使用web.xml配置嵌入式码头吗？

Question

我正在尝试通过Web应用程序以及带有嵌入式码头的自包含jar文件引发战争。对于嵌入式码头（jar文件分发），我添加了一个servlet，如下所示：

public static void main(String[] args) throws Exception {
    Server server = new Server(8080);

    ServletContextHandler context = new ServletContextHandler(ServletContextHandler.SESSIONS);
    context.setContextPath("/");
    server.setHandler(context);

    context.addServlet(new ServletHolder(new HelloServlet()),"/*");

    server.start();
    server.join();
}

war文件分发使用web.xml文件，该文件在web-app部分包含以下内容：

<servlet>
    <servlet-class>com.example.HelloServlet</servlet-class>
    <servlet-name>SimplestServer</servlet-name>
</servlet>
<servlet-mapping>
    <servlet-name>HelloServlet</servlet-name>
    <url-pattern>/*</url-pattern>
</servlet-mapping>

这可行。但是，我想摆脱两种方法之间的重复。即，当我添加一个新的servlet时，我只想在一个位置进行配置。我可以从嵌入式码头加载和使用web.xml文件吗？

Answer 1

用一个
org.eclipse.jetty.webapp.WebAppContext

例：

package jetty;

import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.webapp.WebAppContext;

public class OnWebApp
{
    public static void main(String[] args) throws Exception
    {
        // Create a basic jetty server object that will listen on port 8080.
        // Note that if you set this to port 0 then a randomly available port
        // will be assigned that you can either look in the logs for the port,
        // or programmatically obtain it for use in test cases.
        Server server = new Server(8080);

        // The WebAppContext is the entity that controls the environment in
        // which a web application lives and breathes. In this example the
        // context path is being set to "/" so it is suitable for serving
        // root context requests and then we see it setting the location of
        // the war. A whole host of other configurations are available,
        // ranging from configuring to support annotation scanning in the
        // webapp (through PlusConfiguration) to choosing where the webapp
        // will unpack itself.
        WebAppContext webapp = new WebAppContext();
        webapp.setContextPath("/");
        webapp.setWar("path/to/my/test.war");

        // A WebAppContext is a ContextHandler as well so it needs to be set to
        // the server so it is aware of where to send the appropriate requests.
        server.setHandler(webapp);

        // Start things up! By using the server.join() the server thread will
        // join with the current thread.
        // See http://docs.oracle.com/javase/1.5.0/docs/api/java/lang/Thread.html#join()
        // for more details.
        server.start();
        server.join();
    }
}

请注意，您将构建一个普通的WAR文件，并将其与Jetty一起使用。

如果您有特殊要求，例如注释扫描或JNDI，则需要进入配置规范。

// Enable parsing of jndi-related parts of web.xml and jetty-env.xml
org.eclipse.jetty.webapp.Configuration.ClassList classlist =
   org.eclipse.jetty.webapp.Configuration.ClassList.setServerDefault(server);

// Enable JNDI
classlist.addAfter("org.eclipse.jetty.webapp.FragmentConfiguration",
   "org.eclipse.jetty.plus.webapp.EnvConfiguration",
   "org.eclipse.jetty.plus.webapp.PlusConfiguration");

// Enable Annotation Scanning
classlist.addBefore("org.eclipse.jetty.webapp.JettyWebXmlConfiguration",
  "org.eclipse.jetty.annotations.AnnotationConfiguration");

有关WebAppContext中更长的示例，请参阅ServerWithAnnotations示例。

还要注意，您还将使用此技术将所有webapp类加载器规则都放在适当的位置。这意味着您将为webapp提供一个类加载器，为服务器提供一个类加载器。了解这一点很重要。

您可以对类加载器的WebAppContext进行一些调整，但是您不能消除它们，而只能控制它们的行为。

WebAppContext webapp = new WebAppContext();
// ... various setup of the webapp ...
// Flip the classloader priority from servlet spec where webapp is first to
// Standard java behavior of parent (aka Server classloader) is first.
webapp.setParentLoaderPriority(true);

也可以看看：

• WebAppContext.setClassLoader(ClassLoader classloader)
• WebAppContext.addServerClass(String classOrPackage)
• WebAppContext.addSystemClass(String classOrPackage)