How does Collections utility class behave in multithreaded code?

The Collections utility class in Java provides static methods for operating on collections. However, when used in multithreaded code, special care must be taken as collection operations are not inherently synchronized. This means that if multiple threads access a collection simultaneously, it can lead to inconsistent or unpredictable behavior.

To safely use collections in a multithreaded environment, developers can use synchronized wrappers provided by the Collections class, or they can use concurrent collection classes from the java.util.concurrent package.