优化因为异常导致没有关闭文件流

src/main/java/com/emr/util/Jpg2PdfUtil.java

@@ -1,8 +1,6 @@
 package com.emr.util;
 
-import com.lowagie.text.Document;
-import com.lowagie.text.DocumentException;
-import com.lowagie.text.Element;
+import com.lowagie.text.*;
 import com.lowagie.text.Image;
 import com.lowagie.text.pdf.*;
 import org.apache.commons.lang3.StringUtils;
@@ -73,59 +71,77 @@ public class Jpg2PdfUtil {
     }
 
     public static void mulFile2One(HttpServletResponse response, List<String> files, String waterMarkName) {
-        List<PdfReader> list = new ArrayList<>();
+        List<PdfReader> pdfReaders = new ArrayList<>();
         //遍历删除,除去损坏，文件不存在，抛异常就是空白页
         Iterator<String> iterator = files.iterator();
         while (iterator.hasNext()) {
             PdfReader check = check(iterator.next());
             if(null != check){
-                list.add(check);
+                pdfReaders.add(check);
             }
         }
-        if (!CollectionUtils.isEmpty(list)) {
-            // pdf合并工具类
-            Document document = null;
-            ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        if(!CollectionUtils.isEmpty(pdfReaders)){
+            //创建文档容器
+            Document document = new Document(PageSize.A4,0,0,0,0);
             PdfCopy copy = null;
+            ByteArrayOutputStream bos = null;
             try {
-                response.reset();
-                document = new Document(list.get(0).getPageSize(1));
-                copy = new PdfCopy(document, response.getOutputStream());
+                copy = new PdfCopy(document,response.getOutputStream());
                 document.open();
-                for (PdfReader reader : list) {
-                    bos.flush();
-                    int n = reader.getNumberOfPages();
-                    for (int j = 1; j <= n; j++) {
-                        document.newPage();
-                        PdfImportedPage page = null;
-                        if (StringUtils.isNotBlank(waterMarkName)) {
-                            page = copy.getImportedPage(reader, j);
-                        } else {
-                            page = copy.getImportedPage(reader, j);
-                        }
-                        copy.addPage(page);
+                for (PdfReader reader : pdfReaders) {
+                    bos = new ByteArrayOutputStream();
+                    //判断是否加水印
+                    if (StringUtils.isNotBlank(waterMarkName)) {
+                        reader = new PdfReader(bos.toByteArray());
                     }
-                    reader.close();
-                }
-            } catch (Exception e) {
-                //e.printStackTrace();
-            } finally {
-                if (null != copy) {
-                    copy.close();
+                    //复制合并pdf
+                    copy2Pdf(copy, reader);
                 }
+            }catch (Exception e){
+                e.printStackTrace();
+            }finally {
                 try {
                     bos.flush();
                     bos.close();
-                } catch (Exception e) {
-                    //e.printStackTrace();
+                }catch (Exception e){
+                    e.printStackTrace();
+                }
+                if(null != copy){
+                    copy.close();
                 }
-                if (null != document) {
+                if(null != document){
                     document.close();
                 }
             }
         }
     }
 
+    /**
+     * 合并pdf
+     * @param copy
+     * @param reader
+     * @throws IOException
+     * @throws BadPdfFormatException
+     */
+    private static void copy2Pdf(PdfCopy copy, PdfReader reader) throws IOException, BadPdfFormatException {
+        try {
+            int n = reader.getNumberOfPages();
+            for (int j = 1; j <= n; j++) {
+                PdfImportedPage page = copy.getImportedPage(reader, j);
+                if(null != page) {
+                    copy.addPage(page);
+                }
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        } catch (BadPdfFormatException e) {
+            e.printStackTrace();
+        } finally {
+            if(null != reader){
+                reader.close();
+            }
+        }
+    }
 
     //加水印
     private  void setWatermark(ByteArrayOutputStream bos, PdfReader reader, String waterMarkName, String imgPath) {