SONAR中可能的空指针取消引用

Question

I have tried to point critical issues in Sonar with the following code:

if (candidate.isDirectory() && candidate.canRead() && 
          TEMPLATE.equalsIgnoreCase(candidate.getName())) {  
  List<String> fileContentList = Arrays.asList(candidate.list());

I have also done the change below, but it still didn't work

if(null != Arrays.asList(candidate.list())){
  List<String> fileContentList = Arrays.asList(candidate.list());}

Please help.

Answer 1

The error occures because candidate can be null. See https://www.owasp.org/index.php/Null_Dereference for a description.

You could do sth. like this:

List<String> fileContentList = candidate != null ? Arrays.asList(candidate.list()) : new ArrayList<>();