Jetty初探

一、在jetty中部署web应用

Jetty 和 Tomcat 一样都是一个web server的container, 用户可以在里面 deploy 自己的 war 包，然后启动 Jetty, 进而通过浏览器去访问你的 web content.

从jetty官网下载jetty 9的压缩包，并解压到本地。假设jetty的路径是D:jetty-9, 在CMD里运行

> cd D:jetty-9demo-base
> java -jar ..start.jar

2015-06-04 10:50:44.806:INFO::main: Logging initialized @334ms
2015-06-04 10:50:44.858:WARN:oejs.HomeBaseWarning:main: This instance of Jetty is not running from a separate {jetty.base} directory, this is not recommended.  See documentation at http://www.eclipse.org/jetty/documentation/current/startup.html
2015-06-04 10:50:44.995:INFO:oejs.Server:main: jetty-9.3.0.v20150601
2015-06-04 10:50:45.012:INFO:oejdp.ScanningAppProvider:main: Deployment monitor [file:///opt/jetty-distribution-9.3.0.v20150601/webapps/] at interval 1
2015-06-04 10:50:45.030:INFO:oejs.ServerConnector:main: Started ServerConnector@19dfb72a{HTTP/1.1,[http/1.1]}{0.0.0.0:8080}
2015-06-04 10:50:45.030:INFO:oejs.Server:main: Started @558ms

jetty 被启动，这时便可以访问http://localhost:8080去访问demo相关的内容了。Jetty 9中一项重大的改动就是允许一个server实例的内容与jetty自身的distribution隔离。用户在创建web应用时先创建一个新的Jetty Base.

> JETTY_BASE=/tmp/mybase
> mkdir $JETTY_BASE
> cd $JETTY_BASE
> java -jar $JETTY_HOME/start.jar
WARNING: Nothing to start, exiting ...

Usage: java -jar start.jar [options] [properties] [configs]
       java -jar start.jar --help  # for more information

> java -jar $JETTY_HOME/start.jar --add-to-startd=http,deploy
INFO: server          initialised (transitively) in ${jetty.base}/start.d/server.ini
INFO: http            initialised in ${jetty.base}/start.d/http.ini
INFO: security        initialised (transitively) in ${jetty.base}/start.d/security.ini
INFO: servlet         initialised (transitively) in ${jetty.base}/start.d/servlet.ini
INFO: webapp          initialised (transitively) in ${jetty.base}/start.d/webapp.ini
INFO: deploy          initialised in ${jetty.base}/start.d/deploy.ini
MKDIR: ${jetty.base}/webapps
INFO: Base directory was modified
> cp $JETTY_HOME/demo-base/webapps/async-rest.war webapps/ROOT.war
> java -jar $JETTY_HOME/start.jar
2015-06-04 11:10:16.286:INFO::main: Logging initialized @274ms
2015-06-04 11:10:16.440:INFO:oejs.Server:main: jetty-9.3.0.v20150601
2015-06-04 11:10:16.460:INFO:oejdp.ScanningAppProvider:main: Deployment monitor [file:///tmp/mybase/webapps/] at interval 1
2015-06-04 11:10:16.581:WARN::main: async-rest webapp is deployed. DO NOT USE IN PRODUCTION!
2015-06-04 11:10:16.589:INFO:oejw.StandardDescriptorProcessor:main: NO JSP Support for /, did not find org.eclipse.jetty.jsp.JettyJspServlet
2015-06-04 11:10:16.628:INFO:oejsh.ContextHandler:main: Started o.e.j.w.WebAppContext@1a407d53{/,[file:///tmp/jetty-0.0.0.0-8080-ROOT.war-_-any-4510228025526425427.dir/webapp/, jar:file:///tmp/jetty-0.0.0.0-8080-ROOT.war-_-any-4510228025526425427.dir/webapp/WEB-INF/lib/example-async-rest-jar-9.3.0.v20150601.jar!/META-INF/resources],AVAILABLE}{/ROOT.war}
2015-06-04 11:10:16.645:INFO:oejs.ServerConnector:main: Started ServerConnector@3abbfa04{HTTP/1.1,[http/1.1]}{0.0.0.0:8080}
2015-06-04 11:10:16.646:INFO:oejs.Server:main: Started @634ms

二、在java中部署jetty

Jetty的口号是"Don't deploy your application in Jetty, deploy Jetty in your application"，这也是Jetty与Tomcat最大的不同。在jetty中部署应用其实可以算是jetty的附带功能，jetty真正为人们所广泛应用的是deploy jetty in application.

下面是java中部署jetty的helloworld。

程序入口SimplestServer.main

package com.mustone;

import org.eclipse.jetty.server.Server;

public class SimplestServer {

    public static void main(String[] args) throws Exception {
    Server server = new Server(8081);
        server.setHandler(new HelloHandler());

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

    }
}

package com.mustone;

import org.eclipse.jetty.server.Request;
import org.eclipse.jetty.server.handler.AbstractHandler;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class HelloHandler extends AbstractHandler {
    public void handle(String target, Request baseRequest,HttpServletRequest request, HttpServletResponse response)
    throws IOException {
        response.setContentType("text/html;charset=utf-8");
        response.setStatus(HttpServletResponse.SC_OK);
        baseRequest.setHandled(true);
        response.getWriter().println("<h1>Hello World</h1>");
    }
}

运行SimplestServer, web server就启起来了

2016-03-10 03:05:42.974:INFO:oejs.Server:jetty-7.6.17.v20150415
2016-03-10 03:05:43.043:INFO:oejs.AbstractConnector:Started SelectChannelConnector@0.0.0.0:8081

这时访问http://localhost:8081就可以看到Hello World的字样。