Apollo Education Group interview questions

I got this call through a consultant. The initial phone screen was purely technical on Java concepts, some questions on servlets. Then i was called onsite for a day long interview process. It consisted of 5 interviews. The last one was with a HR and consisted of behavioral questions to find out if i were a good cultural fit for the team they were hiring. My first 4 interviews went very well, so i was pretty confident by the end. Questions: Write a program that reverses only consonants in a string. write a program that given a varargs string argument, appends only the number part to the resultant string buffer. Write a join query on multiple tables. Write a singleton class. Write a program to sort an array of strings using the best performing algorithm of your choice, optimizing for both time and space. Few questions on web services, difference between SOAP and REST.