Java选项Xmx代表什么？

# 1 楼答案

应用程序的最大堆使用量为1024MB

# 2 楼答案

-Xmx设置最大堆大小

# 3 楼答案

C:\java -X

    -Xmixed           mixed mode execution (default)
    -Xint             interpreted mode execution only
    -Xbootclasspath:<directories and zip/jar files separated by ;>
                      set search path for bootstrap classes and resources
    -Xbootclasspath/a:<directories and zip/jar files separated by ;>
                      append to end of bootstrap class path
    -Xbootclasspath/p:<directories and zip/jar files separated by ;>
                      prepend in front of bootstrap class path
    -Xnoclassgc       disable class garbage collection
    -Xincgc           enable incremental garbage collection
    -Xloggc:<file>    log GC status to a file with time stamps
    -Xbatch           disable background compilation
    -Xms<size>        set initial Java heap size
    -Xmx<size>        set maximum Java heap size
    -Xss<size>        set java thread stack size
    -Xprof            output cpu profiling data
    -Xfuture          enable strictest checks, anticipating future default
    -Xrs              reduce use of OS signals by Java/VM (see documentation)
    -Xcheck:jni       perform additional checks for JNI functions
    -Xshare:off       do not attempt to use shared class data
    -Xshare:auto      use shared class data if possible (default)
    -Xshare:on        require using shared class data, otherwise fail.

The -X options are non-standard and subject to change without notice.

# 4 楼答案

看这里：Java Tool Doc，上面写着

-Xmxn
Specify the maximum size, in bytes, of the memory allocation pool. This value must a multiple of 1024 greater than 2MB. Append the letter k or K to indicate kilobytes, or m or M to indicate megabytes. The default value is 64MB. The upper limit for this value will be approximately 4000m on Solaris 7 and Solaris 8 SPARC platforms and 2000m on Solaris 2.6 and x86 platforms, minus overhead amounts. Examples:
           -Xmx83886080
           -Xmx81920k
           -Xmx80m

因此，简单地说，您将Java堆内存设置为可用内存的最大1024MB，而不是更多

注意，在-Xmx和1024m之间没有空间

不管你用大写还是小写。例如：“-Xmx10G”和“-Xmx10G”做完全相同的事情

# 5 楼答案

-Xmx选项更改VM的最大堆空间。java-Xmx1024m意味着虚拟机最多可以分配1024MB的内存。用外行术语来说，这意味着应用程序最多可以使用1024MB的内存

Python中文网

有 Java 编程相关的问题?