Liferay 启动过程分析3-处理启动事件（第一部分）

在MainServlet启动Struts中央控制器之后第一件事情就是去处理启动事件：

protected void processStartupEvents() throws Exception {
StartupAction startupAction = new StartupAction();

startupAction.run(null);
}

它会去调用StartupAction中的run方法，进而调用doRun()方法，这里又做了很多事情：

（1）它在控制台打印出产品版本信息：

// Print release information

System.out.println("Starting " + ReleaseInfo.getReleaseInfo());

这个版本信息，可以从ReleaseInfo类中得到：

public static final String getReleaseInfo() {
return releaseInfo;
}
[code]static String releaseInfo =
releaseInfoPrefix + name + " " + versionDisplayName + " (" + codeName +
" / Build " + build + " / " + date + ")" + releaseInfoSuffix;

[/code]
这些常量都可以在ReleaseInfo类找到：所以控制台中显示：

Starting Liferay Portal Community Edition 6.1.0 CE (Paton / Build 6100 / January 6, 2012)

（2）清空锁信息：

try {
LockLocalServiceUtil.clear();
}

它会调用LockLocalServiceUtil中的clear()方法：

public static void clear()
throws com.liferay.portal.kernel.exception.SystemException {
getService().clear();
}

进而调用LockLocalServiceImpl类中的clear()方法：

public void clear() throws SystemException {
lockPersistence.removeByLtExpirationDate(new Date());
}

进而调用LocalPersistenceImpl类的removeByLtExpirationDate方法：

/**
* Removes all the locks where expirationDate < ? from the database.
*
* @param expirationDate the expiration date
* @throws SystemException if a system exception occurred
*/
public void removeByLtExpirationDate(Date expirationDate)
throws SystemException {
for (Lock lock : findByLtExpirationDate(expirationDate)) {
remove(lock);
}
}

它会从数据库中移除所有到期的锁，以当前日期为标准，下面就不展开了。

（3）关闭所有的hook:

它让当前应用的运行时去关闭所有的Hook：

Runtime runtime = Runtime.getRuntime();

runtime.addShutdownHook(new Thread(new ShutdownHook()));

每个Hook都开启一个新的Thread来关闭，它实现Runnable接口,仅仅做一些打印工作：

public class ShutdownHook implements Runnable {

public void run() {
if (GetterUtil.getBoolean(
System.getProperty("shutdown.hook.print.full.thread.dump"))) {

printFullThreadDump();
}
}
...

而这些hook都会添加到Liferay应用的运行时中，运行时会先检查是否有shutdown hook的权限，然后再做shutdown hook的事情：

public void addShutdownHook(Thread hook) {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
sm.checkPermission(new RuntimePermission("shutdownHooks"));
}
ApplicationShutdownHooks.add(hook);
}

递归找下去，会发现这个permission定义在%LIFERAY_HOME%/tomcat-7.0.23/conf/catalina.policy中，所以我们拥有这个权限：

...
permission java.io.FilePermission
"${catalina.base}${file.separator}logs${file.separator}*", "read, write";

permission java.lang.RuntimePermission "shutdownHooks";
permission java.lang.RuntimePermission "getClassLoader";
permission java.lang.RuntimePermission "setContextClassLoader";
...

之后，就把hook添加到ApplicationShutdownHooks的hashmap中来关闭：

static {
Shutdown.add(1 /* shutdown hook invocation order */,
new Runnable() {
public void run() {
runHooks();
}
});
}

（4）配置Security Manager

// Security manager

String portalSecurityManagerStrategy =
PropsValues.PORTAL_SECURITY_MANAGER_STRATEGY;

if (portalSecurityManagerStrategy.equals("smart")) {
if (ServerDetector.isWebSphere()) {
portalSecurityManagerStrategy = "none";
}
else {
portalSecurityManagerStrategy = "default";
}
}

if (portalSecurityManagerStrategy.equals("liferay")) {
if (System.getSecurityManager() == null) {
System.setSecurityManager(new PortalSecurityManager());
}
}
else if (portalSecurityManagerStrategy.equals("none")) {
System.setSecurityManager(null);
}

它会先检查SecurityManager的策略：

public static final String PORTAL_SECURITY_MANAGER_STRATEGY = PropsUtil.get(PropsKeys.PORTAL_SECURITY_MANAGER_STRATEGY);

它的key来自PropsKeys接口：

public static final String PORTAL_SECURITY_MANAGER_STRATEGY = "portal.security.manager.strategy";

最终我们去访问portal.properties可以看到：

##
## Security Manager
##

#
# Set this property to "default" to use the default security manager
# configured by the application server. A security manager will not be used
# if the application server did not configure one.
#
# Set this property to "liferay" to use Liferay's security manager if the
# application server has not configured a security manager.
#
# Set this property to "none" to explicitly remove the security manager
# regardless of whether one is configured. This ensures that the portal is
# run in a JVM without a security manager.
#
# Set this property to "smart" to allow the portal decide which strategy to
# use based on which application server it is on.
#
portal.security.manager.strategy=smart

所以，它用的是"smart"策略，所以执行下面代码：

if (portalSecurityManagerStrategy.equals("smart")) {
if (ServerDetector.isWebSphere()) {
portalSecurityManagerStrategy = "none";
}
else {
portalSecurityManagerStrategy = "default";
}
}

因为我们的Server用的是tomcat，而不是websphere,所以我们执行else代码段，也就是我们的portalSecurityManagerStrategy用的是"default",这种情况下使用tomcat应用服务器的安全策略。