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How
are Observer and Observable used?
Question:
What is synchronization and why is it important?
How does Java handle integer overflows and
underflows?
Does garbage collection guarantee that a
program will not run out of
memory?
What is the difference between preemptive
scheduling and time slicing?
When a thread is created and started, what
is its initial state?
What is the purpose of finalization?
What is the Locale class?
What is the difference between a while statement
and a do statement?
What is the difference between static and
non-static variables?
How are this() and super() used with constructors?
What are synchronized methods and synchronized
statements?
What is daemon thread and which method is
used to create the daemon thread?
Can applets communicate with each other?
What are the steps in the JDBC connection?
How does a try statement determine which
catch clause should be used to handle an
exception?
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A: | Objects that subclass the Observable class maintain a list of observers. When an Observable object is updated it invokes the update() method of each of its observers to notify the observers that it has changed state. The Observer interface is implemented by objects that observe Observable objects. |
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A: | With respect to multithreading, synchronization is the capability to control the access of multiple threads to shared resources. Without synchronization, it is possible for one thread to modify a shared object while another thread is in the process of using or updating that object's value. This often leads to significant errors. |
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Q: | |
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A: | It uses those low order bytes of the result that can fit into the size of the type allowed by the operation. |
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Q: | When |
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A: | A thread is in the ready state after it has been created and started. |
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Q: | |
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A: | The purpose of finalization is to give an unreachable object the opportunity to perform any cleanup processing before the object is garbage collected. |
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A: | The Locale class is used to tailor program output to the conventions of a particular geographic, political, or cultural region. |
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Q: | |
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A: | This() is used to invoke a constructor of the same class. super() is used to invoke a superclass constructor. |
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A: | Synchronized methods are methods that are used to control access to an object. A thread only executes a synchronized method after it has acquired the lock for the method's object or class. Synchronized statements are similar to synchronized methods. A synchronized statement can only be executed after a thread has acquired the lock for the object or class referenced in the synchronized statement. |
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A: | At this point in time applets may communicate with other applets running in the same virtual machine. If the applets are of the same class, they can communicate via shared static variables. If the applets are of different classes, then each will need a reference to the same class with static variables. In any case the basic idea is to pass the information back and forth through a static variable. An applet can also get references to all other applets on the same page using the getApplets() method of java.applet.AppletContext. Once you get the reference to an applet, you can communicate with it by using its public members. It is conceivable to have applets in different virtual machines that talk to a server somewhere on the Internet and store any data that needs to be serialized there. Then, when another applet needs this data, it could connect to this same server. Implementing this is non-trivial. |
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Q: | |
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A: | While making a JDBC connection we go through the following steps : Step 1 : Register the database driver by using : Class.forName(\" Step Connection Step Statement Step stmt.exceuteUpdate(); |
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