java -jar

JDK8： https://docs.oracle.com/javase/8/docs/technotes/tools/unix/java.html (opens new window)

JDK17：https://docs.oracle.com/en/java/javase/17/docs/specs/man/java.html (opens new window)

java -jar

java [options] -jar <jar 文件> [args...]

Java Options

标准参数（-）

所有JVM都必须实现，向下兼容。

非标准参数（-X）

默认JVM实现，不保证所有JVM实现都满足，不保证向下兼容，选项如有更改, 不另行通知。

java -X 可以列出不标准的参数

非稳定参数（-XX）

各个JVM实现会有所不同，这些都是不稳定的并且不推荐在生产环境中使用。将来可能会随时取消，需要慎重使用，而且如果在新版本有什么改动也不会发布通知。

-XX参数主要用于JVM的调优和debug操作，分两类：

1. 布尔类型

   # 打开/启用name参数
   -XX:+<name>
   # 关闭/禁用name参数
   -XX:-<name>
   

2. 键值类型

   # 将name参数值设置为value
   -XX:<name>=<value>
   

常用参数

Options	Usage
-Xmn	Sets the initial and maximum size (in bytes) of the heap for the young generation (nursery) in the generational collectors. Append the letter k or K to indicate kilobytes, m or M to indicate megabytes, or g or G to indicate gigabytes. The young generation region of the heap is used for new objects. GC is performed in this region more often than in other regions. If the size for the young generation is too small, then a lot of minor garbage collections are performed. If the size is too large, then only full garbage collections are performed, which can take a long time to complete. It is recommended that you do not set the size for the young generation for the G1 collector, and keep the size for the young generation greater than 25% and less than 50% of the overall heap size for other collectors. The following examples show how to set the initial and maximum size of young generation to 256 MB using various units: -Xmn256m -Xmn262144k -Xmn268435456 Instead of the -Xmn option to set both the initial and maximum size of the heap for the young generation, you can use -XX:NewSize to set the initial size and -XX:MaxNewSize to set the maximum size.
-Xms	Sets the minimum and the initial size (in bytes) of the heap. This value must be a multiple of 1024 and greater than 1 MB. Append the letter k or K to indicate kilobytes, m or M to indicate megabytes, or g or G to indicate gigabytes. The following examples show how to set the size of allocated memory to 6 MB using various units: -Xms6291456 -Xms6144k -Xms6m If you do not set this option, then the initial size will be set as the sum of the sizes allocated for the old generation and the young generation. The initial size of the heap for the young generation can be set using the -Xmn option or the -XX:NewSize option. Note that the -XX:InitalHeapSize option can also be used to set the initial heap size. If it appears after -Xms on the command line, then the initial heap size gets set to the value specified with -XX:InitalHeapSize.
-Xmx	Specifies the maximum size (in bytes) of the heap. This value must be a multiple of 1024 and greater than 2 MB. Append the letter k or K to indicate kilobytes, m or M to indicate megabytes, or g or G to indicate gigabytes. The default value is chosen at runtime based on system configuration. For server deployments, -Xms and -Xmx are often set to the same value. The following examples show how to set the maximum allowed size of allocated memory to 80 MB using various units: -Xmx83886080 -Xmx81920k -Xmx80m The -Xmx option is equivalent to -XX:MaxHeapSize.
-XX:+HeapDumpOnOutOfMemoryError	Enables the dumping of the Java heap to a file in the current directory by using the heap profiler (HPROF) when a java.lang.OutOfMemoryError exception is thrown. You can explicitly set the heap dump file path and name using the -XX:HeapDumpPath option. By default, this option is disabled and the heap isn't dumped when an OutOfMemoryError exception is thrown.
-XX:HeapDumpPath=path	Sets the path and file name for writing the heap dump provided by the heap profiler (HPROF) when the -XX:+HeapDumpOnOutOfMemoryError option is set. By default, the file is created in the current working directory, and it's named java_pid.hprof where is the identifier of the process that caused the error.

JDK8	JDK17	Usage
-XX:+PrintGC	-Xlog:gc	Enables printing of messages at every GC. By default, this option is disabled.

Application args

# SpringBoot非选项参数
java -jar <jar 文件> abc def
# SpringBoot选项参数
java -jar <jar 文件> --server.port=8080