使用application.yml配置SpringBoot

Question

I have a little SpringBoot Application, which can execute different functions via OpenLdap.

• getUser
• createUser
• deleteUser
• etc.

That works fine. Now i want to create an application.Yml, where i can manage different environments with different credentials. I read some tutorials, but i still have some understanding problems. Actually my code looks like that:

UserController:

...
protected static String serverURL = "xxxxx:90xx";
protected static String LdapBindDn = "cn=admin, xxxxx";
protected static String LdapPassword = "xxxx";
...

@RequestMapping(value = "/{userid:.+}",method = RequestMethod.GET,consumes="application/json",produces = "application/json")
public UserData getUser(@PathVariable String userid) {          
    DirContext context = connectToLdap();
    //some operations...
    context.close();    
    return user;
}
... // same for the other functions

My plan is now, that i want to specify the credentials in an extra application.yml instead of at the beginning of the UserController (see above).

Then i have created an application.yml in the src/main/resources:

# Actual environment
spring: 
  profiles.actives: development
---
# Dev Profile 
spring:
  profiles: dev  
datasource:
  serverUrl: ldaps://xxxxxx:90xx
  AdminName: xxxx
  AdminPassword: xxxxxx
  BaseDN: xxxxx
---
# Production Profile  
spring:
  profiles: prod     
datasource:
 serverUrl: ldaps://xxxx2:90xx
 AdminName: xxxxx2
 AdminPassword: xxxxx2
 BaseDN: xxxxxx

Now i need to call this configuration. I have read in one tutorial ( http://therealdanvega.com/blog/2017/06/26/spring-boot-configuration-using-yaml ) that i have to create an extra class "ApplicationProperties" for the properties of the .yml file.

@Component
@ConfigurationProperties("datasource")
public class ApplicationProperties {

private String serverURL;
private String adminName;
private String adminPassword;
private String baseDN;

// Getter-/Setter-Methods

}

Now i need to define my variables from the beginning with the values from the .yml, right? I went back to my UserController and tried something like that:

private String serverURL;
private String adminName;
private String adminPassword;
private String baseDN;  

@Autowired   
ApplicationProperties appProp;

@RequestMapping(value = "/{userid:.+}",method = RequestMethod.GET,consumes="application/json",produces = "application/json")
public UserData getUser(@PathVariable String userid) {          
    DirContext context = connectToLdap();
    //some operations...
    context.close();    
    return user;
}
... // same for the other functions


private DirContext connectToLdap(){
    System.out.prinln(appProp.getServerURL());
    System.out.prinln(appProp.getAdminName());
    System.out.prinln(appProp.getAdminPassword());
    .... // Code for the Ldap connection 
}

But the variable "appProp" is still empty. I know, that here is somewhere a big understanding problem. I don't know how to call these properties from the .yml file.

Thanks for every help in advance!

Answer 1

You can get properties from your .yml file by creating a config class:

application.yml

datasource:
    serverUrl: ldaps://xxxxxx:90xx
    adminName: xxxx
    adminPassword: xxxxxx
    baseDN: xxxxx

ApplicationConfig.java class :

@Configuration
@EnableConfigurationProperties
@ConfigurationProperties(prefix = "datasource")
public class ApplicationConfig {

    private String serverUrl;
    private String adminName;
    private String adminPassword;
    private String baseDN;

    //getters setters

}

Then you can call your ApplicationConfig class

@Autowired
public ApplicationConfig app; 

public UserData getUser(@PathVariable String userid) {          
      DirContext context = connectToLdap();
      //some operations...
      appProp.getServerUrl();
      appProp.getAdminName();
      context.close();    
      return user;
}

And I recommend you to create profile based properties as spring boot picks them automatically, like application-{profile}.{properties|yml} You can create application-production.yml file and set your profile by adding @Profile("production") annotation in your class.