不让用常量类，那就用.properties文件配置，放在根目录。

 

1 import java.util.HashMap; 2 import java.util.Iterator; 3 import java.util.Map; 4 import java.util.Properties; 5  6 /** 7  * Created by syl on 2017/12/12 0007. 读取常量properties文件 8  */ 9 public class PropertyUtil {  10     @SuppressWarnings("rawtypes")11     private static Map map = null;  12   13     @SuppressWarnings({ "rawtypes", "unchecked" })14     private static void loadFile() {  15         map = new HashMap();  16         try {  17             Properties p = new Properties();  18             p.load(PropertyUtil.class.getClassLoader().getResourceAsStream("params.properties"));  19             Iterator it = p.keySet().iterator();  20             while (it.hasNext()) {  21                 String key = (String) it.next();  22                 String value = p.getProperty(key);  23                 map.put(key, value);  24             }  25         } catch (Exception e) {  26             e.printStackTrace();  27         }  28     }  29   30     public static String getValue(String str) {  31         if (map == null) {  32             loadFile();  33         }  34         return (String) map.get(str);  35     }  36     37     public static void main(String[] args) {38         String s = PropertyUtil.getValue("test");39         System.out.println(s);40     }41 }

 控制台输出：