java读取properties配置文件

Properties properties =new Properties();

// CASE 1
try{
//在加载的class文件中加载，文件是和类文件放在一下的
ClassLoader loader =PropertiesUtil.class.getClassLoader();
InputStream inStream = loader.getResourceAsStream("config.properties");
properties.load(inStream);
value = properties.getProperty(propKey);
}catch(Exception e){
logger.error("An error occured!");
}

// CASE 2
try{
//loadAllProperties直接使用路径
properties = PropertiesLoaderUtils.loadAllProperties("E:/config.properties");
properties.getProperty(propKey);
}catch(Exception e){
logger.error("An error occured!");
}

// CASE 3
try{
Resource resource = new ClassPathResource("config.properties");
properties =PropertiesLoaderUtils.loadProperties(resource);
value = properties.getProperty(propKey);
}catch(Exception e){
logger.error("An error occured!");
}

// CASE 4
try{
Resource resource = new ClassPathResource("config.properties");
PropertiesLoaderUtils.fillProperties(properties, resource);
value = properties.getProperty(propKey);
}catch(Exception e){
logger.error("An error occured!");
}