深入刨析tomcat 之---第12篇 how tomcat works( 第17章 ) 解析catalina.bat 梳理启动流程

我们如何启动tomcat呢? 答案是双击startup.bat文件,这个文件在bin目录下

@echo off    不显示批处理命令

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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.

if "%OS%" == "Windows_NT" setlocal
rem ---------------------------------------------------------------------------
rem Start script for the CATALINA Server
rem
rem $Id: startup.bat 743401 2009-02-11 17:01:58Z markt $
rem ---------------------------------------------------------------------------

rem Guess CATALINA_HOME if not defined
if not "%CATALINA_HOME%" == "" goto gotHome
set CATALINA_HOME=.
if exist "%CATALINA_HOME%\bin\catalina.bat" goto okHome
set CATALINA_HOME=..
: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

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

rem Check that target executable exists
if exist "%EXECUTABLE%" goto 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       //如果第一个参数为" ",就是 在命令行敲入startup 命令;如果让%1不得"""" ,那么就这样输入 startup start
set CMD_LINE_ARGS=%CMD_LINE_ARGS% %1   如果有参数CMD_LINE_ARGS 变量的值为 参数1的值
shift
goto setArgs
:doneSetArgs

call "%EXECUTABLE%" start %CMD_LINE_ARGS%  最终的命令为  bin\catalina.bat  start

:end

以上批处理文件执行完成就变为了一句话,就是 在cmd 窗口中打   bin\catalina.bat  start

那么接着执行catalina 批处理

set CATALINA_OPTS=%CATALINA_OPTS% -Dsun.io.useCanonCaches=false

rem Guess CATALINA_HOME if not defined
if not "%CATALINA_HOME%" == "" goto gotHome
set CATALINA_HOME=.
if exist "%CATALINA_HOME%\bin\catalina.bat" goto okHome
set CATALINA_HOME=..
: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 Get standard environment variables
if exist "%CATALINA_HOME%\bin\setenv.bat" call "%CATALINA_HOME%\bin\setenv.bat"

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
set BASEDIR=%CATALINA_HOME%
call "%CATALINA_HOME%\bin\setclasspath.bat"

rem Add on extra jar files to CLASSPATH
if "%JSSE_HOME%" == "" goto noJsse
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%
echo Using JAVA_HOME: %JAVA_HOME%

set _EXECJAVA=%_RUNJAVA%
set MAINCLASS=org.apache.catalina.startup.Bootstrap
set ACTION=start
set SECURITY_POLICY_FILE=
set DEBUG_OPTS=
set JPDA=
echo Using _EXECJAVA %_EXECJAVA%

if not ""%1"" == ""jpda"" goto noJpda
set JPDA=jpda
if not "%JPDA_TRANSPORT%" == "" goto gotJpdaTransport
set JPDA_TRANSPORT=dt_shmem
:gotJpdaTransport
if not "%JPDA_ADDRESS%" == "" goto gotJpdaAddress
set JPDA_ADDRESS=jdbconn
:gotJpdaAddress
shift
:noJpda
echo print 参数1 ""%1""
if ""%1"" == ""debug"" goto doDebug
if ""%1"" == ""embedded"" goto doEmbedded
if ""%1"" == ""run"" goto doRun
if ""%1"" == ""start"" goto doStart
if ""%1"" == ""stop"" goto doStop

echo Usage: catalina ( commands ... )
echo commands:
echo debug Start Catalina in a debugger
echo debug -security Debug Catalina with a security manager
echo embedded Start Catalina in embedded mode
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
goto end

:doDebug
shift
set _EXECJAVA=%_RUNJDB%
set DEBUG_OPTS=-sourcepath "%CATALINA_HOME%\..\..\jakarta-tomcat-4.0\catalina\src\share"
if not ""%1"" == ""-security"" goto execCmd
shift
echo Using Security Manager
set SECURITY_POLICY_FILE=%CATALINA_BASE%\conf\catalina.policy
goto execCmd

:doEmbedded
shift
set MAINCLASS=org.apache.catalina.startup.Embedded
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 not "%OS%" == "Windows_NT" goto noTitle
set _EXECJAVA=start "Tomcat" %_RUNJAVA%
echo Print _EXECJAVA %_EXECJAVA%
goto gotTitle
:noTitle
set _EXECJAVA=start %_RUNJAVA%
:gotTitle
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
goto execCmd

: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

rem Execute Java with the applicable properties
if not "%JPDA%" == "" goto doJpda
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%
echo lastword %_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%

goto 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% -Xdebug -Xrunjdwp:transport=%JPDA_TRANSPORT%,address=%JPDA_ADDRESS%,server=y,suspend=n %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% -Xrunjdwp:transport=%JPDA_TRANSPORT%,address=%JPDA_ADDRESS%,server=y,suspend=n %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

