tomcat研究

 

tomcat启动（一）

分类： tomcat调试 2008-07-08 15:14  1085人阅读  评论(0)  收藏  举报

tomcat启动命令

安装tomcat之后,设置CATALINA_HOME=tomcat的安装目录,比如安装在c:/tomcat，那么CATALINA_HOME=c:/tomcat，添加路径到path环境变量，%CATALINA_HOME%/bin，然后打开控制台，进入tomcat的bin目录，这儿有tomcat的启动脚本，startup.bat启动tomcat，shutdown.bat关闭tomcat。我是在windows下做的调试，如果在linux/unix下，相应的启动脚本为startup.sh和shutdown.sh。

tomcat启动脚本解说

用文本编辑器打开startup.bat,你会看到如下，内容： 

 @echo off

 if "%OS%" == "Windows_NT" setlocal

 rem ---------------------------------------------------------------------------

 rem Start script for the CATALINA Server

 rem

 rem $Id: startup.bat,v 1.6 2004/05/27 18:25:11 yoavs Exp $

 rem ---------------------------------------------------------------------------



 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



 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

 set CMD_LINE_ARGS=%CMD_LINE_ARGS% %1

 shift

 goto setArgs

 :doneSetArgs



 call "%EXECUTABLE%" start %CMD_LINE_ARGS%



 :end

 

 第一段,内容如下，先设置好变量CATALINA_HOME，然后判断是否存在脚本文件"%CATALINA_HOME%/bin/catalina.bat",如果找不到该文件，那么退出脚本的执行，提示设置CATALINA_HOME环境变量，这就是我们在安装tomcat后，要设置环境变量CATALINA_HOME的原因。

 

 @echo off

 if "%OS%" == "Windows_NT" setlocal

 rem ---------------------------------------------------------------------------

 rem Start script for the CATALINA Server

 rem

 rem $Id: startup.bat,v 1.6 2004/05/27 18:25:11 yoavs Exp $

 rem ---------------------------------------------------------------------------



 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



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

第二段，内容如下，用EXECUTABLE脚本指向的脚本文件，执行启动命令，传入参数start，既进入启动脚本catalina.bat的执行。

 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

 set CMD_LINE_ARGS=%CMD_LINE_ARGS% %1

 shift

 goto setArgs

 :doneSetArgs



 call "%EXECUTABLE%" start %CMD_LINE_ARGS%



 :end

catalina.bat内容如下：

 @echo off

 if "%OS%" == "Windows_NT" setlocal

 rem ---------------------------------------------------------------------------

 rem Start/Stop Script for the CATALINA Server

 rem

 rem Environment Variable Prequisites

 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                   "stop", or "run" command is executed.

 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

 rem   JAVA_OPTS       (Optional) Java runtime options used when the "start",

 rem                   "stop", or "run" command is executed.

 rem

 rem   JSSE_HOME       (Optional) May point at your Java Secure Sockets Extension

 rem                   (JSSE) installation, whose JAR files will be added to the

 rem                   system class path used to start Tomcat.

 rem

 rem   JPDA_TRANSPORT  (Optional) JPDA transport used when the "jpda start"

 rem                   command is executed. The default is "dt_shmem".

 rem

 rem   JPDA_ADDRESS    (Optional) Java runtime options used when the "jpda start"

 rem                   command is executed. The default is "jdbconn".

 rem

 rem $Id: catalina.bat,v 1.9.2.2 2004/09/23 20:17:14 yoavs Exp $

 rem ---------------------------------------------------------------------------



 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 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=



 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



 if ""%1"" == ""debug"" goto doDebug

 if ""%1"" == ""run"" goto doRun

 if ""%1"" == ""start"" goto doStart

 if ""%1"" == ""stop"" goto doStop

 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   version           What version of tomcat are you running?

 goto end



 :doDebug

 shift

 set _EXECJAVA=%_RUNJDB%

 set DEBUG_OPTS=-sourcepath "%CATALINA_HOME%/../../jakarta-tomcat-catalina/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



 :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%

 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



 :doVersion

 %_EXECJAVA% -classpath "%CATALINA_HOME%/server/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

 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%

 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% -Xdebug -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

解释，1。再次验证catalina.bat；2。调用setclasspath.bat设置java虚拟机相关的环境变量，所以在运行tomcat的前，一定要先安装jdk，并设置好JAVA_HOME环境变量；3。设置启动程序，添加CLASSPATH，bootstrap.jar，和启动类org.apache.catalina.startup.Bootstrap；4。最后执行虚拟机，运行tomcat。

运行tomcat的参数行为%_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%，在我的电脑上调试，将所有的变量内容转译出来，执行的命令即为：start "Tomcat" "C:/j2sdk1.4.2_15/bin/java"    -Djava.endorsed.dirs="C:/Tomcat 5.0/common/endorsed" -classpath "C:/j2sdk1.4.2_15/lib/tools.jar;C:/Tomcat 5.0/bin/bootstrap.jar" -Dcatalina.base="C:/Tomcat 5.0" -Dcatalina.home="C:/Tomcat 5.0" -Djava.io.tmpdir="C:/Tomcat 5.0/temp" org.apache.catalina.startup.Bootstrap  start

在该命令中，start "Tomcat"是在控制态打开一个新的窗口，然后运行java虚拟机C:/j2sdk1.4.2_15/bin/java,现在大家应该明白了，tomcat是从bootstrap.jar中的org.apache.catalina.startup.Bootstrap类的main函数开始启动运行，并且传入了start参数。-D开始的都是虚拟机的运行参数。

