前言
上一章解析了startup.bat脚本，了解tomcat启动时实际触发的是catalina.bat 。本文章向大家介绍解析Tomcat的启动脚本catalina.bat
第一段代码
rem Suppress Terminate batch job on CTRL+C
if not ""%1"" == ""run"" goto mainEntry
if "%TEMP%" == "" goto mainEntry
if exist "%TEMP%\%~nx0.run" goto mainEntry
echo Y>"%TEMP%\%~nx0.run"
if not exist "%TEMP%\%~nx0.run" goto mainEntry
echo Y>"%TEMP%\%~nx0.Y"
call "%~f0" %* <"%TEMP%\%~nx0.Y"
rem Use provided errorlevel
set RETVAL=%ERRORLEVEL%
del Q "%TEMP%\%~nx0.Y" >NUL 2>&1
exit B %RETVAL%
:mainEntry
del Q "%TEMP%\%~nx0.run" >NUL 2>&1
判断用户是否使用catalina.bat run来启动 Tomcat 的，如果用户使用 startup.bat 脚本启动 Tomcat, 那么这段脚本不会被执行。
if not ""%1"" == ""run"" goto mainEntry
"%1"代表调用时第一个参数，正常情况下使用 startup.bat 启动，"%1"=start。如果用户通过catalina.bat，"%1"=run。
if "%TEMP%" == "" goto mainEntry
"%TEMP%"：环境变量值,在cmd命令模式下输入echo %TEMP%"会输出“C:\Users\ADMINI~1\AppData\Local\Temp”，是一个隐藏目录。
if exist "%TEMP%\%~nx0.run" goto mainEntry
~nx0.run：程序的名称+扩展名 ，%0表示可执行程序的名称
判断是否存在“%TEMP%/catalina.bat”
echo Y>"%TEMP%\%~nx0.run"
当“%TEMP%/catalina.bat”不存在时，写入字符 Y 到 %TEMP%\catalina.bat.run
再次判断“%TEMP%/catalina.bat”是否存在，不存在时，写入字符 Y 到 %TEMP%\catalina.bat.Y
call "%~f0" %* <"%TEMP%\%~nx0.Y"
%~f0：表示运行的文件的全路径
%*：表示所有参数
则此行含义为读取%TEMP%\catalina.bat.Y的内容作为参数放到catalina.bat 命令最后
set RETVAL=%ERRORLEVEL%
Linux 中每个命令的执行都会返回一个执行完成之后的退出码.。Linux执行完一条命令之后用 echo $?来查看上一条命令的退出码。在 Windows 命令执行完之后也有自己的退出码.。这里的 %ERRORLEVEL%就是取的上面的 call 命令的退出码 。
del Q "%TEMP%\%~nx0.Y" >NUL 2>&1
①/Q "%TEMP%\%~nx0.Y"：静默删除%TEMP%\catalina.bat.Y
②NUL : 表示将输出重定向到 NUL 中, 你什么也看不到
③2>&1 :
2：错误输出
&1：标准输出,
意思就是将错误消息输出到标准输出中。
④NUL 2>&1 : 就是先将错误消息输出到标准输出中, 然后再输出到 NUL 中.
exit B %RETVAL%
程序退出，/B 输出退出码。即RETVAL
最后删除临时目录中的 catalina.bat.run 。
此段代码作用：判断临时目录中的文件是否存catalina.bat来避免二次回调自己
第二段代码
rem Guess CATALINA_HOME if not defined
set "CURRENT_DIR=%cd%"
if not "%CATALINA_HOME%" == "" goto gotHome
set "CATALINA_HOME=%CURRENT_DIR%"
if exist "%CATALINA_HOME%\bin\catalina.bat" goto okHome
cd ..
