启动脚本

startup.sh

一般是用$CATALINA_HOME/bin/startup.sh脚本启动:

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➜  bin  cat startup.sh
#!/bin/sh

# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# -----------------------------------------------------------------------------
# Start Script for the CATALINA Server
# -----------------------------------------------------------------------------

# Better OS/400 detection: see Bugzilla 31132
os400=false
case "`uname`" in
OS400*) os400=true;;
esac

# resolve links - $0 may be a softlink
PRG="$0"

while [ -h "$PRG" ] ; do
ls=`ls -ld "$PRG"`
link=`expr "$ls" : '.*-> \(.*\)$'`
if expr "$link" : '/.*' > /dev/null; then
PRG="$link"
else
PRG=`dirname "$PRG"`/"$link"
fi
done

PRGDIR=`dirname "$PRG"`
EXECUTABLE=catalina.sh

# Check that target executable exists
if $os400; then
# -x will Only work on the os400 if the files are:
# 1. owned by the user
# 2. owned by the PRIMARY group of the user
# this will not work if the user belongs in secondary groups
eval
else
if [ ! -x "$PRGDIR"/"$EXECUTABLE" ]; then
echo "Cannot find $PRGDIR/$EXECUTABLE"
echo "The file is absent or does not have execute permission"
echo "This file is needed to run this program"
exit 1
fi
fi

exec "$PRGDIR"/"$EXECUTABLE" start "$@"

这个脚本最终调用的是catalina.sh,传入的参数是start和我们的命令行参数

这个脚本除了start,还有其他的命令,相当于其他脚本的一个入口:

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➜  bin  catalina.sh
Using CATALINA_BASE: /Users/qishengli/software/apache-tomcat-8.5.32
Using CATALINA_HOME: /Users/qishengli/software/apache-tomcat-8.5.32
Using CATALINA_TMPDIR: /Users/qishengli/software/apache-tomcat-8.5.32/temp
Using JRE_HOME: /Users/qishengli/software/jdk8/jre
Using CLASSPATH: /Users/qishengli/software/apache-tomcat-8.5.32/bin/bootstrap.jar:/Users/qishengli/software/apache-tomcat-8.5.32/bin/tomcat-juli.jar
Usage: catalina.sh ( commands ... )
commands:
debug Start Catalina in a debugger
debug -security Debug Catalina with a security manager
jpda start Start Catalina under JPDA debugger
run Start Catalina in the current window
run -security Start in the current window with security manager
start Start Catalina in a separate window
start -security Start in a separate window with security manager
stop Stop Catalina, waiting up to 5 seconds for the process to end
stop n Stop Catalina, waiting up to n seconds for the process to end
stop -force Stop Catalina, wait up to 5 seconds and then use kill -KILL if still running
stop n -force Stop Catalina, wait up to n seconds and then use kill -KILL if still running
configtest Run a basic syntax check on server.xml - check exit code for result
version What version of tomcat are you running?
Note: Waiting for the process to end and use of the -force option require that $CATALINA_PID is defined

比如version:

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➜  bin  catalina.sh version
Using CATALINA_BASE: /Users/qishengli/software/apache-tomcat-8.5.32
Using CATALINA_HOME: /Users/qishengli/software/apache-tomcat-8.5.32
Using CATALINA_TMPDIR: /Users/qishengli/software/apache-tomcat-8.5.32/temp
Using JRE_HOME: /Users/qishengli/software/jdk8/jre
Using CLASSPATH: /Users/qishengli/software/apache-tomcat-8.5.32/bin/bootstrap.jar:/Users/qishengli/software/apache-tomcat-8.5.32/bin/tomcat-juli.jar
Server version: Apache Tomcat/8.5.32
Server built: Jun 20 2018 19:50:35 UTC
Server number: 8.5.32.0
OS Name: Mac OS X
OS Version: 11.6
Architecture: aarch64
JVM Version: 1.8.0_282-b08
JVM Vendor: Azul Systems, Inc.

