Doubt on Multiple Inheritance

Question

Hi all,
I am confused by the java statement that "By using interface we can achieve multiple inheritance bcoz java doesn't support Multiple inheritance".
Yes.Ok java doent support Multiple inheritance. Now we know that inheritance means that "one object acquires the property of another object".
So how can it is possible achieve Multiple inheritance by interface.
Interface that contains just undefined methods like below code.
interface Member1
     public void eye();
     public void nose();
     public void mouth();
interface Member2 extends member1
     public void neck();
     public void hand();
     public void stomach();
interface Member3 extends Member1,Member2
     public void leg();
class Man implements Member3
     public man()
     Member3 ref=new Man();
     // Here Implements all 7 methods.
Is the above code defines multiple Inheitance?
undefined methods are eye,nose,mouth,neck,handand stomach are fall in Interface Member3 .Yes. But Inheritance means that one object acquires the property of another object.Property means that code and data.
In here, there is no code just declarations of method which is not to be a code .
So How can we say interface achieve multiple inheritance.
Please any one explain and clear my doubt with simple example.
with cheers,
G.GandhiRaj.

Answer 1

Multiple inheritance is about aquiring both behavior and attributes from two or more sources. A lot of times, this "is a" relationship is confused with "has a" relationships.
For example, a Book "has a" Page. A Book "is a" Publication. So multiple inheretance in this instance would come from stating that a Book "is a" Publication and "is a" PaperProduct. In this example, you could redesign your model and state that a PaperProduct inherits from Publication. However, a Book doesn't have to be limited to being a PaperProduct, it can also be an ElectronicProduct, thus inhereting attributes and behaviors from this new class as well. In essence, the Book can exist in two forms simulataneously (as many actually do). So you still have the need for multiple inheritance - perhaps.
Interfaces define the behavioral aspects of multiple inheritance. You loose the aquisition of attributes from base classes. In many cases this is acceptable. For the first time I recently found a true need for multiple inheritance in one fo my Java apps. Some would say that my data model is poorly designed then. So I tried restructuring the model and that solve the problem.
It is probably a good idea to completely understand your data model from many dimensions first before resorting to the copying of attributes like I almost did. Don't be locked into a design too quickly. Be willing to change your mind and you will probably find a solution that works.