Accessing property file in spring boot - spring-boot

Question

I am creating a simple spring boot application in which I am trying to access an external config.properties file.
IndexController.java
#Controller
public class IndexController {
XmlOperation xmlOperation = new XmlOperation();
#RequestMapping("/")
public String greeting() {
return "greeting";
}
#RequestMapping(params = "btnOpen", method = RequestMethod.POST)
public String uploadFile(#RequestParam("file") MultipartFile file, Model model) {
try {
InputStream is = file.getInputStream();
model.addAttribute("fileContent", xmlOperation.readXml(is));
} catch (IOException e) {
System.out.println(e.getMessage());
}
return "greeting";
}
}
XmlOperation.java
#PropertySource("classpath:config.properties")
public class XmlOperation {
#Autowired
Environment env;
public String readXml(InputStream is) throws IOException {
System.out.println(env.getProperty("filepath"));
StringWriter writer = new StringWriter();
IOUtils.copy(is, writer, StandardCharsets.UTF_8);
String fileContent = writer.toString();
return fileContent;
}
The config.properties file is situated in src/main/resources. I am not able to get the value from the property file.
Any help would be appreciated...

Answer 1

Well config.properties file in src/main/resources is alright but why do you initialize:
XmlOperation xmlOperation = new XmlOperation();
in IndexController? And I am also not sure whether XmlOperation is spring component (you have only #PropertySource over XmlOperation in the question).
Basically I would make XmlOperation as a spring #Component and with IoC inject this component into IndexController.
public String readXml(InputStream is) in XmlOperation behaves like standard service and I would create property filepath and inject value from configuration file (config.properties) with #Value annotation.
FULL EXAMPLE:
#Controller
public class IndexController {
#Autowired
private XmlOperation xmlOperation;
#RequestMapping("/")
public String greeting() {
return "greeting";
}
#RequestMapping(params = "btnOpen", method = RequestMethod.POST)
public String uploadFile(#RequestParam("file") MultipartFile file, Model model) {
try {
InputStream is = file.getInputStream();
model.addAttribute("fileContent", xmlOperation.readXml(is));
} catch (IOException e) {
System.out.println(e.getMessage());
}
return "greeting";
}
}
#Component
#PropertySource("classpath:config.properties")
public class XmlOperation {
// use this when XmlOperation is #Configuration bean and you want to create #Bean-s e.g
// #Autowired
// Environment env;
// for your case inject property like this
#Value("${filepath}")
private String filepath;
public String readXml(InputStream is) throws IOException {
// dont use this
//System.out.println(env.getProperty("filepath"));
// rather this
System.out.println(filepath);
StringWriter writer = new StringWriter();
IOUtils.copy(is, writer, StandardCharsets.UTF_8);
String fileContent = writer.toString();
return fileContent;
}
}