Compare two objects in Java with possible null values

I want to compare two strings for equality when either or both can be null.

So, I can't simply call .equals() as it can contain null values.

The code I have tried so far :

boolean compare(String str1, String str2) {
  return ((str1 == str2) || (str1 != null && str1.equals(str2)));
}

What will be the best way to check for all possible values including null ?

Since Java 7 you can use the static method java.util.Objects.equals(Object, Object) to perform equals checks on two objects without caring about them being null.

If both objects are null it will return true, if one is null and another isn't it will return false. Otherwise it will return the result of calling equals on the first object with the second as argument.

This is what Java internal code uses (on other compare methods):

public static boolean compare(String str1, String str2) {
    return (str1 == null ? str2 == null : str1.equals(str2));
}

For these cases it would be better to use Apache Commons StringUtils#equals, it already handles null strings. Code sample:

public boolean compare(String s1, String s2) {
    return StringUtils.equals(s1, s2);
}

If you dont want to add the library, just copy the source code of the StringUtils#equals method and apply it when you need it.