这篇文章主要讲解了“如何使用eclipse开发felix的OSGI插件”，文中的讲解内容简单清晰，易于学习与理解，下面请大家跟着小编的思路慢慢深入，一起来研究和学习“如何使用eclipse开发felix的OSGI插件”吧！
1、官网下载http://felix.apache.org/downloads.cgi，
当前最新版本6.0.3
运行felix窗口有两种方式
(1) 可以直接下载发布版本
Felix Framework Distribution（org.apache.felix.main.distribution-6.0.3.zip）
解压后目录
进入项目目录，命令行下执行
java -jar ./bin/felix.jar
felix.jar 默认会在当前运行目录的 bundle 文件夹内加载启动所需的插件jar，config 目录下的 config.propeties 和 system.properties 里面加载环境变量，如果将其他目录作为启动根目录，该目录下不存在 felix 启动所需信息，启动就会有问题。项目第一次启动的时候会在启动目录下创建一个felix-cache的目录，用于存放框架运行过程产生的数据，当然该目录可以在启动的时候配置，使用 java -jar ./bin/felix.jar <felix-dir> 即可。
(2) 源码导入eclipse运行
下载子项目Main（org.apache.felix.main-6.0.3-project.zip）
解压org.apache.felix.main-6.0.3-project.zip，进入目录，命令行下
运行mvn eclipse:eclipse工程文件，
再输入mvn package，打包编译
File->Import导入到eclipse
在eclipse的org.apache.felix.main.Main类右键运行Run As Java Application
常用命令
lb:查看已装插件包 start:运行插件包 stop:停止运行插件包 install:安装插件包 uninstall:删除插件包 其它命令可以通过help查看
2、felix开发插件
参考是felix官方例子代码apache-felix-osgi-tutorial里的
apache-felix-tutorial-example-2
apache-felix-tutorial-example-2b
apache-felix-tutorial-example-3
这是一个检查输入单词(英文、中文....)是否正确的例子功能
先定义一个服务类：
package test.penngo.service;
/**
* 简单的定义了一个字典服务接口，该接口的功能只是简单的验证一个词是否正确。
**/
public interface DictionaryService
{
/**
* 检查 单词是否存在
**/
public boolean checkWord(String word);
}英文词典插件包开发
package tutorial.example2;
import java.util.Hashtable;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import test.penngo.service.DictionaryService;
/**
* 英文字典服务插件
**/
public class Activator implements BundleActivator {
/**
* 服务启动
*
* @param context the framework context for the bundle.
**/
public void start(BundleContext context) {
Hashtable<String, String> props = new Hashtable<String, String>();
props.put("Language", "English");
context.registerService(DictionaryService.class.getName(), new DictionaryImpl(), props);
}
/**
* 服务停止
*
* @param context the framework context for the bundle.
**/
public void stop(BundleContext context) {
// NOTE: The service is automatically unregistered.
}
/**
* 英文词典服务实现
**/
private static class DictionaryImpl implements DictionaryService {
String[] m_dictionary = { "welcome", "to", "the", "osgi", "tutorial" };
/**
* 英文单词检测
**/
public boolean checkWord(String word) {
word = word.toLowerCase();
for (int i = 0; i < m_dictionary.length; i++) {
if (m_dictionary[i].equals(word)) {
return true;
}
}
return false;
}
}
}META-INF.MF
Manifest-Version: 1.0 Bundle-ManifestVersion: 2 Bundle-SymbolicName: English Bundle-Name: English dictionary Bundle-Description: A bundle that registers an English dictionary service Bundle-Vendor: penngo Bundle-Version: 1.0.0 Bundle-Activator: tutorial.example2.Activator Import-Package: org.osgi.framework, test.penngo.service
英文词典插件打包导出，eclipse自带的export打包会有问题，本文使用fatjar工具打包，
中文词典插件包开发
package tutorial.example2b;
import java.util.Hashtable;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import test.penngo.service.DictionaryService;
/**
* 中文词典包
**/
public class Activator implements BundleActivator
{
public void start(BundleContext context)
{
Hashtable<String, String> props = new Hashtable<String, String>();
props.put("Language", "Chinese");
context.registerService(
DictionaryService.class.getName(), new DictionaryImpl(), props);
}
public void stop(BundleContext context)
{
// NOTE: The service is automatically unregistered.
}
/**
* 中文词典服务实现
**/
private static class DictionaryImpl implements DictionaryService
{
// The set of words contained in the dictionary.
