load resource file [classpathresource]

<bean id="contents" class="org.springframework.core.io.ClassPathResource">
        <constructor-arg value="aaa.rule.properties"/>
</bean>

@Autowired
    private Resource contents;

    @PostConstruct
    public void (){
        try {
            System.out.println("step 0");

            final InputStream inputStream = contents.getInputStream();
            //use the stream

            System.out.println("step 1");

            BufferedReader br = new BufferedReader(new InputStreamReader(inputStream));

            System.out.println("step 2");
            StringBuilder stringBuilder = new StringBuilder();
            String line;

            System.out.println("step 3");
            while ((line = br.readLine()) != null) {
                stringBuilder.append(line).append('n');
            }
            br.close();

            System.out.println(stringBuilder.toString());
        }catch (IOException e) {
            System.out.println(e.toString());
        }
    }