看一下start对应的源码部分:

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elif [ "$1" = "start" ] ; then

# CATALINA_PID的处理逻辑,此处省略
shift
touch "$CATALINA_OUT"
if [ "$1" = "-security" ] ; then
if [ $have_tty -eq 1 ]; then
echo "Using Security Manager"
fi
shift
eval $_NOHUP "\"$_RUNJAVA\"" "\"$LOGGING_CONFIG\"" $LOGGING_MANAGER $JAVA_OPTS $CATALINA_OPTS \
-D$ENDORSED_PROP="\"$JAVA_ENDORSED_DIRS\"" \
-classpath "\"$CLASSPATH\"" \
-Djava.security.manager \
-Djava.security.policy=="\"$CATALINA_BASE/conf/catalina.policy\"" \
-Dcatalina.base="\"$CATALINA_BASE\"" \
-Dcatalina.home="\"$CATALINA_HOME\"" \
-Djava.io.tmpdir="\"$CATALINA_TMPDIR\"" \
org.apache.catalina.startup.Bootstrap "$@" start \
>> "$CATALINA_OUT" 2>&1 "&"

else
eval $_NOHUP "\"$_RUNJAVA\"" "\"$LOGGING_CONFIG\"" $LOGGING_MANAGER $JAVA_OPTS $CATALINA_OPTS \
-D$ENDORSED_PROP="\"$JAVA_ENDORSED_DIRS\"" \
-classpath "\"$CLASSPATH\"" \
-Dcatalina.base="\"$CATALINA_BASE\"" \
-Dcatalina.home="\"$CATALINA_HOME\"" \
-Djava.io.tmpdir="\"$CATALINA_TMPDIR\"" \
org.apache.catalina.startup.Bootstrap "$@" start \
>> "$CATALINA_OUT" 2>&1 "&"

fi

if [ ! -z "$CATALINA_PID" ]; then
echo $! > "$CATALINA_PID"
fi

echo "Tomcat started."

基本上就是把之前detect到的各种环境变量当做参数,传递给java命令,这个脚本里默认会执行bin/setenv.sh,所以一般会在这个文件中设置tomcat的环境变量,比如本机的设置:

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➜  bin  cat setenv.sh
export CATALINA_OPTS="-agentpath:/Users/qishengli/Downloads/async-profiler-2.5-macos/build/libasyncProfiler.so=start,event=cpu,interval=1ms,file=profile.html -Djava.rmi.server.logCalls=true -Dsun.rmi.server.logLevel=debug"

对应的脚本位置:

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➜  bin  grep -n  setenv catalina.sh
24:# setenv.sh in CATALINA_BASE/bin to keep your customizations separate.
145:# but allow them to be specified in setenv.sh, in rare case when it is needed.
148:if [ -r "$CATALINA_BASE/bin/setenv.sh" ]; then
149: . "$CATALINA_BASE/bin/setenv.sh"
150:elif [ -r "$CATALINA_HOME/bin/setenv.sh" ]; then
151: . "$CATALINA_HOME/bin/setenv.sh"

最终我们能拿到的命令形式:

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"/Users/qishengli/software/jdk8/jre/bin/java" "-Djava.util.logging.config.file=/Users/qishengli/software/apache-tomcat-8.5.32/conf/logging.properties" -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djdk.tls.ephemeralDHKeySize=2048 -Djava.protocol.handler.pkgs=org.apache.catalina.webresources -Dorg.apache.catalina.security.SecurityListener.UMASK=0027 -agentpath:/Users/qishengli/Downloads/async-profiler-2.5-macos/build/libasyncProfiler.so=start,event=cpu,interval=1ms,file=profile.html -Djava.rmi.server.logCalls=true -Dsun.rmi.server.logLevel=debug -Dignore.endorsed.dirs="" -classpath "/Users/qishengli/software/apache-tomcat-8.5.32/bin/bootstrap.jar:/Users/qishengli/software/apache-tomcat-8.5.32/bin/tomcat-juli.jar" -Dcatalina.base="/Users/qishengli/software/apache-tomcat-8.5.32" -Dcatalina.home="/Users/qishengli/software/apache-tomcat-8.5.32" -Djava.io.tmpdir="/Users/qishengli/software/apache-tomcat-8.5.32/temp" org.apache.catalina.startup.Bootstrap start &

