Merge pull request #147 from Lixuhuilll/compression

启用响应体自动压缩，进一步节约服务器带宽

src/main/java/plus/maa/backend/MainApplication.java

@@ -3,7 +3,6 @@
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.context.properties.ConfigurationPropertiesScan;
-import org.springframework.boot.web.servlet.ServletComponentScan;
 import org.springframework.cache.annotation.EnableCaching;
 import org.springframework.scheduling.annotation.EnableAsync;
 import org.springframework.scheduling.annotation.EnableScheduling;
@@ -18,7 +17,6 @@
 @SpringBootApplication
 @ConfigurationPropertiesScan
 @EnableMethodSecurity
-@ServletComponentScan
 public class MainApplication {
     public static void main(String[] args) {
         SpringApplication.run(MainApplication.class, args);

src/main/java/plus/maa/backend/controller/CopilotController.java

@@ -78,8 +78,8 @@ public MaaResult<CopilotInfo> getCopilotById(
     public MaaResult<CopilotPageInfo> queriesCopilot(
             @Parameter(description = "作业查询请求") @Valid CopilotQueriesRequest parsed
     ) {
-        // 两秒防抖，缓解前端重复请求问题
-        response.setHeader(HttpHeaders.CACHE_CONTROL, "private, max-age=2, must-revalidate");
+        // 三秒防抖，缓解前端重复请求问题
+        response.setHeader(HttpHeaders.CACHE_CONTROL, "private, max-age=3, must-revalidate");
         return MaaResult.success(copilotService.queriesCopilot(helper.getUserId(), parsed));
     }
 

src/main/java/plus/maa/backend/filter/ContentLengthRepairFilter.java

@@ -0,0 +1,41 @@
+package plus.maa.backend.filter;
+
+import jakarta.servlet.FilterChain;
+import jakarta.servlet.ServletException;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.stereotype.Component;
+import org.springframework.web.filter.ShallowEtagHeaderFilter;
+import org.springframework.web.util.ContentCachingResponseWrapper;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * 解决了 GZIP 无法对 JSON 响应正常处理 min-response-size 的问题，
+ * 借助了 ETag 处理流程中的 Response 包装类包装所有响应，
+ * 从而正常获取 Content-Length
+ *
+ * @author lixuhuilll
+ */
+
+@Component
+@ConditionalOnProperty(name = "server.compression.enabled", havingValue = "true")
+public class ContentLengthRepairFilter extends ShallowEtagHeaderFilter {
+
+    @Override
+    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
+        if (response instanceof ContentCachingResponseWrapper) {
+            // 不对已包装过的响应体做处理
+            filterChain.doFilter(request, response);
+        } else {
+            super.doFilterInternal(request, response, filterChain);
+        }
+    }
+
+    @Override
+    protected boolean isEligibleForEtag(HttpServletRequest request, HttpServletResponse response, int responseStatusCode, InputStream inputStream) {
+        return false;
+    }
+}

src/main/java/plus/maa/backend/filter/MaaEtagHeaderFilterRegistrationBean.java

@@ -0,0 +1,65 @@
+package plus.maa.backend.filter;
+
+import jakarta.annotation.PostConstruct;
+import jakarta.servlet.Filter;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import org.springframework.boot.web.servlet.FilterRegistrationBean;
+import org.springframework.http.HttpHeaders;
+import org.springframework.stereotype.Component;
+import org.springframework.web.filter.ShallowEtagHeaderFilter;
+
+import java.io.InputStream;
+import java.util.Set;
+
+
+/**
+ * 提供基于 Etag 机制的 HTTP 缓存，有助于降低网络传输的压力
+ *
+ * @author lixuhuilll
+ */
+
+@Component
+public class MaaEtagHeaderFilterRegistrationBean extends FilterRegistrationBean<Filter> {
+
+    /**
+     * 配置需要使用 Etag 机制的 URI，采用 Servlet 的 URI 匹配语法
+     */
+    private final Set<String> ETAG_URI = Set.of(
+            "/arknights/level",
+            "/copilot/query"
+    );
+
+    @PostConstruct
+    public void init() {
+        setFilter(new MaaEtagHeaderFilter());
+        setUrlPatterns(ETAG_URI);
+    }
+
+    private static class MaaEtagHeaderFilter extends ShallowEtagHeaderFilter {
+
+        private static final String CACHE_HEAD = "private, no-cache, max-age=0, must-revalidate";
+
+        @Override
+        protected void initFilterBean() {
+            // Etag 必须使用弱校验才能与自动压缩兼容
+            setWriteWeakETag(true);
+        }
+
+        @Override
+        protected boolean isEligibleForEtag(HttpServletRequest request, HttpServletResponse response,
+                                            int responseStatusCode, InputStream inputStream) {
+
+            if (super.isEligibleForEtag(request, response, responseStatusCode, inputStream)) {
+                // 使用 ETag 机制的 URI，若其响应中不存在缓存控制头，则配置默认值
+                final String cacheControl = response.getHeader(HttpHeaders.CACHE_CONTROL);
+                if (cacheControl == null) {
+                    response.setHeader(HttpHeaders.CACHE_CONTROL, CACHE_HEAD);
+                }
+                return true;
+            }
+
+            return false;
+        }
+    }
+}

src/main/java/plus/maa/backend/filter/package-info.java

@@ -0,0 +1,4 @@
+@NonNullApi
+package plus.maa.backend.filter;
+
+import org.springframework.lang.NonNullApi;

src/main/resources/application.yml

@@ -31,6 +31,8 @@ server:
   tomcat:
     #限制post表单最大为30KB
     max-http-form-post-size: 30KB
+  compression:
+    enabled: true
 
 logging:
   file: