feat(upms): 新增ByteArrayMultipartFile工具类实现内存型文件上传

- 实现基于byte[]的MultipartFile接口适配RemoteFileService
- 提供两种构造方式支持直接byte[]或InputStream输入
- 包含完整文件属性(name/originalFilename/contentType)处理方法
- 内置空文件检查和文件大小计算能力

pigx-upms/pigx-upms-api/src/main/java/com/pig4cloud/pigx/admin/api/utils/ByteArrayMultipartFile.java

@@ -0,0 +1,124 @@
+/*
+ * Copyright 2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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 com.pig4cloud.pigx.admin.api.utils;
+
+import lombok.Value;
+import org.springframework.lang.NonNull;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+import org.springframework.util.FileCopyUtils;
+import org.springframework.web.multipart.MultipartFile;
+
+import java.io.ByteArrayInputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * 基于字节数组实现的内存型MultipartFile ,适配于 RemoteFileService 的 Upload 方法。
+ *
+ * @author lengleng
+ * @date 2025/07/05
+ */
+@Value
+public class ByteArrayMultipartFile implements MultipartFile {
+
+    private final String name;
+
+    private final String originalFilename;
+
+    @Nullable
+    private final String contentType;
+
+    private final byte[] content;
+
+    /**
+     * Create a new ByteArrayMultipartFile with the given content.
+     *
+     * @param name             the name of the file
+     * @param originalFilename the original filename (as on the client's machine)
+     * @param contentType      the content type (if known)
+     * @param content          the content of the file
+     */
+    public ByteArrayMultipartFile(String name, @Nullable String originalFilename, @Nullable String contentType,
+                                  @Nullable byte[] content) {
+
+        Assert.hasLength(name, "Name must not be empty");
+        this.name = name;
+        this.originalFilename = (originalFilename != null ? originalFilename : "");
+        this.contentType = contentType;
+        this.content = (content != null ? content : new byte[0]);
+    }
+
+    /**
+     * Create a new ByteArrayMultipartFile with the given content.
+     *
+     * @param name             the name of the file
+     * @param originalFilename the original filename (as on the client's machine)
+     * @param contentType      the content type (if known)
+     * @param contentStream    the content of the file as stream
+     * @throws IOException if reading from the stream failed
+     */
+    public ByteArrayMultipartFile(String name, @Nullable String originalFilename, @Nullable String contentType,
+                                  InputStream contentStream) throws IOException {
+
+        this(name, originalFilename, contentType, FileCopyUtils.copyToByteArray(contentStream));
+    }
+
+    @Override
+    public String getName() {
+        return this.name;
+    }
+
+    @Override
+    @NonNull
+    public String getOriginalFilename() {
+        return this.originalFilename;
+    }
+
+    @Override
+    @Nullable
+    public String getContentType() {
+        return this.contentType;
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return (this.content.length == 0);
+    }
+
+    @Override
+    public long getSize() {
+        return this.content.length;
+    }
+
+    @Override
+    public byte[] getBytes() throws IOException {
+        return this.content;
+    }
+
+    @Override
+    public InputStream getInputStream() throws IOException {
+        return new ByteArrayInputStream(this.content);
+    }
+
+    @Override
+    public void transferTo(File dest) throws IOException, IllegalStateException {
+        FileCopyUtils.copy(this.content, dest);
+    }
+
+}