feat(core): 新增 MultipartFileUtils，支持 File 转换为 MultipartFile

continew-starter-core/pom.xml

@@ -63,6 +63,13 @@
             <artifactId>mica-ip2region</artifactId>
         </dependency>
 
+        <!-- 文件上传组件（用于处理 multipart/form-data 类型的请求，支持文件上传） -->
+        <dependency>
+            <groupId>commons-fileupload</groupId>
+            <artifactId>commons-fileupload</artifactId>
+            <optional>true</optional>
+        </dependency>
+
         <!-- Hutool 核心模块（核心方法及数据结构包） -->
         <dependency>
             <groupId>cn.hutool</groupId>

continew-starter-core/src/main/java/top/continew/starter/core/util/multipart/CommonsMultipartFile.java

@@ -0,0 +1,238 @@
+/*
+ * 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.core.util.multipart;
+
+import org.apache.commons.fileupload.FileItem;
+import org.apache.commons.fileupload.FileUploadException;
+import org.apache.commons.fileupload.disk.DiskFileItem;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.springframework.core.log.LogFormatUtils;
+import org.springframework.util.FileCopyUtils;
+import org.springframework.web.multipart.MultipartFile;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.Serializable;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+/**
+ * {@link MultipartFile} implementation for Apache Commons FileUpload.
+ * <p>
+ * Spring Boot3（Spring 6）移除了 CommonsMultipartFile 和 CommonsMultipartResolver，彻底废弃了对 Apache Commons FileUpload 的依赖，只保留基于
+ * Servlet 3.1+ 的标准上传机制 StandardMultipartFile。
+ * <br>为了方便在项目中进行 MultipartFile 格式转换，特备份该实现。
+ * </p>
+ *
+ * @author Trevor D. Cook
+ * @author Juergen Hoeller
+ * @author Charles7c
+ * @since 2.15.0
+ */
+@SuppressWarnings("serial")
+public class CommonsMultipartFile implements MultipartFile, Serializable {
+
+    protected static final Log logger = LogFactory.getLog(CommonsMultipartFile.class);
+
+    private final FileItem fileItem;
+
+    private final long size;
+
+    private boolean preserveFilename = false;
+
+    /**
+     * Create an instance wrapping the given FileItem.
+     * 
+     * @param fileItem the FileItem to wrap
+     */
+    public CommonsMultipartFile(FileItem fileItem) {
+        this.fileItem = fileItem;
+        this.size = this.fileItem.getSize();
+    }
+
+    /**
+     * Return the underlying {@code org.apache.commons.fileupload.FileItem}
+     * instance. There is hardly any need to access this.
+     */
+    public final FileItem getFileItem() {
+        return this.fileItem;
+    }
+
+    /**
+     * Set whether to preserve the filename as sent by the client, not stripping off
+     * path information in {@link CommonsMultipartFile#getOriginalFilename()}.
+     * <p>Default is "false", stripping off path information that may prefix the
+     * actual filename e.g. from Opera. Switch this to "true" for preserving the
+     * client-specified filename as-is, including potential path separators.
+     * 
+     * @since 4.3.5
+     * @see #getOriginalFilename()
+     */
+    public void setPreserveFilename(boolean preserveFilename) {
+        this.preserveFilename = preserveFilename;
+    }
+
+    @Override
+    public String getName() {
+        return this.fileItem.getFieldName();
+    }
+
+    @Override
+    public String getOriginalFilename() {
+        String filename = this.fileItem.getName();
+        if (filename == null) {
+            // Should never happen.
+            return "";
+        }
+        if (this.preserveFilename) {
+            // Do not try to strip off a path...
+            return filename;
+        }
+
+        // Check for Unix-style path
+        int unixSep = filename.lastIndexOf('/');
+        // Check for Windows-style path
+        int winSep = filename.lastIndexOf('\\');
+        // Cut off at latest possible point
+        int pos = Math.max(winSep, unixSep);
+        if (pos != -1) {
+            // Any sort of path separator found...
+            return filename.substring(pos + 1);
+        } else {
+            // A plain name
+            return filename;
+        }
+    }
+
+    @Override
+    public String getContentType() {
+        return this.fileItem.getContentType();
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return (this.size == 0);
+    }
+
+    @Override
+    public long getSize() {
