Tomcat 源码分析-启动分析(1)

Tomcat 源码分析-启动分析(1)

文章目录

    • Tomcat 源码分析-启动分析(1)
    • 启动脚本
      • 从startup.bat开始
      • 执行catalina.bat文件
      • 参考资料

系列文章:
Tomcat 源码分析-启动分析(1)
Tomcat 源码分析-启动分析(2)
Tomcat 源码分析-启动分析(3)
Tomcat 源码分析-启动分析(4)

启动脚本

windows是.bat,linux就是.sh了,差不多一个意思。

启动脚本做的事情,大多是系统环境变量的判断,在所有前置条件满足的情况下执行Tomcat 的源码的启动类。

从startup.bat开始

 1	@echo off
16
17	if "%OS%" == "Windows_NT" setlocal
23
25	set "CURRENT_DIR=%cd%"
26	if not "%CATALINA_HOME%" == "" goto gotHome
27	set "CATALINA_HOME=%CURRENT_DIR%"
28	if exist "%CATALINA_HOME%\bin\catalina.bat" goto okHome
29	cd ..
30	set "CATALINA_HOME=%cd%"
31	cd "%CURRENT_DIR%"
32	:gotHome
33	if exist "%CATALINA_HOME%\bin\catalina.bat" goto okHome
34	echo The CATALINA_HOME environment variable is not defined correctly
35	echo This environment variable is needed to run this program
36	goto end
37	:okHome
### 上面是各种系统变量的判断,下面这个为定义catalina.bat文件的路径(会用到)
39	set "EXECUTABLE=%CATALINA_HOME%\bin\catalina.bat"
40
42	if exist "%EXECUTABLE%" goto okExec
43	echo Cannot find "%EXECUTABLE%"
44	echo This file is needed to run this program
45	goto end
46	:okExec
47
49	set CMD_LINE_ARGS=
50	:setArgs
51	if ""%1""=="""" goto doneSetArgs
52	set CMD_LINE_ARGS=%CMD_LINE_ARGS% %1
53	shift
54	goto setArgs
### 48 到 55 行将运行脚本前如果设置了其他参数,将参数保存到 CMD_LINE_ARGS 变量中
55	:doneSetArgs
56
57	call "%EXECUTABLE%" start %CMD_LINE_ARGS%
58
59	:end

