Tomcat源码版本：apache-tomcat-8.5.54-src
JDK源码版本：jdk1.8.0_171
1、 启动容器；
org.apache.catalina.core.StandardHost::startInternal 启动Host
-->org.apache.catalina.core.ContainerBase::startInternal 父类启动容器
public abstract class ContainerBase extends LifecycleMBeanBase implements Container {
@Override
protected synchronized void startInternal() throws LifecycleException {
...
Container children[] = findChildren();
List<Future<Void>> results = new ArrayList<>();
for (int i = 0; i < children.length; i++) {
//使用submit方式提交Callable任务
results.add(startStopExecutor.submit(new StartChild(children[i])));//[] StandardHost启动时还没有子容器
}
MultiThrowable multiThrowable = null;
for (Future<Void> result : results) {
try {
result.get();//异步启动
} catch (Throwable e) {
log.error(sm.getString("containerBase.threadedStartFailed"), e);
if (multiThrowable == null) {
multiThrowable = new MultiThrowable();
}
multiThrowable.add(e);
}
}
if (multiThrowable != null) {
throw new LifecycleException(sm.getString("containerBase.threadedStartFailed"),multiThrowable.getThrowable());
}
//启动管道任务
if (pipeline instanceof Lifecycle) {
((Lifecycle) pipeline).start();//q
}
//修改状态 触发监听事件
setState(LifecycleState.STARTING);
....
}
private static class StartChild implements Callable<Void> {
private Container child;
public StartChild(Container child) {
this.child = child;
}
@Override
public Void call() throws LifecycleException {
child.start();//生命周期-启动
return null;
}
}
......
}
public abstract class LifecycleBase implements Lifecycle {
protected synchronized void setState(LifecycleState state) throws LifecycleException {
setStateInternal(state, null, true);
}
private synchronized void setStateInternal(LifecycleState state, Object data, boolean check)
throws LifecycleException {
.....
this.state = state;
String lifecycleEvent = state.getLifecycleEvent();
if (lifecycleEvent != null) {
fireLifecycleEvent(lifecycleEvent, data);
}
}
protected void fireLifecycleEvent(String type, Object data) {
LifecycleEvent event = new LifecycleEvent(this, type, data);
for (LifecycleListener listener : lifecycleListeners) {
listener.lifecycleEvent(event);//org.apache.catalina.startup.HostConfig
}
}
}
2、 启动监听HostConfig；
org.apache.catalina.startup.HostConfig::start
public class HostConfig implements LifecycleListener {
public void lifecycleEvent(LifecycleEvent event) {
// Identify the host we are associated with
try {
host = (Host) event.getLifecycle();
if (host instanceof StandardHost) {
setCopyXML(((StandardHost) host).isCopyXML());
setDeployXML(((StandardHost) host).isDeployXML());
setUnpackWARs(((StandardHost) host).isUnpackWARs());
setContextClass(((StandardHost) host).getContextClass());
}
} catch (ClassCastException e) {
log.error(sm.getString("hostConfig.cce", event.getLifecycle()), e);
return;
}
// Process the event that has occurred
if (event.getType().equals(Lifecycle.PERIODIC_EVENT)) {
check();
} else if (event.getType().equals(Lifecycle.BEFORE_START_EVENT)) {
beforeStart();
} else if (event.getType().equals(Lifecycle.START_EVENT)) {
start();//启动应用
} else if (event.getType().equals(Lifecycle.STOP_EVENT)) {
stop();
}
}
//启动部署应用
public void start() {
.....
if (host.getDeployOnStartup())
deployApps();
}
//部署三种类型应用
protected void deployApps() {
File appBase = host.getAppBaseFile();
File configBase = host.getConfigBaseFile();
String[] filteredAppPaths = filterAppPaths(appBase.list());
// Deploy XML descriptors from configBase
deployDescriptors(configBase, configBase.list());
// Deploy WARs
deployWARs(appBase, filteredAppPaths);
// Deploy expanded folders
deployDirectories(appBase, filteredAppPaths);
}
//发布XML描述符
protected void deployDescriptors(File configBase, String[] files) {
if (files == null)
return;
ExecutorService es = host.getStartStopExecutor();
List<Future<?>> results = new ArrayList<>();
for (int i = 0; i < files.length; i++) {
File contextXml = new File(configBase, files[i]);
if (files[i].toLowerCase(Locale.ENGLISH).endsWith(".xml")) {
ContextName cn = new ContextName(files[i], true);
if (isServiced(cn.getName()) || deploymentExists(cn.getName()))
continue;
results.add(es.submit(new DeployDescriptor(this, cn, contextXml)));
}
}
for (Future<?> result : results) {
try {
result.get();
} catch (Exception e) {
log.error(sm.getString("hostConfig.deployDescriptor.threaded.error"), e);
}
}
}
//发布XML描述符
protected void deployDescriptor(ContextName cn, File contextXml) {
DeployedApplication deployedApp = new DeployedApplication(cn.getName(), true);
long startTime = 0;
if(log.isInfoEnabled()) {
startTime = System.currentTimeMillis();
log.info(sm.getString("hostConfig.deployDescriptor",
contextXml.getAbsolutePath()));
}
Context context = null;
boolean isExternalWar = false;
boolean isExternal = false;
File expandedDocBase = null;
try (FileInputStream fis = new FileInputStream(contextXml)) {
synchronized (digesterLock) {
try {
context = (Context) digester.parse(fis);
} catch (Exception e) {
