How to read data from java properties file using Spring Boot

I have a spring boot application and I want to read some variable from my application.properties file. In fact below codes do that. But I think there is a good method for this alternative.

Properties prop = new Properties();
InputStream input = null;

try {
    input = new FileInputStream("config.properties");
    prop.load(input);
    gMapReportUrl = prop.getProperty("gMapReportUrl");
} catch (IOException ex) {
    ex.printStackTrace();
} finally {
    ...
}

Solution 1:

You can use @PropertySource to externalize your configuration to a properties file. There is number of way to do get properties:

1. Assign the property values to fields by using @Value with PropertySourcesPlaceholderConfigurer to resolve ${} in @Value:

@Configuration
@PropertySource("file:config.properties")
public class ApplicationConfiguration {

    @Value("${gMapReportUrl}")
    private String gMapReportUrl;

    @Bean
    public static PropertySourcesPlaceholderConfigurer propertyConfigInDev() {
        return new PropertySourcesPlaceholderConfigurer();
    }

}

2. Get the property values by using Environment:

@Configuration
@PropertySource("file:config.properties")
public class ApplicationConfiguration {

    @Autowired
    private Environment env;

    public void foo() {
        env.getProperty("gMapReportUrl");
    }

}

Hope this can help

Solution 2:

I have created following class

ConfigUtility.java

@Configuration
public class ConfigUtility {

    @Autowired
    private Environment env;

    public String getProperty(String pPropertyKey) {
        return env.getProperty(pPropertyKey);
    }
}

and called as follow to get application.properties value

myclass.java

@Autowired
private ConfigUtility configUtil;

public AppResponse getDetails() {

  AppResponse response = new AppResponse();
    String email = configUtil.getProperty("emailid");
    return response;        
}

application.properties

[email protected]

unit tested, working as expected...