refactor(log/core): 重构请求和响应信息获取

web 模块 ServletUtils整理
log/core 模块 删除 RecordableHttpRequest和
RecordableHttpResponse

continew-starter-log/continew-starter-log-core/src/main/java/top/continew/starter/log/handler/AbstractLogHandler.java

@@ -22,20 +22,15 @@ import cn.hutool.core.util.ObjectUtil;
 import com.alibaba.ttl.TransmittableThreadLocal;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.tags.Tag;
-import jakarta.servlet.http.HttpServletRequest;
-import jakarta.servlet.http.HttpServletResponse;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import top.continew.starter.log.annotation.Log;
 import top.continew.starter.log.enums.Include;
-import top.continew.starter.log.http.RecordableHttpRequest;
-import top.continew.starter.log.http.RecordableHttpResponse;
-import top.continew.starter.log.http.servlet.RecordableServletHttpRequest;
-import top.continew.starter.log.http.servlet.RecordableServletHttpResponse;
 import top.continew.starter.log.model.AccessLogContext;
 import top.continew.starter.log.model.AccessLogProperties;
 import top.continew.starter.log.model.LogRecord;
 import top.continew.starter.log.util.AccessLogUtils;
+import top.continew.starter.web.util.ServletUtils;
 
 import java.lang.reflect.Method;
 import java.time.Duration;
@@ -55,19 +50,18 @@ public abstract class AbstractLogHandler implements LogHandler {
     private final TransmittableThreadLocal<AccessLogContext> logContextThread = new TransmittableThreadLocal<>();
 
     @Override
-    public LogRecord.Started start(Instant startTime, HttpServletRequest request) {
-        return LogRecord.start(startTime, new RecordableServletHttpRequest(request));
+    public LogRecord.Started start(Instant startTime) {
+        return LogRecord.start(startTime);
     }
 
     @Override
     public LogRecord finish(LogRecord.Started started,
                             Instant endTime,
-                            HttpServletResponse response,
                             Set<Include> includes,
                             Method targetMethod,
                             Class<?> targetClass) {
         Set<Include> includeSet = this.getIncludes(includes, targetMethod, targetClass);
-        LogRecord logRecord = this.finish(started, endTime, response, includeSet);
+        LogRecord logRecord = this.finish(started, endTime, includeSet);
         // 记录日志描述
         if (includeSet.contains(Include.DESCRIPTION)) {
             this.logDescription(logRecord, targetMethod);
@@ -80,11 +74,8 @@ public abstract class AbstractLogHandler implements LogHandler {
     }
 
     @Override
-    public LogRecord finish(LogRecord.Started started,
-                            Instant endTime,
-                            HttpServletResponse response,
-                            Set<Include> includes) {
-        return started.finish(endTime, new RecordableServletHttpResponse(response, response.getStatus()), includes);
+    public LogRecord finish(LogRecord.Started started, Instant endTime, Set<Include> includes) {
+        return started.finish(endTime, includes);
     }
 
     /**
@@ -174,17 +165,15 @@ public abstract class AbstractLogHandler implements LogHandler {
     public void accessLogStart(AccessLogContext accessLogContext) {
         AccessLogProperties properties = accessLogContext.getProperties().getAccessLog();
         // 是否需要打印 规则: 是否打印开关 或 放行路径
-        if (!properties.isEnabled() || AccessLogUtils.exclusionPath(accessLogContext.getProperties(), accessLogContext
-            .getRequest()
-            .getPath())) {
+        if (!properties.isEnabled() || AccessLogUtils.exclusionPath(accessLogContext.getProperties(), ServletUtils
+            .getReqPath())) {
             return;
         }
         // 构建上下文
         logContextThread.set(accessLogContext);
-        RecordableHttpRequest request = accessLogContext.getRequest();
-        String path = request.getPath();
-        String param = AccessLogUtils.getParam(request, properties);
-        log.info(param != null ? "[Start] [{}] {} param: {}" : "[Start] [{}] {}", request.getMethod(), path, param);
+        String param = AccessLogUtils.getParam(properties);
+        log.info(param != null ? "[Start] [{}] {} param: {}" : "[Start] [{}] {}", ServletUtils
+            .getReqMethod(), ServletUtils.getReqPath(), param);
     }
 