用winrar打开bootstrap.jar打开，在META-INF目录下打开MANIFEST.MF，你会看到如下内容： Manifest-Version: 1.0 Ant-Version: Apache Ant 1.6.1 Created-By: 1.4.2-b28 (Sun Microsystems Inc.) Main-Class: org.apache.catalina.startup.Bootstrap Specification-Title: Catalina Specification-Version: 1.0 Class-Path: jmx.jar commons-daemon.jar commons-logging-api.jar 指定了该jar包从那个类开始运行，依赖那些jar包。

结论

 通过对脚本的研究，我们应该知道，tomcat从那儿开始运行，只有有了运行的线索，那么我们就可以从头开始调试tomcat源代码。调试tomcat源代码的准备工作，从www.apache.org上下载相应版本，带源代码的安装程序，并安装。

 

建立tomcat调试环境（二）

分类： tomcat调试 2008-07-12 01:17  342人阅读  评论(0)  收藏  举报

1。准备工作

下载tomcat,我下载的是tomcat5.0.30,我认为这是一个比较好的版本。下载地址http://archive.apache.org/dist/tomcat/tomcat-5/v5.0.30/bin/，选择window下载安装文件。

安装的时候，选择安装源代码选项，如下图。我的tomcat安装目录是C:/Tomcat 5.0

安装myeclipse，我安装的是5.5版。

2。创建工程

tomcat的整个安装目录拷贝到myeclipse的workspace目录下，如下图： 

然后创建一个名为Tomcat 5.0的java project，如下步骤。

第一步，选择创建project，如下图: 

第二步，选择java project: 

第三步，选择和tomcat拷贝目录同名的project,如下图，选择“Finish”按钮。 

这时候，你已经创建了tomcat的调试环境。

你可能会看到一些红色编译错误，你还需要下载mail.jar，activation.jar两个库文件，添加到工程中。

工程中估计还有一些编译错误，大家可以自己修改代码来解决，应该很简单。

3。开始调试

打开文件Bootstrap.java，所在的包为package org.apache.catalina.startup，如下图：

这就是tomcat的启动文件（大家可以通过文件搜索来找到该文件所在路径），找到main方法，tomcat就从这个main方法的地方开始运行启动，你现在可以设置断点，开始运行。

由于时间的原因，我都写的比较检阅，如果对myeclipse和tomcat有一定了解的朋友，肯定能很快建立环境。

 

tomcat启动main函数(三)

分类： tomcat调试 2008-07-12 02:22  502人阅读  评论(0)  收藏  举报

有了上面的准备工作，我们开始源代码调试。

main函数说明

开打Bootstrap.java，找到main函数，函数源代码如下：

 public static void main(String args[]) {



     try {

         // Attempt to load JMX class

         new ObjectName("test:foo=bar");

     } catch (Throwable t) {

         System.out.println(JMX_ERROR_MESSAGE);

         try {

             // Give users some time to read the message before exiting

             Thread.sleep(5000);

         } catch (Exception ex) {

         }

         return;

     }



     if (daemon == null) {

         daemon = new Bootstrap();

         try {

             daemon.init();

         } catch (Throwable t) {

             t.printStackTrace();

             return;

         }

     }



     try {

         String command = "start";

         if (args.length > 0) {

             command = args[args.length - 1];

         }



         if (command.equals("startd")) {

             args[0] = "start";

             daemon.load(args);

             daemon.start();

         } else if (command.equals("stopd")) {

             args[0] = "stop";

             daemon.stop();

         } else if (command.equals("start")) {

             daemon.setAwait(true);

             daemon.load(args);

             daemon.start();

         } else if (command.equals("stop")) {

             daemon.stopServer(args);

         }

     } catch (Throwable t) {

         t.printStackTrace();

     }

 }

上面的代码一共分成三部分： 第一部分：

 try {

     // Attempt to load JMX class

     new ObjectName("test:foo=bar");

 } catch (Throwable t) {

     System.out.println(JMX_ERROR_MESSAGE);

     try {

         // Give users some time to read the message before exiting

         Thread.sleep(5000);

     } catch (Exception ex) {

     }

     return;

 }

验证jdk基础类是否载入，没有载入，在标准输入打印错误信息，然后退出程序运行。

 

第二部分：

 if (daemon == null) {

     daemon = new Bootstrap();

     try {

         daemon.init();

     } catch (Throwable t) {

         t.printStackTrace();

         return;

     }

 }

初始化运行环境，载入需要的jar包，读取conf/server.xml，生成相应的运行对象：

 

第三部分：

 try {

     String command = "start";

     if (args.length > 0) {

         command = args[args.length - 1];

     }



     if (command.equals("startd")) {

         args[0] = "start";

         daemon.load(args);

         daemon.start();

     } else if (command.equals("stopd")) {

         args[0] = "stop";

         daemon.stop();

     } else if (command.equals("start")) {

         daemon.setAwait(true);

         daemon.load(args);

         daemon.start();

     } else if (command.equals("stop")) {

         daemon.stopServer(args);

     }

 } catch (Throwable t) {

     t.printStackTrace();

 }

装载，开始运行。

 

jar运行库载入(四)

分类： tomcat调试 2008-07-12 17:21  198人阅读  评论(0)  收藏  举报

前面讲述了main函数三段的主要任务，第一段基本库验证没什么好说的了。下面我们开始第二段的调试。

 if (daemon == null) {

     daemon = new Bootstrap();

     try {

         daemon.init();

     } catch (Throwable t) {

         t.printStackTrace();

         return;

     }

 }

从上面我们可以看得出，首先，创建了一个Bootstrap对象，然后进入该对象的额init方法，进行初始化处理。下面我们看看init方法的内容：

 

 public void init()  throws Exception

 {

   // Set Catalina path

   setCatalinaHome();

   setCatalinaBase();

   initClassLoaders();

   Thread.currentThread().setContextClassLoader(catalinaLoader);

   SecurityClassLoad.securityClassLoad(catalinaLoader);

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

   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;