c++ program execution

[snakec]

Hi
can any one tell me how to use java code using c++ means i just wrote a function

code :
void Display()
{
cout<< "hi how are you";
}
but when i run it it should call a java function like System.out.println(" hi how are you")

can anyone tell me how to do this .

2: I know that when ever we compile a program with g++ command it make an executable specified in g++ command or by default a.out

when we run the program we use ./executable name or ./a.out command

Now i have a command which is

command : pipes -input -output -program executable name(executable made from g++ command)

Now can anyone tell me are we running the c++ program ?

how the c++ executable work in this command ?

is all the code of executable will execute ?

is some part of the executable will use ?

I just know the command

first we have to write a c++ program .
than compile the program using g++ command and required header files and library with executable name in g++ command

After compiling the program we use the executable name in above written command .

if we use executable for linking than what part of executable will link ?
is the executable is going to link completely ?

I'm totally confused please explain what the executable is doing in this command?

3: what is swig ? how it is use with c++ ?
please explain with some example.

Please help me with these issues .