CODEWITHSUNDEEP
javamultithreading
user3217224
user3217224

Reputation: 11

for Java, is Class.newInstance() thread safe

a part of code like this:

class Test {

private static final Map<String, Class> urlHandlers = new ConcurrentHashMap<String, Class>();
static {
    urlHandlers.put(urlRegexA, HandlerA.class);
    urlHandlers.put(urlRegexB, HandlerB.class);
    ...
}
public Handler handle(String url) {
    ......
    if(url match urlRegex) {
        Class claz = urlHandlers.get(urlRegex);
        //in multi-thread environment, is it thread-safe?
        return claz.newInstance();
    }
}
}

I want to known whether Class.newInstance() is thread safe? anyone know this?

Upvotes: 0

Views: 1044

Answers (2)

Vivek Vermani
Vivek Vermani

Reputation: 2004

Yes this is thread safe as long as the constructor is not doing anything non-thread safe with the static content of the object.

Upvotes: 0

Sotirios Delimanolis
Sotirios Delimanolis

Reputation: 279940

The javadoc states

The class is instantiated as if by a new expression with an empty argument list.

So it is equivalent to doing

new YourClass();

So it depends entirely on if your YourClass constructor is thread safe.

Upvotes: 7

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