fix：mail send fail #2345 (#2346)

Co-authored-by: dailidong <dailidong66@gmail.com>

dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/ExcelUtils.java

@@ -26,6 +26,7 @@ import org.apache.poi.ss.usermodel.HorizontalAlignment;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.util.*;
@@ -102,7 +103,11 @@ public class ExcelUtils {
 
                for (int i = 0; i < headerList.size(); i++) {
                    sheet.setColumnWidth(i, headerList.get(i).length() * 800);
+               }
 
+               File file = new File(xlsFilePath);
+               if (!file.exists()) {
+                   file.mkdirs();
                }
 
                //setting file output

dolphinscheduler-alert/src/test/java/org/apache/dolphinscheduler/alert/utils/ExcelUtilsTest.java

@@ -89,4 +89,14 @@ public class ExcelUtilsTest {
         ExcelUtils.genExcelFile(incorrectContent1, title, xlsFilePath);
 
     }
+
+    /**
+     * Test GenExcelFile (check directory)
+     */
+    @Test
+    public void testGenExcelFileByCheckDir() {
+        ExcelUtils.genExcelFile("[{\"a\": \"a\"},{\"a\": \"a\"}]", "t", "/tmp/xls");
+        File file = new File("/tmp/xls" + Constants.SINGLE_SLASH + "t" + Constants.EXCEL_SUFFIX_XLS);
+        file.delete();
+    }
 }