Java does not have pointers, no way. Java does have references. A reference is an abstract identifier for an object. It is not a pointer. A reference tags a particular object with a name in the Java virtual machine so that the programmer may refer to it. How exactly the virtual machine implements references at the level of machine code is VM-dependent and completely hidden from the programmer in any case. Most VMs including Sun’s use handles, not pointers. A handle is a pointer to a pointer. At the level of machine code in the CPU a reference is an address in memory where the address of the object is stored. This way the objects can be moved around in memory and only the master pointer needs to be updated rather than all references to the object. This is completely hidden from the Java programmer, though. Only the implementer of the virtual machine needs to worry about it. Indeed, this is not the only way references can be implemented. Microsoft’s VM actually does use pointers rather than handles. Other schemes are possible.
What is MQ and what does it do? Ans. MQ stands for MESSAGE QUEUEING. WebSphere MQ allows application programs to use message queuing to participate in message-driven processing. Application programs can communicate across different platforms by using the appropriate message queuing software products. What is Message driven process? Ans . When messages arrive on a queue, they can automatically start an application using triggering. If necessary, the applications can be stopped when the message (or messages) have been processed. What are advantages of the MQ? Ans. 1. Integration. 2. Asynchrony 3. Assured Delivery 4. Scalability. How does it support the Integration? Ans. Because the MQ is independent of the Operating System you use i.e. it may be Windows, Solaris,AIX.It is independent of the protocol (i.e. TCP/IP, LU6.2, SNA, NetBIOS, UDP).It is not required that both the sender and receiver should be running on the same platform What is Asynchrony? Ans. With messag...
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