+        return this.size;
+    }
+
+    @Override
+    public byte[] getBytes() {
+        if (!isAvailable()) {
+            throw new IllegalStateException("File has been moved - cannot be read again");
+        }
+        byte[] bytes = this.fileItem.get();
+        return (bytes != null ? bytes : new byte[0]);
+    }
+
+    @Override
+    public InputStream getInputStream() throws IOException {
+        if (!isAvailable()) {
+            throw new IllegalStateException("File has been moved - cannot be read again");
+        }
+        InputStream inputStream = this.fileItem.getInputStream();
+        return (inputStream != null ? inputStream : InputStream.nullInputStream());
+    }
+
+    @Override
+    public void transferTo(File dest) throws IOException, IllegalStateException {
+        if (!isAvailable()) {
+            throw new IllegalStateException("File has already been moved - cannot be transferred again");
+        }
+
+        if (dest.exists() && !dest.delete()) {
+            throw new IOException("Destination file [" + dest
+                .getAbsolutePath() + "] already exists and could not be deleted");
+        }
+
+        try {
+            this.fileItem.write(dest);
+            LogFormatUtils.traceDebug(logger, traceOn -> {
+                String action = "transferred";
+                if (!this.fileItem.isInMemory()) {
+                    action = (isAvailable() ? "copied" : "moved");
+                }
+                return "Part '" + getName() + "',  filename '" + getOriginalFilename() + "'" + (Boolean.TRUE
+                    .equals(traceOn) ? ", stored " + getStorageDescription() : "") + ": " + action + " to [" + dest
+                        .getAbsolutePath() + "]";
+            });
+        } catch (FileUploadException ex) {
+            throw new IllegalStateException(ex.getMessage(), ex);
+        } catch (IllegalStateException | IOException ex) {
+            // Pass through IllegalStateException when coming from FileItem directly,
+            // or propagate an exception from I/O operations within FileItem.write
+            throw ex;
+        } catch (Exception ex) {
+            throw new IOException("File transfer failed", ex);
+        }
+    }
+
+    @Override
+    public void transferTo(Path dest) throws IOException, IllegalStateException {
+        if (!isAvailable()) {
+            throw new IllegalStateException("File has already been moved - cannot be transferred again");
+        }
+
+        FileCopyUtils.copy(this.fileItem.getInputStream(), Files.newOutputStream(dest));
+    }
+
+    /**
+     * Determine whether the multipart content is still available.
+     * If a temporary file has been moved, the content is no longer available.
+     */
+    protected boolean isAvailable() {
+        // If in memory, it's available.
+        if (this.fileItem.isInMemory()) {
+            return true;
+        }
+        // Check actual existence of temporary file.
+        if (this.fileItem instanceof DiskFileItem df) {
+            return df.getStoreLocation().exists();
+        }
+        // Check whether current file size is different than original one.
+        return (this.fileItem.getSize() == this.size);
+    }
+
+    /**
+     * Return a description for the storage location of the multipart content.
+     * Tries to be as specific as possible: mentions the file location in case
+     * of a temporary file.
+     */
+    public String getStorageDescription() {
+        if (this.fileItem.isInMemory()) {
+            return "in memory";
+        } else if (this.fileItem instanceof DiskFileItem df) {
+            return "at [" + df.getStoreLocation().getAbsolutePath() + "]";
+        } else {
+            return "on disk";
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "MultipartFile[field=\"" + this.fileItem.getFieldName() + "\"" + (this.fileItem.getName() != null
+            ? ", filename=" + this.fileItem.getName()
+            : "") + (this.fileItem.getContentType() != null
+                ? ", contentType=" + this.fileItem.getContentType()
+                : "") + ", size=" + this.fileItem.getSize() + "]";
+    }
+}

continew-starter-core/src/main/java/top/continew/starter/core/util/multipart/MultipartFileUtils.java

