Java常用实体类

System类

　　访问系统属性 - 遍历

 package org.zln.usefulclass.system;

 import java.util.Properties;

 /**
  * Created by sherry on 000024/6/24 23:08.
  */
 public class TestSystemProperty {
     public static void main(String[] args) {
         //showSystemProperties();
         /*获取某个系统属性*/
         System.out.println(System.getProperty("java.version"));
     }

     /**
      * 遍历系统所有属性
      */
     private static void showSystemProperties() {
         Properties properties = System.getProperties();
         properties.list(System.out);
     }
 }

D:\GitHub\tools\JavaEEDevelop\Lesson1_JavaSe_Demo1\src\org\zln\usefulclass\system\TestSystemProperty.java

　　遍历环境变量

     /**
      * 遍历环境变量
      */
     public static void showEnvProperties(){
         Map<String,String> map = System.getenv();
         Iterator<String> iterator = map.keySet().iterator();
         while (iterator.hasNext()){
             String k = iterator.next();
             String v = map.get(k);
             System.out.println(k+":"+v);
         }
     }

遍历环境变量