1.优化代码结构，抽象预览接口服务

2.新增更多图片预览格式支持

jodconverter-web/src/main/java/cn/keking/service/impl/OfficeFilePreviewImpl.java

@@ -0,0 +1,73 @@
+package cn.keking.service.impl;
+
+import cn.keking.model.FileAttribute;
+import cn.keking.param.ReturnResponse;
+import cn.keking.service.FilePreview;
+import cn.keking.utils.DownloadUtils;
+import cn.keking.utils.FileUtils;
+import cn.keking.utils.OfficeToPdf;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
+import org.springframework.ui.Model;
+import org.springframework.util.StringUtils;
+
+import java.io.File;
+
+/**
+ * Created by kl on 2018/1/17.
+ * Content :处理office文件
+ */
+@Service
+public class OfficeFilePreviewImpl implements FilePreview {
+
+    @Autowired
+    FileUtils fileUtils;
+
+    @Value("${file.dir}")
+    String fileDir;
+
+    @Autowired
+    DownloadUtils downloadUtils;
+
+    @Autowired
+    private OfficeToPdf officeToPdf;
+
+    @Override
+    public String filePreviewHandle(String url, Model model) {
+        FileAttribute fileAttribute=fileUtils.getFileAttribute(url);
+        String suffix=fileAttribute.getSuffix();
+        String fileName=fileAttribute.getName();
+        String decodedUrl=fileAttribute.getDecodedUrl();
+        boolean isHtml = suffix.equalsIgnoreCase("xls") || suffix.equalsIgnoreCase("xlsx");
+        String pdfName = fileName.substring(0, fileName.lastIndexOf(".") + 1) + (isHtml ? "html" : "pdf");
+        // 判断之前是否已转换过，如果转换过，直接返回，否则执行转换
+        if (!fileUtils.listConvertedFiles().containsKey(pdfName)) {
+            String filePath = fileDir + fileName;
+            if (!new File(filePath).exists()) {
+                ReturnResponse<String> response = downloadUtils.downLoad(decodedUrl, suffix, null);
+                if (0 != response.getCode()) {
+                    model.addAttribute("msg", response.getMsg());
+                    return "fileNotSupported";
+                }
+                filePath = response.getContent();
+            }
+            String outFilePath = fileDir + pdfName;
+            if (StringUtils.hasText(outFilePath)) {
+                officeToPdf.openOfficeToPDF(filePath, outFilePath);
+                File f = new File(filePath);
+                if (f.exists()) {
+                    f.delete();
+                }
+                if (isHtml) {
+                    // 对转换后的文件进行操作(改变编码方式)
+                    fileUtils.doActionConvertedFile(outFilePath);
+                }
+                // 加入缓存
+                fileUtils.addConvertedFile(pdfName, fileUtils.getRelativePath(outFilePath));
+            }
+        }
+        model.addAttribute("pdfUrl", pdfName);
+        return isHtml ? "html" : "pdf";
+    }
+}