Multiple databases in dropwizard

Question

I am trying to read and write into two databases and I am running into issues:

config.yml

database1:
  driverClass: com.mysql.jdbc.Driver
  user: user1
  password: user!23
  url: jdbc:mysql://url.to.connect:3306/db1
  properties: charSet: UTF-8
  maxWaitForConnection: 1s
  minSize: 8
  maxSize: 32
  checkConnectionWhileIdle: false
  checkConnectionHealthWhenIdleFor: 10s
  closeConnectionIfIdleFor: 1 minute

database2:
  driverClass: com.mysql.jdbc.Driver
  user: user2
  password: user!23
  url: jdbc:mysql://url.to.connect:3306/db2
  properties: charSet: UTF-8
  maxWaitForConnection: 1s
  minSize: 8
  maxSize: 32
  checkConnectionWhileIdle: false
  checkConnectionHealthWhenIdleFor: 10s
  closeConnectionIfIdleFor: 1 minute

configuration.java

public class ExampleConfiguration extends Configuration {
@Valid
@NotNull
private DataSourceFactory database1 = new DataSourceFactory();

@Valid
@NotNull
private DataSourceFactory database2 = new DataSourceFactory();

@JsonProperty("database1")
public DataSourceFactory getDb1DataSourceFactory() {
    return database1;
}

@JsonProperty("database2")
public DataSourceFactory getDb2DataSourceFactory() {
    return database2;
}
}

Now following: Maintain multiple migration files in parallel in dropwizard, I tried to add a bootstrap bundle as follows:

@Override
  public void initialize(Bootstrap< ExampleConfiguration > bootstrap) {
    bootstrap.addCommand(new RenderCommand());
    bootstrap.addBundle(new AssetsBundle());
    bootstrap.addBundle(new MigrationsBundle<ExampleConfiguration>() {
      @Override
      public DataSourceFactory getDataSourceFactory(ExampleConfiguration configuration) {
        return configuration.getDb1DataSourceFactory();
      }
    });

    bootstrap.addBundle(new MigrationsBundle<ExampleConfiguration>() {
      @Override
      public DataSourceFactory getDataSourceFactory(ExampleConfiguration configuration) {
        return configuration.getDb2DataSourceFactory();
      }
    });
    bootstrap.addBundle(hibernateBundle);

  }

But I got command 'db' has been already used. I am still unclear what is happening in initialize(). How can I switch between DB instances for read and write operations? Thank you.

Answer 1

You should override each MigrationsBundle implementation's method name to provide unique command's name. Then using CLI you will need to specify correct name to use according database configuration.