CRM：新增客户导入模版所属行业、客户等级、客户来源、客户地区单元格下拉选择

yudao-framework/yudao-spring-boot-starter-excel/src/main/java/cn/iocoder/yudao/framework/excel/core/handler/SelectSheetWriteHandler.java

@@ -0,0 +1,105 @@
+package cn.iocoder.yudao.framework.excel.core.handler;
+
+import cn.hutool.core.collection.CollUtil;
+import cn.iocoder.yudao.framework.common.core.KeyValue;
+import com.alibaba.excel.write.handler.SheetWriteHandler;
+import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
+import com.alibaba.excel.write.metadata.holder.WriteWorkbookHolder;
+import org.apache.poi.hssf.usermodel.HSSFDataValidation;
+import org.apache.poi.ss.usermodel.*;
+import org.apache.poi.ss.util.CellRangeAddressList;
+
+import java.util.List;
+
+/**
+ * 基于固定 sheet 实现下拉框
+ *
+ * @author HUIHUI
+ */
+public class SelectSheetWriteHandler implements SheetWriteHandler {
+
+    private List<KeyValue<Integer, List<String>>> selectMap;
+
+    private final char[] alphabet = new char[]{'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L',
+            'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'};
+
+    public SelectSheetWriteHandler(List<KeyValue<Integer, List<String>>> selectMap) {
+        this.selectMap = selectMap;
+    }
+
+    @Override
+    public void afterSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {
+        if (selectMap == null || CollUtil.isEmpty(selectMap)) {
+            return;
+        }
+        // 需要设置下拉框的sheet页
+        Sheet curSheet = writeSheetHolder.getSheet();
+        DataValidationHelper helper = curSheet.getDataValidationHelper();
+        String dictSheetName = "字典sheet";
+        Workbook workbook = writeWorkbookHolder.getWorkbook();
+        // 数据字典的sheet页
+        Sheet dictSheet = workbook.createSheet(dictSheetName);
+        for (KeyValue<Integer, List<String>> keyValue : selectMap) {
+            // 设置下拉单元格的首行、末行、首列、末列
+            CellRangeAddressList rangeAddressList = new CellRangeAddressList(1, 65533, keyValue.getKey(), keyValue.getKey());
+            int rowLen = keyValue.getValue().size();
+            // 设置字典sheet页的值 每一列一个字典项
+            for (int i = 0; i < rowLen; i++) {
+                Row row = dictSheet.getRow(i);
+                if (row == null) {
+                    row = dictSheet.createRow(i);
+                }
+                row.createCell(keyValue.getKey()).setCellValue(keyValue.getValue().get(i));
+            }
+            String excelColumn = getExcelColumn(keyValue.getKey());
+            // 下拉框数据来源 eg:字典sheet!$B1:$B2
+            String refers = dictSheetName + "!$" + excelColumn + "$1:$" + excelColumn + "$" + rowLen;
+            // 创建可被其他单元格引用的名称
+            Name name = workbook.createName();
+            // 设置名称的名字
+            name.setNameName("dict" + keyValue.getKey());
+            // 设置公式
+            name.setRefersToFormula(refers);
+            // 设置引用约束
+            DataValidationConstraint constraint = helper.createFormulaListConstraint("dict" + keyValue.getKey());
+            // 设置约束
+            DataValidation validation = helper.createValidation(constraint, rangeAddressList);
+            if (validation instanceof HSSFDataValidation) {
+                validation.setSuppressDropDownArrow(false);
+            } else {
+                validation.setSuppressDropDownArrow(true);
+                validation.setShowErrorBox(true);
+            }
+            // 阻止输入非下拉框的值
+            validation.setErrorStyle(DataValidation.ErrorStyle.STOP);
+            validation.createErrorBox("提示", "此值不存在于下拉选择中！");
+            // 添加下拉框约束
+            writeSheetHolder.getSheet().addValidationData(validation);
+        }
+    }
+
+    /**
+     * 将数字列转化成为字母列
+     *
+     * @param num 数字
+     * @return 字母
+     */
+    private String getExcelColumn(int num) {
+        String column = "";
+        int len = alphabet.length - 1;
+        int first = num / len;
+        int second = num % len;
+        if (num <= len) {
+            column = alphabet[num] + "";
+        } else {
+            column = alphabet[first - 1] + "";
+            if (second == 0) {
+                column = column + alphabet[len] + "";
+            } else {
+                column = column + alphabet[second - 1] + "";
+            }
+        }
+        return column;
+    }
+
+}

yudao-framework/yudao-spring-boot-starter-excel/src/main/java/cn/iocoder/yudao/framework/excel/core/util/ExcelUtils.java

