Load external properties file with same keys

Question

I have two properties file in a folder in file system. The path of this folder is passed using system properties -D=path/to/properties/folder

ex: java -jar -DpropDir=abc/def app.jar

These are properties files. Please note that both files have common key username,password.

mysql.properties

url=jdbc:mysql://localhost:3306
username=root
password=pass

vertica.properties

dburl=jdbc:vertica://123.123.123:4321/abcd
username=abcd
password=pass123

Now I want to access all these properties in respective classes. MySqlProperties.java and VerticaProperties.java like this.

@Component
public class VerticaProperties {

    @Value("${dburl}")
    private String dburl;
    @Value("${username}")
    private String username;
    @Value("${password}")
    private String password;

    public String getDbUrl() {
        return dburl;
    }

    public String getUsername() {
        return username;
    }

    public String getPassword() {
        return password;
    }
}

and similarly MySqlProperties.java

@Component
public class MySqlProperties {

    @Value("${url}")
    private String url;
    @Value("${username}")
    private String username;
    @Value("${password}")
    private String password;

    public String getDbUrl() {
        return url;
    }

    public String getUsername() {
        return username;
    }

    public String getPassword() {
        return password;
    }
}

But as key is same value is overriding for username and password.

How to access mysql.properties in MySqlProperties.java and vertica.properties in VerticaProperties.java classes.

How you add those properties to context? Using PropertySource? — talex
Only way I see is create your own PropertyPlaceholderConfigurer which will add prefix to keys, but it will be easier to just add prefix manually to your properties. — talex
@talex I tried the prefix method but its not working. config.setPlaceholderPrefix("${mysql."); Getting this error "Could not resolve placeholder 'vertica.dburl' in value "${vertica.dburl}"" — efex09

Noman Khan Noman Khan · Accepted Answer · 2018-12-26T09:55:09

You import external properties using @PropertySource

Given the location is shared as

-Dmysql.properties=file:/path-to-mysql.properties -Dvertica.properties=file:/path-to-vertica.properties

@Component
@PropertySource("${vertica.properties}")
public class VerticaProperties {
.....
}

@Component
@PropertySource("${mysql.properties}")
public class MySqlProperties {
....
}

or Given -Dmysql.properties=/path-to-mysql.properties -Dvertica.properties=/path-to-vertica.properties

@Component
    @PropertySource("file:${vertica.properties}")
    public class VerticaProperties {
    .....
    }

    @Component
    @PropertySource("file:${mysql.properties}")
    public class MySqlProperties {
    ....
    }

Additionally , you may also use prefix with @ConfigurationProperties along with @PropertySource.

The annotation works best when we have hierarchical properties that all have the same prefix, so we mention the prefix too as a part of the annotation.

Add prefix to keys like mysql.url , vertica.url in respective files

@Component
@PropertySource("${vertica.properties}")
@ConfigurationProperties(prefix="vertica")
public class VerticaProperties {
.....
}

@Component
@PropertySource("${mysql.properties}")
@ConfigurationProperties(prefix="mysql")
public class MySqlProperties {
....
}

Load external properties file with same keys

1 Answers