CODEWITHSUNDEEP
javajava.lang.class
seventy2eleven
seventy2eleven

Reputation: 96

Class.forName + ExceptionInInitializerError + static initialization + weird Array init

I recently "inherited" a project and tried to get an instance of a service running locally. I encountered - and fixed - some problems with code similar to...

class A {
   // ...
   public void doSomething() {
      // ...
      Class foo = Class.forName("fully.qualified.package.B"); 
      // ...  
   }
   // ...
}

class B {
    static String[] bar = (String[])Arrays.asList("Something").toArray();
    //...
}

When Class A.doSomething() was run, an ExceptionInInitializerError was thrown. This error has something to do with initializing Class B (static init, no instantiation!!).

FYI > Fixing this Problem can be done in two ways...

What I am interested in is...

Why would the somewhat overengineered initialization via (String[]) Arrays.asList(...).toArray() cause such an error?

Solution/Edit: It has nothing to do with static initialization, the array init is plain wrong, see below...

Upvotes: 0

Views: 429

Answers (1)

Andy Turner
Andy Turner

Reputation: 140318

(String[])Arrays.asList("Something").toArray(); is going to fail at runtime: it's not returning a String[], it's returning an Object[]. Object[] and String[] are reifiable types, so it's a checked cast, and because an Object[] is not a String[], it fails.

Use Arrays.asList("Something").toArray(new String[0]); or just new String[]{"Something"}.

Upvotes: 4

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