How do you use C plus plus code in Java Program?

Answer 1

You don't. There are two possible workarounds.

1. Use the Java Native Interface (JNI). JNI code resembles C-style code and is able to be compiled in the native machine language of the underlying system. This is a rather complicated solution, and is not ideal for a "quick fix."
2. Write your C++ code like normal, compile it, and use Java code to call your compiled code. You can use the Runtime.getRuntime().exec() methods to accomplish this.
   

Answer 2

The syntax is largely the same, so a few Replace All commands will quickly conform a lot of the minor coding differences. However, the object model is much simpler and more abstract (with little or no access to the low-level features of the architecture), so any non-trivial code conversion will be a non-trivial task.

If the aim is to make the code compliant for cross-platform purposes, it would probably be a lot easier to modify the C++ source with conditional compilation to cater for those platforms. Java conversions will rarely perform well against a native machine code implementation. Remember that Java programs must be compiled to byte code suitable for the Java virtual machine. C++ programs stand on their own two feet (so to speak) and have a far greater access to the low-level features of the architecture.

Answer 3

There are several language converters available around the internet - most of them tend to be commercial (pay) licensed, as the market for such a tool is limited, and the problem is very difficult.

Java to C++ has some significant problems, including the issue with C++ lacking a single object hierarchy (i.e. no C++ equivalent of the Java Object class).

Java to Objective-C has major problems with Java being a statically-typed language, while Objective-C being a dynamically-typed one.

Finally, C is not an object-oriented language at all, and conversion of any object-oriented language into a traditional procedural language is difficult at best.

The real answer is that for any non-trivial program, the only really reliable conversion is one that is done manually, as the differences between the languages' syntax and meaning is very significant.

Answer 4

There are utilities available that can do this, however there are many caveats. For instance, Java utilises a built-garbage collector but C++ does not, thus the resultant C++ code will leak resources. You will have to manually edit the code to fix these errors.

Answer 5

The only way to convert C++ to C is via a compiler that uses C code to generate the C++ object code, much like the original C++ compiler (CFront) did. However, the resultant C code will be intentionally machine-readable (low-level) rather than human-readable (high-level). Also, the C code will not include exception handling since that is not and never will be part of the ISO C standard. Nevertheless, if you really want to generate C from C++, the LLVM Compiler is the best tool for the job.