add:通用**模板下载方法

alien-store/src/main/java/shop/alien/store/controller/TemplateDownloadController.java

@@ -0,0 +1,137 @@
+package shop.alien.store.controller;
+
+import io.swagger.annotations.Api;
+import io.swagger.annotations.ApiOperation;
+import io.swagger.annotations.ApiParam;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.core.io.Resource;
+import org.springframework.web.bind.annotation.CrossOrigin;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import javax.servlet.http.HttpServletResponse;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * 通用模板下载控制器
+ * 支持通过type参数下载不同类型的模板文件
+ *
+ * @author system
+ */
+@Api(tags = {"通用模板下载"})
+@Slf4j
+@RestController
+@CrossOrigin
+@RequestMapping("/template")
+public class TemplateDownloadController {
+
+    /**
+     * 模板类型与文件名的映射关系
+     * key: 模板类型
+     * value: 模板文件名（相对于 resources/templates 目录）
+     */
+    private static final Map<String, String> TEMPLATE_MAP = new HashMap<String, String>() {{
+        put("clearing_receipt", "clearing_receipt.xlsx");
+        // 可以根据需要添加更多模板类型映射
+        // put("type2", "template2.xlsx");
+        // put("type3", "template3.xls");
+    }};
+
+    /**
+     * 通用模板下载接口
+     * 
+     * @param type 模板类型，对应 TEMPLATE_MAP 中的 key
+     * @param response HTTP响应对象
+     */
+    @ApiOperation("下载模板文件")
+    @GetMapping("/download")
+    public void downloadTemplate(
+            @ApiParam(value = "模板类型", required = true, example = "clearing_receipt")
+            @RequestParam("type") String type,
+            HttpServletResponse response) {
+        
+        log.info("开始下载模板，type: {}", type);
+        
+        // 验证模板类型
+        if (type == null || type.trim().isEmpty()) {
+            log.error("模板类型参数不能为空");
+            throw new RuntimeException("模板类型参数不能为空");
+        }
+        
+        String fileName = TEMPLATE_MAP.get(type);
+        if (fileName == null) {
+            log.error("不支持的模板类型: {}", type);
+            throw new RuntimeException("不支持的模板类型: " + type);
+        }
+        
+        InputStream inputStream = null;
+        OutputStream outputStream = null;
+        
+        try {
+            // 从resources/templates目录读取模板文件
+            Resource resource = new ClassPathResource("templates/" + fileName);
+            
+            // 检查文件是否存在
+            if (!resource.exists()) {
+                log.error("模板文件不存在: templates/{}", fileName);
+                throw new RuntimeException("模板文件不存在: " + fileName);
+            }
+            
+            inputStream = resource.getInputStream();
+            
+            // 根据文件扩展名设置Content-Type
+            String contentType;
+            if (fileName.toLowerCase().endsWith(".xlsx")) {
+                contentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
+            } else if (fileName.toLowerCase().endsWith(".xls")) {
+                contentType = "application/vnd.ms-excel";
+            } else {
+                contentType = "application/octet-stream";
+            }
+            
+            // 设置响应头
+            response.reset();
+            response.setContentType(contentType);
+            response.setCharacterEncoding("utf-8");
+            
+            // 设置文件下载响应头，支持中文文件名
+            String encodedFileName = URLEncoder.encode(fileName, StandardCharsets.UTF_8.toString()).replaceAll("\\+", "%20");
+            response.setHeader("Content-Disposition", 
+                    "attachment;filename=\"" + encodedFileName + "\";filename*=utf-8''" + encodedFileName);
+            
+            // 输出文件流
+            outputStream = response.getOutputStream();
+            byte[] buffer = new byte[1024];
+            int length;
+            while ((length = inputStream.read(buffer)) > 0) {
+                outputStream.write(buffer, 0, length);
+            }
+            outputStream.flush();
+            
+            log.info("模板下载成功，type: {}, fileName: {}", type, fileName);
+        } catch (Exception e) {
+            log.error("下载模板失败，type: {}, fileName: {}", type, fileName, e);
+            throw new RuntimeException("下载模板失败：" + e.getMessage());
+        } finally {
+            // 关闭流
+            try {
+                if (inputStream != null) {
+                    inputStream.close();
+                }
+                if (outputStream != null) {
+                    outputStream.close();
+                }
+            } catch (Exception e) {
+                log.error("关闭流失败", e);
+            }
+        }
+    }
+}