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Topics about Java SE, Servlet/JSP, JDBC, MultiThread, UML, Design Pattern, CSS, JavaScript, Maven, JBoss, Tomcat, ...
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Question How do you delete a Cookie within a JSP? (JSP)

Answer

Cookie mycook = new Cookie("name","value");

response.addCookie(mycook);

Cookie killmycook = new Cookie("mycook","value");

killmycook.setMaxAge(0);

killmycook.setPath("/");

killmycook.addCookie(killmycook);

Question How many types of protocol implementations does RMI have? (RMI)

Answer RMI has at least three protocol implementations: Java

Remote Method Protocol(JRMP), Internet Inter ORB Protocol(IIOP),

and Jini Extensible Remote Invocation(JERI). These are alternatives,

not part of the same thing, All three are indeed layer 6 protocols for

those who are still speaking OSI reference model.

Question What are the different identifier states of a Thread?

(Core Java)

Answer The different identifiers of a Thread are:

R - Running or runnable thread

S - Suspended thread

CW - Thread waiting on a condition variable

MW - Thread waiting on a monitor lock

MS - Thread suspended waiting on a monitor lock


Question What is the fastest type of JDBC driver? (JDBC)

Answer JDBC driver performance will depend on a number of

issues:

(a) the quality of the driver code,

(b) the size of the driver code,

(c) the database server and its load,

(d) network topology,

(e) the number of times your request is translated to a different API.

In general, all things being equal, you can assume that the more your

request and response change hands, the slower it will be. This

means that Type 1 and Type 3 drivers will be slower than Type 2

drivers (the database calls are make at least three translations versus

two), and Type 4 drivers are the fastest (only one translation).

Question Request parameter How to find whether a parameter

exists in the request object? (Servlets)

Answer 1.boolean hasFoo = !(request.getParameter("foo") ==

null || request.getParameter("foo").equals(""));

2. boolean hasParameter =

request.getParameterMap().contains(theParameter);

(which works in Servlet 2.3+)


Question How can I send user authentication information while

makingURLConnection? (Servlets)

Answer You’ll want to use

HttpURLConnection.setRequestProperty and set all the appropriate

headers to HTTP authorization.

Question How do I convert a numeric IP address like 192.18.97.39

into a hostname like java.sun.com? (Networking)

Answer

Question How many methods do u implement if implement the

Serializable Interface? (Core Java)

Answer The Serializable interface is just a "marker" interface,

with no methods of its own to implement. Other ’marker’ interfaces

are

java.rmi.Remote

java.util.EventListener

String hostname =InetAddress.getByName("192.18.97.39").getHostName();

posted on 2010-10-25 17:08 Sun River 阅读(285) 评论(0)  编辑  收藏 所属分类: Interview Preparation