String[] m_dictionary =
{ "欢迎", "你好", "教程", "模块" };
public boolean checkWord(String word)
{
word = word.toLowerCase();
for (int i = 0; i < m_dictionary.length; i++)
{
if (m_dictionary[i].equals(word))
{
return true;
}
}
return false;
}
}
}Manifest-Version: 1.0 Bundle-ManifestVersion: 2 Bundle-SymbolicName: Chinese Bundle-Name: Chinese dictionary Bundle-Description: A bundle that registers a Chinese dictionary service Bundle-Vendor: penngo Bundle-Version: 1.1.0 Bundle-Activator: tutorial.example2b.Activator Import-Package: org.osgi.framework, test.penngo.service
插件打包
客户端调用词典开发，也是作为一个felix插件
package tutorial.example3;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
import test.penngo.service.DictionaryService;
/**
* 此客户端在启动时，接收控制台输入，检查输入的单词是否正确，并且打印初相应的检测结果，
* 注意：当我们没有输入任何信息的时候，单词检测便会结束，如果需要重新进入单词检测程序，我们需要重新启动插件。
**/
public class Activator implements BundleActivator
{
public void start(BundleContext context) throws Exception
{
// 获取所有词典插件
ServiceReference[] refs = context.getServiceReferences(
DictionaryService.class.getName(), "(Language=*)");
if (refs != null)
{
System.out.println("=======当前可用词典插件:" + refs.length);
try
{
System.out.println("Enter a blank line to exit.");
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
String word = "";
while (true)
{
System.out.print("Enter word: ");
word = in.readLine();
if (word.length() == 0)
{
break;
}
boolean isCorrect = false;
for(ServiceReference service:refs) {
DictionaryService dictionary =
(DictionaryService) context.getService(service);
if (dictionary.checkWord(word))
{
isCorrect = true;
System.out.println("Correct.");
}
}
if(isCorrect == false)
{
System.out.println("Incorrect.");
}
}
} catch (IOException ex) {
ex.printStackTrace();
}
}
else
{
System.out.println("Couldn't find any dictionary service...");
}
}
/**
* Implements BundleActivator.stop(). Does nothing since
* the framework will automatically unget any used services.
* @param context the framework context for the bundle.
**/
public void stop(BundleContext context)
{
// NOTE: The service is automatically released.
}
}Manifest-Version: 1.0 Bundle-ManifestVersion: 2 Bundle-SymbolicName: client Bundle-Name: Dictionary client Bundle-Description: A bundle that uses the dictionary service if it finds it at startup Bundle-Vendor: penngo Bundle-Version: 1.3.0 Bundle-Activator: tutorial.example3.Activator Export-Package: test.penngo.service Import-Package: org.osgi.framework #//注意：test.penngo.service这个包与tutorial.example3打在同一个jar中，如果example3.jar更新，其它依赖test.penngo.service的也需要更新或重启felix.
安装插件
把上边生成的插件包example2.jar,example2b.jar,example3.jar入到org.apache.felix.main-6.0.3项目的plugins文件夹中
安装和运行效果：
通过插件方式开发，后期继续扩展增加其它语言词典（日语，俄语，韩语），不需要重启服务，也不影响已存在的语言词典功能（英文、中文）。
3、开发http服务插件
package test.penngo.http.example;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class TestServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
resp.getWriter().write("hello penngo");
}
}package test.penngo.http.example;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
import org.osgi.service.http.HttpService;
import org.osgi.util.tracker.ServiceTracker;
public class Activator implements BundleActivator {
private ServiceTracker httpTracker;
public void start(BundleContext context) throws Exception {
httpTracker = new ServiceTracker(context, HttpService.class.getName(), null) {
public void removedService(ServiceReference reference, Object service) {
// HTTP service is no longer available, unregister our servlet...
try {
((HttpService) service).unregister("/hello");
} catch (IllegalArgumentException exception) {
// Ignore; servlet registration probably failed earlier on...
}
}
public Object addingService(ServiceReference reference) {
// HTTP service is available, register our servlet...
HttpService httpService = (HttpService) this.context.getService(reference);
try {
httpService.registerServlet("/hello", new TestServlet(), null, null);
} catch (Exception exception) {
exception.printStackTrace();
}
return httpService;
}
};
// start tracking all HTTP services...
httpTracker.open();
}
public void stop(BundleContext context) throws Exception {
// stop tracking all HTTP services...
httpTracker.close();
}
}#MANIFEST.MF Manifest-Version: 1.0 Bundle-ManifestVersion: 2 Bundle-SymbolicName: hello Bundle-Name: hello penngo Bundle-Description: Http Hello World Bundle-Vendor: penngo Bundle-Version: 1.0.0 Bundle-Activator: test.penngo.http.example.Activator Import-Package: org.osgi.framework, org.osgi.service.http, org.osgi.util.tracker, javax.servlet.http, javax.servlet
注意htpp插件包依赖:
org.apache.felix.http.base-4.0.6.jar, org.apache.felix.http.bridge-4.0.8.jar, org.apache.felix.http.jetty-4.0.10.jar, org.apache.felix.http.servlet-api-1.1.2.jar, org.apache.felix.http.whiteboard-4.0.0.jar
需要先安装上边的插件包，才能正常在felix中运行http功能。
安装运行效果
浏览器访问：
感谢各位的阅读，以上就是“如何使用eclipse开发felix的OSGI插件”的内容了，经过本文的学习后，相信大家对如何使用eclipse开发felix的OSGI插件这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是亿速云，小编将为大家推送更多相关知识点的文章，欢迎关注！
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