classloader¶
View hierarchy, urls and classes-loading info for the class-loaders.
classloader can search and print out the URLs for a specified resource from one particular classloader. It is quite handy when analyze ResourceNotFoundException.
Options¶
| Name | Specification |
|---|---|
| [l] | list all class loader instances |
| [t] | print classloader's hierarchy |
| [a] | list all the classes loaded by all the class loaders (use it with great caution since the output can be huge) |
| [c:] | print classloader's hashcode |
| [c: r:] | using class loader to search resource |
Usage¶
- View statistics categorized by class type
$ classloader
name numberOfInstances loadedCountTotal
com.taobao.pandora.service.loader.ModuleClassLoader 29 11659
com.taobao.pandora.boot.loader.ReLaunchURLClassLoader 1 5308
BootstrapClassLoader 1 3711
com.taobao.arthas.agent.ArthasClassloader 2 2825
sun.reflect.DelegatingClassLoader 332 332
java.net.URLClassLoader 1 285
sun.misc.Launcher$AppClassLoader 1 77
sun.misc.Launcher$ExtClassLoader 1 46
com.alibaba.fastjson.util.ASMClassLoader 2 3
org.jvnet.hk2.internal.DelegatingClassLoader 2 2
sun.reflect.misc.MethodUtil 1 1
Affect(row-cnt:11) cost in 66 ms.
- View statistics categorized by loaded classes number
$ classloader -l
name loadedCount hash parent
BootstrapClassLoader 3711 null null
com.alibaba.fastjson.util.ASMClassLoader@3bbaa1b8 2 3bbaa1b8 monitor's ModuleClassLoader
com.alibaba.fastjson.util.ASMClassLoader@5e255d0b 1 5e255d0b eagleeye-core's ModuleClassLoader
com.taobao.arthas.agent.ArthasClassloader@4fa2d7e6 1795 4fa2d7e6 sun.misc.Launcher$ExtClassLoader@a38d7a3
com.taobao.arthas.agent.ArthasClassloader@522400c2 1033 522400c2 sun.misc.Launcher$ExtClassLoader@a38d7a3
com.taobao.pandora.boot.loader.ReLaunchURLClassLoader@1817d444 5308 1817d444 sun.misc.Launcher$AppClassLoader@14dad5dc
tbsession's ModuleClassLoader 285 609cd4d8 null
pandora-qos-service's ModuleClassLoader 267 2f8dad04 null
pandora-framework's ModuleClassLoader 78 4009e306 null
filesync-client's ModuleClassLoader 4 4b8ee4de null
rocketmq-client's ModuleClassLoader 431 247bddad null
eagleeye-core's ModuleClassLoader 451 1ba9117e null
alimonitor-jmonitor's ModuleClassLoader 134 22fcf7ab null
metaq-client's ModuleClassLoader 35 41a2befb null
hsf-mock's ModuleClassLoader 3 2002fc1d null
monitor's ModuleClassLoader 1427 131ef10 null
spas-sdk-service's ModuleClassLoader 7 10d307f1 null
vipserver-client's ModuleClassLoader 137 7a419da4 null
metrics's ModuleClassLoader 146 696da30b null
mtop-uncenter's ModuleClassLoader 922 79d8407f null
spas-sdk-client's ModuleClassLoader 235 4944252c null
live-profiler-pandora's ModuleClassLoader 1 6913c1fb null
notify-tr-client's ModuleClassLoader 472 fba92d3 null
ons-sdk's ModuleClassLoader 70 23348b5d null
tair-plugin's ModuleClassLoader 1053 7c9d8e2 null
tddl-client's ModuleClassLoader 2354 4988d8b8 null
config-client's ModuleClassLoader 93 429bffaa null
diamond-client's ModuleClassLoader 360 3d5c822d null
pandolet's ModuleClassLoader 99 41e1e210 null
hsf's ModuleClassLoader 1796 3232a28a null
acl.plugin's ModuleClassLoader 379 67080771 null
buc.sso.client.plugin's ModuleClassLoader 195 13b6aecc null
unitrouter's ModuleClassLoader 64 7e5afaa6 null
switch's ModuleClassLoader 104 24313fcc null
hsf-notify-client's ModuleClassLoader 57 4d0f2471 null
java.net.URLClassLoader@7ec7ffd3 285 7ec7ffd3 sun.misc.Launcher$ExtClassLoader@a38d7a3
javax.management.remote.rmi.NoCallStackClassLoader@53f65459 1 53f65459 null
javax.management.remote.rmi.NoCallStackClassLoader@2833cc44 1 2833cc44 null
org.jvnet.hk2.internal.DelegatingClassLoader@72cda8ee 1 72cda8ee monitor's ModuleClassLoader
org.jvnet.hk2.internal.DelegatingClassLoader@1f57f96d 1 1f57f96d monitor's ModuleClassLoader
sun.misc.Launcher$AppClassLoader@14dad5dc 77 14dad5dc sun.misc.Launcher$ExtClassLoader@a38d7a3
sun.misc.Launcher$ExtClassLoader@a38d7a3 46 a38d7a3 null
sun.reflect.misc.MethodUtil@1201f221 1 1201f221 sun.misc.Launcher$AppClassLoader@14dad5dc
- View class-loaders hierarchy
$ classloader -t
+-BootstrapClassLoader
+-unitrouter's ModuleClassLoader
+-diamond-client's ModuleClassLoader
+-sun.misc.Launcher$ExtClassLoader@548a102f
| +-sun.misc.Launcher$AppClassLoader@14dad5dc
| +-com.taobao.arthas.agent.AgentLauncher$1@334e6bb8
| | +-sun.reflect.DelegatingClassLoader@328b3a05
| | +-sun.reflect.DelegatingClassLoader@73f44f24
- Show the URLs from which to load classes and resources for one particular URLClassLoader
$ classloader -c 5ffe9775
file:/Users/hello/soft/taobao-tomcat-7.0.64/deploy/taobao-hsf.sar/lib/commons-lang-2.6.jar
file:/Users/hello/soft/taobao-tomcat-7.0.64/deploy/taobao-hsf.sar/lib/log4j-1.2.16.jar
file:/Users/hello/soft/taobao-tomcat-7.0.64/deploy/taobao-hsf.sar/lib/logger.api-0.1.4.jar
file:/Users/hello/soft/taobao-tomcat-7.0.64/deploy/taobao-hsf.sar/lib/pandora.api-2.0.7-SNAPSHOT.jar
file:/Users/hello/soft/taobao-tomcat-7.0.64/deploy/taobao-hsf.sar/lib/pandora.container-2.0.7-SNAPSHOT.jar
file:/Users/hello/soft/taobao-tomcat-7.0.64/deploy/taobao-hsf.sar/lib/pandora.thirdcontainer-2.0.7-SNAPSHOT.jar
file:/Users/hello/soft/taobao-tomcat-7.0.64/deploy/taobao-hsf.sar/lib/picocontainer-2.14.3.jar
- Use one class loader to search one particular resource
$ classloader -c 226b143b -r META-INF/MANIFEST.MF
jar:file:/Users/hello/.m2/repository/javax/enterprise/cdi-api/1.0/cdi-api-1.0.jar!/META-INF/MANIFEST.MF
jar:file:/Users/hello/.m2/repository/javax/annotation/jsr250-api/1.0/jsr250-api-1.0.jar!/META-INF/MANIFEST.MF
- Use one class loader to search one particular class
$ classloader -c 1b6d3586 -r java/lang/String.class
jar:file:/Library/Java/JavaVirtualMachines/jdk1.8.0_60.jdk/Contents/Home/jre/lib/rt.jar!/java/lang/String.class