RESTX JDBC support with BoneCP for connexion pool and Flyway for migration

AppModule.java

// In AppModule class, or could be in a dedicated module.


    @Provides
    public DBI dbi(@Named("datasource") DataSource ds) {
        return new DBI(ds);
    }

BoneCpModule.java

import com.google.common.base.Optional;
import com.google.common.base.Throwables;
import com.jolbox.bonecp.BoneCPDataSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import restx.config.Settings;
import restx.config.SettingsKey;
import restx.factory.AutoStartable;
import restx.factory.Module;
import restx.factory.Provides;

import javax.inject.Named;
import javax.sql.DataSource;

@Module
public class BoneCpModule {
    private static final Logger logger = LoggerFactory.getLogger(BoneCpModule.class);

    @Settings
    public static interface DatasourceSettings {
        @SettingsKey(key = "restx.jdbc.driver")
        String jdbcDriver();
        @SettingsKey(key = "restx.jdbc.url")
        String jdbcUrl();
        @SettingsKey(key = "restx.jdbc.username")
        String jdbcUsername();
        @SettingsKey(key = "restx.jdbc.password")
        Optional<String> jdbcPassword();
        @SettingsKey(key = "restx.jdbc.admin.username")
        Optional<String> jdbcAdminUsername();
        @SettingsKey(key = "restx.jdbc.admin.password")
        Optional<String> jdbcAdminPassword();
    }

    @Provides
    public AutoStartable startDatasources(@Named("datasource") DataSource dataSource,
                                          @Named("adminDatasource") DataSource adminDatasource) {
        return new AutoStartable() {
            @Override
            public void start() {
                logger.info("connected to database");
            }
        };
    }

    // datasource used for the app, DML grants are enough
    @Provides
    public DataSource datasource(DatasourceSettings settings) {
        try {
            Class.forName(settings.jdbcDriver());
        } catch (ClassNotFoundException e) {
            throw new IllegalArgumentException("invalid driver " + settings.jdbcDriver() + ": it can't be loaded." +
                    " Check your classpath and settings.");
        }
        BoneCPDataSource ds = new BoneCPDataSource();
        ds.setJdbcUrl(settings.jdbcUrl());
        ds.setUsername(settings.jdbcUsername());
        ds.setPassword(settings.jdbcPassword().or(""));
        return ds;
    }

    // datasource used to migrate the schema, need DDL grants
    @Provides
    public DataSource adminDatasource(DatasourceSettings settings) {
        try {
            Class.forName(settings.jdbcDriver());
        } catch (ClassNotFoundException e) {
            throw new IllegalArgumentException("invalid driver " + settings.jdbcDriver() + ": it can't be loaded." +
                    " Check your classpath and settings.");
        }
        BoneCPDataSource ds = new BoneCPDataSource();
        ds.setJdbcUrl(settings.jdbcUrl());
        ds.setUsername(settings.jdbcAdminUsername().or(settings.jdbcUsername() + "-admin"));
        ds.setPassword(settings.jdbcAdminPassword().or(settings.jdbcPassword()).or(""));
        return ds;
    }
}

DBIContext.java

import org.skife.jdbi.v2.Handle;

import static com.google.common.base.Preconditions.checkNotNull;

/**
 * Store current DBI context in a thread local
 */
public class DBIContext {
    private static final ThreadLocal<Handle> current = new ThreadLocal<>();

    public static void set(Handle handle) {
        current.set(handle);
    }

    public static Handle get() {
        return checkNotNull(current.get());
    }

    public static void clear() {
        current.remove();
    }
}

DBIFilter.java

import com.google.common.base.Optional;
import org.skife.jdbi.v2.DBI;
import org.skife.jdbi.v2.Handle;
import restx.*;
import restx.factory.Component;

import java.io.IOException;

/**
 * Auto Open DBI Handle for each request, setting the current Handle in DBIContext.
 */
@Component
public class DBIFilter implements RestxFilter, RestxHandler {
    private final DBI dbi;

    public DBIFilter(DBI dbi) {
        this.dbi = dbi;
    }

    @Override
    public Optional<RestxHandlerMatch> match(RestxRequest req) {
        if (req.getRestxPath().startsWith("/@")) {
            return Optional.absent();
        }
        return RestxHandlerMatch.of(Optional.of(new StdRestxRequestMatch(req.getRestxPath())), this);
    }

    @Override
    public void handle(RestxRequestMatch match, RestxRequest req, RestxResponse resp, RestxContext ctx) throws IOException {
        try (Handle h = dbi.open()) {
            DBIContext.set(h);

            ctx.nextHandlerMatch().handle(req, resp, ctx);
        } finally {
            DBIContext.clear();
        }
    }
}

FlywayAutoMigrate.java

import com.googlecode.flyway.core.Flyway;
import restx.AppSettings;
import restx.factory.AutoStartable;
import restx.factory.Component;

import javax.inject.Named;
import javax.sql.DataSource;

@Component
public class FlywayAutoMigrate implements AutoStartable {
    private final DataSource dataSource;
    private final AppSettings appSettings;

    public FlywayAutoMigrate(@Named("adminDatasource") DataSource dataSource,
                             AppSettings appSettings) {
        this.dataSource = dataSource;
        this.appSettings = appSettings;
    }

    @Override
    public void start() {
        Flyway flyway = new Flyway();
        flyway.setDataSource(dataSource);

        // set the locations depending on the mode, allow for instance to have more scripts in 'dev', like data initialization
        if ("dev".equals(appSettings.mode())) {
            flyway.setLocations("db");
        }

        flyway.migrate();
    }
}