-
Class and Instance Variable
What is the difference between a class variable and an instance variable?
ravi_1229
- Mar 24th, 2008
Instance variables created per copy. for ex: class A{ private String instVariable="Hello"; public static void main(String a[]){ A obj1=new A(); A obj2=new A(); ?...
-
throw and throws
what is the difference between throw and throws
ravi_1229
- Mar 24th, 2008
if user program explicitly wants to throw an exception(inbuilt or userdefined) then throw keyword is used. if the user program wants to throw an exception in a particular condition then throw k...
ravi_1229
- Mar 24th, 2008
if user program explicitly wants to throw an exception(inbuilt or userdefined) then throw keyword is used.if the user program wants to throw an exception in a particular condition then throw key...
-
What is the difference between exit(o) and exit(1) in Java?
ravi_1229
- Mar 24th, 2008
The number is only the status code for the termination of the JVM. It does not effect the actual command. By convention 0 means a normal exit, any other number is an abnormal termination.
-
How do you track Ip in Java ?
ravi_1229
- Mar 24th, 2008
try this piece of code: java.net.InetAddress remoteInetAddress = java.net.InetAddress.getByName(request.getRemoteHost()); String client=remoteInetAddress.getHostName(); System.out.print(client);
-
Why finalize method in object class is protected ?
vimalraj
- Mar 24th, 2008
The fact that class Object declares a finalize method means that the finalize method for any class can always invoke the finalize method for its superclass. This should always be done, unless it is th...
ravi_1229
- Mar 24th, 2008
Every user defined class extends object class in java . so if the user defined class having some resources to deallocate(such as database connection, file closing, streams closing) the finalize method is overriden in the current class. thats y the finalize method in object class is protected.
-
Serializable is used to read or write the object and find the state of an object. What is the use of finding the state of an object, Explain with an example?
VenkitaKrishnan
- Apr 20th, 2009
The concept of Serializable is that we can recreate the state of an object from a permanent source like a file, xml etc.Example: I had personally implemented used in scenario where i had an organizati...
richakharya
- Apr 20th, 2009
When the object supposed to be sent across the network serializing technique makes sure the data is not lost in case of network failure. Seralizaing is converting the object to its byte code form and then sending it accross the network.
-
-
Can we override the main method?
Read Best Answer
Editorial / Best Answer
ashish_setia- Member Since Oct-2006 | Oct 3rd, 2006
check out this example
class Checkmain{
public static void main(String args[]){
args[1]="ashish";
System.out.println("hello ");
}
}
class Checkmain1 extends Checkmain{
public static void main(String args[]){
System.out.println("how r u");
}}
class Jo{
public static void main(String args[]){
String S[]=new String[10] ;Checkmain.main(S);
Checkmain1.main(S);
}}vivek
- Aug 26th, 2017
Yes you can only do that by overriding main method signature for eg main(String[] args) to main(). Certainly there are no other ways to do that because JVM needs strings array arguments to take comma...
Dharmendra Singh
- Sep 15th, 2016
yes we can"java public class HelloWorld { // arguments are passed using the text field below this editor public static void main(String[] args) { String []s =new Str...
-
What JSP lifecycle methods can I override?
You cannot override the _jspService() method within a JSP page. You can however, override the jspInit() and jspDestroy() methods within a JSP page. jspInit() can be useful for allocating resources like database connections, network connections, and so forth for the JSP page. It is good programming practice to free any allocated resources within jspDestroy().The jspInit() and jspDestroy() methods are...
-
Explain Struts navigation flow
Read Best Answer
Editorial / Best Answer
ravi_1229- Member Since Nov-2006 | May 9th, 2009
1) When first the request is made from a JSP/HTML/XSLT to the server with a particular URI(/something.do), the controll first reaches Web.xml file.
2) it checks the mapping for /something.do in web.xml and finds the ActionServlet and loads ActionServlet.
......
<servlet-name>action</servlet-name>
<servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
.....
<servlet-mapping>
<servlet-name>action</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
3) As part of loading ActionServlet calls the init() as every other servlet does.
(Note: ActionServlet extends HttpServlet only)
......................
<init-param>
<param-name>config</param-name>
<param-value>/WEB-INF/struts-config.xml</param-value>
</init-param>
........................
4) in init() it takes the init-parameters as struts-config.xml and loads the xml file.
5) then the ActionServlet calls the proceed() of RequestProcessor class.
6) in proceed() , it checks the appropriate mapping for current request, creates and ActionMapping object and maps the URI to the action in the struts-config.xml.
7) then it creates an object to ActionForm associated to that action mapped object
8) calls the setters and reset().
9) if the action tag in struts-config.xml contains validate="true", then the validate method is called.
10) if any validation errors, it return to view component (any jsp,XSLT) which is specified as an attribute of input="/error.jsp"
11) if there are not validation errors, it then creates an Action class for that mapping and search for execute method and executes it.
12) execute method performs the bussinesslogic which you provide and returns with an ActionForward key.
13) now the returned key is searched in the mapping object which is specified as forward tag.
14) it looks for the appropriate view component and performs the getters on that view component and returns the response to the browser.
Simple, Thats it.
Thanks
Ravi
Prabhakar122
- Oct 31st, 2010
Struts navigation flow================1) When application server gets started,container loads the web.xml1) When first request is made from a JSP/HTML/XSLT to the server with a particular URI(/somethi...
devabscmca
- Oct 7th, 2010
Struts flow After developing the struts application after deploying it is the server & when you started the server then following things will happened Container initializes the web.xml When co...