@@ -0,0 +1,96 @@
+/*
+ * 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.core.util.multipart;
+
+import cn.hutool.core.io.IoUtil;
+import org.apache.commons.fileupload.FileItem;
+import org.apache.commons.fileupload.disk.DiskFileItemFactory;
+import org.springframework.http.MediaType;
+import org.springframework.web.multipart.MultipartFile;
+import top.continew.starter.core.exception.BaseException;
+
+import java.io.*;
+import java.nio.file.Files;
+
+/**
+ * MultipartFile 工具类
+ *
+ * @author Charles7c
+ * @since 2.15.0
+ */
+public class MultipartFileUtils {
+
+    private MultipartFileUtils() {
+    }
+
+    /**
+     * 转换为 MultipartFile
+     *
+     * @param file 文件
+     * @return MultipartFile
+     */
+    public static MultipartFile toMultipartFile(File file) throws IOException {
+        FileItem fileItem = createFileItem(Files.newInputStream(file.toPath()), file.getName());
+        return new CommonsMultipartFile(fileItem);
+    }
+
+    /**
+     * 转换为 MultipartFile
+     *
+     * @param bytes    文件字节
+     * @param fileName 文件名
+     * @return MultipartFile
+     */
+    public static MultipartFile toMultipartFile(byte[] bytes, String fileName) {
+        FileItem fileItem = createFileItem(new ByteArrayInputStream(bytes), fileName);
+        return new CommonsMultipartFile(fileItem);
+    }
+
+    /**
+     * 创建 FileItem
+     *
+     * @param is       输入流
+     * @param fileName 文件名
+     * @return FileItem
+     */
+    public static FileItem createFileItem(InputStream is, String fileName) {
+        return createFileItem(is, "file", fileName, MediaType.MULTIPART_FORM_DATA_VALUE);
+    }
+
+    /**
+     * 创建 FileItem
+     *
+     * @param is          输入流
+     * @param fieldName   字段名
+     * @param fileName    文件名
+     * @param contentType 内容类型
+     * @return FileItem
+     */
+    public static FileItem createFileItem(InputStream is, String fieldName, String fileName, String contentType) {
+        DiskFileItemFactory factory = new DiskFileItemFactory();
+        FileItem fileItem = factory.createItem(fieldName, contentType, true, fileName);
+        // 拷贝流
+        try (OutputStream os = fileItem.getOutputStream()) {
+            IoUtil.copy(is, os);
+        } catch (IOException e) {
+            throw new BaseException("创建文件项失败", e);
+        } finally {
+            IoUtil.close(is);
+        }
+        return fileItem;
+    }
+}

continew-starter-dependencies/pom.xml

@@ -80,6 +80,8 @@
         <snakeyaml.version>2.5</snakeyaml.version>
         <nashorn.version>15.7</nashorn.version>
 
+        <commons-fileupload.version>1.6.0</commons-fileupload.version>
+
         <!-- Security Vulnerability Fix Versions -->
         <commons-beanutils.version>1.11.0</commons-beanutils.version>
         <commons-io.version>2.20.0</commons-io.version>
@@ -404,6 +406,13 @@
                 <version>${nashorn.version}</version>
             </dependency>
 
+            <!-- 文件上传组件（用于处理 multipart/form-data 类型的请求，支持文件上传） -->
+            <dependency>
+                <groupId>commons-fileupload</groupId>
+                <artifactId>commons-fileupload</artifactId>
+                <version>${commons-fileupload.version}</version>
+            </dependency>
+
             <!-- 解决部分传递依赖漏洞问题 -->
             <dependency>
                 <groupId>commons-beanutils</groupId>