EMFactory.java

package model;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.persistence.spi.PersistenceUnitTransactionType;
import java.util.Arrays;
import java.util.HashMap;
import java.util.logging.Level;

import static logger.Logger.LOGGER;
import static org.eclipse.persistence.config.PersistenceUnitProperties.*;

public class EMFactory {
  private final EntityManagerFactory emf;

  public EMFactory(String rawDbContext, boolean dropAndCreateTables) {
    this.emf =
      Persistence.createEntityManagerFactory(
        "ParserPU",
        initProperties(rawDbContext, dropAndCreateTables)
      );


    if (dropAndCreateTables) {
      emf.getMetamodel().getEntities().forEach(
        e ->
          LOGGER.log(
            Level.INFO,
            String.join(" ", "Dropping table", e.getName())
          )
      );
    }
  }

  public EntityManager createEntityManager()
  {
    return emf.createEntityManager();
  }

  private HashMap<String, Object> initProperties(
    String rawDbContext, boolean dropAndCreateTables)
  {
    HashMap<String, Object> properties = new HashMap<>();
    String[] splitByColon = rawDbContext.split(":");
    String dbType = splitByColon[0];
    String contextString = splitByColon[1];
    boolean isSqlite = dbType.equals("sqlite");
    String driver =
      isSqlite ? "org.sqlite.JDBC" : "org.postgresql.Driver";
    String[] contextList = contextString.split(";");
    HashMap<String, String> contextMap = new HashMap<>();

    if (dropAndCreateTables) {
      properties.put("eclipselink.ddl-generation", "drop-and-create-tables");
    } else {
      properties.put("eclipselink.ddl-generation", "create-tables");
    }


    properties.put(
      TRANSACTION_TYPE,
      PersistenceUnitTransactionType.RESOURCE_LOCAL.name()
    );

    Arrays.stream(contextList).forEach(c -> {
      String[] splitContext = c.split("=");
      contextMap.put(splitContext[0], splitContext[1]);
    });

    String connString =
      isSqlite ?
        "jdbc:" + "sqlite" + ":/" +
          contextMap.get("database")
            .replaceFirst("^~", System.getProperty("user.home"))
        :
        "jdbc:" + "postgresql" + "://" +
          contextMap.get("host") + ":" +
          contextMap.get("port") + "/" +
          contextMap.get("database");

    properties.put(JDBC_DRIVER, driver);
    properties.put(JDBC_URL, connString);

    if (!isSqlite) {
      properties.put(JDBC_USER, contextMap.get("user"));
      properties.put(JDBC_PASSWORD, contextMap.get("password"));
    }

    return properties;
  }

  public EntityManagerFactory getEmf() {
    return emf;
  }
}