set "CATALINA_HOME=%cd%"
cd "%CURRENT_DIR%"
:gotHome
if exist "%CATALINA_HOME%\bin\catalina.bat" goto okHome
echo The CATALINA_HOME environment variable is not defined correctly
echo This environment variable is needed to run this program
goto end
:okHome
rem Copy CATALINA_BASE from CATALINA_HOME if not defined
if not "%CATALINA_BASE%" == "" goto gotBase
set "CATALINA_BASE=%CATALINA_HOME%"
:gotBase
此段代码主要是设置了两个环境变量 CATALINA_HOME 和 CATALINA_BASE ，如果没有配置 CATALINA_BASE 环境变量的话, 直接引用 CATALINA_HOME 的值
第三段代码
rem Ensure that neither CATALINA_HOME nor CATALINA_BASE contains a semi-colon
rem as this is used as the separator in the classpath and Java provides no
rem mechanism for escaping if the same character appears in the path. Check this
rem by replacing all occurrences of ';' with '' and checking that neither
rem CATALINA_HOME nor CATALINA_BASE have changed
if "%CATALINA_HOME%" == "%CATALINA_HOME:;=%" goto homeNoSemicolon
echo Using CATALINA_HOME: "%CATALINA_HOME%"
echo Unable to start as CATALINA_HOME contains a semicolon (;) character
goto end
:homeNoSemicolon
if "%CATALINA_BASE%" == "%CATALINA_BASE:;=%" goto baseNoSemicolon
echo Using CATALINA_BASE: "%CATALINA_BASE%"
echo Unable to start as CATALINA_BASE contains a semicolon (;) character
goto end
:baseNoSemicolon
判断 CATALINA_HOME 环境变量的值 和 CATALINA_BASE 环境变量的值是否以 分号为结尾, 如果以 分号为结尾的话, 就报错退出。
第四段代码
rem Ensure that any user defined CLASSPATH variables are not used on startup,
rem but allow them to be specified in setenv.bat, in rare case when it is needed.
set CLASSPATH=
rem Get standard environment variables
if not exist "%CATALINA_BASE%\bin\setenv.bat" goto checkSetenvHome
call "%CATALINA_BASE%\bin\setenv.bat"
goto setenvDone
:checkSetenvHome
if exist "%CATALINA_HOME%\bin\setenv.bat" call "%CATALINA_HOME%\bin\setenv.bat"
:setenvDone
rem Get standard Java environment variables
if exist "%CATALINA_HOME%\bin\setclasspath.bat" goto okSetclasspath
echo Cannot find "%CATALINA_HOME%\bin\setclasspath.bat"
echo This file is needed to run this program
goto end
:okSetclasspath
call "%CATALINA_HOME%\bin\setclasspath.bat" %1
if errorlevel 1 goto end
①设置一个临时环境变量: CLASSPATH。
②如果 Tomcat 的 bin 目录下面存在 setnv.bat 脚本的话, 就执行它。
③ 继而判断 setclasspath.bat 脚本是否存在, 如果不存在的话, 直接报错, 停止启动 Tomcat。如果存在就执行它，并传入第一个参数。
④ setclasspath.bat 设置了哪些环境变量呢？
JAVA_HOME
JRE_HOME
JAVA_ENDORSED_DIRS = %CATALINA_HOME%\endorsed：扩展库
_RUNJAVA = %JRE_HOME%\bin\java.exe：java运行环境
_RUNJDB = %JAVA_HOME%\bin\jdb.exe：调试器debug
rem Otherwise either JRE or JDK are fine
if not "%JRE_HOME%" == "" goto gotJreHome
if not "%JAVA_HOME%" == "" goto gotJavaHome
echo Neither the JAVA_HOME nor the JRE_HOME environment variable is defined
echo At least one of these environment variable is needed to run this program
goto exit
:needJavaHome
rem Check if we have a usable JDK
if "%JAVA_HOME%" == "" goto noJavaHome
if not exist "%JAVA_HOME%\bin\java.exe" goto noJavaHome
if not exist "%JAVA_HOME%\bin\jdb.exe" goto noJavaHome
if not exist "%JAVA_HOME%\bin\javac.exe" goto noJavaHome
#设置JRE_HOME
set "JRE_HOME=%JAVA_HOME%"
goto okJava
:noJavaHome
echo The JAVA_HOME environment variable is not defined correctly.
echo It is needed to run this program in debug mode.
echo NB: JAVA_HOME should point to a JDK not a JRE.
goto exit
:gotJavaHome
rem No JRE given, use JAVA_HOME as JRE_HOME
#设置JRE_HOME
set "JRE_HOME=%JAVA_HOME%"
:gotJreHome
rem Check if we have a usable JRE
if not exist "%JRE_HOME%\bin\java.exe" goto noJreHome
goto okJava
:noJreHome
rem Needed at least a JRE
echo The JRE_HOME environment variable is not defined correctly
echo This environment variable is needed to run this program
goto exit
:okJava
rem Don't override the endorsed dir if the user has set it previously
if not "%JAVA_ENDORSED_DIRS%" == "" goto gotEndorseddir
rem Java 9 no longer supports the java.endorsed.dirs
rem system property. Only try to use it if
rem CATALINA_HOME/endorsed exists.
