增加保护

blade-service/blade-archive/src/main/java/org/springblade/archive/utils/ArchiveTreeUtil.java

@@ -49,7 +49,7 @@ public class ArchiveTreeUtil {
                 if (subTree.getChildren() == null || subTree.getChildren().size() == 0) {
                     continue;
                 }
-                if (subTree.getChildren().get(0).getExtType() == 2) {
+                if (subTree.getChildren().get(0).getExtType() != null && subTree.getChildren().get(0).getExtType() == 2) {
                     for (ArchiveTreeContractVO2 contractNode : subTree.getChildren()) {
                         subTreeList.add(contractNode);
                     }