fix defects reported by coverity

[kortemik]

Description
fix defects reported by coverity:
461131 Dereference null return value
452917 Dereference null return value

[51-code]

Reopened the issue because there is still defects to fix:

467201 CT: Constructor throws
456623 Dm: Dubious method used
456622 Dm: Dubious method used
456284 Dm: Dubious method used
452921 SS: Unread field should be static (not actually changing to static, but changing it to a local variable)
452920 WMI: Inefficient Map Iterator
452918 Dm: Dubious method used

These, in my opinion, would lead to bad coding practices if fixed:
467200 PI: Do not reuse public identifiers from Java Standard Library
461131 Dereference null return value