作者：david_zhang@sh 【转载时请以超链接形式标明文章】
https://www.cnblogs.com/david-zhang-index/p/16846493.html
参数太多，傻傻分不清楚，简单说
1，program arguments是main函数args[]参数
2，vm arguments是java环境变量
3，environment variable是jvm环境变量
看代码如何获取这些参数：
public class TestProgram {public static void main(String[] args) {// program arguments对应的args参数for (String arg : args) {System.out.println(arg);}System.out.println("==============program arguments对应的args参数===============");System.out.println();// getProperty()获取java的环境变量String value1 = System.getProperty("key1");String value2 = System.getProperty("key2");System.out.println("System.getProperty(\"key1\")----->" + value1);System.out.println("System.getProperty(\"key2\")----->" + value2);Properties properties = System.getProperties();System.out.println("System.getProperties():=======>" + properties);System.out.println("==============getProperty()获取java的环境变量===============");System.out.println();// 获取运行jvm环境变量System.getenv();Map<String, String> getenv = System.getenv();System.out.println("System.getenv():----->" + getenv);String env1 = System.getenv("env1");String env2 = System.getenv("env2");System.out.println("System.getenv(\"env1\")=======>" + env1);System.out.println("System.getenv(\"env2\")=======>" + env2);System.out.println("===============获取运行jvm环境变量===============");System.out.println();}
}
-argu=111
-arge=222
==============program arguments对应的args参数===============
System.getProperty("key1")----->v1
System.getProperty("key2")----->v2
==============getProperty()获取java的环境变量===============
System.getenv("env1")=======>test
System.getenv("env2")=======>prod
==============获取运行jvm环境变量===============
参数设置
总结：
System.getProperty();
System.getProperties();
System.getenv();
