessionServerRequestCache;
+import org.springframework.security.web.server.util.matcher.ServerWebExchangeMatcher;
 import org.springframework.stereotype.Component;
+import org.springframework.util.Assert;
 import org.springframework.web.reactive.function.server.RouterFunction;
 import org.springframework.web.reactive.function.server.RouterFunctions;
 import org.springframework.web.reactive.function.server.ServerResponse;
@@ -34,9 +40,13 @@ import run.halo.app.theme.router.ModelConst;
 @RequiredArgsConstructor
 @Order(0)
 public class LogoutSecurityConfigurer implements SecurityConfigurer {
+
     private final RememberMeServices rememberMeServices;
+
     private final ApplicationContext applicationContext;
 
+    private final ServerRequestCache serverRequestCache = new HaloServerRequestCache();
+
     @Override
     public void configure(ServerHttpSecurity http) {
         var serverLogoutHandlers = getLogoutHandlers();
@@ -45,48 +55,54 @@ public class LogoutSecurityConfigurer implements SecurityConfigurer {
         );
     }
 
+    @Bean
+    RouterFunction<ServerResponse> logoutPage(
+        UserService userService,
+        GlobalInfoService globalInfoService
+    ) {
+        return RouterFunctions.route()
+            .GET("/logout", request -> {
+                var user = ReactiveSecurityContextHolder.getContext()
+                    .map(SecurityContext::getAuthentication)
+                    .map(Authentication::getName)
+                    .flatMap(userService::getUser);
+                var exchange = request.exchange();
+                var contextPath = exchange.getRequest().getPath().contextPath().value();
+
+                return ServerResponse.ok().render("logout", Map.of(
+                    "globalInfo", globalInfoService.getGlobalInfo(),
+                    "action", contextPath + "/logout",
+                    "user", user
+                ));
+            })
+            .before(request -> {
+                request.exchange().getAttributes().put(ModelConst.NO_CACHE, true);
+                return request;
+            })
+            .filter((request, next) ->
+                // Save request before handling the logout
+                serverRequestCache.saveRequest(request.exchange()).then(next.handle(request))
+            )
+            .build();
+    }
+
+
     private class LogoutSuccessHandler implements ServerLogoutSuccessHandler {
 
         private final ServerLogoutSuccessHandler defaultHandler;
         private final ServerLogoutHandler logoutHandler;
 
-        public LogoutSuccessHandler(ServerLogoutHandler... logoutHandler) {
+        public LogoutSuccessHandler(ServerLogoutHandler... logoutHandlers) {
-            var defaultHandler = new RedirectServerLogoutSuccessHandler();
+            var redirectHandler = new RequestCacheRedirectLogoutSuccessHandler();
-            defaultHandler.setLogoutSuccessUrl(URI.create("/login?logout"));
+            redirectHandler.setRequestCache(serverRequestCache);
-            this.defaultHandler = defaultHandler;
+            this.defaultHandler = redirectHandler;
-            if (logoutHandler.length == 1) {
+            if (logoutHandlers.length == 1) {
-                this.logoutHandler = logoutHandler[0];
+                this.logoutHandler = logoutHandlers[0];
             } else {
-                this.logoutHandler = new DelegatingServerLogoutHandler(logoutHandler);
+                this.logoutHandler = new DelegatingServerLogoutHandler(logoutHandlers);
             }
         }
 
-        @Bean
-        RouterFunction<ServerResponse> logoutPage(
-            UserService userService,
-            GlobalInfoService globalInfoService
-        ) {
-            return RouterFunctions.route()
-                .GET("/logout", request -> {
-                    var user = ReactiveSecurityContextHolder.getContext()
-                        .map(SecurityContext::getAuthentication)
-                        .map(Authentication::getName)
-                        .flatMap(userService::getUser);
-                    var exchange = request.exchange();
-                    var contextPath = exchange.getRequest().getPath().contextPath().value();
-                    return ServerResponse.ok().render("logout", Map.of(
-                        "globalInfo", globalInfoService.getGlobalInfo(),
-                        "action", contextPath + "/logout",
-                        "user", user
-                    ));
-                })
-                .before(request -> {
-                    request.exchange().getAttributes().put(ModelConst.NO_CACHE, true);
-                    return request;
-                })
-                .build();
-        }
-
         @Override
         public Mono<Void> onLogoutSuccess(WebFilterExchange exchange,
             Authentication authentication) {
@@ -94,13 +110,14 @@ public class LogoutSecurityConfigurer implements SecurityConfigurer {
                 .then(rememberMeServices.loginFail(exchange.getExchange()))
                 .then(ignoringMediaTypeAll(MediaType.APPLICATION_JSON)
                     .matches(exchange.getExchange())
-                    .flatMap(matchResult -> {
+                    .filter(ServerWebExchangeMatcher.MatchResult::isMatch)
-                        if (matchResult.isMatch()) {
+                    .switchIfEmpty(Mono.defer(() ->
-                            var response = exchange.getExchange().getResponse();
+                        defaultHandler.onLogoutSuccess(exchange, authentication).then(Mono.empty())
-                            response.setStatusCode(HttpStatus.NO_CONTENT);
+                    ))
-                            return response.setComplete();
+                    .flatMap(match -> {
-                        }
+                        var response = exchange.getExchange().getResponse();
-                        return defaultHandler.onLogoutSuccess(exchange, authentication);
+                        response.setStatusCode(HttpStatus.NO_CONTENT);
+                        return response.setComplete();
                     })
                 );
         }
@@ -110,4 +127,38 @@ public class LogoutSecurityConfigurer implements SecurityConfigurer {
         return applicationContext.getBeansOfType(ServerLogoutHandler.class).values()
             .toArray(new ServerLogoutHandler[0]);
     }
+
+    private static class RequestCacheRedirectLogoutSuccessHandler
+        implements ServerLogoutSuccessHandler {
+
+        private final ServerRedirectStrategy redirectStrategy = new DefaultServerRedirectStrategy();
+
+        private URI location = URI.create("/login?logout");
+
+        private ServerRequestCache requestCache = new WebSessionServerRequestCache();
+
+        public RequestCacheRedirectLogoutSuccessHandler() {
+        }
+
+        public RequestCacheRedirectLogoutSuccessHandler(String location) {
+            this.location = URI.create(location);
+        }
+
+        public void setRequestCache(@NonNull ServerRequestCache requestCache) {
+            Assert.notNull(requestCache, "requestCache cannot be null");
+            this.requestCache = requestCache;
+        }
+
+        @Override
+        public Mono<Void> onLogoutSuccess(
+            WebFilterExchange exchange, Authentication authentication
+        ) {
+            return this.requestCache.getRedirectUri(exchange.getExchange())
+                .defaultIfEmpty(this.location)
+                .flatMap(location ->
+                    this.redirectStrategy.sendRedirect(exchange.getExchange(), location)
+                );
+        }
+
+    }
 }