How tomcat works 读书笔记十七 启动tomcat 下

在上一节中,我们程序的起始位置还是Bootstrap,现在我们通过bat文件来启动这个类。

在分析catalina.bat之前,我们先看看几个简单的我们能用到的dos命令。

基础知识

1 rem 注释,解释器不会执行rem开始的命令

2 pause 用于暂停正在执行的批处理文件,按任意键后继续

3 echo 在控制台显示一段文本

     如果显示变量的值需要在变量前后加% 如echo %var% 如果要输出操作系统的名字 就是 echo %os%

4 echo off 可以将命令本身隐藏 如果要连echo off 本身也要隐藏 就是@echo off

5 set 设置一个变量

可以看下面的一个例子

@echo off

echo 你好呀?

pause

set a=15

echo %a%

echo 再按就退出

echo %os%

pause



6 label 使用:标识一个标签,和goto合起来使用

7 goto 跳转到相应的label处

看下面的例子

echo start

goto end

echo 你看不到我

:end

echo endss

pause

运行上面的命令后,控制台上只会出现

start

endss



8 if 执行条件测试

有三种用法

 测试变量的值

  set var=15

 if %var%=15 echo 是15

 测试文件是否存在

 if exist c:/file.text echo 存在文件



9 not 取反

  set var=15

 if not %var%=15 echo 不是15



10 接收参数

用%1表示第一个参数 %2表示第二个 以此类推

如果有一个ss.bat里面如下

echo %1

在控制台用下面的命令调用ss

ss hello

就会输出第一个参数hello



11 shift

将参数后移 等于是把%2复制给了%1;%3给了%2



12 call 调用另一条命令



13 setLocal 使得对变量的修改只在本bat文件内有效 bat文件结束后变量恢复原值



14 start 打开一个新的窗口

start name command

name是新的窗口的名字 后面带着的是在新窗口中要执行的命令

当然也可以没有命令





在tomcat的安装目录下有bin文件夹

cd进去后 在命令行形式下运行catalina 就可以运行bat文件了

不过在运行的时候 还需要一些参数





下来激动人心的时刻到了 看源码



我们就按照调用 catalina start 来看代码

我用//来做注释

Catalina.bat

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

//上面的是注释 不管 os就是windows_NT        setlocal上面有
if "%OS%" == "Windows_NT" setlocal
rem ---------------------------------------------------------------------------
rem Start/Stop Script for the CATALINA Server
rem
rem Environment Variable Prerequisites
rem
rem   Do not set the variables in this script. Instead put them into a script
rem   setenv.bat in CATALINA_BASE/bin to keep your customizations separate.
rem
rem   CATALINA_HOME   May point at your Catalina "build" directory.
rem
rem   CATALINA_BASE   (Optional) Base directory for resolving dynamic portions
rem                   of a Catalina installation.  If not present, resolves to
rem                   the same directory that CATALINA_HOME points to.
rem
rem   CATALINA_OPTS   (Optional) Java runtime options used when the "start",
rem                   "run" or "debug" command is executed.
rem                   Include here and not in JAVA_OPTS all options, that should
rem                   only be used by Tomcat itself, not by the stop process,
rem                   the version command etc.
rem                   Examples are heap size, GC logging, JMX ports etc.
rem
rem   CATALINA_TMPDIR (Optional) Directory path location of temporary directory
rem                   the JVM should use (java.io.tmpdir).  Defaults to
rem                   %CATALINA_BASE%\temp.
rem
rem   JAVA_HOME       Must point at your Java Development Kit installation.
rem                   Required to run the with the "debug" argument.
rem
rem   JRE_HOME        Must point at your Java Runtime installation.
rem                   Defaults to JAVA_HOME if empty. If JRE_HOME and JAVA_HOME
rem                   are both set, JRE_HOME is used.
rem
rem   JAVA_OPTS       (Optional) Java runtime options used when any command
rem                   is executed.
rem                   Include here and not in CATALINA_OPTS all options, that
rem                   should be used by Tomcat and also by the stop process,
rem                   the version command etc.
rem                   Most options should go into CATALINA_OPTS.
rem
rem   JAVA_ENDORSED_DIRS (Optional) Lists of of semi-colon separated directories
rem                   containing some jars in order to allow replacement of APIs
rem                   created outside of the JCP (i.e. DOM and SAX from W3C).
rem                   It can also be used to update the XML parser implementation.
rem                   Defaults to $CATALINA_HOME/endorsed.
rem
rem   JPDA_TRANSPORT  (Optional) JPDA transport used when the "jpda start"
rem                   command is executed. The default is "dt_socket".
rem
rem   JPDA_ADDRESS    (Optional) Java runtime options used when the "jpda start"
rem                   command is executed. The default is 8000.
rem
rem   JPDA_SUSPEND    (Optional) Java runtime options used when the "jpda start"
rem                   command is executed. Specifies whether JVM should suspend
rem                   execution immediately after startup. Default is "n".
rem
rem   JPDA_OPTS       (Optional) Java runtime options used when the "jpda start"
rem                   command is executed. If used, JPDA_TRANSPORT, JPDA_ADDRESS,
rem                   and JPDA_SUSPEND are ignored. Thus, all required jpda
rem                   options MUST be specified. The default is:
rem
rem                   -agentlib:jdwp=transport=%JPDA_TRANSPORT%,
rem                       address=%JPDA_ADDRESS%,server=y,suspend=%JPDA_SUSPEND%
rem
rem   LOGGING_CONFIG  (Optional) Override Tomcat's logging config file
rem                   Example (all one line)
rem                   set LOGGING_CONFIG="-Djava.util.logging.config.file=%CATALINA_BASE%\conf\logging.properties"
rem
rem   LOGGING_MANAGER (Optional) Override Tomcat's logging manager
rem                   Example (all one line)
rem                   set LOGGING_MANAGER="-Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager"
rem
rem   TITLE           (Optional) Specify the title of Tomcat window. The default
rem                   TITLE is Tomcat if it's not specified.
rem                   Example (all one line)
rem                   set TITLE=Tomcat.Cluster#1.Server#1 [%DATE% %TIME%]
rem
rem
rem
rem $Id: catalina.bat 1344732 2012-05-31 14:08:02Z kkolinko $
rem ---------------------------------------------------------------------------

