Java generates formatted Word statistics report

@RestController
@RequestMapping("/api/reports")
public class ReportController {
    
    @Autowired
    private BookReportService bookReportService;
    
    @GetMapping("/books")
    public ResponseEntity<String> generateBookReport() {
        try {
            String fileName = "Book Statistics Report_" + () + ".docx";
            String outputPath = "reports/" + fileName;
            
            (outputPath);
            
            return ("Report generation successfully: " + outputPath);
        } catch (Exception e) {
            return (500)
                    .body("Report generation failed: " + ());
        }
    }
}

public interface BookReportMapper {
    // Get the total number of books    int selectTotalBookCount();
    
    // Statistics the number of books by category    List<Map<String, Object>> selectBooksByCategory();
    
    // Get the top 10 popular books    List<Map<String, Object>> selectPopularBooks();
    
    // Get borrowing statistics    List<Map<String, Object>> selectBorrowStats();
}

@Service
public class BookReportService {
    
    @Autowired
    private BookReportMapper bookReportMapper;

    public void generateReport(String outputPath) throws Exception {
        // Create Word Document        XWPFDocument document = new XWPFDocument();
        
        try {
            // Add report title            addTitle(document, "Library Book Statistics Report");
            
            // Add a generation date            addGenerationDate(document);
            
            // Add total book count            addTotalBookCount(document);
            
            // Add a classification statistics table            addCategoryStatistics(document);
            
            // Add a list of popular books            addPopularBooks(document);
            
            // Add borrowing statistics            addBorrowStatistics(document);
            
            // Save the document            saveDocument(document, outputPath);
        } finally {
            ();
        }
    }
    
    // Create a report main title, set centered, bold and large fonts    private void addTitle(XWPFDocument document, String titleText) {
        XWPFParagraph title = ();
        ();
        
        XWPFRun titleRun = ();
        (titleText);
        (true);
        (20);
        ("Songyi");
        
        // Add empty lines        ();
    }
    
    // Add report generation date in the upper right corner    private void addGenerationDate(XWPFDocument document) {
        XWPFParagraph datePara = ();
        ();
        
        XWPFRun dateRun = ();
        ("Generation Date: " + ().toString());
        (12);
        ("Songyi");
        
        // Add empty lines        ();
    }
    
    // Show the total library collection    private void addTotalBookCount(XWPFDocument document) {
        int totalCount = ();
        
        XWPFParagraph sectionTitle = createSectionTitle(document, "1. Statistics of total books");
        
        XWPFParagraph content = ();
        XWPFRun run = ();
        (("The library currently has a total collection of books: %s volumes", formatNumber(totalCount)));
        (14);
        ("Songyi");
        
        // Add empty lines        ();
    }
    
    // Create a classification statistics table, including serial number, classification name, quantity and proportion    private void addCategoryStatistics(XWPFDocument document) throws Exception {
        // Create chapter title        XWPFParagraph sectionTitle = createSectionTitle(document, "2. Book classification statistics");
        
        // Get classified data        List<Map<String, Object>> categories = ();
        int total = ();
        
        // Create a table        XWPFTable table = (1, 4);
        ("100%");
        
        // Set the table header        setTableHeader(table, "Serial Number", "Book Classification", "quantity", "Percentage");
        
        // Fill in data        int index = 1;
        for (Map<String, Object> category : categories) {
            XWPFTableRow row = ();
            (0).setText((index++));
            (1).setText(("categoryName").toString());
            
            int count = (("count").toString());
            (2).setText(formatNumber(count));
            
            double percent = (count * 100.0) / total;
            (3).setText(("%.1f%%", percent));
        }
        
        // Add summary line        XWPFTableRow footer = ();
        (1).setText("total");
        (2).setText(formatNumber(total));
        (3).setText("100%");
        
        // Add empty lines        ();
    }
    
    // List the top 10 popular books, the top three are bolded in blue    private void addPopularBooks(XWPFDocument document) {
        // Create chapter title        XWPFParagraph sectionTitle = createSectionTitle(document, "Three, Top 10 Popular Books");
        
        List<Map<String, Object>> popularBooks = ();
        
        for (int i = 0; i < (); i++) {
            Map<String, Object> book = (i);
            
            XWPFParagraph item = ();
            (200);
            
            XWPFRun run = ();
            (("%d. 《%s》 - %s (Borrowing volume: %sSecond-rate)", 
                i + 1,
                ("title"),
                ("author"),
                formatNumber((("borrowCount").toString()))
            );
            (12);
            ("Songyi");
            
            // Highlight the top three            if (i < 3) {
                (true);
                ("0000FF");
            }
        }
        
        // Add empty lines        ();
    }
    
    // Create a borrowing statistics table to display monthly borrowing volume and year-on-year growth rate    private void addBorrowStatistics(XWPFDocument document) {
        // Create chapter title        XWPFParagraph sectionTitle = createSectionTitle(document, "IV. Borrowing Statistics");
        
        List<Map<String, Object>> borrowStats = ();
        
        // Create a table        XWPFTable table = (1, 3);
        ("100%");
        
        // Set the table header        setTableHeader(table, "month", "Loan volume", "Year-over-year growth");
        
        // Fill in data        for (Map<String, Object> stat : borrowStats) {
            XWPFTableRow row = ();
            (0).setText(("month").toString());
            (1).setText(formatNumber((("count").toString())));
            
            // Calculate year-on-year growth            if (("growthRate")) {
                double growth = (("growthRate").toString());
                (2).setText(("%.1f%%", growth * 100));
                
                // Set color: Grow to red, drop to green                XWPFRun growthRun = (2).getParagraphs().get(0).getRuns().get(0);
                if (growth > 0) {
                    ("FF0000");
                } else if (growth < 0) {
                    ("00FF00");
                }
            } else {
                (2).setText("N/A");
            }
        }
    }
    
    // Auxiliary method to create a unified chapter title format    private XWPFParagraph createSectionTitle(XWPFDocument document, String title) {
        XWPFParagraph paragraph = ();
        XWPFRun run = ();
        (title);
        (true);
        (16);
        ("Songyi");
        
        return paragraph;
    }
    
    // Auxiliary method, set the table header style    private void setTableHeader(XWPFTable table, String... headers) {
        XWPFTableRow headerRow = (0);
        for (int i = 0; i < ; i++) {
            XWPFRun run = (i).getParagraphs().get(0).createRun();
            (headers[i]);
            (true);
            (12);
            ("Songyi");
            
            // Set cell background color            (i).setColor("D3D3D3");
        }
    }
    
    // Format the number display and add thousands separator    private String formatNumber(long number) {
        return ("%,d", number);
    }
    
    // Save Word document to the specified path    private void saveDocument(XWPFDocument document, String outputPath) throws IOException {
        // Make sure the directory exists        File outputFile = new File(outputPath);
        ().mkdirs();
        
        try (FileOutputStream out = new FileOutputStream(outputFile)) {
            (out);
        }
    }
}