Alternative for old Springframework util.Assert?

Question

While I was just about to use an old class that is about 2 years old I realized it used the old Springframework. The new framework is rather hard to navigate, and I don't need it for anything else.

The class is a nice implementation of strtotime (AKA String to Time). https://github.com/collegeman/stringtotime/blob/master/src/main/java/com/clutch/dates/StringToTime.java

Of course when I go to compile all I get is this: NoClassDefFoundError occured : org/springframework/util/Assert and even when I try including an old spring jar it makes no difference.

The only part of the class depending on it is the .util.Assert:

Assert.notNull(dateTimeString);
Assert.notNull(now);
Assert.notNull(simpleDateFormat);

Is anyone aware of the following:

• A link to the Assert source (can't find it via Google)
• A substitute library
• A better class just like StringToTime

Thanks!

Answer 1

• commons-lang Validate
• guava Preconditions

Here's an article comparing them.