没有静态初始化程序的java.lang.ExceptionInInitializerError

Question

I get a java.lang.ExceptionInInitializerError but I don´t have a static initializer.

Code:

public static final File STANDARD_INDEX_FILE = new File(HTMLFileLoader.class.getClassLoader().getResource("index.html").getPath()); // Line 16 

The HTMLFileLoader class is empty.

Exception:

Exception in thread "main" java.lang.ExceptionInInitializerError
    at net.guardian.Guardian.main(Guardian.java:12)
Caused by: java.lang.NullPointerException
    at net.guardian.socket.MainSocket.<init>(MainSocket.java:16)
    at net.guardian.socket.MainSocket.<clinit>(MainSocket.java:24)
    ... 1 more

Answer 1

This:

public static final File STANDARD_INDEX_FILE = new File(HTMLFileLoader.class.getClassLoader().getResource("index.html").getPath()); // Line 16 

is exactly the same as this:

public static final File STANDARD_INDEX_FILE;

static {
  STANDARD_INDEX_FILE = new File(HTMLFileLoader.class.getClassLoader().getResource("index.html").getPath()); // Line 16 
}

As in, this is what it looks like in the compiled code.

As such, you do have a static initializer; and the exception is occuring somewhere in that initializer block.