最后终于到了对应的java代码org.apache.catalina.startup.Bootstrap start

idea

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/Users/qishengli/software/apache-tomcat-8.5.32/bin/catalina.sh run
NOTE: Picked up JDK_JAVA_OPTIONS: --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.io=ALL-UNNAMED --add-opens=java.rmi/sun.rmi.transport=ALL-UNNAMED
-Dcatalina.base=/Users/qishengli/Library/Caches/JetBrains/IntelliJIdea2021.2/tomcat/15632928-a384-44e8-ba78-fe9ca3f37059
[2021-10-31 05:19:05,458] Artifact web:war exploded: Waiting for server connection to start artifact deployment...

直接调用的catalina.sh的run命令

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376 elif [ "$1" = "run" ]; then
377
378 shift
379 if [ "$1" = "-security" ] ; then
380 if [ $have_tty -eq 1 ]; then
381 echo "Using Security Manager"
382 fi
383 shift
384 eval exec "\"$_RUNJAVA\"" "\"$LOGGING_CONFIG\"" $LOGGING_MANAGER $JAVA_OPTS $CATALINA_OPTS \
385 -D$ENDORSED_PROP="\"$JAVA_ENDORSED_DIRS\"" \
386 -classpath "\"$CLASSPATH\"" \
387 -Djava.security.manager \
388 -Djava.security.policy=="\"$CATALINA_BASE/conf/catalina.policy\"" \
389 -Dcatalina.base="\"$CATALINA_BASE\"" \
390 -Dcatalina.home="\"$CATALINA_HOME\"" \
391 -Djava.io.tmpdir="\"$CATALINA_TMPDIR\"" \
392 org.apache.catalina.startup.Bootstrap "$@" start
393 else
394 eval exec "\"$_RUNJAVA\"" "\"$LOGGING_CONFIG\"" $LOGGING_MANAGER $JAVA_OPTS $CATALINA_OPTS \
395 -D$ENDORSED_PROP="\"$JAVA_ENDORSED_DIRS\"" \
396 -classpath "\"$CLASSPATH\"" \
397 -Dcatalina.base="\"$CATALINA_BASE\"" \
398 -Dcatalina.home="\"$CATALINA_HOME\"" \
399 -Djava.io.tmpdir="\"$CATALINA_TMPDIR\"" \
400 org.apache.catalina.startup.Bootstrap "$@" start
401 fi

跟脚本里启动相比,这里有两点不同:

  • 没有创建PID文件

  • 使用的是eval exec,而不是eval

  • 通过-Dcatalina.base=xxx,指定了catalina.base的位置为idea自定义的目录(tomcat 默认读取catalina.base下的web.xml)

catalina.sh run starts tomcat in the foreground, displaying the logs on the console that you started it. Hitting Ctrl-C will terminate tomcat.

startup.sh will start tomcat in the background. You’ll have to tail -f logs/catalina.out to see the logs.

Both will do the same things, apart from the foreground/background distinction.

后续的流程就到了java代码里

Java代码中的启动流程

Bootstrap

The purpose of this roundabout approach is to keep the Catalina internal classes (and any
other classes they depend on, such as an XML parser) out of the system
class path and therefore not visible to application level classes.

bootstrap只是一张皮,先初始化了org.apache.catalina.startup.Catalina,然后调用其start方法。这么做的原因,注释中也给出了解释——防止tomcat的内部类被应用层感知(不在class path中,class path中只引入两个jar包,一个叫/bin/bootstrap.jar,一个叫/tomcat-juli.jar,其他的内部的jar包都在lib目录中,这部分是不在class path中的)。

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// org.apache.catalina.startup.Bootstrap#start
/**
* Start the Catalina daemon.
* @throws Exception Fatal start error
*/
public void start()
throws Exception {
if( catalinaDaemon==null ) init();

Method method = catalinaDaemon.getClass().getMethod("start", (Class [] )null);
method.invoke(catalinaDaemon, (Object [])null);