rem Suppress Terminate batch job on CTRL+C
if not ""%1"" == ""run"" goto mainEntry  //如果第一个参数不是run 去mainEntry标签 11行后
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             //看不懂
del /Q "%TEMP%\%~nx0.run" >NUL 2>&1

rem Guess CATALINA_HOME if not defined
set "CURRENT_DIR=%cd%"        //cd就是当前路径
if not "%CATALINA_HOME%" == "" goto gotHome  //不等于空 就去gotHome
set "CATALINA_HOME=%CURRENT_DIR%"            //要是等于空 就认为catalina.bat所在的文件夹就是                             //CATALINA_HOME
if exist "%CATALINA_HOME%\bin\catalina.bat" goto okHome
cd ..       //判定CATALINA_HOME里是不是存在bin\catalina.bat
        //如果不存在 返回上一级目录
        //要记得正常情况下 catalina.bat本来就在bin目录下
set "CATALINA_HOME=%cd%"
cd "%CURRENT_DIR%"
:gotHome     

if exist "%CATALINA_HOME%\bin\catalina.bat" goto okHome  //到这里就好了 存在这个bat文件 去okhome   //看看
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  //英文注释说的很清楚了
set "CATALINA_BASE=%CATALINA_HOME%"
:gotBase

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  //就是调用setenv.bat
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 //调用setclasspath
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
set BASEDIR=%CATALINA_HOME%
call "%CATALINA_HOME%\bin\setclasspath.bat"
//setclasspath.bat 会检查环境变量java_home
//并且会设置以下的变量
//set JAVA_ENDORSED_DIRS=%BASEDIR%\common\endorsed
//set CLASSPATH=%JAVA_HOME%\lib\tools.jar
//set _RUNJAVA="%JAVA_HOME%\bin\java"
//set _RUNJAVAW="%JAVA_HOME%\bin\javaw"
//set _RUNJDB="%JAVA_HOME%\bin\jdb"
//set _RUNJAVAC="%JAVA_HOME%\bin\javac"

rem Add on extra jar files to CLASSPATH
if "%JSSE_HOME%" == "" goto noJsse //看英文注释
set CLASSPATH=%CLASSPATH%;%JSSE_HOME%\lib\jcert.jar;%JSSE_HOME%\lib\jnet.jar;%JSSE_HOME%\lib\jsse.jar
:noJsse
set CLASSPATH=%CLASSPATH%;%CATALINA_HOME%\bin\bootstrap.jar

if not "%CATALINA_BASE%" == "" goto gotBase
set CATALINA_BASE=%CATALINA_HOME%
:gotBase

if not "%CATALINA_TMPDIR%" == "" goto gotTmpdir
set CATALINA_TMPDIR=%CATALINA_BASE%\temp
:gotTmpdir