     @Override
@@ -194,11 +183,9 @@ public abstract class AbstractLogHandler implements LogHandler {
             return;
         }
         try {
-            RecordableHttpRequest request = logContext.getRequest();
-            RecordableHttpResponse response = accessLogContext.getResponse();
             Duration timeTaken = Duration.between(logContext.getStartTime(), accessLogContext.getEndTime());
-            log.info("[End] [{}] {} {} {}ms", request.getMethod(), request.getPath(), response.getStatus(), timeTaken
-                .toMillis());
+            log.info("[End] [{}] {} {} {}ms", ServletUtils.getReqMethod(), ServletUtils.getReqPath(), ServletUtils
+                .getRespStatus(), timeTaken.toMillis());
         } finally {
             logContextThread.remove();
         }

continew-starter-log/continew-starter-log-core/src/main/java/top/continew/starter/log/handler/LogHandler.java

@@ -16,8 +16,6 @@
 
 package top.continew.starter.log.handler;
 
-import jakarta.servlet.http.HttpServletRequest;
-import jakarta.servlet.http.HttpServletResponse;
 import top.continew.starter.log.enums.Include;
 import top.continew.starter.log.model.AccessLogContext;
 import top.continew.starter.log.model.LogRecord;
@@ -39,28 +37,25 @@ public interface LogHandler {
      * 开始日志记录
      *
      * @param startTime 开始时间
-     * @param request   请求对象
      * @return 日志记录器
      */
-    LogRecord.Started start(Instant startTime, HttpServletRequest request);
+    LogRecord.Started start(Instant startTime);
 
     /**
      * 结束日志记录
      *
      * @param started  开始日志记录器
      * @param endTime  结束时间
-     * @param response 响应对象
      * @param includes 包含信息
      * @return 日志记录
      */
-    LogRecord finish(LogRecord.Started started, Instant endTime, HttpServletResponse response, Set<Include> includes);
+    LogRecord finish(LogRecord.Started started, Instant endTime, Set<Include> includes);
 
     /**
      * 结束日志记录
      *
      * @param started      开始日志记录器-
      * @param endTime      结束时间
-     * @param response     响应对象
      * @param includes     包含信息
      * @param targetMethod 目标方法
      * @param targetClass  目标类
@@ -68,7 +63,6 @@ public interface LogHandler {
      */
     LogRecord finish(LogRecord.Started started,
                      Instant endTime,
-                     HttpServletResponse response,
                      Set<Include> includes,
                      Method targetMethod,
                      Class<?> targetClass);

continew-starter-log/continew-starter-log-core/src/main/java/top/continew/starter/log/http/RecordableHttpRequest.java

@@ -1,84 +0,0 @@
-/*
- * Copyright (c) 2022-present Charles7c Authors. All Rights Reserved.
- * <p>
- * Licensed under the GNU LESSER GENERAL PUBLIC LICENSE 3.0;
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- * <p>
- * http://www.gnu.org/licenses/lgpl.html
- * <p>
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package top.continew.starter.log.http;
-
-import java.net.URI;
-import java.util.Map;
-
-/**
- * 可记录的 HTTP 请求信息
- *
- * @author Andy Wilkinson（Spring Boot Actuator）
- * @author Phillip Webb（Spring Boot Actuator）
- * @author Charles7c
- * @author echo
- * @see RecordableHttpResponse
- * @since 1.1.0
- */
-public interface RecordableHttpRequest {
-
-    /**
-     * 获取请求方式
-     *
-     * @return 请求方式
-     */
-    String getMethod();
-
-    /**
-     * 获取 URL
-     *
-     * @return URL
-     */
-    URI getUrl();
-
-    /**
-     * 获取路径
-     * <p>/foo/bar</p>
-     *
-     * @return 路径
-     * @since 2.10.0
-     */
-    String getPath();
-
-    /**
-     * 获取请求头
-     *
-     * @return 请求头
-     */
-    Map<String, String> getHeaders();
-
-    /**
-     * 获取请求体
-     *
-     * @return 请求体
-     */
-    String getBody();
-
-    /**
-     * 获取请求参数
-     *
-     * @return 请求参数
-     */
-    Map<String, Object> getParam();
-
-    /**
-     * 获取 IP
-     *
-     * @return IP
-     */
-    String getIp();
-}