if not exist "%CATALINA_HOME%\endorsed" goto gotEndorseddir
set "JAVA_ENDORSED_DIRS=%CATALINA_HOME%\endorsed"
:gotEndorseddir
rem Don't override _RUNJAVA if the user has set it previously
if not "%_RUNJAVA%" == "" goto gotRunJava
rem Set standard command for invoking Java.
rem Also note the quoting as JRE_HOME may contain spaces.
set _RUNJAVA="%JRE_HOME%\bin\java.exe"
:gotRunJava
#设置调试器
rem Don't override _RUNJDB if the user has set it previously
rem Also note the quoting as JAVA_HOME may contain spaces.
if not "%_RUNJDB%" == "" goto gotRunJdb
set _RUNJDB="%JAVA_HOME%\bin\jdb.exe"
:gotRunJdb
goto end
:exit
exit b 1
:end
exit b 0
第五段代码
rem Add on extra jar file to CLASSPATH
rem Note that there are no quotes as we do not want to introduce random
rem quotes into the CLASSPATH
if "%CLASSPATH%" == "" goto emptyClasspath
set "CLASSPATH=%CLASSPATH%;"
:emptyClasspath
set "CLASSPATH=%CLASSPATH%%CATALINA_HOME%\bin\bootstrap.jar"
if not "%CATALINA_TMPDIR%" == "" goto gotTmpdir
set "CATALINA_TMPDIR=%CATALINA_BASE%\temp"
:gotTmpdir
rem Add tomcat-juli.jar to classpath
rem tomcat-juli.jar can be over-ridden per instance
if not exist "%CATALINA_BASE%\bin\tomcat-juli.jar" goto juliClasspathHome
set "CLASSPATH=%CLASSPATH%;%CATALINA_BASE%\bin\tomcat-juli.jar"
goto juliClasspathDone
:juliClasspathHome
set "CLASSPATH=%CLASSPATH%;%CATALINA_HOME%\bin\tomcat-juli.jar"
:juliClasspathDone
①把 Tomcat bin 目录下的 bootstrap.jar 加入到环境变量中
②设置 CATALINA_TMPDIR 环境变量的值为 Tomcat 目录下的 temp 目录
③把 Tomcat bin 目录下的 tomcat-juli.jar 加入到环境变量中（ tomcat的日志实现 ）
第六段代码
rem Add tomcat-juli.jar to classpath
rem tomcat-juli.jar can be over-ridden per instance
if not exist "%CATALINA_BASE%\bin\tomcat-juli.jar" goto juliClasspathHome
set "CLASSPATH=%CLASSPATH%;%CATALINA_BASE%\bin\tomcat-juli.jar"
goto juliClasspathDone
:juliClasspathHome
set "CLASSPATH=%CLASSPATH%;%CATALINA_HOME%\bin\tomcat-juli.jar"
:juliClasspathDone
if not "%JSSE_OPTS%" == "" goto gotJsseOpts
set JSSE_OPTS="-Djdk.tls.ephemeralDHKeySize=2048"
:gotJsseOpts
set "JAVA_OPTS=%JAVA_OPTS% %JSSE_OPTS%"
rem Register custom URL handlers
rem Do this here so custom URL handles (specifically 'war:...') can be used in the security policy
set "JAVA_OPTS=%JAVA_OPTS% -Djava.protocol.handler.pkgs=org.apache.catalina.webresources"
if not "%LOGGING_CONFIG%" == "" goto noJuliConfig
set LOGGING_CONFIG=-Dnop
if not exist "%CATALINA_BASE%\conf\logging.properties" goto noJuliConfig
set LOGGING_CONFIG=-Djava.util.logging.config.file="%CATALINA_BASE%\conf\logging.properties"
:noJuliConfig
if not "%LOGGING_MANAGER%" == "" goto noJuliManager
set LOGGING_MANAGER=-Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
:noJuliManager
rem Configure JAVA 9 specific start-up parameters
set "JDK_JAVA_OPTIONS=%JDK_JAVA_OPTIONS% --add-opens=java.base/java.lang=ALL-UNNAMED"
set "JDK_JAVA_OPTIONS=%JDK_JAVA_OPTIONS% --add-opens=java.base/java.io=ALL-UNNAMED"
set "JDK_JAVA_OPTIONS=%JDK_JAVA_OPTIONS% --add-opens=java.rmi/sun.rmi.transport=ALL-UNNAMED"
追加启动参数到 JDK_JAVA_OPTIONS这个环境变量中。
第七段代码
set ENDORSED_PROP=ignore.endorsed.dirs
if "%JAVA_ENDORSED_DIRS%" == "" goto noEndorsedVar
