SpotBugs - NP_NULL_ON_SOME_PATH

Description

NP: Possible null pointer dereference

There is a branch of statement that, if executed, guarantees that a null value will be dereferenced, which would generate a NullPointerException when the code is executed. Of course, the problem might be that the branch or statement is infeasible and that the null pointer exception can't ever be executed; deciding that is beyond the ability of FindBugs.

在多個分支中的某個變數，可能在使用時會是null，而造成nullpointer exception。

Solution

增加null檢查或Refactoring程式碼。

Example

Before:

    IUser user = findUser(uid);
    if( user != null ){
        removeUser(uid);
    }
    logger.debug("Remove user {}.", user.getKey());

After:

    IUser user = findUser(uid);
    if( user != null ){
        removeUser(uid);
        logger.debug("Remove user {}.", user.getKey());
    }

有時被找出來只是findbugs無法確定這個是不是問題，但大都是存在一定的機率會發生。