Java interview questions (2)

This is the topic discussed during the last interview and is recorded.

• How can I put an object in Hashtable and rewrite it? How to implement it?
• Implement a singleton mode? Thread synchronization, delayed loading, and generics are required.
• Design and implement a cache management module, which requires that 10,000 objects can be cached.
• Design and implement a log module.
• Design and implement an iterator. You can use filter rules to filter elements in the set. During iteration, only elements that comply with the rules are output.
• How to serialize objects.
• APIS for starting, committing, and rolling back transactions using JDBC.
• There are 10,000 webpages, including phone numbers. Now we need to extract the phone numbers and remove them. How should we design and use them.