continew-starter-log/continew-starter-log-core/src/main/java/top/continew/starter/log/http/RecordableHttpResponse.java

@@ -1,58 +0,0 @@
-/*
- * Copyright (c) 2022-present Charles7c Authors. All Rights Reserved.
- * <p>
- * Licensed under the GNU LESSER GENERAL PUBLIC LICENSE 3.0;
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- * <p>
- * http://www.gnu.org/licenses/lgpl.html
- * <p>
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package top.continew.starter.log.http;
-
-import java.util.Map;
-
-/**
- * 可记录的 HTTP 响应信息
- *
- * @author Andy Wilkinson（Spring Boot Actuator）
- * @author Charles7c
- * @see RecordableHttpRequest
- * @since 1.1.0
- */
-public interface RecordableHttpResponse {
-
-    /**
-     * 获取状态码
-     *
-     * @return 状态码
-     */
-    int getStatus();
-
-    /**
-     * 获取响应头
-     *
-     * @return 响应头
-     */
-    Map<String, String> getHeaders();
-
-    /**
-     * 获取响应体
-     *
-     * @return 响应体
-     */
-    String getBody();
-
-    /**
-     * 获取响应参数
-     *
-     * @return 响应参数
-     */
-    Map<String, Object> getParam();
-}

continew-starter-log/continew-starter-log-core/src/main/java/top/continew/starter/log/http/servlet/RecordableServletHttpRequest.java

@@ -1,108 +0,0 @@
-/*
- * Copyright (c) 2022-present Charles7c Authors. All Rights Reserved.
- * <p>
- * Licensed under the GNU LESSER GENERAL PUBLIC LICENSE 3.0;
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- * <p>
- * http://www.gnu.org/licenses/lgpl.html
- * <p>
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package top.continew.starter.log.http.servlet;
-
-import cn.hutool.core.text.CharSequenceUtil;
-import cn.hutool.extra.servlet.JakartaServletUtil;
-import cn.hutool.json.JSONUtil;
-import jakarta.servlet.http.HttpServletRequest;
-import org.springframework.web.util.UriUtils;
-import top.continew.starter.core.constant.StringConstants;
-import top.continew.starter.log.http.RecordableHttpRequest;
-import top.continew.starter.web.util.RepeatReadRequestWrapper;
-
-import java.net.URI;
-import java.net.URISyntaxException;
-import java.nio.charset.StandardCharsets;
-import java.util.Collections;
-import java.util.Map;
-
-/**
- * 可记录的 HTTP 请求信息适配器
- *
- * @author Andy Wilkinson（Spring Boot Actuator）
- * @author Charles7c
- * @author echo
- * @since 1.1.0
- */
-public final class RecordableServletHttpRequest implements RecordableHttpRequest {
-
-    private final HttpServletRequest request;
-
-    public RecordableServletHttpRequest(HttpServletRequest request) {
-        this.request = request;
-    }
-
-    @Override
-    public String getMethod() {
-        return request.getMethod();
-    }
-
-    @Override
-    public URI getUrl() {
-        String queryString = request.getQueryString();
-        if (CharSequenceUtil.isBlank(queryString)) {
-            return URI.create(request.getRequestURL().toString());
-        }
-        try {
-            StringBuilder urlBuilder = this.appendQueryString(queryString);
-            return new URI(urlBuilder.toString());
-        } catch (URISyntaxException e) {
-            String encoded = UriUtils.encodeQuery(queryString, StandardCharsets.UTF_8);
-            StringBuilder urlBuilder = this.appendQueryString(encoded);
-            return URI.create(urlBuilder.toString());
-        }
-    }
-
-    @Override
-    public String getPath() {
-        return request.getRequestURI();
-    }
-
-    @Override
-    public Map<String, String> getHeaders() {
-        return JakartaServletUtil.getHeaderMap(request);
-    }
-
-    @Override
-    public String getBody() {
-        if (request instanceof RepeatReadRequestWrapper wrapper && !wrapper.isMultipartContent(request)) {
-            String body = JakartaServletUtil.getBody(request);
-            return JSONUtil.isTypeJSON(body) ? body : null;
-        }
-        return null;
-    }
-
-    @Override
-    public Map<String, Object> getParam() {
-        String body = this.getBody();
-        return CharSequenceUtil.isNotBlank(body) && JSONUtil.isTypeJSON(body)
-            ? JSONUtil.toBean(body, Map.class)
-            : Collections.unmodifiableMap(JakartaServletUtil.getParamMap(request));
-    }
-
-    @Override
-    public String getIp() {
-        return JakartaServletUtil.getClientIP(request);
-    }
-
-    private StringBuilder appendQueryString(String queryString) {
-        return new StringBuilder().append(request.getRequestURL())
-            .append(StringConstants.QUESTION_MARK)
-            .append(queryString);
-    }
-}

