Tuesday, January 23, 2007
How can I customize the seralization process?
| Yes it is possible to have control over serialization process. The class should implement Externalizable interface. This interface contains two methods namely readExternal and writeExternal. You should implement these methods and write the logic for customizing the serialization process. How does Java handle integer overflows and underflows? It uses those low order bytes of the result that can fit into the size of the type allowed by the operation. Why do threads block on I/O? Threads block on i/o (that is enters the waiting state) so that other threads may execute while the i/o Operation is performed. |
Does importing a package imports the subpackages as well? e.g. Does importing com.MyTest.* also import com.MyTest.UnitTests.*?
| No you will have to import the subpackages explicitly. Importing com.MyTest.* will import classes in the package MyTest only. It will not import any class in any of it's subpackage. What is the difference between declaring a variable and defining a variable? In declaration we just mention the type of the variable and it's name. We do not initialize it. But defining means declaration + initialization. e.g String s; is just a declaration while String s = new String ("abcd"); Or String s = "abcd"; are both definitions. Can a level class be private or protected? No. A level class can not be private or protected. It can have either "public" or no modifier. If it does not have a modifier it is supposed to have a default access. If a level class is declared as private the compiler will complain that the "modifier private is not allowed here". This means that a level class can not be private. Same is the case with protected. What type of parameter passing does Java support? In Java the arguments are always passed by value . Primitive data types are passed by reference or pass by value? Primitive data types are passed by value. Objects are passed by value or by reference? Java only supports pass by value. With objects, the object reference itself is passed by value and so both the original reference and parameter copy both refer to the same object . |
Monday, January 01, 2007
what are the differences between a Web container, Web server, servlet container and an application server?
| Typically, a Web server refers to an execution infrastructure that handles HTTP requests and responses; a servlet container refers to a component that handles the lifecycle for servlets; an application server refers to a framework (servlet container, EJB container, JSP engine, MQ container, etc.) for handling Web applications. However, a Web container has a couple of meanings depending on the source. Most refer to a Web container as the part of an application server that manages servlets, JavaServer Pages (JSP) files, and other Web-tier components. Some refer to a Web container as the infrastructure for managing the lifecycle for Web services. |