[FIXED] Multiple databases in dropwizard

Issue

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.

Solution

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.

Answered By - Yurii Melnychuk