continew-starter-log/continew-starter-log-core/src/main/java/top/continew/starter/log/http/servlet/RecordableServletHttpResponse.java

@@ -1,71 +0,0 @@
-/*
- * Copyright (c) 2022-present Charles7c Authors. All Rights Reserved.
- * <p>
- * Licensed under the GNU LESSER GENERAL PUBLIC LICENSE 3.0;
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- * <p>
- * http://www.gnu.org/licenses/lgpl.html
- * <p>
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package top.continew.starter.log.http.servlet;
-
-import cn.hutool.core.text.CharSequenceUtil;
-import cn.hutool.json.JSONUtil;
-import jakarta.servlet.http.HttpServletResponse;
-import top.continew.starter.web.util.ServletUtils;
-import top.continew.starter.web.util.RepeatReadResponseWrapper;
-import top.continew.starter.log.http.RecordableHttpResponse;
-
-import java.util.Map;
-
-/**
- * 可记录的 HTTP 响应信息适配器
- *
- * @author Andy Wilkinson（Spring Boot Actuator）
- * @author Charles7c
- * @author echo
- * @since 1.1.0
- */
-public final class RecordableServletHttpResponse implements RecordableHttpResponse {
-
-    private final HttpServletResponse response;
-
-    private final int status;
-
-    public RecordableServletHttpResponse(HttpServletResponse response, int status) {
-        this.response = response;
-        this.status = status;
-    }
-
-    @Override
-    public int getStatus() {
-        return this.status;
-    }
-
-    @Override
-    public Map<String, String> getHeaders() {
-        return ServletUtils.getHeaderMap(response);
-    }
-
-    @Override
-    public String getBody() {
-        if (response instanceof RepeatReadResponseWrapper wrapper && !wrapper.isStreamingResponse()) {
-            String body = wrapper.getResponseContent();
-            return JSONUtil.isTypeJSON(body) ? body : null;
-        }
-        return null;
-    }
-
-    @Override
-    public Map<String, Object> getParam() {
-        String body = this.getBody();
-        return CharSequenceUtil.isNotBlank(body) && JSONUtil.isTypeJSON(body) ? JSONUtil.toBean(body, Map.class) : null;
-    }
-}

continew-starter-log/continew-starter-log-core/src/main/java/top/continew/starter/log/model/AccessLogContext.java

@@ -16,9 +16,6 @@
 
 package top.continew.starter.log.model;
 
-import top.continew.starter.log.http.RecordableHttpRequest;
-import top.continew.starter.log.http.RecordableHttpResponse;
-
 import java.time.Instant;
 
 /**
@@ -39,16 +36,6 @@ public class AccessLogContext {
      */
     private Instant endTime;
 
