fix: failed to build due to wrong type (#2712)

#### What type of PR is this?
/kind bug
/area core
/milestone 2.0

#### What this PR does / why we need it:
修复上一个 PR 没有拉取最新代码合并后导致无法构建的问题

#### Special notes for your reviewer:
/cc @halo-dev/sig-halo 
#### Does this PR introduce a user-facing change?

```release-note
None
```

src/main/java/run/halo/app/search/IndicesServiceImpl.java

@@ -2,14 +2,13 @@ package run.halo.app.search;
 
 import org.springframework.stereotype.Service;
 import reactor.core.Exceptions;
-import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Schedulers;
 import run.halo.app.core.extension.Post;
 import run.halo.app.plugin.extensionpoint.ExtensionGetter;
 import run.halo.app.search.post.PostDoc;
 import run.halo.app.search.post.PostSearchService;
 import run.halo.app.theme.finders.PostFinder;
+import run.halo.app.theme.finders.vo.PostVo;
 
 @Service
 public class IndicesServiceImpl implements IndicesService {
@@ -25,13 +24,18 @@ public class IndicesServiceImpl implements IndicesService {
     @Override
     public Mono<Void> rebuildPostIndices() {
         return extensionGetter.getEnabledExtension(PostSearchService.class)
-            // TODO Optimize listing posts with non-blocking.
-            .flatMap(searchService -> Flux.fromStream(() -> postFinder.list(0, 0)
-                    .stream()
-                    .filter(post -> Post.isPublished(post.getMetadata()))
-                    .peek(post -> postFinder.content(post.getMetadata().getName()))
-                    .map(PostDoc::from))
-                .subscribeOn(Schedulers.boundedElastic())
+            .flatMap(searchService -> postFinder.listAll()
+                .filter(post -> Post.isPublished(post.getMetadata()))
+                .flatMap(listedPostVo -> {
+                    PostVo postVo = PostVo.from(listedPostVo);
+                    return postFinder.content(postVo.getMetadata().getName())
+                        .map(content -> {
+                            postVo.setContent(content);
+                            return postVo;
+                        })
+                        .defaultIfEmpty(postVo);
+                })
+                .map(PostDoc::from)
                 .limitRate(100)
                 .buffer(100)
                 .doOnNext(postDocs -> {

src/main/java/run/halo/app/search/post/PostEventListener.java

@@ -29,18 +29,18 @@ public class PostEventListener {
     @Async
     @EventListener(PostPublishedEvent.class)
     public void handlePostPublished(PostPublishedEvent publishedEvent) throws InterruptedException {
-        var postVo = postFinder.getByName(publishedEvent.getPostName());
-        var postDoc = PostDoc.from(postVo);
-
         var latch = new CountDownLatch(1);
-        extensionGetter.getEnabledExtension(PostSearchService.class)
-            .doOnNext(searchService -> {
-                try {
-                    searchService.addDocuments(List.of(postDoc));
-                } catch (Exception e) {
-                    throw Exceptions.propagate(e);
-                }
-            })
+        postFinder.getByName(publishedEvent.getPostName())
+            .map(PostDoc::from)
+            .flatMap(postDoc -> extensionGetter.getEnabledExtension(PostSearchService.class)
+                .doOnNext(searchService -> {
+                    try {
+                        searchService.addDocuments(List.of(postDoc));
+                    } catch (Exception e) {
+                        throw Exceptions.propagate(e);
+                    }
+                })
+            )
             .doFinally(signalType -> latch.countDown())
             .subscribe();
         latch.await();

src/main/java/run/halo/app/theme/finders/PostFinder.java

@@ -1,6 +1,7 @@
 package run.halo.app.theme.finders;
 
 import org.springframework.lang.Nullable;
+import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import run.halo.app.core.extension.Post;
 import run.halo.app.extension.ListResult;
@@ -24,6 +25,8 @@ public interface PostFinder {
 
     Mono<NavigationPostVo> cursor(String current);
 
+    Flux<ListedPostVo> listAll();
+
     Mono<ListResult<ListedPostVo>> list(@Nullable Integer page, @Nullable Integer size);
 
     Mono<ListResult<ListedPostVo>> listByCategory(@Nullable Integer page, @Nullable Integer size,

src/main/java/run/halo/app/theme/finders/impl/PostFinderImpl.java

@@ -124,6 +124,12 @@ public class PostFinderImpl implements PostFinder {
             .defaultIfEmpty(NavigationPostVo.empty());
     }
 
+    @Override
+    public Flux<ListedPostVo> listAll() {
+        return client.list(Post.class, FIXED_PREDICATE, defaultComparator())
+            .flatMap(this::getListedPostVo);
+    }
+
     static Pair<String, String> postPreviousNextPair(List<String> postNames,
         String currentName) {
         FixedSizeSlidingWindow<String> window = new FixedSizeSlidingWindow<>(3);