Java Programming Questions
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What are applets? |
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- Applets are small applications that are accessed from web server, automatically installed and run from the browser.
- Once an applet arrives on the client it has limited access to resources thus ensuring security for the end user.
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An applet is controlled by the software that runs it.
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Usually, the underlying software is a browser, but it can also be applet viewer.
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All applets should inherit from applet class.
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2. |
What are class loader? |
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Java was designed thinking platform independency in mind.
- So from loading libraries point of view it should not rely only on file systems.
- In short its not necessary that you should be able to load libraries which are in only file systems but also from other sources like FTP, HTTP etc.
- So JAVA went one step further you can load classes from across network or from any other source like FTP, HTTP etc. In order to attain this Class loaders came in to picture.
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Class loader is the class responsible for finding and loading classes at runtime.
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3. |
Give a few reasons for using Java? |
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Java is a fun language. Let's look at some of the reasons.-
Built support for multi threading socket communication and memory management (automatic garbage collection).
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Object Oriented (OO).
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Better portability than other language across operating systems.
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Support a Web based applications (applet, Servlet, JSP) distributed applications (sockets, RMI, EJB ect) and network protocols (HTTP, JRMP etc ) with the help of extensive standardized APIs (Application Programming Interfaces).
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4. |
How Java achieves platform independence? |
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- Java is platform independent because of the consistent data sizes at all platforms which Java code is run.
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The output of a Java compiler is not an executable code it is bytecode, bytecode is highly optimized set of instructions designed to be executed by a virtual machine that the Java run time system emulates.
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As Java programs are interpreted, rather than compiled it is much easier to run them in a variety of run time environments.
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