目录
# options
提示
全局开关
| 名称 | 默认值 | 描述 |
|---|---|---|
| unsafe | false | 是否支持对系统级别的类进行增强，打开该开关可能导致把 JVM 搞挂，请慎重选择！ |
| dump | false | 是否支持被增强了的类 dump 到外部文件中，如果打开开关，class 文件会被 dump 到/${application working dir}/arthas-class-dump/目录下，具体位置详见控制台输出 |
| batch-re-transform | true | 是否支持批量对匹配到的类执行 retransform 操作 |
| json-format | false | 是否支持 json 化的输出 |
| disable-sub-class | false | 是否禁用子类匹配，默认在匹配目标类的时候会默认匹配到其子类，如果想精确匹配，可以关闭此开关 |
| support-default-method | true | 是否支持匹配到 default method， 默认会查找 interface，匹配里面的 default method。参考 #1105在新窗口打开 |
| save-result | false | 是否打开执行结果存日志功能，打开之后所有命令的运行结果都将保存到~/logs/arthas-cache/result.log中 |
| job-timeout | 1d | 异步后台任务的默认超时时间，超过这个时间，任务自动停止；比如设置 1d, 2h, 3m, 25s，分别代表天、小时、分、秒 |
| print-parent-fields | true | 是否打印在 parent class 里的 filed |
| verbose | false | 是否打印更多详细信息 |
| strict | true | 是否启用 strict 模式 |
# 查看所有的 options
$ options
LEVEL TYPE NAME VALUE SUMMARY DESCRIPTION
-------------------------------------------------------------------------------------------------------
0 boolea unsafe false Option to support sy This option enables to proxy functionality
n stem-level class of JVM classes. Due to serious security r
isk a JVM crash is possibly be introduced.
Do not activate it unless you are able to
manage.
1 boolea dump false Option to dump the e This option enables the enhanced classes t
n nhanced classes o be dumped to external file for further d
e-compilation and analysis.
1 boolea batch-re-tra true Option to support ba This options enables to reTransform classe
n nsform tch reTransform Clas s with batch mode.
s
2 boolea json-format false Option to support JS This option enables to format object outpu
n ON format of object t with JSON when -x option selected.
output
1 boolea disable-sub- false Option to control in This option disable to include sub class w
n class clude sub class when hen matching class.
class matching
1 boolea support-defa true Option to control in This option disable to include default met
n ult-method clude default method hod in interface when matching class.
in interface when c
lass matching
1 boolea save-result false Option to print comm This option enables to save each command's
n and's result to log result to log file, which path is ${user.
file home}/logs/arthas-cache/result.log.
2 String job-timeout 1d Option to job timeou This option setting job timeout,The unit c
t an be d, h, m, s for day, hour, minute, se
cond. 1d is one day in default
1 boolea print-parent true Option to print all This option enables print files in parent
n -fields fileds in parent cla class, default value true.
ss
1 boolea verbose false Option to print verb This option enables print verbose informat
n ose information ion, default value false.
1 boolea strict true Option to strict mod By default, strict mode is true, not allow
n e ed to set object properties. Want to set o
bject properties, execute `options strict
false`
# 获取 option 的值
$ options json-format
LEVEL TYPE NAME VALUE SUMMARY DESCRIPTION
--------------------------------------------------------------------------------------------
2 bool json-format false Option to support This option enables to format object
ean JSON format of obj output with JSON when -x option selec
ect output ted.
提示
默认情况下json-format为 false，如果希望watch/tt等命令结果以 json 格式输出，则可以设置json-format为 true。
# 设置指定的 option
例如，想打开执行结果存日志功能，输入如下命令即可：
$ options save-result true
NAME BEFORE-VALUE AFTER-VALUE
----------------------------------------
save-result false true
# 打开 unsafe 开关，支持 jdk package 下的类
默认情况下，watch/trace/tt/trace/monitor等命令不支持java.* package 下的类。可以设置unsafe为 true，则可以增强。
$ options unsafe true
NAME BEFORE-VALUE AFTER-VALUE
-----------------------------------
unsafe false true
$ watch java.lang.invoke.Invokers callSiteForm
Press Q or Ctrl+C to abort.
Affect(class count: 1 , method count: 1) cost in 61 ms, listenerId: 1
# 关闭 strict 模式，允许在 ognl 表达式里设置对象属性
提示
since 3.6.0
对于新用户，在编写 ognl 表达式时，可能会出现误用。
比如对于Student，判断年龄等于 18 时，可能条件表达式会误写为target.age=18，这个表达式实际上是把当前对象的age设置为 18 了。正确的写法是target.age==18。
为了防止出现类似上面的误用，Arthas 默认启用strict模式，在ognl表达式里，禁止更新对象的 Property 或者调用setter函数。
以MathGame为例，会出现以下的错误提示。
$ watch demo.MathGame primeFactors 'target' 'target.illegalArgumentCount=1'
Press Q or Ctrl+C to abort.
Affect(class count: 1 , method count: 1) cost in 206 ms, listenerId: 1
watch failed, condition is: target.illegalArgumentCount=1, express is: target, By default, strict mode is true, not allowed to set object properties. Want to set object properties, execute `options strict false`, visit /Users/admin/logs/arthas/arthas.log for more details.
用户如果确定要在ognl表达式里更新对象，可以执行options strict false，关闭strict模式。
- 更多信息参考： https://github.com/alibaba/arthas/issues/2128