}

初始化的时候,会初始化三个类加载器commonLoadercatalinaLoadersharedLoader。这三个类加载器本质上都是URLClassLoader,只是负责的加载的路径不同,可以在catalina.properties中配置:

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38 # List of comma-separated paths defining the contents of the "common"
39 # classloader.
53 common.loader="${catalina.base}/lib","${catalina.base}/lib/*.jar","${catalina.home}/lib","${catalina.home}/lib/*.jar"

56 # List of comma-separated paths defining the contents of the "server"
57 # classloader.
71 server.loader=

73 #
74 # List of comma-separated paths defining the contents of the "shared"
75 # classloader.
90 shared.loader=

这部分涉及到tomcat的类加载机制,会单独写一篇解析的文章,可以暂且跳过。

接力棒转交到Catalina之后,就涉及到配置文件的解析、tomcat的各个组件的启动了,会在第二篇中接着讲。

idea tomcat configuration 启动

从火焰图中看,Servlet是在RMI的线程中加载的:

debug,获取对应的socket信息

可以看出这个RMI调用是idea发起的,server是tomcat

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➜  conf  lsof -i:54276
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
java 28192 qishengli 84u IPv6 0x9b294f61ef653d83 0t0 TCP localhost:54268->localhost:54276 (ESTABLISHED)
idea 55040 qishengli 227u IPv4 0x9b294f61f4b22e13 0t0 TCP localhost:54276->localhost:54268 (ESTABLISHED)

查看idea此时的栈信息,可以找到对应的线程栈:

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"javaee connector" #5620 prio=4 os_prio=31 cpu=17.64ms elapsed=926.91s tid=0x000000036be2e400 nid=0x4e78b runnable  [0x000000039bbb9000]
java.lang.Thread.State: RUNNABLE
at java.net.SocketInputStream.socketRead0(java.base@11.0.12/Native Method)
at java.net.SocketInputStream.socketRead(java.base@11.0.12/SocketInputStream.java:115)
at java.net.SocketInputStream.read(java.base@11.0.12/SocketInputStream.java:168)
at java.net.SocketInputStream.read(java.base@11.0.12/SocketInputStream.java:140)
at java.io.BufferedInputStream.fill(java.base@11.0.12/BufferedInputStream.java:252)
at java.io.BufferedInputStream.read(java.base@11.0.12/BufferedInputStream.java:271)
- locked <0x0000000794f63408> (a java.io.BufferedInputStream)
at java.io.DataInputStream.readByte(java.base@11.0.12/DataInputStream.java:270)
at sun.rmi.transport.StreamRemoteCall.executeCall(java.rmi@11.0.12/StreamRemoteCall.java:240)
at sun.rmi.server.UnicastRef.invoke(java.rmi@11.0.12/UnicastRef.java:164)
at jdk.jmx.remote.internal.rmi.PRef.invoke(jdk.remoteref/Unknown Source)
at javax.management.remote.rmi.RMIConnectionImpl_Stub.invoke(java.management.rmi@11.0.12/Unknown Source)
at javax.management.remote.rmi.RMIConnector$RemoteMBeanServerConnection.invoke(java.management.rmi@11.0.12/RMIConnector.java:1021)
at com.intellij.javaee.oss.util.AbstractConnectorCommand.invokeOperation(AbstractConnectorCommand.java:139)
at org.jetbrains.idea.tomcat.admin.TomcatAdminServerBase$2.doExecute(TomcatAdminServerBase.java:159)
at org.jetbrains.idea.tomcat.admin.TomcatAdminServerBase$2.doExecute(TomcatAdminServerBase.java:155)
at com.intellij.javaee.oss.util.AbstractConnectorCommand$1.call(AbstractConnectorCommand.java:36)
at java.util.concurrent.FutureTask.run(java.base@11.0.12/FutureTask.java:264)
at java.util.concurrent.ThreadPoolExecutor.runWorker(java.base@11.0.12/ThreadPoolExecutor.java:1128)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(java.base@11.0.12/ThreadPoolExecutor.java:628)
at java.lang.Thread.run(java.base@11.0.12/Thread.java:829)

idea的社区版里没有找到这个类,用arthas 反编译org.jetbrains.idea.tomcat.admin.TomcatAdminServerBase,得到源码:

