[Java][Liferay] 解决Liferay ext项目deploy的问题

Liferay ext project在install war包之后需要重启服务器，重启服务器中会执行ExtHotDeployListener中的逻辑，这里有一个坑，如果是第二次以后install ext war包，会发现新修改的文件不起作用，原因如下

ExtHotDeployListener.java

    protected void doInvokeDeploy(HotDeployEvent hotDeployEvent)
        throws Exception {

        ServletContext servletContext = hotDeployEvent.getServletContext();

        String servletContextName = servletContext.getServletContextName();

        if (_log.isDebugEnabled()) {
            _log.debug("Invoking deploy for " + servletContextName);
        }

        String xml = HttpUtil.URLtoString(
            servletContext.getResource(
                "/WEB-INF/ext-" + servletContextName + ".xml"));

        if (xml == null) {
            return;
        }

        if (_log.isInfoEnabled()) {
            _log.info(
                "Registering extension environment for " + servletContextName);
        }

        /*
        * Ext 项目在重启tomcat的时候会checkd liferay-portal/tomcat-xxx/webapps/ROOT/WEB-INF/ext-project-***-ext.xml是否存在
        * 如果存在，就不执行后面的逻辑，也就不会执行installExt(***)，那么也不会重新拷贝替换的文件
        *
        */
        if (ExtRegistry.isRegistered(servletContextName)) {
            if (_log.isInfoEnabled()) {
                _log.info(
                    "Extension environment for " + servletContextName +
                        " has been applied.");
            }

            return;
        }

        Map<String, Set<String>> conflicts = ExtRegistry.getConflicts(
            servletContext);

        if (!conflicts.isEmpty()) {
            StringBundler sb = new StringBundler();

            sb.append(
                "Extension environment for " + servletContextName +
                    " cannot be applied because of detected conflicts:");

            for (Map.Entry<String, Set<String>> entry : conflicts.entrySet()) {
                String conflictServletContextName = entry.getKey();
                Set<String> conflictFiles = entry.getValue();

                sb.append("
	");
                sb.append(conflictServletContextName);
                sb.append(":");

                for (String conflictFile : conflictFiles) {
                    sb.append("
		");
                    sb.append(conflictFile);
                }
            }

            _log.error(sb.toString());

            return;
        }

        installExt(servletContext, hotDeployEvent.getContextClassLoader());

        FileAvailabilityUtil.reset();

        if (_log.isInfoEnabled()) {
            _log.info(
                "Extension environment for " + servletContextName +
                    " has been applied. You must reboot the server and " +
                        "redeploy all other plugins.");
        }
    }

xxx-ext.xml格式如下

<ext-info>
	<servlet-context-name>hsf-plugins-shared-ext</servlet-context-name>
	<files>
		<file>xxxx-ext.xml</file>
		<file>ext-impl/classes/com/liferay/portal/action/xxx.class</file>
                ....
		<file>ext-web/docroot/html/js/xxx.js</file>
		<file>web.xml</file>
	</files>
</ext-info>

解决方案

1>. 去除掉doInvokeDeploy中这段逻辑，不管是否包含ext-project-***-ext.xml都执行install

if (ExtRegistry.isRegistered(servletContextName)) {
    if (_log.isInfoEnabled()) {
        _log.info(
            "Extension environment for " + servletContextName +
                " has been applied.");
    }

    return;
}

2>. 在第二次install ext project war包之后需要删除liferay-portal/tomcat-xxx/webapps/ROOT/WEB-INF/ext-project-***-ext.xml，然后重启tomcat