set ENDORSED_PROP=java.endorsed.dirs
goto doneEndorsed
:noEndorsedVar
if not exist "%CATALINA_HOME%\endorsed" goto doneEndorsed
set ENDORSED_PROP=java.endorsed.dirs
:doneEndorsed
rem ----- Execute The Requested Command ---------------------------------------
echo Using CATALINA_BASE: "%CATALINA_BASE%"
echo Using CATALINA_HOME: "%CATALINA_HOME%"
echo Using CATALINA_TMPDIR: "%CATALINA_TMPDIR%"
if ""%1"" == ""debug"" goto use_jdk
echo Using JRE_HOME: "%JRE_HOME%"
goto java_dir_displayed
:use_jdk
echo Using JAVA_HOME: "%JAVA_HOME%"
:java_dir_displayed
echo Using CLASSPATH: "%CLASSPATH%"
set _EXECJAVA=%_RUNJAVA%
set MAINCLASS=org.apache.catalina.startup.Bootstrap
set ACTION=start
set SECURITY_POLICY_FILE=
set DEBUG_OPTS=
set JPDA=
if not ""%1"" == ""jpda"" goto noJpda
set JPDA=jpda
if not "%JPDA_TRANSPORT%" == "" goto gotJpdaTransport
set JPDA_TRANSPORT=dt_socket
:gotJpdaTransport
if not "%JPDA_ADDRESS%" == "" goto gotJpdaAddress
set JPDA_ADDRESS=localhost:8000
:gotJpdaAddress
if not "%JPDA_SUSPEND%" == "" goto gotJpdaSuspend
set JPDA_SUSPEND=n
:gotJpdaSuspend
if not "%JPDA_OPTS%" == "" goto gotJpdaOpts
set JPDA_OPTS=-agentlib:jdwp=transport=%JPDA_TRANSPORT%,address=%JPDA_ADDRESS%,server=y,suspend=%JPDA_SUSPEND%
:gotJpdaOpts
shift
:noJpda
if ""%1"" == ""debug"" goto doDebug
if ""%1"" == ""run"" goto doRun
if ""%1"" == ""start"" goto doStart
if ""%1"" == ""stop"" goto doStop
if ""%1"" == ""configtest"" goto doConfigTest
if ""%1"" == ""version"" goto doVersion
echo Usage: catalina ( commands ... )
echo commands:
echo debug Start Catalina in a debugger
echo debug -security Debug Catalina with a security manager
echo jpda start Start Catalina under JPDA debugger
echo run Start Catalina in the current window
echo run -security Start in the current window with security manager
echo start Start Catalina in a separate window
echo start -security Start in a separate window with security manager
echo stop Stop Catalina
echo configtest Run a basic syntax check on server.xml
echo version What version of tomcat are you running?
goto end
:doDebug
shift
set _EXECJAVA=%_RUNJDB%
set DEBUG_OPTS=-sourcepath "%CATALINA_HOME%\..\..\java"
if not ""%1"" == ""-security"" goto execCmd
shift
echo Using Security Manager
set "SECURITY_POLICY_FILE=%CATALINA_BASE%\conf\catalina.policy"
goto execCmd
:doRun
shift
if not ""%1"" == ""-security"" goto execCmd
shift
echo Using Security Manager
set "SECURITY_POLICY_FILE=%CATALINA_BASE%\conf\catalina.policy"
goto execCmd
:doStart
shift
if "%TITLE%" == "" set TITLE=Tomcat
set _EXECJAVA=start "%TITLE%" %_RUNJAVA%
if not ""%1"" == ""-security"" goto execCmd
shift
echo Using Security Manager
set "SECURITY_POLICY_FILE=%CATALINA_BASE%\conf\catalina.policy"
goto execCmd
:doStop
shift
set ACTION=stop
set CATALINA_OPTS=
goto execCmd
:doConfigTest
shift
set ACTION=configtest
set CATALINA_OPTS=
goto execCmd
:doVersion
设置环境变量：
_RUNJAVA : %JRE_HOME%\bin\java.exe
MAINCLASS : 指定了 Tomcat 的启动类, main 方法就是在这个类里面。
ACTION : 动作为启动
SECURITY_POLICY_FILE : 安全策略文件, 如果启动的时候加上了 -security 参数的话, 下面会对这个参数指定到 Tomcat 的 conf 目录下的 catalina.policy 文件.