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[arthas@55040]$ jad org.jetbrains.idea.tomcat.admin.TomcatAdminServerBase$2

ClassLoader:
+-PluginClassLoader(plugin=PluginDescriptor(name=Tomcat and TomEE, id=Tomcat, descriptorPath=plugin.xml, path=/Applications/IntelliJ IDEA.app/Contents/plugins/Tomcat, version=2
12.5284.40, package=null), packagePrefix=null, instanceId=190, state=active)

Location:


/*
* Decompiled with CFR.
*
* Could not load the following classes:
* org.jetbrains.idea.tomcat.admin.TomcatJmxAdminServerBase
* org.jetbrains.idea.tomcat.admin.TomcatJmxAdminServerBase$TomcatConnectorCommandBase
*/
package org.jetbrains.idea.tomcat.admin;

import java.io.IOException;
import javax.management.JMException;
import javax.management.MBeanServerConnection;
import javax.management.ObjectName;
import org.jetbrains.idea.tomcat.admin.TomcatJmxAdminServerBase;

class TomcatAdminServerBase.2
extends TomcatJmxAdminServerBase.TomcatConnectorCommandBase<String> {
final /* synthetic */ String val$contextPath;
final /* synthetic */ String val$deploymentPath;

TomcatAdminServerBase.2(String string, String string2) {
this.val$contextPath = string;
this.val$deploymentPath = string2;
super((TomcatJmxAdminServerBase)TomcatAdminServerBase.this);
}

protected String doExecute(MBeanServerConnection connection) throws JMException, IOException {
/*159*/ return (String)TomcatAdminServerBase.2.invokeOperation((MBeanServerConnection)connection, (ObjectName)TomcatAdminServerBase.2.createObjectName((String)TomcatAdminServerBase.this.getFactoryObjectName()), (String)"createStandardContext", (Object[])new Object[]{TomcatAdminServerBase.this.getHostObjectName(), this.val$contextPath, this.val$deploymentPath});
}

protected Integer getTimeoutSeconds() {
/*167*/ return null;
}
}

Affect(row-cnt:1) cost in 2415 ms.

正是这里调用了tomcat的createStandardContext

idea为何这么做?

idea通过RMI调用tomcat的DynamicBean,可以显示的指定app的class目录,而无需放到tomcat的指定目录下:

同时,ide里对应配置的修改,也会反应到idea自己创建的web.xml上:

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➜  conf  cat  /Users/qishengli/Library/Caches/JetBrains/IntelliJIdea2021.2/tomcat/15632928-a384-44e8-ba78-fe9ca3f37059/conf/server.xml
<Server port="8005" shutdown="SHUTDOWN">
<Listener className="org.apache.catalina.startup.VersionLoggerListener" />
<Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" />
<Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" />
<Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />
<Listener className="org.apache.catalina.core.ThreadLocalLeakPreventionListener" />
<GlobalNamingResources>
<Resource name="UserDatabase" auth="Container" type="org.apache.catalina.UserDatabase" description="User database that can be updated and saved" factory="org.apache.catalina.users.MemoryUserDatabaseFactory" pathname="conf/tomcat-users.xml" />
</GlobalNamingResources>
<Service name="Catalina">
<Connector port="8087" protocol="HTTP/1.1" connectionTimeout="20000" redirectPort="8443" />
<Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />
<Engine name="Catalina" defaultHost="localhost">
<Realm className="org.apache.catalina.realm.LockOutRealm">
<Realm className="org.apache.catalina.realm.UserDatabaseRealm" resourceName="UserDatabase" />
</Realm>
<Host name="localhost" appBase="/Users/qishengli/software/apache-tomcat-8.5.32/webapps" unpackWARs="true" autoDeploy="true" deployOnStartup="false" deployIgnore="^(?!(manager)|(tomee)$).*">
<Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs" prefix="localhost_access_log" suffix=".txt" pattern="%h %l %u %t &quot;%r&quot; %s %b" />
</Host>
</Engine>
</Service>
</Server>

参考