Hibernate: External connection config file-CodePudding

I currently have my Hibernate configuration file hibernate.cfg.xml in my Spring web app classpath and use Maven resources plugin to set different values for my dev and production databases like this:

reources/hibernate.cfg.xml:

<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD//EN"
        "../hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.driver_class">@hibernate.connection.driver_class@</property>
        <property name="hibernate.connection.url">@hibernate.connection.url@</property>
        <property name="hibernate.dialect">@hibernate.dialect@</property>
        <property name="hibernate.default_schema">@hibernate.default_schema@</property>
        <property name="hibernate.connection.username">@hibernate.connection.username@</property>
        <property name="hibernate.connection.password">@hibernate.connection.password@</property>
        <property name="hibernate.connection.requireSSL">false</property>
        <property name="hibernate.connection.autoReconnect">true</property>
        <property name="hibernate.enable_lazy_load_no_trans">true</property>
        <!--<property name="hbm2ddl.auto">update</property>-->
        <property name="hibernate.show_sql">false</property>
        <property name="hibernate.format_sql">false</property>
        <property name="hibernate.connection.CharSet">utf8</property>
        <property name="hibernate.connection.characterEncoding">utf8</property>
        <property name="hibernate.connection.useUnicode">true</property>

        <property name="hibernate.connection.provider_class">org.hibernate.c3p0.internal.C3P0ConnectionProvider</property>
        <property name="hibernate.c3p0.min_size">1</property>
        <property name="hibernate.c3p0.max_size">50</property>
        <property name="hibernate.c3p0.timeout">120</property>
        <property name="hibernate.c3p0.max_statements">50</property>
    </session-factory>
</hibernate-configuration>

pom.xml (example) :

    <profiles>
        <profile>
            <id>dev</id>
            <activation>
                <activeByDefault>true</activeByDefault>
            </activation>
            <properties>
                <hibernate.connection.driver_class>com.mysql.cj.jdbc.Driver</hibernate.connection.driver_class>
                <hibernate.connection.url>jdbc:mysql://localhost:3306/dev_db</hibernate.connection.url>
                <hibernate.dialect>org.hibernate.dialect.MySQL5Dialect</hibernate.dialect>
                <hibernate.default_schema></hibernate.default_schema>
                <hibernate.connection.username>dev_username</hibernate.connection.username>
                <hibernate.connection.password>dev_password</hibernate.connection.password>
            </properties>
        </profile>
        <profile>
            <id>deploy</id>
            <properties>
                <hibernate.connection.driver_class>com.mysql.cj.jdbc.Driver</hibernate.connection.driver_class>
                <hibernate.connection.url>jdbc:mysql://localhost:3306/deploy_db</hibernate.connection.url>
                <hibernate.dialect>org.hibernate.dialect.MySQL5Dialect</hibernate.dialect>
                <hibernate.default_schema></hibernate.default_schema>
                <hibernate.connection.username>deploy_username</hibernate.connection.username>
                <hibernate.connection.password>deploy_password</hibernate.connection.password>
            </properties>
        </profile>
    </profiles>

Those settings are loaded by a LocalSessionFactoryBean like this:

    @Bean( name = "sessionFactory" )
    public LocalSessionFactoryBean sessionFactory() {
        LocalSessionFactoryBean localSessionFactoryBean = new LocalSessionFactoryBean();
        localSessionFactoryBean.setDataSource( dataSource() );
        localSessionFactoryBean.setConfigLocation( new ClassPathResource( "hibernate.cfg.xml" ) );
        localSessionFactoryBean.setPackagesToScan( "org.example" );

        return localSessionFactoryBean;
    }

But now I need to ship software to a client who obviously won't want me to know their DB connection properties, so I want to move these properties out of my project to some local resource (like C:\MyEpicProgram\db.properties) which will be set separately in each environment (mine local, client's test server, client's deploy server etc.) and just linked to my app via JVM arguments (like -DdbConfigPath=C:\MyEpicProgram\db.properties)

So that I get something like that: db.properties:

hibernate.connection.driver_class com.mysql.cj.jdbc.Driver
hibernate.connection.url jdbc:mysql://localhost:3306/client_db
hibernate.dialect org.hibernate.dialect.MySQL5Dialect
hibernate.default_schema
hibernate.connection.username client_username
hibernate.connection.password client_password

And those will be automatically used on project startup in that environment. How can I achieve that? I've been trying to modify my session factory bean to manually set up each parameter but as of now failed to do that correctly.