设置一些系统执行脚本需要的环境变量,以及最重要的CATALINA_HOME环境变量【这里的值是tomcat的bin目录下的catalina.bat 文件】

最后会执行catalina.bat文件,带上参数start

执行catalina.bat文件

@echo off
 16
 17	if "%OS%" == "Windows_NT" setlocal
 98
100	if not ""%1"" == ""run"" goto mainEntry
101	if "%TEMP%" == "" goto mainEntry
102	if exist "%TEMP%\%~nx0.run" goto mainEntry
103	echo Y>"%TEMP%\%~nx0.run"
104	if not exist "%TEMP%\%~nx0.run" goto mainEntry
105	echo Y>"%TEMP%\%~nx0.Y"
106	call "%~f0" %* <"%TEMP%\%~nx0.Y"
108	set RETVAL=%ERRORLEVEL%
109	del /Q "%TEMP%\%~nx0.Y" >NUL 2>&1
110	exit /B %RETVAL%
111	:mainEntry
112	del /Q "%TEMP%\%~nx0.run" >NUL 2>&1
113
115	set "CURRENT_DIR=%cd%"
116	if not "%CATALINA_HOME%" == "" goto gotHome
117	set "CATALINA_HOME=%CURRENT_DIR%"
118	if exist "%CATALINA_HOME%\bin\catalina.bat" goto okHome
119	cd ..
120	set "CATALINA_HOME=%cd%"
121	cd "%CURRENT_DIR%"
122	:gotHome
### CATALINA_HOME变量,这里又验证了一次,防止用户直接运行 catalina.bat 文件
124	if exist "%CATALINA_HOME%\bin\catalina.bat" goto okHome
125	echo The CATALINA_HOME environment variable is not defined correctly
126	echo This environment variable is needed to run this program
127	goto end
128	:okHome
129
131	if not "%CATALINA_BASE%" == "" goto gotBase
132	set "CATALINA_BASE=%CATALINA_HOME%"
133	:gotBase
134
137	set CLASSPATH=
138
140	if not exist "%CATALINA_BASE%\bin\setenv.bat" goto checkSetenvHome
141	call "%CATALINA_BASE%\bin\setenv.bat"
142	goto setenvDone
143	:checkSetenvHome
144	if exist "%CATALINA_HOME%\bin\setenv.bat" call "%CATALINA_HOME%\bin\setenv.bat"
145	:setenvDone
146
148	if exist "%CATALINA_HOME%\bin\setclasspath.bat" goto okSetclasspath
149	echo Cannot find "%CATALINA_HOME%\bin\setclasspath.bat"
150	echo This file is needed to run this program
151	goto end
152	:okSetclasspath
153	call "%CATALINA_HOME%\bin\setclasspath.bat" %1
154	if errorlevel 1 goto end
### setclasspath.bat 主要功能校验是否设置JAVA_HOME变量,没有则在控制台显示出提示信息。注意该文件中第 79 行将会设置_RUNJAVA变量,该变量的值即JAVA_HOME或JRE_HOME的 bin 目录下的 java.exe 文件
159	if "%CLASSPATH%" == "" goto emptyClasspath
160	set "CLASSPATH=%CLASSPATH%;"
161	:emptyClasspath
162	set "CLASSPATH=%CLASSPATH%%CATALINA_HOME%\bin\bootstrap.jar"
163
164	if not "%CATALINA_TMPDIR%" == "" goto gotTmpdir
165	set "CATALINA_TMPDIR=%CATALINA_BASE%\temp"
166	:gotTmpdir
167
170	if not exist "%CATALINA_BASE%\bin\tomcat-juli.jar" goto juliClasspathHome
171	set "CLASSPATH=%CLASSPATH%;%CATALINA_BASE%\bin\tomcat-juli.jar"
172	goto juliClasspathDone
173	:juliClasspathHome
174	set "CLASSPATH=%CLASSPATH%;%CATALINA_HOME%\bin\tomcat-juli.jar"
175	:juliClasspathDone
176
177	if not "%LOGGING_CONFIG%" == "" goto noJuliConfig
178	set LOGGING_CONFIG=-Dnop
179	if not exist "%CATALINA_BASE%\conf\logging.properties" goto noJuliConfig
180	set LOGGING_CONFIG=-Djava.util.logging.config.file="%CATALINA_BASE%\conf\logging.properties"
181	:noJuliConfig
182	set JAVA_OPTS=%JAVA_OPTS% %LOGGING_CONFIG%
183
184	if not "%LOGGING_MANAGER%" == "" goto noJuliManager
185	set LOGGING_MANAGER=-Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
186	:noJuliManager
187	set JAVA_OPTS=%JAVA_OPTS% %LOGGING_MANAGER%
188
191	echo Using CATALINA_BASE:   "%CATALINA_BASE%"
192	echo Using CATALINA_HOME:   "%CATALINA_HOME%"
193	echo Using CATALINA_TMPDIR: "%CATALINA_TMPDIR%"
194	if ""%1"" == ""debug"" goto use_jdk
195	echo Using JRE_HOME:        "%JRE_HOME%"
196	goto java_dir_displayed
197	:use_jdk
198	echo Using JAVA_HOME:       "%JAVA_HOME%"
199	:java_dir_displayed
200	echo Using CLASSPATH:       "%CLASSPATH%"
201
202	set _EXECJAVA=%_RUNJAVA%   	### ※
203	set MAINCLASS=org.apache.catalina.startup.Bootstrap   	### ※
204	set ACTION=start   			### ※	
### 这3个变量最后启动分析时将会用到
205	set SECURITY_POLICY_FILE=
206	set DEBUG_OPTS=
207	set JPDA=
208
209	if not ""%1"" == ""jpda"" goto noJpda
210	set JPDA=jpda
211	if not "%JPDA_TRANSPORT%" == "" goto gotJpdaTransport
212	set JPDA_TRANSPORT=dt_socket
213	:gotJpdaTransport
214	if not "%JPDA_ADDRESS%" == "" goto gotJpdaAddress
215	set JPDA_ADDRESS=8000
216	:gotJpdaAddress
217	if not "%JPDA_SUSPEND%" == "" goto gotJpdaSuspend
218	set JPDA_SUSPEND=n
219	:gotJpdaSuspend
220	if not "%JPDA_OPTS%" == "" goto gotJpdaOpts
221	set JPDA_OPTS=-agentlib:jdwp=transport=%JPDA_TRANSPORT%,address=%JPDA_ADDRESS%,server=y,suspend=%JPDA_SUSPEND%
222	:gotJpdaOpts
223	shift
224	:noJpda
225
226	if ""%1"" == ""debug"" goto doDebug
227	if ""%1"" == ""run"" goto doRun
228	if ""%1"" == ""start"" goto doStart
229	if ""%1"" == ""stop"" goto doStop
230	if ""%1"" == ""configtest"" goto doConfigTest
231	if ""%1"" == ""version"" goto doVersion
232
233	echo Usage:  catalina ( commands ... )
234	echo commands:
235	echo   debug             Start Catalina in a debugger
236	echo   debug -security   Debug Catalina with a security manager
237	echo   jpda start        Start Catalina under JPDA debugger
238	echo   run               Start Catalina in the current window
239	echo   run -security     Start in the current window with security manager
240	echo   start             Start Catalina in a separate window
241	echo   start -security   Start in a separate window with security manager
242	echo   stop              Stop Catalina
243	echo   configtest        Run a basic syntax check on server.xml
244	echo   version           What version of tomcat are you running?
245	goto end
246
247	:doDebug
248	shift
249	set _EXECJAVA=%_RUNJDB%
250	set DEBUG_OPTS=-sourcepath "%CATALINA_HOME%\..\..\java"
251	if not ""%1"" == ""-security"" goto execCmd
252	shift
253	echo Using Security Manager
254	set "SECURITY_POLICY_FILE=%CATALINA_BASE%\conf\catalina.policy"
255	goto execCmd
256
257	:doRun
258	shift
259	if not ""%1"" == ""-security"" goto execCmd
260	shift
261	echo Using Security Manager
262	set "SECURITY_POLICY_FILE=%CATALINA_BASE%\conf\catalina.policy"
263	goto execCmd
264
265	:doStart
266	shift  ### 校验和设置一些变量
267	if not "%OS%" == "Windows_NT" goto noTitle
268	if "%TITLE%" == "" set TITLE=Tomcat
269	set _EXECJAVA=start "%TITLE%" %_RUNJAVA%
270	goto gotTitle
271	:noTitle
272	set _EXECJAVA=start %_RUNJAVA%
273	:gotTitle
274	if not ""%1"" == ""-security"" goto execCmd
275	shift
276	echo Using Security Manager
277	set "SECURITY_POLICY_FILE=%CATALINA_BASE%\conf\catalina.policy"
278	goto execCmd
279
280	:doStop
281	shift
282	set ACTION=stop
283	set CATALINA_OPTS=
284	goto execCmd
285
286	:doConfigTest
287	shift
288	set ACTION=configtest
289	set CATALINA_OPTS=
290	goto execCmd
291
292	:doVersion
293	%_EXECJAVA% -classpath "%CATALINA_HOME%\lib\catalina.jar" org.apache.catalina.util.ServerInfo
294	goto end
295
296
297	:execCmd
299	set CMD_LINE_ARGS=
300	:setArgs
301	if ""%1""=="""" goto doneSetArgs
302	set CMD_LINE_ARGS=%CMD_LINE_ARGS% %1
303	shift
304	goto setArgs
305	:doneSetArgs
306
308	if not "%JPDA%" == "" goto doJpda
309	if not "%SECURITY_POLICY_FILE%" == "" goto doSecurity
310	%_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%
### 
311	goto end
312	:doSecurity
313	%_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%

