新增pdf页码

src/main/java/com/gunshi/project/hsz/service/ForecastProjectService.java

@@ -7,6 +7,7 @@ import com.gunshi.project.hsz.mapper.ForecastProjectMapper;
 import com.gunshi.project.hsz.model.ForecastProject;
 import com.gunshi.project.hsz.model.ForecastResults;
 import com.itextpdf.io.font.PdfEncodings;
+import com.itextpdf.kernel.colors.Color;
 import com.itextpdf.kernel.colors.DeviceRgb;
 import com.itextpdf.kernel.events.Event;
 import com.itextpdf.kernel.events.IEventHandler;
@@ -19,6 +20,7 @@ import com.itextpdf.kernel.pdf.PdfDocument;
 import com.itextpdf.kernel.pdf.PdfPage;
 import com.itextpdf.kernel.pdf.PdfWriter;
 import com.itextpdf.kernel.pdf.canvas.PdfCanvas;
+import com.itextpdf.kernel.pdf.colorspace.PdfColorSpace;
 import com.itextpdf.layout.Canvas;
 import com.itextpdf.layout.Document;
 import com.itextpdf.layout.element.Cell;
@@ -32,6 +34,7 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
+import java.awt.*;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.math.BigDecimal;
@@ -92,18 +95,115 @@ public class ForecastProjectService extends ServiceImpl<ForecastProjectMapper, F
     }
 
     public void generatePdf(ForecastProject project, ZipOutputStream outputStream) {
+        // 第一次生成：获取总页码
+        int totalPages = calculateTotalPages(project);
 
-        // 使用ByteArrayOutputStream作为缓冲
+        // 第二次生成：正式生成带页码的PDF
+        generatePdfWithPageNumbers(project, outputStream, totalPages);
+    }
+
+    // 第一次生成：计算总页码
+    private int calculateTotalPages(ForecastProject project) {
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        PdfDocument pdfDoc = null;
+
-        Document document = null;
+        try (PdfWriter writer = new PdfWriter(baos);
-        try{
+             PdfDocument pdfDoc = new PdfDocument(writer);
-            PdfWriter writer = new  PdfWriter(baos);
+             Document document = new Document(pdfDoc, PageSize.A4.rotate())) {
-            pdfDoc = new PdfDocument(writer);
+
-            document = new Document(pdfDoc,PageSize.A4.rotate());
             // 设置字体
             String fontPath = "/fonts/ChineseFonts.ttf";
             PdfFont font = PdfFontFactory.createFont(fontPath, PdfEncodings.IDENTITY_H);
+
+            // 添加内容（但不添加页码）
+            addContentToDocument(document, font, project, false);
+
+            // 返回总页数
+            return pdfDoc.getNumberOfPages();
+
+        } catch (Exception e) {
+            log.error("计算PDF页数失败", e);
+            throw new RuntimeException("PDF页数计算失败");
+        }
+    }
+
+    // 第二次生成：正式生成带页码的PDF
+    private void generatePdfWithPageNumbers(ForecastProject project, ZipOutputStream outputStream, int totalPages) {
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+
+        try (PdfWriter writer = new PdfWriter(baos);
+             PdfDocument pdfDoc = new PdfDocument(writer);
+             Document document = new Document(pdfDoc, PageSize.A4.rotate())) {
+
+            // 设置字体
+            String fontPath = "/fonts/ChineseFonts.ttf";
+            PdfFont font = PdfFontFactory.createFont(fontPath, PdfEncodings.IDENTITY_H);
+
+            // 添加页码处理器
+            PageNumberEventHandler eventHandler = new PageNumberEventHandler(font, totalPages);
+            pdfDoc.addEventHandler(PdfDocumentEvent.END_PAGE, eventHandler);
+
+            // 添加内容
+            addContentToDocument(document, font, project, true);
+
+        } catch (Exception e) {
+            log.error("生成PDF失败", e);
+            throw new RuntimeException("PDF生成失败");
+        }
+
+        // 在try-with-resources块外获取字节数组并写入输出流
+        try {
+            byte[] pdfBytes = baos.toByteArray();
+            outputStream.write(pdfBytes);
+        } catch (IOException e) {
+            log.error("写入ZIP失败", e);
+            throw new RuntimeException("写入ZIP失败");
+        }
+    }
+
+    // 页码事件处理器 - 简化版本
+    private static class PageNumberEventHandler implements IEventHandler {
+        private final PdfFont font;
+        private final int totalPages;
+
+        public PageNumberEventHandler(PdfFont font, int totalPages) {
+            this.font = font;
+            this.totalPages = totalPages;
+        }
+
+        @Override
+        public void handleEvent(Event event) {
+            PdfDocumentEvent docEvent = (PdfDocumentEvent) event;
+            PdfDocument pdfDoc = docEvent.getDocument();
+            PdfPage page = docEvent.getPage();
+            int currentPage = pdfDoc.getPageNumber(page);
+
+            // 获取页面尺寸
+            Rectangle pageSize = page.getPageSize();
+
+            // 创建画布
+            PdfCanvas pdfCanvas = new PdfCanvas(page.newContentStreamAfter(), page.getResources(), pdfDoc);
+
+            // 设置页码文本
+            String pageText = "第 " + currentPage + " 页 / 共 " + totalPages + " 页";
+
+            // 直接使用PdfCanvas绘制文本（更简单的方式）
+            pdfCanvas.beginText()
+                    .setFontAndSize(font, 10)
+                    .moveText((pageSize.getLeft() + pageSize.getRight()) / 2 - 50, pageSize.getBottom() + 20)
+                    .showText(pageText)
+                    .endText();
+
+            pdfCanvas.release();
+        }
+    }
+
+    // 添加内容到文档的公共方法
+    private void addContentToDocument(Document document, PdfFont font, ForecastProject project, boolean addPageMargins) throws IOException {
+        if (addPageMargins) {
+            // 为页码预留底部边距
+            document.setMargins(36, 36, 36, 50);
+        }
+
         // 第一行：基本信息
         Paragraph header1 = new Paragraph()
                 .add("预见期(小时): " + (project.getForecastPeriod() != null ? project.getForecastPeriod() : "无") + "    ")
@@ -131,7 +231,7 @@ public class ForecastProjectService extends ServiceImpl<ForecastProjectMapper, F
 
         // 第三行：数据表格
         if (CollectionUtils.isNotEmpty(project.getVoList())) {
-                    Table table = new Table(9); // 10列
+            Table table = new Table(9);
             table.setWidth(UnitValue.createPercentValue(100));
 
             // 表头
@@ -162,21 +262,6 @@ public class ForecastProjectService extends ServiceImpl<ForecastProjectMapper, F
         } else {
             document.add(new Paragraph("无预报结果数据").setFont(font));
         }
-                // 5. 关闭文档（关键：先关闭Document，再关闭PdfDocument）
-                document.close();
-                pdfDoc.close();
-        } catch (Exception e) {
-            log.error("生成PDF失败", e);
-            throw new RuntimeException("PDF生成失败");
-        }
-
-        try {
-            byte[] pdfBytes = baos.toByteArray();
-            outputStream.write(pdfBytes);
-        }catch (IOException e){
-            log.error("写入ZIP失败", e);
-            throw new RuntimeException("写入ZIP失败");
-        }
     }
 
     // 辅助方法：创建表格单元格