将web容器置于OSGi框架下,其实就是将web容器做成OSGi支持的Bundle,再安装到OSGi框架中,这里使用的是Jetty容器。
1、创建一个Eclipse插件项目,在此插件下创建一个WebRoot文件夹,里面创建两个文件夹一个是images,一个是pages,里面分别放置一个图片文件,一个简单的html页面和一个简单的jsp文件。大致目录结构如下图所示:
2.
index.jsp文件的内容如下:
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <img src="images/08.png" width="200" height="150"> </body> </html>
3、MANIFEST.MF文件的内容如下:
Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: osgi_jetty
Bundle-SymbolicName: osgi_jetty;singleton:=true
Bundle-Version: 1.0.0
Bundle-Activator: com.javaworld.samples.osgi_jetty.Activator
Bundle-RequiredExecutionEnvironment: JavaSE-1.6
Import-Package: javax.servlet;version="2.6.0",
javax.servlet.http;version="2.6.0",
org.osgi.framework;version="1.3.0"
Require-Bundle: org.eclipse.equinox.http.registry;bundle-version="1.1.300",
org.eclipse.equinox.jsp.jasper.registry;bundle-version="1.0.300",
org.eclipse.equinox.http.jetty;bundle-version="3.0.100"
当插件使用到Eclipse的扩展点机制时,必须在Bundle-SymbolicName属性值最后设置singleton的值为true。
4、HelloServlet.java文件的内容如下:
package com.javaworld.samples.osgi_jetty; import java.io.IOException; import java.text.SimpleDateFormat; import java.util.Date; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class HelloServlet extends HttpServlet { private static final long serialVersionUID = -5560032300646459304L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=GBK"); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String date = sdf.format(new Date()); response.getWriter().println("现在的时间是:" + date); } }
5、如果要通过web容器访问bundle中的web资源,必须要通过某种方式来告诉OSGi框架,哪些资源可以访问,访问的规则是什么。新增一个名为“plugin.xml”的配置文件,内容如下:
<?xml version="1.0" encoding="UTF-8"?> <?eclipse version="3.0"?> <plugin> <extension point="org.eclipse.equinox.http.registry.resources"> <resource alias="/images" base-name="WebRoot/images"/> <resource alias="/pages" base-name="WebRoot/pages"/> </extension> <extension point="org.eclipse.equinox.http.registry.servlets"> <servlet alias="/hello" class="com.javaworld.samples.osgi_jetty.HelloServlet" load-on-startup="true"/> <servlet alias="/*.jsp" class="org.eclipse.equinox.jsp.jasper.registry.JSPFactory:/WebRoot/Pages/"/> </extension> </plugin>
6、启动项目。启动项目后,可以通过类似以下的路径来访问: