我正在使用Freemarker和DCEVM+HotSwapManager代理。这基本上允许我在添加/删除方法时热交换类。
一切都像魅力一样工作，直到Freemarker将热交换的类用作模型。即使反射显示该方法存在（在调试会话期间进行检查），它仍会抛出freemarker.ext.beans.InvalidPropertyException：没有这样的bean属性。
我正在使用
final Method clearInfoMethod = beanWrapper.getClass().getDeclaredMethod("removeIntrospectionInfo", Class.class);
clearInfoMethod.setAccessible(true);
clearInfoMethod.invoke(clazz);
我尝试清除缓存，但是不起作用。我甚至尝试使用反射获取classCache成员字段并清除它，但也没有起作用。
我做错了什么？我只需要强制freemarker放弃对已经获取的模型类/类的任何内省。
有什么办法吗？
更新
示例代码
Application.java
// Application.java
public class Application
{
public static final String TEMPLATE_PATH = "TemplatePath";
public static final String DEFAULT_TEMPLATE_PATH = "./";
private static Application INSTANCE;
private Configuration freemarkerConfiguration;
private BeansWrapper beanWrapper;
public static void main(String[] args)
{
final Application application = new Application();
INSTANCE = application;
try
{
application.run(args);
}
catch (InterruptedException e)
{
System.out.println("Exiting");
}
catch (IOException e)
{
System.out.println("IO Error");
e.printStackTrace();
}
}
public Configuration getFreemarkerConfiguration()
{
return freemarkerConfiguration;
}
public static Application getInstance()
{
return INSTANCE;
}
private void run(String[] args) throws InterruptedException, IOException
{
final String templatePath = System.getProperty(TEMPLATE_PATH) != null
? System.getProperty(TEMPLATE_PATH)
: DEFAULT_TEMPLATE_PATH;
final Configuration configuration = new Configuration();
freemarkerConfiguration = configuration;
beanWrapper = new BeansWrapper();
beanWrapper.setUseCache(false);
configuration.setObjectWrapper(beanWrapper);
try
{
final File templateDir = new File(templatePath);
configuration.setTemplateLoader(new FileTemplateLoader(templateDir));
}
catch (IOException e)
{
throw new RuntimeException(e);
}
final RunnerImpl runner = new RunnerImpl();
try
{
runner.run(args);
}
catch (RuntimeException e)
{
e.printStackTrace();
}
}
public BeansWrapper getBeanWrapper()
{
return beanWrapper;
}
}
RunnerImpl.java
// RunnerImpl.java
public class RunnerImpl implements Runner
{
@Override
public void run(String[] args) throws InterruptedException
{
long counter = 0;
while(true)
{
++counter;
System.out.printf("Run %d\n", counter);
// Application.getInstance().getFreemarkerConfiguration().setObjectWrapper(new BeansWrapper());
Application.getInstance().getBeanWrapper().clearClassIntrospecitonCache();
final Worker worker = new Worker();
worker.doWork();
Thread.sleep(1000);
}
}
Worker.java
// Worker.java
public class Worker
{
void doWork()
{
final Application application = Application.getInstance();
final Configuration freemarkerConfiguration = application.getFreemarkerConfiguration();
try
{
final Template template = freemarkerConfiguration.getTemplate("test.ftl");
final Model model = new Model();
final PrintWriter printWriter = new PrintWriter(System.out);
printObjectInto(model);
System.out.println("-----TEMPLATE MACRO PROCESSING-----");
template.process(model, printWriter);
System.out.println();
System.out.println("-----END OF PROCESSING------");
System.out.println();
}
catch (IOException e)
{
e.printStackTrace();
}
catch (TemplateException e)
{
e.printStackTrace();
}
}
private void printObjectInto(Object o)
{
final Class<?> aClass = o.getClass();
final Method[] methods = aClass.getDeclaredMethods();
for (final Method method : methods)
{
System.out.println(String.format("Method name: %s, public: %s", method.getName(), Modifier.isPublic(method.getModifiers())));
}
}
}
Model.java
// Model.java
public class Model
{
public String getMessage()
{
return "Hello";
}
public String getAnotherMessage()
{
return "Hello World!";
}
}
这个例子完全不起作用。即使在运行时更改BeansWrapper也没有任何效果。
removeFromClassIntrospectionCache的Javadoc注释让我感到困惑：“如果类仍将被使用，则缓存条目将被静默重新创建”-这是否意味着当模板缓存包含有关所讨论的类的映射时，内省不会获取其重新加载的版本？谢谢！ - plesatejvlkbeanInfo = java.beans.Introspector.getBeanInfo(aClass)而不是使用反射，然后使用beanInfo.getMethodDescriptors()列出方法。同样的，通过beanInfo.getPropertyDescriptors()来列出属性，因为我猜测在模板中你可能正在访问这些属性（但我还没有看到）。也许问题在于 DCEVM 没有清理 Java 的BeanIntrospector缓存。这只是一个猜测。 - ddekany