Added a command to get suggestion data into excel

src/main/java/com/alttd/util/ExcelWriter.java

@@ -0,0 +1,57 @@
+package com.alttd.util;
+
+import net.dv8tion.jda.api.interactions.InteractionHook;
+import net.dv8tion.jda.api.utils.FileUpload;
+import org.apache.poi.ss.usermodel.*;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+public class ExcelWriter {
+
+    private final String fileName = "suggestions.xlsx";
+    private final String sheetName = "Sheet1";
+    private final Workbook workbook;
+    private final Sheet sheet;
+    private int currentRow = 0;
+    private boolean done = false;
+
+    public ExcelWriter() {
+        this.workbook = new XSSFWorkbook();
+
+        // Create a new sheet in the workbook
+        this.sheet = workbook.createSheet(sheetName);
+    }
+
+    public synchronized void addRow(String... data) {
+        if (done) {
+            Logger.warning("Tried to write to finished excel file");
+            return;
+        }
+        Row row = sheet.createRow(currentRow++);
+        int curCel = 0;
+        for (String entry : data) {
+            Cell cell = row.createCell(curCel++);
+            cell.setCellValue(entry);
+        }
+    }
+
+    public synchronized void saveAndSend(InteractionHook reply) {
+        done = true;
+        try {
+            File file = new File(fileName);
+            FileOutputStream outputStream = new FileOutputStream(file);
+            workbook.write(outputStream);
+            workbook.close();
+            reply.sendFiles(FileUpload.fromData(file)).queue(done -> {
+                //noinspection ResultOfMethodCallIgnored
+                file.delete();
+            });
+        } catch (IOException e) {
+            reply.sendMessageEmbeds(Util.genericErrorEmbed("Error", "Error while uploading excel file")).queue();
+        }
+    }
+}