-XX:+PrintCommandLineFlags -XX:+PrintFlagsFinal 
jvm启动时打印 命令行jvm参数及最终所有参数和值

jcmd PID VM.flags 

jcmd PID VM.flags -all
加上all  输出所有参数及值 与 PrintFlagsFinal 输出的一样


jcmd PID VM.command_line

VM Arguments:
jvm_args
java_command
java_class_path

jcmd PID VM.flags -all |grep  manageable

输出所有可管理的参数  

     intx CMSAbortablePrecleanWaitMillis            = 100                                 {manageable}
     intx CMSTriggerInterval                        = -1                                  {manageable}
     intx CMSWaitDuration                           = 2000                                {manageable}
     bool HeapDumpAfterFullGC                       = false                               {manageable}
     bool HeapDumpBeforeFullGC                      = false                               {manageable}
     bool HeapDumpOnOutOfMemoryError                = false                               {manageable}
    ccstr HeapDumpPath                              =                                     {manageable}
    uintx MaxHeapFreeRatio                          = 70                                  {manageable}
    uintx MinHeapFreeRatio                          = 40                                  {manageable}
     bool PrintClassHistogram                       = false                               {manageable}
     bool PrintClassHistogramAfterFullGC            = false                               {manageable}
     bool PrintClassHistogramBeforeFullGC           = false                               {manageable}
     bool PrintConcurrentLocks                      = false                               {manageable}
     bool PrintGC                                  := true                                {manageable}
     bool PrintGCDateStamps                         = false                               {manageable}
     bool PrintGCDetails                           := true                                {manageable}
     bool PrintGCID                                 = false                               {manageable}
     bool PrintGCTimeStamps                        := true                                {manageable}
     
     
不带冒号的是默认值

开启HeapDumpAfterFullGC 
jinfo -flag +HeapDumpAfterFullGC PID

关闭HeapDumpAfterFullGC 
jinfo -flag -HeapDumpAfterFullGC PID
 
jinfo -flag $name         
print the value of the named VM flag
 
jinfo -flag [+|-]$name    
enable or disable the named VM flag

jinfo -flag $name=$value 
set the named VM flag to the given value


-XX:+PrintFlagsFinal -XX:+PrintCommandLineFlags -verbose:gc -XX:+PrintGC -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps -XX:+UseConcMarkSweepGC

-XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps

-XX:+PrintFlagsFinal -XX:+PrintCommandLineFlags -verbose:gc -XX:+PrintGC -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+UseConcMarkSweepGC

-XX:+PrintFlagsFinal -XX:+PrintCommandLineFlags -verbose:gc -XX:+PrintGC -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+UseG1GC

-XX:+PrintFlagsFinal -XX:+PrintCommandLineFlags -verbose:gc -XX:+PrintGC -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+UseSerialGC

-XX:+PrintFlagsFinal -XX:+PrintCommandLineFlags -verbose:gc -XX:+PrintGC -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+UseParallelGC