這是很容易編寫自定義的範圍做這...
public class CustomScope implements Scope, BeanFactoryPostProcessor {
@Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
String name = "myScope";
beanFactory.registerScope(name, this);
Assert.state(beanFactory instanceof BeanDefinitionRegistry,
"BeanFactory was not a BeanDefinitionRegistry, so CustomScope cannot be used.");
BeanDefinitionRegistry registry = (BeanDefinitionRegistry) beanFactory;
for (String beanName : beanFactory.getBeanDefinitionNames()) {
BeanDefinition definition = beanFactory.getBeanDefinition(beanName);
if (name.equals(definition.getScope())) {
BeanDefinitionHolder proxyHolder = ScopedProxyUtils.createScopedProxy(new BeanDefinitionHolder(definition, beanName), registry, false);
registry.registerBeanDefinition(beanName, proxyHolder.getBeanDefinition());
}
}
}
@Override
public Object get(String name, ObjectFactory<?> objectFactory) {
return objectFactory.getObject(); // a new one every time
}
@Override
public String getConversationId() {
return null;
}
@Override
public void registerDestructionCallback(String name, Runnable callback) {
}
@Override
public Object remove(String name) {
return null;
}
@Override
public Object resolveContextualObject(String arg0) {
return null;
}
}
public class Foo implements MessageListener {
private Bar bar;
public void setBar(Bar bar) {
this.bar = bar;
}
@Override
public void onMessage(Message message) {
System.out.println(bar.getId());
}
}
@ContextConfiguration
@RunWith(SpringJUnit4ClassRunner.class)
public class FooTests {
@Autowired
private Foo foo;
@Test
public void test() {
Message message = mock(Message.class);
foo.onMessage(message);
foo.onMessage(message);
}
}
和樣本背景...
<bean class="foo.CustomScope" />
<bean id="baz" class="foo.BazImpl" scope="myScope" />
<bean id="bar" class="foo.BarImpl" scope="myScope">
<property name="baz" ref="baz" />
</bean>
<bean id="foo" class="foo.Foo">
<property name="bar" ref="bar" />
</bean>
注意:在這個簡單的範圍內,您必須將所有引用的bean放在範圍內(上面的bar 和 baz)。您可以使所有引用的bean繼承範圍,但需要一些工作。這就是說 - 有一個如何在Spring-Step的StepScope中做到這一點的例子。
注#2這將爲每個方法調用獲取一個新實例。如果您調用多個方法,則每次調用都會得到一個新的bean。如果您想要將其範圍限制爲允許onMessage中的所有調用使用同一個實例,則需要添加更多技巧。
編輯: 這裏有一些更新,以支持在onMessage()內的一個實例多次調用...
private final ThreadLocal<Map<String, Object>> holder = new ThreadLocal<Map<String, Object>>();
...
@Override
public Object get(String name, ObjectFactory<?> objectFactory) {
Map<String, Object> cache = this.holder.get();
if (cache == null) {
cache = new HashMap<String, Object>();
this.holder.set(cache);
}
Object object = cache.get(name);
if (object == null) {
object = objectFactory.getObject();
cache.put(name, object);
}
return object;
}
public void clearCache() {
this.holder.remove();
}
現在,你做必須清除緩存...
@Override
public void onMessage(Message message) {
try {
System.out.println(bar.getId());
System.out.println(bar.getId());
}
finally {
this.scope.clearCache();
}
}
但即使這樣做可以在AOP @After建議中完成,以保持聽衆完全清潔。
我找到你後hrlpfull我。請解釋爲什麼'prototype' does not work,以及爲什麼你需要每jms消息一個sepate bean。 – 2014-01-17 20:04:04