Spring 3.1 WebApplicationInitializer和嵌入式Jetty 8 AnnotationConfiguration
问题内容:
我正在尝试使用Spring 3.1和嵌入式Jetty 8服务器创建一个没有任何XML配置的简单webapp。
但是,我很难让Jetty认识到Spring WebApplicationInitializer 接口的实现。
项目结构:
src
+- main
+- java
| +- JettyServer.java
| +- Initializer.java
|
+- webapp
+- web.xml (objective is to remove this - see below).
上面的 Initializer 类是 WebApplicationInitializer 的简单实现:
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import org.springframework.web.WebApplicationInitializer;
public class Initializer implements WebApplicationInitializer {
@Override
public void onStartup(ServletContext servletContext) throws ServletException {
System.out.println("onStartup");
}
}
同样, JettyServer 是嵌入式Jetty服务器的简单实现:
import org.eclipse.jetty.annotations.AnnotationConfiguration;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.webapp.Configuration;
import org.eclipse.jetty.webapp.WebAppContext;
public class JettyServer {
public static void main(String[] args) throws Exception {
Server server = new Server(8080);
WebAppContext webAppContext = new WebAppContext();
webAppContext.setResourceBase("src/main/webapp");
webAppContext.setContextPath("/");
webAppContext.setConfigurations(new Configuration[] { new AnnotationConfiguration() });
webAppContext.setParentLoaderPriority(true);
server.setHandler(webAppContext);
server.start();
server.join();
}
}
我的理解是,在启动时,Jetty将使用 AnnotationConfiguration 来扫描
ServletContainerInitializer的带 注释的实现;它应该找到 初始化器 并将其连接到…
但是,当我从Eclipse中启动Jetty服务器时,在命令行上看到以下内容:
2012-11-04 16:59:04.552:INFO:oejs.Server:jetty-8.1.7.v20120910
2012-11-04 16:59:05.046:INFO:/:No Spring WebApplicationInitializer types detected on classpath
2012-11-04 16:59:05.046:INFO:oejsh.ContextHandler:started o.e.j.w.WebAppContext{/,file:/Users/duncan/Coding/spring-mvc-embedded-jetty-test/src/main/webapp/}
2012-11-04 16:59:05.117:INFO:oejs.AbstractConnector:Started SelectChannelConnector@0.0.0.0:8080
重要的一点是:
No Spring WebApplicationInitializer types detected on classpath
请注意, src / main / java 在Eclipse中定义为源文件夹,因此应位于类路径上。另请注意,“动态Web模块构面”设置为3.0。
我敢肯定有一个简单的解释,但是我正在努力寻找树木的树木!我怀疑关键在于以下几行:
...
webAppContext.setResourceBase("src/main/webapp");
...
这对于使用web.xml的2.5 servlet有意义(请参阅下文),但是在使用 AnnotationConfiguration 时应该是什么呢?
注意:如果我将“配置”更改为以下内容,则一切正常启动:
...
webAppContext.setConfigurations(new Configuration[] { new WebXmlConfiguration() });
...
在这种情况下,它将在 src / main / webapp 下找到 web.xml ,并使用它以通常的方式(完全绕过上述
WebApplicationInitializer 实现)使用 DispatcherServlet 和
AnnotationConfigWebApplicationContext连接 Servlet 。
这感觉上很像类路径问题,但是我很难理解Jetty如何将其自身与 WebApplicationInitializer的 实现相关联 -任何建议将不胜感激!
有关信息,我使用以下内容:
spring3.1.1码头8.1.7 STS 3.1.0
问题答案:
问题在于Jetty的AnnotationConfiguration
类不会扫描类路径上的非jar资源(在WEB-INF / classes下除外)。
WebApplicationInitializer
如果我注册了一个子类,则除了容器和web-
inf位置之外,它还会AnnotationConfiguration
覆盖其子类configure(WebAppContext)
以扫描主机类路径,从而找到我的。
大多数子类是(非常)从父级复制粘贴。这包括:
parseHostClassPath
configure方法末尾的额外解析调用();- 该
parseHostClassPath
方法主要是复制自AnnotationConfiguration
的parseWebInfClasses
; getHostClassPathResource
从类加载器中获取第一个非jar URL 的方法(至少对我来说,这是指向eclipse中我的类路径的文件url)。
我正在使用Jetty(8.1.7.v20120910)和Spring(3.1.2_RELEASE)稍有不同的版本,但是我想相同的解决方案会起作用。
编辑:我在github中创建了一个工作示例项目,并进行了一些修改(以下代码从Eclipse可以正常运行,但在带阴影的jar中运行时效果不佳)-https:
//github.com/steveliles/jetty-embedded-spring-mvc-
noxml
在OP的JettyServer类中,必要的更改将第15行替换为:
webAppContext.setConfigurations (new Configuration []
{
new AnnotationConfiguration()
{
@Override
public void configure(WebAppContext context) throws Exception
{
boolean metadataComplete = context.getMetaData().isMetaDataComplete();
context.addDecorator(new AnnotationDecorator(context));
AnnotationParser parser = null;
if (!metadataComplete)
{
if (context.getServletContext().getEffectiveMajorVersion() >= 3 || context.isConfigurationDiscovered())
{
parser = createAnnotationParser();
parser.registerAnnotationHandler("javax.servlet.annotation.WebServlet", new WebServletAnnotationHandler(context));
parser.registerAnnotationHandler("javax.servlet.annotation.WebFilter", new WebFilterAnnotationHandler(context));
parser.registerAnnotationHandler("javax.servlet.annotation.WebListener", new WebListenerAnnotationHandler(context));
}
}
List<ServletContainerInitializer> nonExcludedInitializers = getNonExcludedInitializers(context);
parser = registerServletContainerInitializerAnnotationHandlers(context, parser, nonExcludedInitializers);
if (parser != null)
{
parseContainerPath(context, parser);
parseWebInfClasses(context, parser);
parseWebInfLib (context, parser);
parseHostClassPath(context, parser);
}
}
private void parseHostClassPath(final WebAppContext context, AnnotationParser parser) throws Exception
{
clearAnnotationList(parser.getAnnotationHandlers());
Resource resource = getHostClassPathResource(getClass().getClassLoader());
if (resource == null)
return;
parser.parse(resource, new ClassNameResolver()
{
public boolean isExcluded (String name)
{
if (context.isSystemClass(name)) return true;
if (context.isServerClass(name)) return false;
return false;
}
public boolean shouldOverride (String name)
{
//looking at webapp classpath, found already-parsed class of same name - did it come from system or duplicate in webapp?