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  //第一个参数是start 去看nojpda 15行后
set JPDA=jpda
if not "%JPDA_TRANSPORT%" == "" goto gotJpdaTransport
set JPDA_TRANSPORT=dt_socket
:gotJpdaTransport
if not "%JPDA_ADDRESS%" == "" goto gotJpdaAddress
set JPDA_ADDRESS=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  //呵呵
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       //移动参数
if not "%OS%" == "Windows_NT" goto noTitle   //刚才已经说了 os就是Windows_NT
if "%TITLE%" == "" set TITLE=Tomcat
set _EXECJAVA=start "%TITLE%" %_RUNJAVA%  //title是tomcat
goto gotTitle                   //_EXECJAVA这就是以后的命令
:noTitle
set _EXECJAVA=start %_RUNJAVA%
:gotTitle        //之前移动了参数了 但是我们确实没有第二个参数 去看execCmd 24行后
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
%_EXECJAVA% -classpath "%CATALINA_HOME%\lib\catalina.jar" org.apache.catalina.util.ServerInfo
goto end

:execCmd
rem Get remaining unshifted command line arguments and save them in the
set CMD_LINE_ARGS=
:setArgs    //此时的第一个参数为空 所以去看doneSetArgs
if ""%1""=="""" goto doneSetArgs
set CMD_LINE_ARGS=%CMD_LINE_ARGS% %1
shift
goto setArgs
:doneSetArgs

rem Execute Java with the applicable properties
if not "%JPDA%" == "" goto doJpda  //两个变量都为空
if not "%SECURITY_POLICY_FILE%" == "" goto doSecurity

%_EXECJAVA% %JAVA_OPTS% %CATALINA_OPTS% %DEBUG_OPTS% -Djava.endorsed.dirs="%JAVA_ENDORSED_DIRS%" -classpath "%CLASSPATH%" -Dcatalina.base="%CATALINA_BASE%" -Dcatalina.home="%CATALINA_HOME%" -Djava.io.tmpdir="%CATALINA_TMPDIR%" %MAINCLASS% %CMD_LINE_ARGS% %ACTION%
// 在我的电脑上将上面的变量赋值后就是
//start "Tomcat" "C:\j2sdk1.4.2_02\bin\java" -
//Djava.endorsed.dirs="..\common\endorsed" -classpath
//"C:\j2sdk1.4.2_02\lib\tools.jar;..\bin\bootstrap.jar" -
//Dcatalina.base=".." -Dcatalina,home=".." -Djava.io.tmpdir="..\temp"
//org.apache.catalina.startup.Bootstrap start
//解释一下
//启动一个新的窗口叫tomcat 然后就调用java命令 从-Djava到/temp都是参数
//运行的是org.apache.catalina.startup.Bootstrap 参数是start
//我累个去 重要写完啦
//感谢glt
goto end //去看end
:doSecurity
%_EXECJAVA% %JAVA_OPTS% %CATALINA_OPTS% %DEBUG_OPTS% -Djava.endorsed.dirs="%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% %JAVA_OPTS% %CATALINA_OPTS% %JPDA_OPTS% %DEBUG_OPTS% -Djava.endorsed.dirs="%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
%_EXECJAVA% %JAVA_OPTS% %CATALINA_OPTS% %JPDA_OPTS% %DEBUG_OPTS% -Djava.endorsed.dirs="%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  //对end在这

其实还没有到最开始的那个类

当当当当~~~

Startup.bat

@echo off
if "%OS%" == "Windows_NT" setlocal
rem ---------------------------------------------------------------------------
rem Start script for the CATALINA Server
rem
rem $Id: startup.bat,v 1.4 2002/01/15 02:55:38 patrickl Exp $
rem ---------------------------------------------------------------------------

rem Guess CATALINA_HOME if not defined
if not "%CATALINA_HOME%" == "" goto gotHome
set CATALINA_HOME=.    // 一个点是当前目录

if exist "%CATALINA_HOME%\bin\catalina.bat" goto okHome
set CATALINA_HOME=..   //两个点事上级目录 哎 今天涨姿势了
:gotHome
//上一级目录里面是有bin文件夹的 所以去okhome
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

set EXECUTABLE=%CATALINA_HOME%\bin\catalina.bat

rem Check that target executable exists
if exist "%EXECUTABLE%" goto okExec   //EXECUTABLE肯定有呀 去看okExec
echo Cannot find %EXECUTABLE%
echo This file is needed to run this program
goto end
:okExec

rem Get remaining unshifted command line arguments and save them in the
set CMD_LINE_ARGS=
:setArgs
if ""%1""=="""" goto doneSetArgs   //这里没有参数 所以去doneSetArgs
set CMD_LINE_ARGS=%CMD_LINE_ARGS% %1
shift
goto setArgs
:doneSetArgs

call "%EXECUTABLE%" start %CMD_LINE_ARGS%  //调用bin\catalina.bat并且参数为start

:end

tomcat终于结束了 感谢glt