java - 重新编译时，Matlab 看不到 java 类的变化

Question

我使用 Matlab 并尝试从中启动 java 类。所以我将java类的路径添加到Matlab中的classpath.txt中。然后我创建了一个 java 类 HelloWorld 的对象，它完美地工作了:

o = HelloWorld;
javaMethod('main', o);

但是，当我更改 Helloworld 中的代码时，Matlab 没有看到这一点:我需要重新启动 Matlab 才能使用 Helloworld 中更改的代码。

有没有办法强制 Matlab 在不重新启动的情况下查看 Helloworld 中的更改？

Answer 1

我猜你尝试过Matlab clear classes没有成功

如果我摘自 Yair Altman“MATLAB-Java 编程的未记录 secret ”:

如果您没有更改 java 类签名，您也许可以逃脱它:

Java classes are not reloaded automatically by Matlab, when recompiled outside Matlab . to reload a modified Java class, we need to restart the JVM by restarting Matlab . For classes placed on the dynamic classpath, you can try Matlab’s clear(‘java’) command, while remembering its side effect of clearing all globals . However, this does not always work (e .g ., if the class signature has changed).

显然，如果您觉得自己是一名专业的 Java 程序员，那么有一些潜在的解决方法:

Expert Java programmers can try to use Paul Milenkovic’s suggestion for a proxy classloader, as an alternative to restarting Matlab or clearing Java . as Dan Spielman explains, “the rough idea is that you create a classloader for your class, and then access it through the classloader . after you recompile, you kill the classloader and then create a new instance of it, which then reads the recompiled class” .

但底线是:

In practice, I suggest restarting Matlab after Java classes are recompiled, even when this is not strictly necessary . It may save a lot of frustrating debugging and chasing down errors that only happen because Matlabkeeps an old class in memory.