Java中读取properties配置文件的八种方式

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/**
 * @desc: Properties读取配置文件属性值的方式
 */
public class PropertiesTest {
 
    /**
     * 1. 方式一
     * 从当前的类加载器的getResourcesAsStream来获取
     * InputStream inputStream = ().getResourceAsStream(name)
     *
     * @throws IOException
     */
    @Test
    public void test1() throws IOException {
        InputStream inputStream = ().getResourceAsStream("");
        Properties properties = new Properties();
        (inputStream);
        ();
        ("==============================================");
        String property = ("");
        ("property = " + property);
    }
 
    /**
     * 2. 方式二
     * 从当前的类加载器的getResourcesAsStream来获取
     * InputStream inputStream = ().getClassLoader().getResourceAsStream(name)
     *
     * @throws IOException
     */
    @Test
    public void test5() throws IOException {
        InputStream inputStream = ().getClassLoader().getResourceAsStream("config/");
        Properties properties = new Properties();
        (inputStream);
        ();
        ("==============================================");
        String property = ("");
        ("property = " + property);
    }
 
    /**
     * 3. 方式三
     * 使用Class类的getSystemResourceAsStream方法 和使用当前类的ClassLoader是一样的
     * InputStream inputStream = (name)
     *
     * @throws IOException
     */
    @Test
    public void test4() throws IOException {
        InputStream inputStream = ("config/");
        Properties properties = new Properties();
        (inputStream);
        ();
        ("==============================================");
        String property = ("");
        ("property = " + property);
    }
 
    /**
     * 4. 方式四
     * Resource resource = new ClassPathResource(path)
     *
     * @throws IOException
     */
    @Test
    public void test2() throws IOException {
        Resource resource = new ClassPathResource("config/");
        Properties properties = (resource);
        ();
        ("==============================================");
        String property = ("");
        ("property = " + property);
    }
 
    /**
     * 5. 方式五
     * 从文件中获取,使用InputStream字节,主要是需要加上当前配置文件所在的项目src目录地址。路径配置需要精确到绝对地址级别
     * BufferedInputStream继承自InputStream
     * InputStream inputStream = new BufferedInputStream(new FileInputStream(name)
     * 这种方法读取需要完整的路径，优点是可以读取任意路径下的文件，缺点是不太灵活
     * @throws IOException
     */
    @Test
    public void test3() throws IOException {
        InputStream inputStream = new BufferedInputStream(new FileInputStream("src/main/resources/config/"));
        Properties properties = new Properties();
        (inputStream);
        ();
        ("==============================================");
        String property = ("");
        ("property = " + property);
    }
 
    /**
     * 6. 方式六
     * 从文件中获取,使用InputStream字节,主要是需要加上当前配置文件所在的项目src目录地址。路径配置需要精确到绝对地址级别
     * FileInputStream继承自InputStream
     * InputStream inputStream = new FileInputStream(name)
     * 这种方法读取需要完整的路径，优点是可以读取任意路径下的文件，缺点是不太灵活
     * @throws IOException
     */
    @Test
    public void test6() throws IOException {
        InputStream inputStream = new FileInputStream("src/main/resources/config/");
        Properties properties = new Properties();
        (inputStream);
        ();
        ("==============================================");
        String property = ("");
        ("property = " + property);
    }
 
    /**
     * 7. 方式七
     * 使用InputStream流来进行操作ResourceBundle，获取流的方式由以上几种。
     * ResourceBundle resourceBundle = new PropertyResourceBundle(inputStream);
     * @throws IOException
     */
    @Test
    public void test7() throws IOException {
        InputStream inputStream = ("config/");
        ResourceBundle resourceBundle = new PropertyResourceBundle(inputStream);
        Enumeration<String> keys = ();
        while (()) {
            String s = ();
            (s + " = " + (s));
        }
    }
 
    /**
     * 8. 方式八
     * 的路径访问和 类似，默认从根目录下读取，也可以读取resources目录下的文件
     * ResourceBundle rb = ("b") //不需要指定文件名的后缀,只需要写文件名前缀即可
     */
    @Test
    public void test8(){
        //ResourceBundle rb = ("jdbc"); //读取resources目录下的
        ResourceBundle rb2 = ("config/application");//读取resources/config目录下的
        for(String key : ()){
            String value = (key);
            (key + ":" + value);
        }
 
    }
 
 
 
    /**
     * 单独抽取的方法，用户检测能否正确操纵Properties
     *
     * @param inputStream
     * @throws IOException
     */
    private void printKeyValue(InputStream inputStream) throws IOException {
        Properties properties = new Properties();
        (inputStream);
        Set<Object> keys = ();
        for (Object key : keys) {
            (key + " = " + (key));
        }
    }
}