如何在Java中处理NullPointerException

Question

如何NullPointerException在Java中处理？请提供详细信息,以便我可以摆脱这个问题

Answer 1

你应该避免使用NullPointerExceptions:

if(someObject != null) {
    someObject.doSomething();
} else {
    // do something other
}

Normally you should ensure that the objects which you use are not null.

You also can catch the NullPointerException and except using an if-condition.

try {
    someObject.doSomething();
} catch(NullPointerException e) {
    // do something other
}

Normally there is a bug in your code, when a NullPointerException occurs.

Answer 2

try {
    // something stupid
} catch(NullPointerException e) {
    // probably don't bother doing clean up
} finally {
    // carry on as if nothing went wrong
}