调整项目模块，jodconverter-core重命名为office-plugin。jdocnverter-web重命名为server

server/src/main/java/cn/keking/service/FilePreviewFactory.java

@@ -0,0 +1,26 @@
+package cn.keking.service;
+
+import cn.keking.model.FileAttribute;
+import org.springframework.context.ApplicationContext;
+import org.springframework.stereotype.Service;
+
+import java.util.Map;
+
+/**
+ * Created by kl on 2018/1/17.
+ * Content :
+ */
+@Service
+public class FilePreviewFactory {
+
+    private final ApplicationContext context;
+
+    public FilePreviewFactory(ApplicationContext context) {
+        this.context = context;
+    }
+
+    public FilePreview get(FileAttribute fileAttribute) {
+        Map<String, FilePreview> filePreviewMap = context.getBeansOfType(FilePreview.class);
+        return filePreviewMap.get(fileAttribute.getType().getInstanceName());
+    }
+}