Java 几个有用的命令 - All Options, Memory Options, GC Options, System Properties, Thread Dump, Heap Dump

• jcmd  ##Refer to http://www.cnblogs.com/tang88seng/p/4497725.html
• java -XX:+PrintFlagsFinal -version   ##Display all JVM options
• java -XX:+PrintCommandLineFlags -version   ##Display default JVM Memory and GC options

-XX:InitialHeapSize= -XX:MaxHeapSize= -XX:+PrintCommandLineFlags -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:-UseLargePagesIndividualAllocation -XX:+UseParallelGC
java version "1.8.0_60"
Java(TM) SE Runtime Environment (build 1.8.0_60-b27)
Java HotSpot(TM) -Bit Server VM (build 25.60-b23, mixed mode)

• java -XshowSettings　　##Display system properties

java -XshowSettings
VM settings:
    Max. Heap Size (Estimated): .05G
    Ergonomics Machine Class: server
    Using VM: Java HotSpot(TM) -Bit Server VM

Property settings:
    awt.toolkit = sun.awt.X11.XToolkit
    file.encoding = UTF-
    file.encoding.pkg = sun.io
    file.separator = /
    java.awt.graphicsenv = sun.awt.X11GraphicsEnvironment
    java.awt.printerjob = sun.print.PSPrinterJob
    java.class.path = /XXXXX
    java.class.version = 51.0
    java.endorsed.dirs = /ptc/Windchill_10./Java/jre/lib/endorsed
    java.ext.dirs = /ptc/Windchill_10./Java/jre/lib/ext
        /usr/java/packages/lib/ext
    java.home = /ptc/Windchill_10./Java/jre
    java.io.tmpdir = /tmp
    java.library.path = /usr/java/packages/lib/amd64
        /usr/lib64
        /lib64
        /lib
        /usr/lib
    java.runtime.name = Java(TM) SE Runtime Environment
    java.runtime.version = 1.7.0_72-b14
    java.specification.name = Java Platform API Specification
    java.specification.vendor = Oracle Corporation
    java.specification.version = 1.7
    java.vendor = Oracle Corporation
    java.vendor.url = http://java.oracle.com/
    java.vendor.url.bug = http://bugreport.sun.com/bugreport/
    java.version = 1.7.0_72
    java.vm.info = mixed mode
    java.vm.name = Java HotSpot(TM) -Bit Server VM
    java.vm.specification.name = Java Virtual Machine Specification
    java.vm.specification.vendor = Oracle Corporation
    java.vm.specification.version = 1.7
    java.vm.vendor = Oracle Corporation
    java.vm.version = 24.72-b04
    line.separator = \n
    os.arch = amd64
    os.name = Linux
    os.version = 2.6.-371.8..el5
    path.separator = :
    sun.arch.data.model =
    sun.boot.class.path = /ptc/Windchill_10./Java/jre/lib/resources.jar
        /ptc/Windchill_10./Java/jre/lib/rt.jar
        /ptc/Windchill_10./Java/jre/lib/sunrsasign.jar
        /ptc/Windchill_10./Java/jre/lib/jsse.jar
        /ptc/Windchill_10./Java/jre/lib/jce.jar
        /ptc/Windchill_10./Java/jre/lib/charsets.jar
        /ptc/Windchill_10./Java/jre/lib/jfr.jar
        /ptc/Windchill_10./Java/jre/classes
    sun.boot.library.path = /ptc/Windchill_10./Java/jre/lib/amd64
    sun.cpu.endian = little
    sun.cpu.isalist =
    sun.desktop = gnome
    sun.io.unicode.encoding = UnicodeLittle
    sun.java.launcher = SUN_STANDARD
    sun.jnu.encoding = UTF-
    sun.management.compiler = HotSpot -Bit Tiered Compilers
    sun.os.patch.level = unknown
    user.country = US
    user.dir = /ptc/Windchill_10./Windchill/codebase/wt/workflow/expr
    user.home = /home/wcadmin
    user.language = en
    user.name = wcadmin
    user.timezone = 

Locale settings:
    default locale = English
    default display locale = English (United States)
    default format locale = English (United States)
    available locales = ar, ar_AE, ar_BH, ar_DZ, ar_EG, ar_IQ, ar_JO, ar_KW,
        ar_LB, ar_LY, ar_MA, ar_OM, ar_QA, ar_SA, ar_SD, ar_SY,
        ar_TN, ar_YE, be, be_BY, bg, bg_BG, ca, ca_ES,
        cs, cs_CZ, da, da_DK, de, de_AT, de_CH, de_DE,
        de_LU, el, el_CY, el_GR, en, en_AU, en_CA, en_GB,
        en_IE, en_IN, en_MT, en_NZ, en_PH, en_SG, en_US, en_ZA,
        es, es_AR, es_BO, es_CL, es_CO, es_CR, es_DO, es_EC,
        es_ES, es_GT, es_HN, es_MX, es_NI, es_PA, es_PE, es_PR,
        es_PY, es_SV, es_US, es_UY, es_VE, et, et_EE, fi,
        fi_FI, fr, fr_BE, fr_CA, fr_CH, fr_FR, fr_LU, ga,
        ga_IE, hi_IN, hr, hr_HR, hu, hu_HU, in, in_ID,
        is, is_IS, it, it_CH, it_IT, iw, iw_IL, ja,
        ja_JP, ja_JP_JP_#u-ca-japanese, ko, ko_KR, lt, lt_LT, lv, lv_LV,
        mk, mk_MK, ms, ms_MY, mt, mt_MT, nl, nl_BE,
        nl_NL, no, no_NO, no_NO_NY, pl, pl_PL, pt, pt_BR,
        pt_PT, ro, ro_RO, ru, ru_RU, sk, sk_SK, sl,
        sl_SI, sq, sq_AL, sr, sr_BA, sr_BA_#Latn, sr_CS, sr_ME,
        sr_ME_#Latn, sr_RS, sr_RS_#Latn, sr__#Latn, sv, sv_SE, th, th_TH,
        th_TH_TH_#u-nu-thai, tr, tr_TR, uk, uk_UA, vi, vi_VN, zh,
        zh_CN, zh_HK, zh_SG, zh_TW