$JAVA_HOME/bin下
| 命令 | 说明 |
|---|---|
| jps | 查看所有jvm进程 |
| jinfo | 查看进程的运行环境参数，主要是jvm命令行参数 |
| jstat | 对jvm应用程序的资源和性能进行实时监控 |
| jstack | 查看所有线程的运行状态 |
| jmap | 查看jvm占用物理内存的状态 |
| jhat | +UseParNew |
| jconsole | |
| jvisualvm |
jps：Java virutal machine Process Status tool，
jps [-q] [-mlvV] []
-q：静默模式；
-v：显示传递给jvm的命令行参数；
-m：输出传入main方法的参数；
-l：输出main类或jar完全限定名称；
-v：显示通过flag文件传递给jvm的参数；
[]：主机id，默认为localhost；
详细列出当前Java进程信息
[root@tomcat ~]#jps -l -v
21560 org.netbeans.Main -Djdk.home=/usr/local/jdk -Dnetbeans.default_userdir_root=/root/.visualvm -Dnetbeans.dirs=/usr/local/jdk/lib/visualvm/visualvm:/usr/local/jdk/lib/visualvm/profiler: -Dnetbeans.home=/usr/local/jdk/lib/visualvm/platform -Xms24m -Xmx256m -Dsun.jvmstat.perdata.syncWaitMs=10000 -Dsun.java2d.noddraw=true -Dsun.java2d.d3d=false -Dnetbeans.keyring.no.master=true -Dplugin.manager.install.global=false --add-exports=java.desktop/sun.awt=ALL-UNNAMED --add-exports=jdk.jvmstat/sun.jvmstat.monitor.event=ALL-UNNAMED --add-exports=jdk.jvmstat/sun.jvmstat.monitor=ALL-UNNAMED --add-exports=java.desktop/sun.swing=ALL-UNNAMED --add-exports=jdk.attach/sun.tools.attach=ALL-UNNAMED --add-modules=java.activation -XX:+IgnoreUnrecognizedVMOptions -XX:+HeapDumponOutOfMemoryError -XX:HeapDumpPath=/root/.visualvm/8u131/var/log/heapdump.hprof
22270 sun.tools.jps.Jps -Denv.class.path=/usr/local/jdk/lib/:/usr/local/jdk/jre/lib/ -Dapplication.home=/usr/local/jdk1.8.0_241 -Xms8m
21407 HelloWorld -Xms256m -Xmx512m
jinfo：输出给定的java进程的所有配置信息；
jinfo [option]
-flags：打印 VM flags
-sysprops：to print Java system properties
-flag ：to print the value of the named VM flag
先获得一个java进程ID，然后jinfo
[root@tomcat ~]#jps
22357 Jps
21560 Main
21407 HelloWorld
[root@tomcat ~]#jinfo 21407
Attaching to process ID 21407, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 25.241-b07
Java System Properties:
java.runtime.name = Java(TM) SE Runtime Environment
java.vm.version = 25.241-b07
sun.boot.library.path = /usr/local/jdk1.8.0_241/jre/lib/amd64
java.vendor.url = http://java.oracle.com/
java.vm.vendor = Oracle Corporation
path.separator = :
java.rmi.server.randomIDs = true
file.encoding.pkg = sun.io
java.vm.name = Java HotSpot(TM) 64-Bit Server VM
sun.os.patch.level = unknown
sun.java.launcher = SUN_STANDARD
user.country = US
user.dir = /data
java.vm.specification.name = Java Virtual Machine Specification
java.runtime.version = 1.8.0_241-b07
java.awt.graphicsenv = sun.awt.X11GraphicsEnvironment
os.arch = amd64
java.endorsed.dirs = /usr/local/jdk1.8.0_241/jre/lib/endorsed
java.io.tmpdir = /tmp
line.separator =
java.vm.specification.vendor = Oracle Corporation
os.name = Linux
sun.jnu.encoding = UTF-8
java.library.path = /usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
java.specification.name = Java Platform API Specification
java.class.version = 52.0
sun.management.compiler = HotSpot 64-Bit Tiered Compilers
os.version = 4.18.0-147.el8.x86_64
user.home = /root
user.timezone = Asia/Shanghai
java.awt.printerjob = sun.print.PSPrinterJob
file.encoding = UTF-8
java.specification.version = 1.8
user.name = root
java.class.path = /usr/local/jdk/lib/:/usr/local/jdk/jre/lib/
java.vm.specification.version = 1.8
sun.arch.data.model = 64
sun.java.command = HelloWorld
java.home = /usr/local/jdk1.8.0_241/jre
user.language = en
java.specification.vendor = Oracle Corporation
awt.toolkit = sun.awt.X11.XToolkit
java.vm.info = mixed mode
java.version = 1.8.0_241
java.ext.dirs = /usr/local/jdk1.8.0_241/jre/lib/ext:/usr/java/packages/lib/ext
sun.boot.class.path = /usr/local/jdk1.8.0_241/jre/lib/resources.jar:/usr/local/jdk1.8.0_241/jre/lib/rt.jar:/usr/local/jdk1.8.0_241/jre/lib/sunrsasign.jar:/usr/local/jdk1.8.0_241/jre/lib/jsse.jar:/usr/local/jdk1.8.0_241/jre/lib/jce.jar:/usr/local/jdk1.8.0_241/jre/lib/charsets.jar:/usr/local/jdk1.8.0_241/jre/lib/jfr.jar:/usr/local/jdk1.8.0_241/jre/classes
java.vendor = Oracle Corporation
file.separator = /
java.vendor.url.bug = http://bugreport.sun.com/bugreport/
sun.io.unicode.encoding = UnicodeLittle
sun.cpu.endian = little
sun.cpu.isalist =
VM Flags:
Non-default VM flags: -XX:CICompilerCount=2 -XX:InitialHeapSize=268435456 -XX:MaxHeapSize=536870912 -XX:MaxNewSize=178913280 -XX:MinHeapDeltaBytes=196608 -XX:NewSize=89456640 -XX:OldSize=178978816 -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseFastUnorderedTimeStamps
Command line: -Xms256m -Xmx512m
[root@tomcat ~]#jinfo -flags 21407
Attaching to process ID 21407, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 25.241-b07
Non-default VM flags: -XX:CICompilerCount=2 -XX:InitialHeapSize=268435456 -XX:MaxHeapSize=536870912 -XX:MaxNewSize=178913280 -XX:MinHeapDeltaBytes=196608 -XX:NewSize=89456640 -XX:OldSize=178978816 -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseFastUnorderedTimeStamps
Command line: -Xms256m -Xmx512m
jstat：输出指定的java进程的统计信息
jstat -help|-options
jstat -