if (context.isParentLoaderPriority())
return false;
return true;
}
});
//TODO - where to set the annotations discovered from WEB-INF/classes?
List<DiscoveredAnnotation> annotations = new ArrayList<DiscoveredAnnotation>();
gatherAnnotations(annotations, parser.getAnnotationHandlers());
context.getMetaData().addDiscoveredAnnotations (annotations);
}
private Resource getHostClassPathResource(ClassLoader loader) throws IOException
{
if (loader instanceof URLClassLoader)
{
URL[] urls = ((URLClassLoader)loader).getURLs();
for (URL url : urls)
if (url.getProtocol().startsWith("file"))
return Resource.newResource(url);
}
return null;
}
},
});
更新 :Jetty 8.1.8引入了与上面的代码不兼容的内部更改。对于8.1.8,以下似乎有效:
webAppContext.setConfigurations (new Configuration []
{
// This is necessary because Jetty out-of-the-box does not scan
// the classpath of your project in Eclipse, so it doesn't find
// your WebAppInitializer.
new AnnotationConfiguration()
{
@Override
public void configure(WebAppContext context) throws Exception {
boolean metadataComplete = context.getMetaData().isMetaDataComplete();
context.addDecorator(new AnnotationDecorator(context));
//Even if metadata is complete, we still need to scan for ServletContainerInitializers - if there are any
AnnotationParser parser = null;
if (!metadataComplete)
{
//If metadata isn't complete, if this is a servlet 3 webapp or isConfigDiscovered is true, we need to search for annotations
if (context.getServletContext().getEffectiveMajorVersion() >= 3 || context.isConfigurationDiscovered())
{
_discoverableAnnotationHandlers.add(new WebServletAnnotationHandler(context));
_discoverableAnnotationHandlers.add(new WebFilterAnnotationHandler(context));
_discoverableAnnotationHandlers.add(new WebListenerAnnotationHandler(context));
}
}
//Regardless of metadata, if there are any ServletContainerInitializers with @HandlesTypes, then we need to scan all the
//classes so we can call their onStartup() methods correctly
createServletContainerInitializerAnnotationHandlers(context, getNonExcludedInitializers(context));
if (!_discoverableAnnotationHandlers.isEmpty() || _classInheritanceHandler != null || !_containerInitializerAnnotationHandlers.isEmpty())
{
parser = createAnnotationParser();
parse(context, parser);
for (DiscoverableAnnotationHandler h:_discoverableAnnotationHandlers)
context.getMetaData().addDiscoveredAnnotations(((AbstractDiscoverableAnnotationHandler)h).getAnnotationList());
}
}
private void parse(final WebAppContext context, AnnotationParser parser) throws Exception
{
List<Resource> _resources = getResources(getClass().getClassLoader());
for (Resource _resource : _resources)
{
if (_resource == null)
return;
parser.clearHandlers();
for (DiscoverableAnnotationHandler h:_discoverableAnnotationHandlers)
{
if (h instanceof AbstractDiscoverableAnnotationHandler)
((AbstractDiscoverableAnnotationHandler)h).setResource(null); //
}
parser.registerHandlers(_discoverableAnnotationHandlers);
parser.registerHandler(_classInheritanceHandler);
parser.registerHandlers(_containerInitializerAnnotationHandlers);
parser.parse(_resource,
new ClassNameResolver()
{
public boolean isExcluded (String name)
{
if (context.isSystemClass(name)) return true;
if (context.isServerClass(name)) return false;
return false;
}
public boolean shouldOverride (String name)
{
//looking at webapp classpath, found already-parsed class of same name - did it come from system or duplicate in webapp?
if (context.isParentLoaderPriority())
return false;
return true;
}
});
}
}
private List<Resource> getResources(ClassLoader aLoader) throws IOException
{
if (aLoader instanceof URLClassLoader)
{
List<Resource> _result = new ArrayList<Resource>();
URL[] _urls = ((URLClassLoader)aLoader).getURLs();
for (URL _url : _urls)
_result.add(Resource.newResource(_url));
return _result;
}
return Collections.emptyList();
}
}
});