Cache static resources, including plugin, theme, console, attachment (#3074)

#### What type of PR is this?

/kind improvement
/area core
/milestone 2.1.x

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

Add cache control and last modified headers for responses of static resources.

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

Fixes https://github.com/halo-dev/halo/issues/2966

#### Special notes for your reviewer:

We can check the response header of statis resources to know if the cache control is working correctly.

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

```release-note
完善静态资源的缓存策略
```

src/main/java/run/halo/app/config/WebFluxConfig.java

@@ -8,7 +8,6 @@ import static run.halo.app.infra.utils.FileUtils.checkDirectoryTraversal;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import java.net.URI;
 import java.time.Duration;
-import java.time.Instant;
 import java.util.List;
 import java.util.Objects;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
@@ -105,7 +104,7 @@ public class WebFluxConfig implements WebFluxConfigurer {
         var indexResource = applicationContext.getResource(indexLocation);
         try {
             return ServerResponse.ok()
-                .lastModified(Instant.ofEpochMilli(indexResource.lastModified()))
+                .cacheControl(CacheControl.noStore())
                 .body(BodyInserters.fromResource(indexResource));
         } catch (Throwable e) {
             return Mono.error(e);
@@ -119,16 +118,19 @@ public class WebFluxConfig implements WebFluxConfigurer {
     @Override
     public void addResourceHandlers(ResourceHandlerRegistry registry) {
         var attachmentsRoot = haloProp.getWorkDir().resolve("attachments");
+        var cacheControl = CacheControl.maxAge(Duration.ofDays(365 / 2));
 
         // Mandatory resource mapping
         var uploadRegistration = registry.addResourceHandler("/upload/**")
             .addResourceLocations(FILE_URL_PREFIX + attachmentsRoot.resolve("upload") + "/")
             .setUseLastModified(true)
-            .setCacheControl(CacheControl.maxAge(Duration.ofDays(365)));
+            .setCacheControl(cacheControl);
 
         // For console project
         registry.addResourceHandler("/console/**")
             .addResourceLocations(haloProp.getConsole().getLocation())
+            .setCacheControl(cacheControl)
+            .setUseLastModified(true)
             .resourceChain(true)
             .addResolver(new EncodedResourceResolver())
             .addResolver(new PathResourceResolver());
@@ -145,7 +147,9 @@ public class WebFluxConfig implements WebFluxConfigurer {
             staticResource.getLocations().forEach(location -> {
                 var path = attachmentsRoot.resolve(location);
                 checkDirectoryTraversal(attachmentsRoot, path);
-                registration.addResourceLocations(FILE_URL_PREFIX + path + "/");
+                registration.addResourceLocations(FILE_URL_PREFIX + path + "/")
+                    .setCacheControl(cacheControl)
+                    .setUseLastModified(true);
             });
         });
 

src/main/java/run/halo/app/plugin/PluginAutoConfiguration.java

@@ -1,8 +1,13 @@
 package run.halo.app.plugin;
 
+import static run.halo.app.plugin.resources.BundleResourceUtils.getJsBundleResource;
+
 import java.io.File;
+import java.io.IOException;
 import java.lang.reflect.Constructor;
 import java.nio.file.Path;
+import java.time.Duration;
+import java.time.Instant;
 import lombok.extern.slf4j.Slf4j;
 import org.pf4j.ClassLoadingStrategy;
 import org.pf4j.CompoundPluginLoader;
@@ -22,13 +27,14 @@ import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.core.io.Resource;
+import org.springframework.http.CacheControl;
 import org.springframework.util.StringUtils;
 import org.springframework.web.reactive.accept.RequestedContentTypeResolver;
+import org.springframework.web.reactive.function.BodyInserters;
 import org.springframework.web.reactive.function.server.RouterFunction;
 import org.springframework.web.reactive.function.server.RouterFunctions;
 import org.springframework.web.reactive.function.server.ServerResponse;
-import run.halo.app.plugin.resources.BundleResourceUtils;
+import reactor.core.publisher.Mono;
 
