Fwd: 10/01/14, 5:30PM, BofA phone interview with Wilson

---------- Forwarded message ----------
From: Hai Yi
Date: Thu, Oct 2, 2014 at 11:47 PM
Subject: 10/01/14, 5:30PM, BofA phone interview with Wilson

Java
1. Explain how HashMap works
2. Compare HashTable and ConcurrentHashMap. Explain how CHM handle concurrency.
3. There is an arraylist of 1,2,2,3, how do you output unique values?
how do you only output dup values?
4. Can you remove an element during iteration? How do you do it properly?
5. Can you update elements in an arrayList if its reference is defined
as "final". If so, what do you do to prevent it?
6. Name JSP internal objects. If in URL there is "id=12345", how to
retrieve that value?
7. Difference b/w StringBuffer and StringBuilder; and their difference
with String?
8. What design patterns can you name? What's singleton?
9. How do you implement Producer-consumer pattern?
10. Explain Executor framework and Threadpool
11. Explain volatile and transient
12. Explain Breath-first traversal and depth-first traversal
13. What's the new feature in JDK 8? What's the "default" keyword used
for in JDK 8 context?


Database
1. What's Union and Union all?
2. explain left join and inner join
3. There is a table "Salary" with two columns "id" and "salary", this
is oracle, write sql to list first 4. 100 record with salary from
highest to lowest
4. How do you dump the data from table A to table B, if table B
doesn't exist. Do it in one SQL statement.
5. Difference b/w function and store procedure
6. What's view? What's trigger?
7. How to call a store procedure from Java? The JDBC API.
8. What are the transaction isolation levels?
9. How do you get the current date using Oracle?
10. In PL/SQL, how do you throw an exception and how to catch it?

Unix
1. what's the command to find the files that were updated in the past 10 days?
2. How to find a file with a particular name, like "hello.java"?
3. What's the command to kill a running Java process and generate threaddump?
4. There is a file of 10 million lines, whats' the command to list
first 10 line?
5. What's the command to count the line number in a file, what parameter to use?
6. In shell script, how to split a string with dilimiter?
7. In shell script, how to check if a file exists or not?
8. what's the command to sort a file?
9. what's the command to list all running processes?
10. In VI, how to replace a repeated word in the whole text?