-    /**
-     * 请求信息
-     */
-    private final RecordableHttpRequest request;
-
-    /**
-     * 响应信息
-     */
-    private final RecordableHttpResponse response;
-
     /**
      * 配置信息
      */
@@ -57,8 +44,6 @@ public class AccessLogContext {
     private AccessLogContext(Builder builder) {
         this.startTime = builder.startTime;
         this.endTime = builder.endTime;
-        this.request = builder.request;
-        this.response = builder.response;
         this.properties = builder.properties;
     }
 
@@ -70,14 +55,6 @@ public class AccessLogContext {
         return endTime;
     }
 
-    public RecordableHttpRequest getRequest() {
-        return request;
-    }
-
-    public RecordableHttpResponse getResponse() {
-        return response;
-    }
-
     public LogProperties getProperties() {
         return properties;
     }
@@ -97,8 +74,6 @@ public class AccessLogContext {
 
         private Instant startTime;
         private Instant endTime;
-        private RecordableHttpRequest request;
-        private RecordableHttpResponse response;
         private LogProperties properties;
 
         private Builder() {
@@ -114,16 +89,6 @@ public class AccessLogContext {
             return this;
         }
 
-        public Builder request(RecordableHttpRequest request) {
-            this.request = request;
-            return this;
-        }
-
-        public Builder response(RecordableHttpResponse response) {
-            this.response = response;
-            return this;
-        }
-
         public Builder properties(LogProperties properties) {
             this.properties = properties;
             return this;

continew-starter-log/continew-starter-log-core/src/main/java/top/continew/starter/log/model/LogRecord.java

@@ -17,8 +17,6 @@
 package top.continew.starter.log.model;
 
 import top.continew.starter.log.enums.Include;
-import top.continew.starter.log.http.RecordableHttpRequest;
-import top.continew.starter.log.http.RecordableHttpResponse;
 
 import java.time.Duration;
 import java.time.Instant;
@@ -80,22 +78,20 @@ public class LogRecord {
     /**
      * 开始记录日志
      *
-     * @param request 请求信息
      * @return 日志记录器
      */
-    public static Started start(RecordableHttpRequest request) {
-        return start(Instant.now(), request);
+    public static Started start() {
+        return start(Instant.now());
     }
 
     /**
      * 开始记录日志
      *
      * @param timestamp 开始时间
-     * @param request   请求信息
      * @return 日志记录器
      */
-    public static Started start(Instant timestamp, RecordableHttpRequest request) {
-        return new Started(timestamp, request);
+    public static Started start(Instant timestamp) {
+        return new Started(timestamp);
     }
 
     /**
@@ -105,24 +101,20 @@ public class LogRecord {
 
         private final Instant timestamp;
 
-        private final RecordableHttpRequest request;
-
-        private Started(Instant timestamp, RecordableHttpRequest request) {
+        private Started(Instant timestamp) {
             this.timestamp = timestamp;
-            this.request = request;
         }
 
         /**
          * 结束日志记录
          *
          * @param timestamp 结束时间
-         * @param response  响应信息
          * @param includes  包含信息
          * @return 日志记录
          */
-        public LogRecord finish(Instant timestamp, RecordableHttpResponse response, Set<Include> includes) {
-            LogRequest logRequest = new LogRequest(this.request, includes);
-            LogResponse logResponse = new LogResponse(response, includes);
+        public LogRecord finish(Instant timestamp, Set<Include> includes) {
+            LogRequest logRequest = new LogRequest(includes);
+            LogResponse logResponse = new LogResponse(includes);
             Duration duration = Duration.between(this.timestamp, timestamp);
             return new LogRecord(this.timestamp, logRequest, logResponse, duration);
         }

continew-starter-log/continew-starter-log-core/src/main/java/top/continew/starter/log/model/LogRequest.java

