1. Difference between sleep() & wait()
http://www.cnblogs.com/DreamSea/archive/2012/01/11/JavaThread.html#Introduction
http://www.cnblogs.com/DreamSea/archive/2012/01/16/SleepAndWaitDifferent.html
2. When use assert
3. EJB(SessionBean, EntityBean), the life cycle of them and how to manage transaction?
4. Singleton
http://www.cnblogs.com/garinzhang/archive/2013/04/01/2994031.html
http://www.cnblogs.com/garinzhang/archive/2013/04/04/2999331.html
5. Four technical in page:
a. Page: only limit in current page, for property/object/attribute
b. Request: sent from client, transform parameter to server and other page
c. Session: used to record the use authority
d. Application: web server, contain all, global variable
6. J2EE is a platform or framework? What technology J2EE contains?
a. J2EE is a standard, a for Enterprise Distributed Application standard platform
b. Also is a framework, contain JDBC, JNDI, RMI, JMS, EJB, JTA and so on.
7. What services provide by EJB container?
a. Life cycle management, code management, continue management, security, transaction management, lock, concurrent
8. 23 J2EE design pattern
a. Factory, Builder, Factory Method, Prototype, Singleton, Façade, Adapter, Bridge, Composite, Decorator, Flyweight, Proxy, Command, Interpreter, Visitor, Iterator, Mediator, Memento, Observer, State, Strategy, Template Method, Chain Of Responsibleity
9. Often use package and class, interface:
a. Package: java.util, java.io, java.sql, javax.servlet, java.exception, java.lang
b. Class: String, Integer, ArrayList, FileReader, FileWriter, BufferedWriter, BufferedWriter
c. Interface: Collection, List, Map, SortedMap, Iterator
10. What is JDO?
a. Java persistent new standard. Java Data Object, use to save/fetch object of datahourse's new standard API
11. Factory Design pattern:
a. Factory:
i. Creator
ii. Concrete Creator
iii. Product
iv. Concrete Product
b. Abstract Factory:
i. Abstract Factory
ii. Concrete Factory
iii. Abstract Product
iv. Concrete Factory
12. Difference between abstract factory & factory method
a. Abstract factory: have many product abstract product class and only one factory abstract class, the factory can generate all products
b. Factory method: have many abstract factory class, only one product abstract class, every factory can only generate one product
参考：http://leayer.iteye.com/blog/907953
13. Difference for forward, include, reDirect
a. Forward: server jump and return the resource to client
b. Include: include dynamic page, jsp
i. <%@ include file="" %> // involve static file(.html), not check the file content
ii. <jsp:include page="" flush="true" /> // involve dynamic file(*.jsp)
c. reDirect: server sent link to client and browser jump
14. ArrayList & Vector, HashMap, HashTable & HashSet
a. ArrayList & Vector: thread safe(Vector),
b. HashMap(Unthread safe), HashTable(thread safe), HashSet(Unduplicate elements)
15. Difference between Statement & PreparedStatement?
a. PreparedStatement is more safe than Statement
b. PreparedStatement is pre-compile, have good efficient for batch sql, also call JDBC procedure
c. Statement, when only need one time save/fetch database, recommend to use it. The cost of PreparedStatement is bigger than Statement, so for one-time operate database recommend use Statement.
d. Oracle will cache the sql of PreparedStatement, when next invoke the Oracle will cache the sql of PreparedStatement, when next invoke the sql with different value, the efficient will bigger.
16. How to iterate a collection:
Iterator I = colllection.iterator();
While(i.hasNext()){
System.out.println(i.next())
}
For(Object o:colllection) {
System.out.println(0);
}
17. Reverse the string, such as input abc, and out put is cba
String str = "abc";
Char[] ch = str.toCharArray();
Char[] ch1 = new char[ch.length];
For(int I = ch.length - 1, j = 0; I >= 0 ; i--) {
Ch1[j] = ch[i];
j++;
}
String str = new String(ch1);
18. Sort int array:
Int[] data = {5, 3, 7, 4, 8, 9, 4, 3, 5}
Int temp;
For(int I = data.length - 1; I >= 0; i--) {
For(int j = 0; j < i; j++) {
If(data[j] > data[j+1]) {
Temp = data[j]
Data[j] = data[j+1];
Data[j+1] = temp;
}
}
}