//静态代码块class test16 {private static final String URL;private static final String DEVICE;private static final String USER;private static final String ROOT;static test16 self;static {URL="歌谣";DEVICE="笔记本电脑";USER="root";ROOT="歌谣";if(self==null){self=new test16();}}public static String getURL() {return URL;}public static String getDEVICE() {return DEVICE;}public static String getUSER() {return USER;}public static String getROOT() {return ROOT;}public test16(){}
}

定义一个测试类

public class test17 {public static void main(String[] args){System.out.println(test16.getDEVICE());}
}

运行结果