$ help
NAME DESCRIPTION
help Display Arthas Help
keymap Display all the available keymap for the specified connection.
sc Search all the classes loaded by JVM
sm Search the method of classes loaded by JVM
classloader Show classloader info
jad Decompile class
getstatic Show the static field of a class
monitor Monitor method execution statistics, e.g. total/success/failure count, average rt, fail rate, etc.
stack Display the stack trace for the specified class and method
thread Display thread info, thread stack
trace Trace the execution time of specified method invocation.
watch Display the input/output parameter, return object, and thrown exception of specified method invocation
tt Time Tunnel
jvm Display the target JVM information
dashboard Overview of target jvm's thread, memory, gc, vm, tomcat info.
dump Dump class byte array from JVM
options View and change various Arthas options
cls Clear the screen
reset Reset all the enhanced classes
version Display Arthas version
shutdown Shut down Arthas server and exit the console
session Display current session information
sysprop Display, and change the system properties.
redefine Redefine classes. @see Instrumentation#redefineClasses(ClassDefinition...)
$
这里主要说一下 watch ，这个命令对变量进行数据监测。
SUMMARY:
Display the input/output parameter, return object, and thrown exception of specif
ied method invocation
The express may be one of the following expression (evaluated dynamically):
target : the object
clazz : the object's class
method : the constructor or method
params[0..n] : the parameters of method
returnObj : the returned object of method
throwExp : the throw exception of method
isReturn : the method ended by return
isThrow : the method ended by throwing exception
#cost : the execution time in ms of method invocation
Examples:
watch -Eb org\.apache\.commons\.lang\.StringUtils isBlank params[0]
watch -b org.apache.commons.lang.StringUtils isBlank params[0]
watch -f org.apache.commons.lang.StringUtils isBlank returnObj
watch -bf *StringUtils isBlank params[0]
watch *StringUtils isBlank params[0]
watch *StringUtils isBlank params[0] params[0].length==1
watch *StringUtils isBlank '#cost>100'
OPTIONS:
-b, --before Watch before invocation
-e, --exception Watch after throw exception
-x, --expand <value> Expand level of object (1 by default)
-f, --finish Watch after invocation, enable by default
-h, --help this help
-n, --limits <value> Threshold of execution times
-E, --regex Enable regular expression to match (wildcard matching b
y default)
-M, --sizeLimit <value> Upper size limit in bytes for the result (10 * 1024 * 1
024 by default)
-s, --success Watch after successful invocation
<class-pattern> The full qualified class name you want to watch
<method-pattern> The method name you want to watch
<express> the content you want to watch, written by ognl.
Examples:
params[0]
'params[0]+params[1]'
returnObj
throwExp
target
clazz
method