@@ -1,11 +1,13 @@
 package cn.iocoder.yudao.framework.excel.core.util;
 
+import cn.iocoder.yudao.framework.common.core.KeyValue;
+import cn.iocoder.yudao.framework.excel.core.handler.SelectSheetWriteHandler;
 import com.alibaba.excel.EasyExcel;
 import com.alibaba.excel.converters.longconverter.LongStringConverter;
 import com.alibaba.excel.write.style.column.LongestMatchColumnWidthStyleStrategy;
+import jakarta.servlet.http.HttpServletResponse;
 import org.springframework.web.multipart.MultipartFile;
 
-import jakarta.servlet.http.HttpServletResponse;
 import java.io.IOException;
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
@@ -21,12 +23,12 @@ public class ExcelUtils {
     /**
      * 将列表以 Excel 响应给前端
      *
-     * @param response 响应
-     * @param filename 文件名
+     * @param response  响应
+     * @param filename  文件名
      * @param sheetName Excel sheet 名
-     * @param head Excel head 头
-     * @param data 数据列表哦
-     * @param <T> 泛型，保证 head 和 data 类型的一致性
+     * @param head      Excel head 头
+     * @param data      数据列表哦
+     * @param <T>       泛型，保证 head 和 data 类型的一致性
      * @throws IOException 写入失败的情况
      */
     public static <T> void write(HttpServletResponse response, String filename, String sheetName,
@@ -38,12 +40,37 @@ public class ExcelUtils {
                 .registerConverter(new LongStringConverter()) // 避免 Long 类型丢失精度
                 .sheet(sheetName).doWrite(data);
         // 设置 header 和 contentType。写在最后的原因是，避免报错时，响应 contentType 已经被修改了
-        response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(filename, StandardCharsets.UTF_8));
+        response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(filename, StandardCharsets.UTF_8.name()));
+        response.setContentType("application/vnd.ms-excel;charset=UTF-8");
+    }
+
+    /**
+     * 将列表以 Excel 响应给前端
+     *
+     * @param response  响应
+     * @param filename  文件名
+     * @param sheetName Excel sheet 名
+     * @param head      Excel head 头
+     * @param data      数据列表哦
+     * @param selectMap 下拉选择数据 Map
+     * @throws IOException 写入失败的情况
+     */
+    public static <T> void write(HttpServletResponse response, String filename, String sheetName,
+                                 Class<T> head, List<T> data, List<KeyValue<Integer, List<String>>> selectMap) throws IOException {
+        // 输出 Excel
+        EasyExcel.write(response.getOutputStream(), head)
+                .autoCloseStream(false) // 不要自动关闭，交给 Servlet 自己处理
+                .registerWriteHandler(new LongestMatchColumnWidthStyleStrategy()) // 基于 column 长度，自动适配。最大 255 宽度
+                .registerWriteHandler(new SelectSheetWriteHandler(selectMap)) // 基于固定 sheet 实现下拉框
+                .registerConverter(new LongStringConverter()) // 避免 Long 类型丢失精度
+                .sheet(sheetName).doWrite(data);
+        // 设置 header 和 contentType。写在最后的原因是，避免报错时，响应 contentType 已经被修改了
+        response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(filename, StandardCharsets.UTF_8.name()));
         response.setContentType("application/vnd.ms-excel;charset=UTF-8");
     }
 
     public static <T> List<T> read(MultipartFile file, Class<T> head) throws IOException {
-       return EasyExcel.read(file.getInputStream(), head, null)
+        return EasyExcel.read(file.getInputStream(), head, null)
                 .autoCloseStream(false)  // 不要自动关闭，交给 Servlet 自己处理
                 .doReadAllSync();
     }