Java to C++ Converter FAQ

Q: Are entire folders converted?

You can select Java folders to convert. All ".java" files within that folder will be converted and output as either traditional .h/.cpp files or C++20 modules to the directory you specify. However, Java to C++ Converter does not construct the new C++ project file. This is due to the lack of similarity between Java project types and formats and C++ project types and formats.

Q: Are the original Java files altered in any way?

Your existing code is left completely intact. The new C++ files are output to the new location that you specify.

Q: What version of Java is converted?

We attempt to convert as much as possible and are continually updating the converter to handle newer Java features. However, some new Java features have no C++ equivalent so the output will require adjustments.

Q: What is the conversion accuracy?

Our accuracy is very high, but there will be significant adjustments required for all but the simplest conversions. There are no direct equivalents for some aspects of Java. Read the rest of the FAQ to get an idea of a few things that are not converted. Java to C++ Converter is intended to reduce the amount of work you'll have to do to convert code to C++, but it is just the first step.

Q: How are anonymous inner classes handled?

Anonymous inner classes are converted to C++ nested private classes, but if the interface is a functional interface, then the interface is converted to a function pointer typedef and the anonymous inner class is converted to a lambda.

Q: Are Java functional interfaces converted?

Yes — try out our Free Edition to see the conversion details. We optionally convert Java functional interfaces to C++ function pointers.

Q: What about Java UI code?

The converter does not convert Java UI types due to the lack of similarity between these types and C++ UI types.

Q: Is there an option to produce C++/CLI code?

No. Despite the name, C++/CLI has very little in common with C++.

Q: What are the most common manual adjustments?

Java to C++ Converter converts only some Java library types to C++ equivalents. The converter offers options to use your own custom replacements.
Java to C++ Converter cannot ensure proper deallocation of pointer variables. In some cases, a call to the delete operator is made, but in general complete memory deallocation is not included in the conversion. However, the converter contains options for converting to smart pointers.
Java's event handling model has no direct equivalent in C++.
Java wildcard generics have no equivalent in C++, unless used in a method declaration parameter list.
Java local classes cannot be declared within methods in C++. These are marked with a comment.
There will be occasional qualifier symbol adjustments required. For example, it is possible that Java to C++ Converter fails to determine whether a particular Java dot operator should be replaced by a C++ arrow, double colon, or dot. If type analysis fails to determine the equivalent, heuristics are used to determine the most probable equivalent.
There is no acceptable equivalent to an exception 'finally' clause.
Java local final variables have no exact equivalent in C++. These are converted to constexpr, which requires that the assigned value be a compile-time constant. For cases where the assigned value is not a compile-time constant, you will have to remove the constexpr qualifier.

Additional Resources

Java and C++ comparison and equivalents chart