### %_EXECJAVA%   == start Tomcat java.exe 
### %JAVA_OPTS% %CATALINA_OPTS% %DEBUG_OPTS% 。。。  ==  jvm 内存等运行参数和系统属性 
### 启动单独窗口 名字Tomcat 运行java.exe CATALINA_OPTS
### %MAINCLASS% == org.apache.catalina.startup.Bootstrap 
### %CMD_LINE_ARGS%  == 命令行参数 
### %ACTION% == start
### 最终就是:javac Bootstrap.main(..,start) -jvm..配置。。。

314	goto end
315	:doJpda
316	if not "%SECURITY_POLICY_FILE%" == "" goto doSecurityJpda
317	%_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%
318	goto end
319	:doSecurityJpda
320	%_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%
321	goto end
322
323	:end

还是对一些变量环境参数做了一些条件的判断,以及执行了setenv.batsetclasspath.bat文件

最终,执行 org.apache.catalina.startup.Bootstrap的main方法,同时带上参数 start;

【以不同参数启动tamcat,都是到这个main方法,只是添加了不同了的如参;】


参考资料

分析资料:http://www.iocoder.cn/Tomcat/yuliu/Start-analysis-1-start-script/

源码调试【用IDEA调试tomcat源码】 https://blog.csdn.net/mrhuangxiutao/article/details/78261155


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