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);
    }
}

　　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);
        }
    }