JPDA : 启用远程调试功能
如果我们用 startup.bat 启动 Tomcat 的话, 这里的 "%1" 的值是 start
如果通过 catalina.bat run 启动 Tomcat 的话, 这里的 "%1" 的值是 run
start与run的区别：“if "%TITLE%" == "" set TITLE=Tomcat”
如果是 startup.bat 脚本启动的话, 会启动一个新的 cmd 窗口, 并且把 cmd 的 title 设置为 Tomcat.
如果是 catalina.bat run 启动的话, 不会新建 cmd 窗口, 也不会设置 cmd 的 title.
第八段代码
:execCmd
rem Get remaining unshifted command line arguments and save them in the
set CMD_LINE_ARGS=
:setArgs
if ""%1""=="""" goto doneSetArgs
set CMD_LINE_ARGS=%CMD_LINE_ARGS% %1
shift
goto setArgs
:doneSetArgs
利用 "%1" 来取出启动命令之后的参数, 如果存的话, 追加到 CMD_LINE_ARGS 环境变量上, 并把这个参数移除。
第九段代码
rem Execute Java with the applicable properties
if not "%JPDA%" == "" goto doJpda
if not "%SECURITY_POLICY_FILE%" == "" goto doSecurity
%_EXECJAVA% %LOGGING_CONFIG% %LOGGING_MANAGER% %JAVA_OPTS% %CATALINA_OPTS% %DEBUG_OPTS% -D%ENDORSED_PROP%="%JAVA_ENDORSED_DIRS%" -classpath "%CLASSPATH%" -Dcatalina.base="%CATALINA_BASE%" -Dcatalina.home="%CATALINA_HOME%" -Djava.io.tmpdir="%CATALINA_TMPDIR%" %MAINCLASS% %CMD_LINE_ARGS% %ACTION%
goto end
:doSecurity
%_EXECJAVA% %LOGGING_CONFIG% %LOGGING_MANAGER% %JAVA_OPTS% %CATALINA_OPTS% %DEBUG_OPTS% -D%ENDORSED_PROP%="%JAVA_ENDORSED_DIRS%" -classpath "%CLASSPATH%" -Djava.security.manager -Djava.security.policy=="%SECURITY_POLICY_FILE%" -Dcatalina.base="%CATALINA_BASE%" -Dcatalina.home="%CATALINA_HOME%" -Djava.io.tmpdir="%CATALINA_TMPDIR%" %MAINCLASS% %CMD_LINE_ARGS% %ACTION%
goto end
:doJpda
if not "%SECURITY_POLICY_FILE%" == "" goto doSecurityJpda
%_EXECJAVA% %LOGGING_CONFIG% %LOGGING_MANAGER% %JAVA_OPTS% %JPDA_OPTS% %CATALINA_OPTS% %DEBUG_OPTS% -D%ENDORSED_PROP%="%JAVA_ENDORSED_DIRS%" -classpath "%CLASSPATH%" -Dcatalina.base="%CATALINA_BASE%" -Dcatalina.home="%CATALINA_HOME%" -Djava.io.tmpdir="%CATALINA_TMPDIR%" %MAINCLASS% %CMD_LINE_ARGS% %ACTION%
goto end
:doSecurityJpda
#启动tomcat
%_EXECJAVA% %LOGGING_CONFIG% %LOGGING_MANAGER% %JAVA_OPTS% %JPDA_OPTS% %CATALINA_OPTS% %DEBUG_OPTS% -D%ENDORSED_PROP%="%JAVA_ENDORSED_DIRS%" -classpath "%CLASSPATH%" -Djava.security.manager -Djava.security.policy=="%SECURITY_POLICY_FILE%" -Dcatalina.base="%CATALINA_BASE%" -Dcatalina.home="%CATALINA_HOME%" -Djava.io.tmpdir="%CATALINA_TMPDIR%" %MAINCLASS% %CMD_LINE_ARGS% %ACTION%
goto end
:end
启动代码，我的如下
D:\Program Files\Java\jdk1.8.0_172\bin\java.exe -Djava.util.logging.config.file=D:\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 -Dignore.endorsed.dirs= -classpath D:\apache-tomcat-8.5.32\bin\bootstrap.jar;D:\apache-tomcat-8.5.32\bin\tomcat-juli.jar -Djava.security.manager -Djava.security.policy== -Dcatalina.base=D:\apache-tomcat-8.5.32 -Dcatalina.home=D:\apache-tomcat-8.5.32 -Djava.io.tmpdir=D:\apache-tomcat-8.5.32\temp org.apache.catalina.startup.Bootstrap start