@@ -22,7 +22,6 @@ import top.continew.starter.core.util.ExceptionUtils;
 import top.continew.starter.core.util.IpUtils;
 import top.continew.starter.web.util.ServletUtils;
 import top.continew.starter.log.enums.Include;
-import top.continew.starter.log.http.RecordableHttpRequest;
 
 import java.net.URI;
 import java.util.Map;
@@ -81,15 +80,15 @@ public class LogRequest {
      */
     private String os;
 
-    public LogRequest(RecordableHttpRequest request, Set<Include> includes) {
-        this.method = request.getMethod();
-        this.url = request.getUrl();
-        this.ip = request.getIp();
-        this.headers = (includes.contains(Include.REQUEST_HEADERS)) ? request.getHeaders() : null;
+    public LogRequest(Set<Include> includes) {
+        this.method = ServletUtils.getReqMethod();
+        this.url = ServletUtils.getReqUrl();
+        this.ip = ServletUtils.getReqIp();
+        this.headers = (includes.contains(Include.REQUEST_HEADERS)) ? ServletUtils.getReqHeaders() : null;
         if (includes.contains(Include.REQUEST_BODY)) {
-            this.body = request.getBody();
+            this.body = ServletUtils.getReqBody();
         } else if (includes.contains(Include.REQUEST_PARAM)) {
-            this.param = request.getParam();
+            this.param = ServletUtils.getReqParam();
         }
         this.address = (includes.contains(Include.IP_ADDRESS))
             ? ExceptionUtils.exToNull(() -> IpUtils.getIpv4Address(this.ip))

continew-starter-log/continew-starter-log-core/src/main/java/top/continew/starter/log/model/LogResponse.java

@@ -17,7 +17,7 @@
 package top.continew.starter.log.model;
 
 import top.continew.starter.log.enums.Include;
-import top.continew.starter.log.http.RecordableHttpResponse;
+import top.continew.starter.web.util.ServletUtils;
 
 import java.util.Map;
 import java.util.Set;
@@ -50,13 +50,13 @@ public class LogResponse {
      */
     private Map<String, Object> param;
 
-    public LogResponse(RecordableHttpResponse response, Set<Include> includes) {
-        this.status = response.getStatus();
-        this.headers = (includes.contains(Include.RESPONSE_HEADERS)) ? response.getHeaders() : null;
+    public LogResponse(Set<Include> includes) {
+        this.status = ServletUtils.getRespStatus();
+        this.headers = (includes.contains(Include.RESPONSE_HEADERS)) ? ServletUtils.getRespHeaders() : null;
         if (includes.contains(Include.RESPONSE_BODY)) {
-            this.body = response.getBody();
+            this.body = ServletUtils.getRespBody();
         } else if (includes.contains(Include.RESPONSE_PARAM)) {
-            this.param = response.getParam();
+            this.param = ServletUtils.getRespParam();
         }
     }
 

continew-starter-log/continew-starter-log-core/src/main/java/top/continew/starter/log/util/AccessLogUtils.java

@@ -18,9 +18,9 @@ package top.continew.starter.log.util;
 
 import cn.hutool.core.util.ObjectUtil;
 import cn.hutool.json.JSONUtil;
-import top.continew.starter.log.http.RecordableHttpRequest;
 import top.continew.starter.log.model.AccessLogProperties;
 import top.continew.starter.log.model.LogProperties;
+import top.continew.starter.web.util.ServletUtils;
 import top.continew.starter.web.util.SpringWebUtils;
 
 import java.util.HashMap;
@@ -45,11 +45,10 @@ public class AccessLogUtils {
     /**
      * 获取参数信息
      *
-     * @param request    请求
      * @param properties 属性
      * @return {@link String }
      */
-    public static String getParam(RecordableHttpRequest request, AccessLogProperties properties) {
+    public static String getParam(AccessLogProperties properties) {
         // 是否需要打印请求参数
         if (!properties.isPrintRequestParam()) {
             return null;
@@ -58,7 +57,7 @@ public class AccessLogUtils {
         // 参数为空返回空
         Map<String, Object> params;
         try {
-            params = request.getParam();
+            params = ServletUtils.getReqParam();
         } catch (Exception e) {
             return null;
         }