[java学习点滴]PropertiesUtil 读取properties配置帮助类

  1 package com.hager.util;
  2 
  3 import java.io.File;
  4 import java.io.FileInputStream;
  5 import java.io.IOException;
  6 import java.io.InputStream;
  7 import java.util.Map;
  8 import java.util.Properties;
  9 
 10 /**
 11  * @Author wzh
 12  * @Date 2017/1/16.
 13  * @Version V1.0 15  * @Description 读取properties配置帮助类
 16  */
 17 public class PropertiesUtil {
 18 
 19 
 20     private PropertiesUtil() {
 21     }
 22 
 23     /**
 24      * 读取properties文件
 25      *
 26      * @param file 文件路径
 27      * @return 返回properties 对象
 28      */
 29     public static Properties fromFile(String file) {
 30         InputStream stream = null;
 31 
 32         try {
 33             stream = new FileInputStream(new File(file));
 34             return fromStream(stream);
 35         } catch (IOException e) {
 36             throw new RuntimeException(e);
 37         } finally {
 38             close(stream);
 39         }
 40     }
 41 
 42     /**
 43      * 读取properties文件
 44      *
 45      * @param file 文件路径
 46      * @return 返回properties 对象
 47      */
 48     public static Properties fromClasspath(String file) {
 49         InputStream stream = null;
 50         try {
 51             stream = Thread.currentThread().getContextClassLoader().getResourceAsStream(file);
 52             return fromStream(stream);
 53         } catch (Exception e) {
 54             throw new RuntimeException(e);
 55         } finally {
 56             close(stream);
 57         }
 58     }
 59 
 60     /**
 61      * convert stream  to properties
 62      *
 63      * @param stream InputStream
 64      * @return Properties
 65      * @throws IOException
 66      */
 67     private static Properties fromStream(InputStream stream) throws IOException {
 68         Properties dest = new Properties();
 69         Properties src = new Properties();
 70         src.load(stream);
 71 
 72         // 如果key value为字符串，需要trim一下
 73         for (Map.Entry<Object, Object> entry : src.entrySet()) {
 74             Object key = entry.getKey();
 75             Object value = entry.getValue();
 76 
 77             Object newKey = key;
 78             Object newValue = value;
 79             if (newKey instanceof String) {
 80                 newKey = key.toString().trim();
 81             }
 82 
 83             if (newValue instanceof String) {
 84                 newValue = value.toString().trim();
 85             }
 86 
 87             dest.put(newKey, newValue);
 88         }
 89 
 90         return dest;
 91     }
 92 
 93     /**
 94      * dispose stream
 95      *
 96      * @param stream InputStream
 97      */
 98     private static void close(InputStream stream) {
 99         if (stream != null) {
100             try {
101                 stream.close();
102             } catch (IOException e) {
103             }
104         }
105     }
106 }

配置文件：

位于

src/main/resources/test.properties;
内容简单：

test=aaa

测试：

 1  @Test
 2     public void fromClasspath() throws Exception {
 3         String fileName = "test.properties";
 4 
 5         Properties properties = PropertiesUtil.fromClasspath(fileName);
 6         String values = properties.getProperty("test");
 7         System.out.println(JsonHelper.serialize(properties));
 8 
 9         Assert.assertEquals("aaa", values);
10         Assert.assertNotNull(properties);
11     }

结果：

{"test":"aaa"}

Process finished with exit code 0