為了模擬java.lang.OutOfMemoryError: Metaspace，您必須加載許多不同的類。首先必須設置以下元空間設置：-XX:MaxMetaspaceSize=10m-XX:MetaspaceSize=2M-XX:MaxMetaspaceFreeRatio=1-XX:MaxMetaspaceExpansion=1K-XX:MinMetaspaceFreeRatio=1-XX:InitialBootClassLoaderMetaspaceSize=2M然后下面的代碼讓類加載器加載了很多不同的類。這是通過獲取類的編譯字節碼mypackage.Myclass0并通過更改類名和調整類名的長度來調整以迭代地創建新類來實現的：    public static void main(String[] args) throws Exception {        String clazzBase64 ="yv66vgAAADcADAEAEm15cGFja2FnZS9NeWNsYXNzMAcAAQEAEGphdmEvbGFuZy9PYmplY3QHAAMBAApTb3VyY2VGaWxlAQANTXljbGFzczAuamF2YQEABjxpbml0PgEAAygpVgwABwAICgAEAAkBAARDb2RlACEAAgAEAAAAAAABAAEABwAIAAEACwAAABEAAQABAAAABSq3AAqxAAAAAAABAAUAAAACAAY=";        byte[] compiledClazz = Base64.getDecoder().decode(clazzBase64);        int classNameLength = Integer.valueOf(compiledClazz[12]);        MyClassLoader myClassLoader = new MyClassLoader(Thread.currentThread().getContextClassLoader());        for (int i = 0; ; i++) {            byte[] bytes = String.valueOf(i).getBytes();            byte[] bytecode = new byte[compiledClazz.length + bytes.length - 1];            System.arraycopy(compiledClazz, 0, bytecode, 0, 30);            bytecode[12] = (byte) (classNameLength + bytes.length - 1 & 0xFF);            System.arraycopy(bytes, 0, bytecode, 30, bytes.length);            System.arraycopy(compiledClazz, 31, bytecode, 30 + bytes.length, compiledClazz.length - 31);            String classname = "mypackage.Myclass" + i;            Class c = myClassLoader.getClass(classname, bytecode);        }    }    public static class MyClassLoader extends ClassLoader {        public MyClassLoader(ClassLoader parent) {            super(parent);        }        public Class<?> getClass(String name, byte[] code) {            return defineClass(name, code, 0, code.length);        }    }