CodePudding user response：

You can try to do that like this. However, it's not really recommended to do that, because you're coupling that file to your application.

@Configuration
public class Configuration {
    @Autowired
    private Environment environment;

    @Bean
    public LocalSessionFactoryBean localSessionFactoryBean() {
        LocalSessionFactoryBean localSessionFactoryBean = new LocalSessionFactoryBean();
        localSessionFactoryBean.setDataSource( dataSource() );
        localSessionFactoryBean.setConfigLocation( new ClassPathResource( "hibernate.cfg.xml" ) );
        localSessionFactoryBean.setPackagesToScan( "org.example" );

        Properties properties = new Properties();
        properties.load(new FileInputStream(environment.getProperty("dbConfigPath")));

        localSessionFactoryBean.setHibernateProperties(properties);
        
        return localSessionFactoryBean;
    }
}

What you could do instead is using an environment variable to define your Hibernate properties which is described here.

CodePudding user response：

So, I have solved my problem like this, taking inspiration from Flavalacious' suggestion:

@Configuration
public class DBConfig {
    private final Logger logger = Logger.getLogger( this.getClass() );

    private String dataSourceDriverClass;
    private String dataSourceDialect;
    private String dataSourceUrl;
    private String dataSourceUsername;
    private String dataSourcePassword;

    public DBConfig() {
        Properties jdbcProperties = new Properties();

        if ( System.getProperty( "dbConfigPath" ) == null )
            throw new IllegalStateException( "Property -DdbConfigPath must be provided in VM options." );

        try ( InputStream fileStream = new FileInputStream( filePath ) ) {
            // load properties from file
            jdbcProperties.load( fileStream );

            // setting properties from file to local variables for usage in various beans
            dataSourceUrl = jdbcProperties.getProperty( "url" );
            dataSourceUsername = jdbcProperties.getProperty( "username" );
            dataSourcePassword = jdbcProperties.getProperty( "password" );
            dataSourceDriverClass = jdbcProperties.getProperty( "driverClass" );
            dataSourceDialect = jdbcProperties.getProperty( "dialect" );
        } catch ( IOException e ) {
            logger.error( "Couldn't load JDBC properties." );
        }
    }

    @Bean(name = "dataSource")
    public DriverManagerDataSource dataSource() {
        DriverManagerDataSource driverManagerDataSource = new DriverManagerDataSource();

        // use loaded parameters to configure datasource
        driverManagerDataSource.setDriverClass( dataSourceDriverClass );
        driverManagerDataSource.setJdbcUrl( dataSourceUrl );
        driverManagerDataSource.setUser( dataSourceUsername );
        driverManagerDataSource.setPassword( dataSourcePassword );
        return driverManagerDataSource;
    }

    @Bean( name = "sessionFactory" )
    public LocalSessionFactoryBean sessionFactory() {
        LocalSessionFactoryBean localSessionFactoryBean = new LocalSessionFactoryBean();
        localSessionFactoryBean.setDataSource( dataSource() );
        localSessionFactoryBean.setConfigLocation( new ClassPathResource( "hibernate.cfg.xml" ) ); // the following properties are not present in this XML
        localSessionFactoryBean.setPackagesToScan( "org.example" );

        // set our properties to be discoverable by SessionFactory
        localSessionFactoryBean.getHibernateProperties().setProperty( "hibernate.connection.driver_class", dataSourceDriverClass );
        localSessionFactoryBean.getHibernateProperties().setProperty( "hibernate.connection.url", dataSourceUrl );
        localSessionFactoryBean.getHibernateProperties().setProperty( "hibernate.connection.username", dataSourceUsername );
        localSessionFactoryBean.getHibernateProperties().setProperty( "hibernate.connection.password", dataSourcePassword );
        localSessionFactoryBean.getHibernateProperties().setProperty( "hibernate.dialect", dataSourceDialect );
        if ( dataSourceDefaultSchema != null )
            localSessionFactoryBean.getHibernateProperties().setProperty( "hibernate.default_schema", dataSourceDefaultSchema );

        return localSessionFactoryBean;
    }
}

Path to the db.properties file must be provided in VM options like this: -DdbConfigPath=C:\path\to\db.properties