OSGi 系列（十二）之 Http Service

OSGi 系列（十二）之 Http Service

1. 原始的 HttpService

(1) 新建 web-osgi 工程，目录结构如下：

(2) HomeServlet

package com.github.binarylei.servlet;

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

public class HomeServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().write("<h1>osgi http service</h1>");
    }
}

(3) Activator

package com.github.binarylei.servlet;

import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
import org.osgi.framework.ServiceRegistration;
import org.osgi.service.http.HttpContext;
import org.osgi.service.http.HttpService;

import javax.servlet.Servlet;
import java.util.Dictionary;
import java.util.Hashtable;

public class Activator implements BundleActivator {

    private HttpService http = null;
    private ServiceRegistration<Servlet> serviceRegistration;
    
    public void start(BundleContext context) throws Exception {

        ServiceReference<HttpService> ref = context.getServiceReference(HttpService.class);
        if(ref == null) {
            System.out.println("http service is null");
        } else {
            http = context.getService(ref);
            
            HttpContext httpContext = http.createDefaultHttpContext();
            
            //注册servlet
            http.registerServlet("/home", new HomeServlet(), null, httpContext);
            
            //注册静态资源
            http.registerResources("/static", "web", httpContext);
        }
        
        //通过发布服务的方式，注册servlet。不能注册静态资源
        Dictionary<String, String> properties = new Hashtable<>();
        properties.put("alias", "/home2");
        serviceRegistration = context.registerService(Servlet.class, new HomeServlet(), properties);
    }

    public void stop(BundleContext context) throws Exception {
        if(http != null) {
            http.unregister("/home");
            http.unregister("/static");
        }
        serviceRegistration.unregister();
    }
}

(4) karaf 测试：

先测试 http.registerServlet() 注册方式

feature:install http

注意： 要先启动 http 服务，再启动 web-osgi

再测试 context.registerService(Servlet.class, new HomeServlet(), properties) 注册方式

feature:install http http-whiteboard

2. OSGi 中运行 war 包

(1) 新建 webapp-osgi 工程，目录结构如下：

(2) LoginServlet

@WebServlet("/web/app")
public class LoginServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().write("this is osgi web app");
    }
}

(3) web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
                      http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
  version="3.0"
  metadata-complete="false">

</web-app>

(4) 配制 war 打包方式

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-war-plugin</artifactId>
    <version>2.6</version>
    <configuration>
        <archive>
            <!-- 表示 MANIFEST.MF 的内容由 maven-bundle-plugin 插件生成 -->
            <manifestFile>${project.build.outputDirectory}/META-INF/MANIFEST.MF</manifestFile>
        </archive>
    </configuration>
</plugin>
<plugin>
    <groupId>org.apache.felix</groupId>
    <artifactId>maven-bundle-plugin</artifactId>
    <version>3.0.0</version>
    <executions>
        <execution>
            <id>bundle-manifest</id>
            <phase>process-classes</phase>
            <goals>
                <goal>manifest</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
        <supportedProjectTypes>
            <supportedProjectType>war</supportedProjectType>
        </supportedProjectTypes>
        <instructions>
            <Web-ContextPath>/osgiweb</Web-ContextPath>
            <Bundle-ClassPath>.,WEB-INF/classes</Bundle-ClassPath>
        </instructions>
    </configuration>
</plugin>

(5) 测试：

karaf 默认是不支持 war 包安装方式

feature:install war