Jetty：默认servlet上下文路径

Question

我需要设置Servlet（由于某些原因，只有Servlet而不是handler）来处理WAR以外的文件。在这里https://stackoverflow.com/a/28735121/5057736我找到了以下解决方案：

Server server = new Server(8080);

ServletContextHandler ctx = new ServletContextHandler();
ctx.setContextPath("/");

DefaultServlet defaultServlet = new DefaultServlet();
ServletHolder holderPwd = new ServletHolder("default", defaultServlet);
holderPwd.setInitParameter("resourceBase", "./src/webapp/");

ctx.addServlet(holderPwd, "/*");//LINE N
ctx.addServlet(InfoServiceSocketServlet.class, "/info");

server.setHandler(ctx);

这个解决方案的工作，这是我需要的。但是，当我将第N行更改为ctx.addservlet(holderPwd,“/foo/*”）；时，它就停止工作。我尝试了“/foo/”和“/foo”，但是结果是一样的--我得到了not found。为什么？我怎样才能使它在这种特定的上下文中工作？我使用jetty 9.2.15也是出于同样的原因。

Answer 1

DefaultServlet旨在查看ContextPath之后的请求URI。

在示例代码中，当您将servlet的URL模式从/更改为/foo/*时，在磁盘上查找的结果文件现在包括/foo/部分。

换句话说，/css/main.css的请求URI将导致它希望找到的文件（在磁盘上）为./src/webapp/foo/css/main.css

您的示例有一些缺陷。为ServletContextHandler提供空的资源库是不明智的，因为ServletContext本身需要访问该配置值。

你可以通过移除...

holderPwd.setInitParameter("resourceBase", "./src/webapp/");

而是使用ServletContexThandler.setBaseResource（资源）...

ctx.setResourceBase(Resource.newResource(new File("./src/webapp")));

null

像这样：

// Lastly, the default servlet for root content
// It is important that this is added last.
String defName = "default"; // the important "default" name
ServletHolder holderDef = new ServletHolder(defName, DefaultServlet.class);
holderDef.setInitParameter("dirAllowed","true");
ctx.addServlet(holderDef,"/"); // the servlet spec "default url-pattern"

现在，如果您还需要从不属于webapp的目录中的请求URI/foo/*提供静态内容，您也可以这样做。这将要求您设置另一个不参与ServletContext的DefaultServlet。

这种设置的一个例子是...

package jetty;

import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.ServerConnector;
import org.eclipse.jetty.servlet.DefaultServlet;
import org.eclipse.jetty.servlet.ServletContextHandler;
import org.eclipse.jetty.servlet.ServletHolder;
import org.eclipse.jetty.util.resource.PathResource;

import java.io.File;
import java.nio.file.Path;

public class ManyDefaultServlet
{
    public static void main(String[] args) throws Exception {
        Server server = new Server();
        ServerConnector connector = new ServerConnector(server);
        connector.setPort(8080);
        server.addConnector(connector);

        // The filesystem paths we will map
        Path homePath = new File(System.getProperty("user.home")).toPath().toRealPath();
        Path pwdPath = new File(System.getProperty("user.dir")).toPath().toRealPath();

        // Setup the basic application "context" for this application at "/"
        // This is also known as the handler tree (in jetty speak)
        ServletContextHandler context = new ServletContextHandler(ServletContextHandler.SESSIONS);
        context.setContextPath("/");
        context.setBaseResource(new PathResource(pwdPath));
        server.setHandler(context);

        // Fist, add special pathspec of "/home/" content mapped to the homePath
        ServletHolder holderHome = new ServletHolder("static-home", DefaultServlet.class);
        holderHome.setInitParameter("resourceBase",homePath.toUri().toASCIIString());
        holderHome.setInitParameter("dirAllowed","true");
        // Use request pathInfo, don't calculate from contextPath
        holderHome.setInitParameter("pathInfoOnly","true");
        context.addServlet(holderHome,"/foo/*"); // must end in "/*" for pathInfo to work

        // Lastly, the default servlet for root content
        // It is important that this is last.
        String defName = "default"; // the important "default" name
        ServletHolder holderDef = new ServletHolder(defName, DefaultServlet.class);
        holderDef.setInitParameter("dirAllowed","true");
        context.addServlet(holderDef,"/"); // the servlet spec "default url-pattern"

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