How many ways can we track
client and what are they?
The
servlet API provides two ways to track client state and they are: a) Using
Session tracking and b) Using Cookies.
Blog Author: Vijay Kumar
Wednesday 27 March 2013
What are the different servers available for developing and deploying Servlets?
What are the different servers
available for developing and deploying Servlets?
a) Java Web Server
b) JRun
g) Apache Server
h)
Netscape Information Server
i) Web Logic
Blog Author: Vijay Kumar
Who is loading the init() method of servlet?
What is the life cycle of a servlet?
What is the life cycle of a
servlet?
Each Servlet has the same
life cycle:
a) A server loads and initializes the servlet by init () method.
b)
The servlet handles zero or more client’s requests through service() method.
c)
The server removes the servlet through destroy() method.
Blog Author: Vijay Kumar
What is the difference between doPost and doGet methods?
What is the difference between
doPost and doGet methods?
a) doGet()
method is used to get information, while doPost() method is used for posting
information. b) doGet() requests can’t send large amount of information and is
limited to 240-255 characters. However, doPost()requests passes all of its
data, of unlimited length.
c) A doGet() request is appended to the request URL
in a query string and this allows the exchange is visible to the client,
whereas a doPost() request passes directly over the socket connection as part
of its HTTP request body and the exchange are invisible to the client.
Blog Author: Vijay Kumar
What is the difference between an applet and a servlet?
What is the difference between
an applet and a servlet?
a)
Servlets are to servers what applets are to browsers. b) Applets must have
graphical user interfaces whereas servlets have no graphical user interfaces.
Blog Author: Vijay Kumar
What is servlet?
What is servlet?
Servlets are modules that extend
request/response-oriented servers, such as java-enabled web servers. For
example, a servlet might be responsible for taking data in an HTML order-entry
form and applying the business logic used to update a company’s order database.
Blog Author: Vijay Kumar
How to create and call stored procedures?
How to create and call stored
procedures?
To create stored
procedures: Create procedure procedurename (specify in, out and in out
parameters) BEGIN Any multiple SQL statement; END; To call stored procedures:
CallableStatement csmt = con. prepareCall(”{call procedure name(?,?)}”); csmt.
registerOutParameter(column no. , data type); csmt. setInt(column no. , column
name) csmt. execute();
Blog Author: Vijay Kumar
What is stored procedure?
What is stored procedure?
Stored procedure is a group of SQL statements
that forms a logical unit and performs a particular task. Stored Procedures are
used to encapsulate a set of operations or queries to execute on database.
Stored procedures can be compiled and executed with different parameters and
results and may have any combination of input/output parameters.
Blog Author: Vijay Kumar
What are the types of statements in JDBC?
What are the types of
statements in JDBC?
Statement: to be used
createStatement() method for executing single SQL statement PreparedStatement —
To be used preparedStatement() method for executing same SQL statement over and
over. CallableStatement — To be used prepareCall() method for multiple SQL
statements over and over.
Blog Author: Vijay Kumar
What type of driver did you use in project?
What type of driver did you use
in project?
JDBC-ODBC Bridge driver (is
a driver that uses native(C language) libraries and makes calls to an existing
ODBC driver to access a database engine).
Blog Author: Vijay Kumar
What are the steps involved for making a connection with a database or how do you connect to a database?
What are the steps involved for
making a connection with a database or how do you connect to a database?
a)
Loading the driver : To load the driver, Class. forName() method is used.
Class. forName(”sun. jdbc. odbc. JdbcOdbcDriver”); When the driver is loaded,
it registers itself with the java. sql. DriverManager class as an available
database driver. b) Making a connection with database: To open a connection to
a given database, DriverManager. getConnection() method is used. Connection con
= DriverManager. getConnection (”jdbc:odbc:somedb”, “user”, “password”); c)
Executing SQL statements : To execute a SQL query, java. sql. statements class
is used. createStatement() method of Connection to obtain a new Statement
object. Statement stmt = con. createStatement(); A query that returns data can
be executed using the executeQuery() method of Statement. This method executes
the statement and returns a java. sql. ResultSet that encapsulates the
retrieved data: ResultSet rs = stmt. executeQuery(”SELECT * FROM some table”);
d) Process the results : ResultSet returns one row at a time. Next() method of
ResultSet object can be called to move to the next row. The getString() and
getObject() methods are used for retrieving column values: while(rs. next()) {
String event = rs. getString(”event”); Object count = (Integer) rs.
getObject(”count”);
Blog Author: Vijay Kumar
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