 /**
  * Plugin autoconfiguration for Spring Boot.
@@ -163,13 +169,20 @@ public class PluginAutoConfiguration {
                 String pluginName = request.pathVariable("name");
                 String fileName = request.pathVariable("resource");
 
-                Resource jsBundleResource =
-                    BundleResourceUtils.getJsBundleResource(haloPluginManager, pluginName,
-                        fileName);
-                if (jsBundleResource == null) {
+                var jsBundle = getJsBundleResource(haloPluginManager, pluginName, fileName);
+                if (jsBundle == null || !jsBundle.exists()) {
                     return ServerResponse.notFound().build();
                 }
-                return ServerResponse.ok().bodyValue(jsBundleResource);
+                try {
+                    var lastModified = Instant.ofEpochMilli(jsBundle.lastModified());
+                    return request.checkNotModified(lastModified)
+                        .switchIfEmpty(Mono.defer(() -> ServerResponse.ok()
+                                .cacheControl(CacheControl.maxAge(Duration.ofDays(365 / 2)))
+                                .lastModified(lastModified)
+                                .body(BodyInserters.fromResource(jsBundle))));
+                } catch (IOException e) {
+                    throw new RuntimeException(e);
+                }
             })
             .build();
     }

src/main/java/run/halo/app/theme/ThemeConfiguration.java

@@ -2,15 +2,21 @@ package run.halo.app.theme;
 
 import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
 import static org.springframework.web.reactive.function.server.RequestPredicates.accept;
+import static org.springframework.web.reactive.function.server.RouterFunctions.route;
 
+import java.io.IOException;
 import java.nio.file.Path;
+import java.time.Duration;
+import java.time.Instant;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.io.FileSystemResource;
+import org.springframework.http.CacheControl;
 import org.springframework.http.MediaType;
+import org.springframework.web.reactive.function.BodyInserters;
 import org.springframework.web.reactive.function.server.RouterFunction;
-import org.springframework.web.reactive.function.server.RouterFunctions;
 import org.springframework.web.reactive.function.server.ServerResponse;
+import reactor.core.publisher.Mono;
 import run.halo.app.infra.properties.HaloProperties;
 import run.halo.app.infra.utils.FilePathUtils;
 import run.halo.app.theme.dialect.LinkExpressionObjectDialect;
@@ -29,17 +35,23 @@ public class ThemeConfiguration {
 
     @Bean
     public RouterFunction<ServerResponse> themeAssets() {
-        return RouterFunctions
-            .route(GET("/themes/{themeName}/assets/{*resource}")
-                    .and(accept(MediaType.TEXT_HTML)),
-                request -> {
-                    String themeName = request.pathVariable("themeName");
-                    String resource = request.pathVariable("resource");
-                    FileSystemResource fileSystemResource =
-                        new FileSystemResource(getThemeAssetsPath(themeName, resource));
-                    return ServerResponse.ok()
-                        .bodyValue(fileSystemResource);
-                });
+        return route(
+            GET("/themes/{themeName}/assets/{*resource}").and(accept(MediaType.TEXT_PLAIN)),
+            request -> {
+                var themeName = request.pathVariable("themeName");
+                var resource = request.pathVariable("resource");
+                var fsRes = new FileSystemResource(getThemeAssetsPath(themeName, resource));
+                try {
+                    var lastModified = Instant.ofEpochMilli(fsRes.lastModified());
+                    return request.checkNotModified(lastModified)
+                        .switchIfEmpty(Mono.defer(() -> ServerResponse.ok()
+                            .cacheControl(CacheControl.maxAge(Duration.ofDays(356 / 2)))
+                            .lastModified(lastModified)
+                            .body(BodyInserters.fromResource(fsRes))));
+                } catch (IOException e) {
+                    return Mono.error(e);
+                }
+            });
     }
 
     private Path getThemeAssetsPath(String themeName, String resource) {