log.error(sm.getString(
"hostConfig.deployDescriptor.error",
contextXml.getAbsolutePath()), e);
} finally {
digester.reset();
if (context == null) {
context = new FailedContext();
}
}
}
Class<?> clazz = Class.forName(host.getConfigClass());
LifecycleListener listener = (LifecycleListener) clazz.getConstructor().newInstance();
context.addLifecycleListener(listener);
context.setConfigFile(contextXml.toURI().toURL());
context.setName(cn.getName());
context.setPath(cn.getPath());
context.setWebappVersion(cn.getVersion());
if (context.getDocBase() != null) {
File docBase = new File(context.getDocBase());
if (!docBase.isAbsolute()) {
docBase = new File(host.getAppBaseFile(), context.getDocBase());
}
// If external docBase, register .xml as redeploy first
if (!docBase.getCanonicalPath().startsWith(
host.getAppBaseFile().getAbsolutePath() + File.separator)) {
isExternal = true;
deployedApp.redeployResources.put(
contextXml.getAbsolutePath(),
Long.valueOf(contextXml.lastModified()));
deployedApp.redeployResources.put(docBase.getAbsolutePath(),
Long.valueOf(docBase.lastModified()));
if (docBase.getAbsolutePath().toLowerCase(Locale.ENGLISH).endsWith(".war")) {
isExternalWar = true;
}
} else {
log.warn(sm.getString("hostConfig.deployDescriptor.localDocBaseSpecified",docBase));
context.setDocBase(null);
}
}
host.addChild(context);
} catch (Throwable t) {
ExceptionUtils.handleThrowable(t);
log.error(sm.getString("hostConfig.deployDescriptor.error",contextXml.getAbsolutePath()), t);
} finally {
expandedDocBase = new File(host.getAppBaseFile(), cn.getBaseName());
if (context.getDocBase() != null
&& !context.getDocBase().toLowerCase(Locale.ENGLISH).endsWith(".war")) {
expandedDocBase = new File(context.getDocBase());
if (!expandedDocBase.isAbsolute()) {
expandedDocBase = new File(host.getAppBaseFile(), context.getDocBase());
}
}
boolean unpackWAR = unpackWARs;
if (unpackWAR && context instanceof StandardContext) {
unpackWAR = ((StandardContext) context).getUnpackWAR();
}
if (isExternalWar) {
if (unpackWAR) {
deployedApp.redeployResources.put(expandedDocBase.getAbsolutePath(),
Long.valueOf(expandedDocBase.lastModified()));
addWatchedResources(deployedApp, expandedDocBase.getAbsolutePath(), context);
} else {
addWatchedResources(deployedApp, null, context);
}
} else {
if (!isExternal) {
File warDocBase = new File(expandedDocBase.getAbsolutePath() + ".war");
if (warDocBase.exists()) {
deployedApp.redeployResources.put(warDocBase.getAbsolutePath(),
Long.valueOf(warDocBase.lastModified()));
} else {
deployedApp.redeployResources.put(
warDocBase.getAbsolutePath(),
Long.valueOf(0));
}
}
if (unpackWAR) {
deployedApp.redeployResources.put(expandedDocBase.getAbsolutePath(),
Long.valueOf(expandedDocBase.lastModified()));
addWatchedResources(deployedApp,
expandedDocBase.getAbsolutePath(), context);
} else {
addWatchedResources(deployedApp, null, context);
}
if (!isExternal) {
deployedApp.redeployResources.put(
contextXml.getAbsolutePath(),
Long.valueOf(contextXml.lastModified()));
}
}
addGlobalRedeployResources(deployedApp);
}
if (host.findChild(context.getName()) != null) {
deployed.put(context.getName(), deployedApp);
}
if (log.isInfoEnabled()) {
log.info(sm.getString("hostConfig.deployDescriptor.finished",
contextXml.getAbsolutePath(), Long.valueOf(System.currentTimeMillis() - startTime)));
}
}
//发布war包
protected void deployWARs(File appBase, String[] files) {
if (files == null)
return;
ExecutorService es = host.getStartStopExecutor();
List<Future<?>> results = new ArrayList<>();
for (int i = 0; i < files.length; i++) {
if (files[i].equalsIgnoreCase("META-INF"))
continue;
if (files[i].equalsIgnoreCase("WEB-INF"))
continue;
File war = new File(appBase, files[i]);
if (files[i].toLowerCase(Locale.ENGLISH).endsWith(".war") &&
war.isFile() && !invalidWars.contains(files[i]) ) {
ContextName cn = new ContextName(files[i], true);
if (isServiced(cn.getName())) {
continue;
}
if (deploymentExists(cn.getName())) {
DeployedApplication app = deployed.get(cn.getName());
boolean unpackWAR = unpackWARs;
if (unpackWAR && host.findChild(cn.getName()) instanceof StandardContext) {
unpackWAR = ((StandardContext) host.findChild(cn.getName())).getUnpackWAR();
}
if (!unpackWAR && app != null) {
File dir = new File(appBase, cn.getBaseName());
if (dir.exists()) {
if (!app.loggedDirWarning) {
log.warn(sm.getString(
"hostConfig.deployWar.hiddenDir",
dir.getAbsoluteFile(),
war.getAbsoluteFile()));
app.loggedDirWarning = true;
}
} else {
app.loggedDirWarning = false;
}
}
continue;
}
if (!validateContextPath(appBase, cn.getBaseName())) {
log.error(sm.getString(
"hostConfig.illegalWarName", files[i]));
invalidWars.add(files[i]);
continue;
}
results.add(es.submit(new DeployWar(this, cn, war)));
}
}
for (Future<?> result : results) {
try {
result.get();
} catch (Exception e) {
log.error(sm.getString(
"hostConfig.deployWar.threaded.error"), e);
}
}
}
}