Updated SeaweedFS Java Client (markdown)

SeaweedFS-Java-Client.md

@@ -95,4 +95,21 @@ You can also use this API for standard file manipulation: directory listing, fil
   filerClient.rm("/new_folder/new_empty_file", false, true);
   filerClient.rm("/new_folder", true, true);
 
+```
+
+## Advanced Usage
+Sometimes you may need to go deeper. For example, change modification time `mtime`.
+
+```
+  // load existing entry
+  FilerProto.Entry entry = filerClient.lookupEntry("/some/dir","entryName");
+
+  // change the attribute
+  FilerProto.Entry.Builder entryBuilder = FilerProto.Entry.newBuilder(entry);
+  FilerProto.FuseAttributes.Builder attrBuilder = FilerProto.FuseAttributes.newBuilder(entry.getAttributes());
+  attrBuilder.setMtime(...)
+
+  // save the new entry
+  entryBuilder.setAttributes(attrBuilder);
+  filerClient.updateEntry("/some/dir", entryBuilder.build());
 ```