有没有一种方法可以使用JNI从Java调用C ++的STL库？

Question

有没有一种方法可以从JNI调用STL库，我相信JNI为本地调用提供了一个类似于C的接口，我们如何为C ++模板库实现此功能？

Answer 1

I agree that if you're looking for just the plain STL, you could probably use a Java library instead. However, if you insist on wrapping STL, SWIG provides some STL wrapping in JNI out of the box (see this for the basic mechanism), which should produce relatively stable, tested code.

Answer 2

Yes. You required to use the swig typemap to convert C++ STL classes to Java objects... and vice versa. For more information, please visit, http://www.swig.org/Doc2.0/Android.html

Answer 3

I know this is possible, although I haven't done it myself. But JNI code can crash the JVM if you are not VERY CAREFUL. Also, JNI code is much more difficult to maintain than Java code. I was on one project where the Java -> JNI -> STL and COM code was thrown away and we replaced it with C# accessing the same STL and COM and a socket. We never looked back.

If you are doing only a small amount of JNI, it may be worth it. If you are creating a large interface via JNI, I strongly recommend instead writing the component that interacts with STL in C# instead of Java, and using a socket to communicate between the C# and Java components. It will be far easier to write, test, and maintain.

Answer 4

I have to ask why you find it necessary to use the STL libraries from Java. Is there something in them that's not provided by Java's own massive set of libraries?

I understand why you'd have to call your own code (and I'm assuming you've profiled the Java code and found it wanting, otherwise your effort is wasted) but you seem to be asking how to call STL stuff directly.

We've often had trouble with JNI and it makes our code less portable, so you have to have a very good reason for wanting to use it in our shop, and you have to prove with hard data, why the Java-supplied stuff is not adequate.