最后打印的内容为

D:\dev\apache-tomcat-4.1.40\bin>catalina.bat start
Using CATALINA_BASE: ..
Using CATALINA_HOME: ..
Using CATALINA_TMPDIR: ..\temp
Using JAVA_HOME: D:\dev\JDK8
Using _EXECJAVA "D:\dev\JDK8\bin\java"
print 鍙傛暟1 ""start""
Print _EXECJAVA start "Tomcat" "D:\dev\JDK8\bin\java"
最终指令::==>  start "Tomcat" "D:\dev\JDK8\bin\java" -Dsun.io.useCanonCaches=false -Djava.endorsed.dirs="..\common\endorsed" -classpath "D:\dev\JDK8\lib\tools.jar;..\bin\bootstrap.jar" -Dcatalina.base=".." -Dcatalina.home=".." -Djava.io.tmpdir="..\temp" org.apache.catalina.startup.Bootstrap start

start "Tomcat" 是启动一个新cmd 窗口命名为"Tomcat",那么最后的只看指令就是java  -classpath   ..\bin\bootstrap.jar"  org.apache.catalina.startup.Bootstrap start

那么类路径在bin下面有一个 bootstrap.jar文件,如果你打开看就是

org.apache.catalina.startup.Bootstrap类

    public static void main(String args[]) {

        // Set the debug flag appropriately
        for (int i = 0; i < args.length; i++)  {
            if ("-debug".equals(args[i]))
                debug = 1;
        }

        // Configure catalina.base from catalina.home if not yet set
        if (System.getProperty("catalina.base") == null)
            System.setProperty("catalina.base", getCatalinaHome());

        // Construct the class loaders we will need
        ClassLoader commonLoader = null;
        ClassLoader catalinaLoader = null;
        ClassLoader sharedLoader = null;
        try {

            File unpacked[] = new File[1];
            File packed[] = new File[1];
            File packed2[] = new File[2];
            ClassLoaderFactory.setDebug(debug);

            unpacked[0] = new File(getCatalinaHome(),
                                   "common" + File.separator + "classes");
            packed2[0] = new File(getCatalinaHome(),
                                  "common" + File.separator + "endorsed");
            packed2[1] = new File(getCatalinaHome(),
                                  "common" + File.separator + "lib");
            commonLoader =
                ClassLoaderFactory.createClassLoader(unpacked, packed2, null);

            unpacked[0] = new File(getCatalinaHome(),
                                   "server" + File.separator + "classes");
            packed[0] = new File(getCatalinaHome(),
                                 "server" + File.separator + "lib");
            catalinaLoader =
                ClassLoaderFactory.createClassLoader(unpacked, packed,
                                                     commonLoader);

            unpacked[0] = new File(getCatalinaBase(),
                                   "shared" + File.separator + "classes");
            packed[0] = new File(getCatalinaBase(),
                                 "shared" + File.separator + "lib");
            sharedLoader =
                ClassLoaderFactory.createClassLoader(unpacked, packed,
                                                     commonLoader);
        } catch (Throwable t) {

            log("Class loader creation threw exception", t);
            System.exit(1);

        }

        Thread.currentThread().setContextClassLoader(catalinaLoader);

        // Load our startup class and call its process() method
        try {

            SecurityClassLoad.securityClassLoad(catalinaLoader);

            // Instantiate a startup class instance
            if (debug >= 1)
                log("Loading startup class");
            Class startupClass =
                catalinaLoader.loadClass
                ("org.apache.catalina.startup.Catalina");
            Object startupInstance = startupClass.newInstance();

            // Set the shared extensions class loader
            if (debug >= 1)
                log("Setting startup class properties");
            String methodName = "setParentClassLoader";
            Class paramTypes[] = new Class[1];
            paramTypes[0] = Class.forName("java.lang.ClassLoader");
            Object paramValues[] = new Object[1];
            paramValues[0] = sharedLoader;
            Method method =
                startupInstance.getClass().getMethod(methodName, paramTypes);
            method.invoke(startupInstance, paramValues);

            // Call the process() method
            if (debug >= 1)
                log("Calling startup class process() method");
            methodName = "process";
            paramTypes = new Class[1];
            paramTypes[0] = args.getClass();
            paramValues = new Object[1];
            paramValues[0] = args;
            method =
                startupInstance.getClass().getMethod(methodName, paramTypes);
            method.invoke(startupInstance, paramValues);

        } catch (Exception e) {
            System.out.println("Exception during startup processing");
            e.printStackTrace(System.out);
            System.exit(2);
        }

    }

那么执行这个mian 方法,那么tomcat 的源码在哪里呢?

具体为什么在这里,那么就要分析他的编译过程,下一篇就写下这个吧