插件开发入门——过滤脏话

一、简述

openfire为了扩展其他功能，适用于不同的需求，提供了插件的机制。

提前准备：把openfire源码导入到eclipse 或者 IDEA中。

二、说明

编写openfire插件，必须实现一个插件接口Plugin，只要实现了这个接口，就会被openfire认为是插件。

public interface Plugin {    /**     * Initializes the plugin.     *     * @param manager the plugin manager.     * @param pluginDirectory the directory where the plugin is located.     */    void initializePlugin( PluginManager manager, File pluginDirectory );    /**     * Destroys the plugin.     *     * Implementations of this method must release all resources held     * by the plugin such as file handles, database or network connections,     * and references to core Openfire classes. In other words, a     * garbage collection executed after this method is called must be able     * to clean up all plugin classes.     */    void destroyPlugin();}

1. initializePlugin初始化插件

对数据库连接、rides等初始化。

2. destroyPlugin销毁插件

在这里必须释放所有用到的资源。

3. 插件启动

initializePlugin有三种情况会被调用，上传插件、重启插件、openfire启动时。

4. 插件目录结构

插件目录在：\src\plugins\下，一个插件一个目录。

举例：fastpath插件目录结构介绍

目录结构：

\src\plugins\fastpath\src\plugins\fastpath\lib\src\plugins\fastpath\src\src\plugins\fastpath\logo_small.gif\src\plugins\fastpath\logo_large.gif\src\plugins\fastpath\changelog.html\src\plugins\fastpath\plugin.xml\src\plugins\fastpath\readme.html

lib:引用的jar包

logo_large.gif和logo_small.gif表示的是插件的logo，也支持png格式的文件，大小分别是32_32和16_16

changelog.html: 是发布日志，记录插件各个版本的变化情况。

plugin.xml:插件的配置文件。这个文件非常重要，openfire需要读取插件信息，例如插件的启动类是哪一个，需要在plugin.xml中定义

readme.html：插件的介绍和使用

三、编写过滤脏话插件

过滤脏话，就需要获取到消息内容，这个插件就要实现对数据包Packet拦截，必须要实现PacketInterceptor接口，这个接口就是包拦截器接口。

public interface PacketInterceptor {    /**     * Invokes the interceptor on the specified packet. The interceptor can either modify     * the packet, or throw a PacketRejectedException to block it from being sent or processed     * (when read).     *     * An exception can only be thrown when processed is false which means that the read     * packet has not been processed yet or the packet was not sent yet. If the exception is thrown     * with a "read" packet then the sender of the packet will receive an answer with an error. But     * if the exception is thrown with a "sent" packet then nothing will happen.
     *     * Note that for each packet, every interceptor will be called twice: once before processing     * is complete (processing==true) and once after processing is complete. Typically,     * an interceptor will want to ignore one or the other case.     *     * @param packet the packet to take action on.     * @param session the session that received or is sending the packet.     * @param incoming flag that indicates if the packet was read by the server or sent from     *      the server.     * @param processed flag that indicates if the action (read/send) was performed. (PRE vs. POST).     * @throws PacketRejectedException if the packet should be prevented from being processed.     */    void interceptPacket(Packet packet, Session session, boolean incoming, boolean processed)            throws PacketRejectedException;}interceptPacket这个函数会在有packet传输到openfire的时候被调用。

1. 创建插件文件夹

仿照上面介绍的目录创建。添加src、plugin.xml等。

2. 将插件添加到Java Build Path中

创建了上面的文件夹，不添加到Java Build Path中是不能编译的。

3. 创建MessageFilterPlugin.java

package com.lwenhao;import java.io.File;import org.jivesoftware.openfire.container.Plugin;import org.jivesoftware.openfire.container.PluginManager;import org.jivesoftware.openfire.muc.MUCEventDispatcher;import org.jivesoftware.openfire.muc.MUCEventListener;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.xmpp.packet.Message;import com.group.action.GroupMessage;import com.muc.interceptor.MUCEventListenerImpl;/** * 插件的入口类，负责注入这个插件的功能 * @author liuwenhao * */public class MessageFilterPlugin implements Plugin, PacketInterceptor {    // 拦截器管理器，所有的拦截器都在这里注册    private InterceptorManager interceptorManager;    // plugin的接口    public void initializePlugin(PluginManager pManager, File pluginDirectory) {        // InterceptorManager是一个单例类        interceptorManager = InterceptorManager.getInstance();        // 将拦截器注册进来，这样有Packet来的时候，就会调用interceptPacket        interceptorManager.addInterceptor(this);    }    // plugin的接口        public void destroyPlugin() {        // 插件卸载时，记得将拦截器从系统中移出。        //当插件被卸载的时候，主要通过openfire管理控制台卸载插件时，被调用。        //注意interceptorManager的addInterceptor和removeInterceptor需要成对调用。        interceptorManager.removeInterceptor(this);    }    // PacketInterceptor的接口，包处理函数，对包的处理，在这里进行。    public void interceptPacket(Packet packet, Session session, boolean read,        boolean processed) throws PacketRejectedException {            //processed为false，表示本条消息没有被openfire处理过。            if (false == incoming && processed) {                // packet可能是IQ、Presence、Message，这里当packet是message的时候，进行处理。                if (packet instanceof Message) {                    // 将packet强制转换为Message                    Message msg = (Message)packet;                    // 取得message中的body内容，就是消息正文                    String body = msg.getBody();                    // 如果内容中包含fuck，则拒绝处理消息                    if(body != null  && body.contains("fuck")){                        //这里通过抛出异常的方式，来阻止程序流程继续执行下去。                        PacketRejectedException rejectedException =  new PacketRejectedException();                        rejectedException.setRejectionMessage("fuck is error");                        throw rejectedException;                    }                }            }    }}

4. 创建或者修改plugin.xml


    
        
     
      com.lwenhao.MessageFilterPlugin
         
     
      MessageFilterPlugin
         
     
      Message Filter Plugin
         
     
      liuwenhao
         
     
      0.0.1
         
     
      09/03/2018
         
     
      4.2.2
     
    class：插件的启动类name：插件名称description：描述author：作者version：版本date：日期minServerVersion：这个插件需要在openfire为4.2.2以上的版本运行

5.编译插件

在\build\build.properties.template修改

## Directory where the jar files will be deployed (see the deployjar task)#deploy.jar.dir=plugin = MessageFilterPlugin## Directory where plugin development is done. This is assumed to be the# root directory:## /home/joeuser/java/myplugins/          <- Point to this directory#                       |- fooplugin/#                       |- barplugin/#plugin.dev.dir= MessageFilter## Path to your Install4j installation. Typically this is c:\Program Files\install4j# This property is set by default in the build.xml file as c:\Program Files\install4j so# if you used the standard location you won't need to edit the property below.## installer.install4j.home=## Path to a bundled JRE you wish to use with the installer.rpm ant target#jre.bundle.location=

Eclipse->Window->Show View->Othre->Ant->Ant

双击 plugins编译插件，即可在目录\target\openfire\plugins中找到插件