package liquibase.precondition.core;
   
   import liquibase.changelog.DatabaseChangeLog;
   import liquibase.changelog.ChangeSet;
   import liquibase.database.Database;
   import liquibase.exception.PreconditionErrorException;
   import liquibase.exception.PreconditionFailedException;
   import liquibase.exception.ValidationErrors;
   import liquibase.exception.Warnings;
  import liquibase.precondition.Precondition;
  
  /**
   * Precondition for specifying the type of database (oracle, mysql, etc.).
   */
  
  public class DBMSPrecondition implements Precondition {
      private String type;
  
      public DBMSPrecondition() {
      }
  
      public String getType() {
          return type;
      }
  
      public void setType(String atype) {
          this.type = atype.toLowerCase();
      }
  
      public Warnings warn(Database database) {
          return new Warnings();
      }
  
      public ValidationErrors validate(Database database) {
          return new ValidationErrors();
      }
  
      public void check(Database database, DatabaseChangeLog changeLog, ChangeSet changeSet)
              throws PreconditionFailedException, PreconditionErrorException {
          try {
              String dbType = database.getTypeName();
              if (!type.equals(dbType)) {
                  throw new PreconditionFailedException("DBMS Precondition failed: expected " + type + ", got " + dbType,
                          changeLog, this);
              }
          } catch (PreconditionFailedException e) {
              throw e;
          } catch (Exception e) {
              throw new PreconditionErrorException(e, changeLog, this);
          }
      }
  
      public String getName() {
          return "dbms";
      }
  
  }