How to use

getJavaType

method

in

com.facebook.presto.spi.session.PropertyMetadata

private static <T> Expression getExpression(PropertyMetadata<T> property, Object value)
    throws PrestoException
{
  return toExpression(property.encode(property.getJavaType().cast(value)));
}

public void validateCatalogSessionProperty(ConnectorId connectorId, String catalogName, String propertyName, String propertyValue)
{
  String fullPropertyName = catalogName + "." + propertyName;
  PropertyMetadata<?> propertyMetadata = getConnectorSessionPropertyMetadata(connectorId, propertyName)
      .orElseThrow(() -> new PrestoException(INVALID_SESSION_PROPERTY, "Unknown session property " + fullPropertyName));
  decodePropertyValue(fullPropertyName, propertyValue, propertyMetadata.getJavaType(), propertyMetadata);
}

public void validateSystemSessionProperty(String propertyName, String propertyValue)
{
  PropertyMetadata<?> propertyMetadata = getSystemSessionPropertyMetadata(propertyName)
      .orElseThrow(() -> new PrestoException(INVALID_SESSION_PROPERTY, "Unknown session property " + propertyName));
  decodePropertyValue(propertyName, propertyValue, propertyMetadata.getJavaType(), propertyMetadata);
}

private static <T> T decodePropertyValue(String fullPropertyName, @Nullable String propertyValue, Class<T> type, PropertyMetadata<?> metadata)
{
  if (metadata.getJavaType() != type) {
    throw new PrestoException(INVALID_SESSION_PROPERTY, format("Property %s is type %s, but requested type was %s", fullPropertyName,
        metadata.getJavaType().getName(),
        type.getName()));
  }
  if (propertyValue == null) {
    return type.cast(metadata.getDefaultValue());
  }
  Object objectValue = deserializeSessionProperty(metadata.getSqlType(), propertyValue);
  try {
    return type.cast(metadata.decode(objectValue));
  }
  catch (PrestoException e) {
    throw e;
  }
  catch (Exception e) {
    // the system property decoder can throw any exception
    throw new PrestoException(INVALID_SESSION_PROPERTY, format("%s is invalid: %s", fullPropertyName, propertyValue), e);
  }
}

if (!Primitives.wrap(property.getJavaType()).isInstance(value)) {
  throw new PrestoException(errorCode, format(
      "Property %s for %s should have value of type %s, not %s",
      propertyName,
      toQualifedName(objectName, columnName),
      property.getJavaType().getName(),
      value.getClass().getName()));

this.sessionProperties = hiveSessionProperties.getSessionProperties().stream()
    .collect(toImmutableMap(PropertyMetadata::getName,
        entry -> session.getProperty(entry.getName(), entry.getJavaType()).toString()));

sessionPropertyManager.decodeProperty(fullPropertyName, value, metadata.getJavaType());

public <T> T decodeProperty(String name, @Nullable String value, Class<T> type)
{
  requireNonNull(name, "name is null");
  requireNonNull(type, "type is null");
  SessionProperty<?> sessionProperty = allSessionProperties.get(name);
  if (sessionProperty == null) {
    throw new PrestoException(INVALID_SESSION_PROPERTY, "Unknown session property " + name);
  }
  PropertyMetadata<?> metadata = sessionProperty.getMetadata();
  if (metadata.getJavaType() != type) {
    throw new PrestoException(INVALID_SESSION_PROPERTY, format("Property %s is type %s, but requested type was %s", name,
        metadata.getJavaType().getName(),
        type.getName()));
  }
  if (value == null) {
    return type.cast(metadata.getDefaultValue());
  }
  Object objectValue = deserializeSessionProperty(metadata.getSqlType(), value);
  try {
    return type.cast(metadata.decode(objectValue));
  }
  catch (PrestoException e) {
    throw e;
  }
  catch (Exception e) {
    // the system property decoder can throw any exception
    throw new PrestoException(INVALID_SESSION_PROPERTY, format("%s is invalid: %s", name, value), e);
  }
}

private SessionProperty(Optional<String> catalogName, PropertyMetadata<T> propertyMetadata)
{
  this.catalogName = catalogName;
  this.propertyName = propertyMetadata.getName();
  String fullName = propertyMetadata.getName();
  if (catalogName.isPresent()) {
    fullName = catalogName.get() + "." + fullName;
  }
  this.propertyMetadata = new PropertyMetadata<>(
      fullName,
      propertyMetadata.getDescription(),
      propertyMetadata.getSqlType(),
      propertyMetadata.getJavaType(),
      propertyMetadata.getDefaultValue(),
      propertyMetadata.isHidden(),
      propertyMetadata::decode);
}

metadata.getSessionPropertyManager().decodeProperty(propertyName.toString(), value, propertyMetadata.getJavaType());
stateMachine.addSetSessionProperties(propertyName.toString(), value);