ParameterType.java
package org.opentrafficsim.base.parameters;
import java.io.Serializable;
import org.djutils.base.Identifiable;
import org.djutils.exceptions.Throw;
import org.opentrafficsim.base.Type;
import org.opentrafficsim.base.parameters.constraint.Constraint;
/**
* Defines meta-information of a parameter, defining the parameter uniquely.
* <p>
* Copyright (c) 2013-2024 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
* BSD-style license. See <a href="https://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
* </p>
* @author <a href="https://github.com/averbraeck">Alexander Verbraeck</a>
* @author <a href="https://github.com/wjschakel">Wouter Schakel</a>
* @param <T> Type of the value.
*/
public class ParameterType<T> implements Serializable, Identifiable, Type<ParameterType<T>>
{
/** */
private static final long serialVersionUID = 20160400L;
/** Short name of parameter. */
private final String id;
/** Parameter description or full name. */
private final String description;
/** Default constraint. */
private final Constraint<? super T> constraint;
/** Class of the value. */
private final Class<T> valueClass;
/** Default value. */
@SuppressWarnings("checkstyle:visibilitymodifier")
protected final T defaultValue;
/**
* Construct a new AbstractParameterType without default value and constraint.
* @param id short name of the new AbstractParameterType
* @param description description or full name of the new AbstractParameterType
* @param valueClass class of the value of the new AbstractParameterType
*/
public ParameterType(final String id, final String description, final Class<T> valueClass)
{
this(id, description, valueClass, null, null, false);
}
/**
* Construct a new AbstractParameterType without default value and with constraint.
* @param id short name of the new AbstractParameterType
* @param description description or full name of the new AbstractParameterType
* @param valueClass class of the value of the new AbstractParameterType
* @param constraint constraint that applies to the value of the new AbstractParameterType
*/
public ParameterType(final String id, final String description, final Class<T> valueClass,
final Constraint<? super T> constraint)
{
this(id, description, valueClass, null, constraint, false);
}
/**
* Construct a new AbstractParameterType with default value, without constraint.
* @param id short name of the new AbstractParameterType
* @param description description or full name of the new AbstractParameterType
* @param valueClass class of the value of the new AbstractParameterType
* @param defaultValue default value of the new AbstractParameterType
*/
public ParameterType(final String id, final String description, final Class<T> valueClass, final T defaultValue)
{
this(id, description, valueClass, defaultValue, null, true);
}
/**
* Construct a new AbstractParameterType with default value and constraint.
* @param id short name of the new AbstractParameterType
* @param description description or full name of the new AbstractParameterType
* @param valueClass class of the value of the new AbstractParameterType
* @param defaultValue default value of the new AbstractParameterType
* @param constraint constraint that applies to the value of the new AbstractParameterType
*/
public ParameterType(final String id, final String description, final Class<T> valueClass, final T defaultValue,
final Constraint<? super T> constraint)
{
this(id, description, valueClass, defaultValue, constraint, true);
}
/**
* Protected constructor with default value and constraint, which may check the default value.
* @param id short name of the new AbstractParameterType
* @param description description or full name of the new AbstractParameterType
* @param valueClass class of the value of the new AbstractParameterType
* @param defaultValue default value of the new AbstractParameterType
* @param constraint constraint that applies to the value of the new AbstractParameterType
* @param hasDefaultValue if true a check is performed to ensure that the default value is not null and does not violate the
* constraint
*/
private ParameterType(final String id, final String description, final Class<T> valueClass, final T defaultValue,
final Constraint<? super T> constraint, final boolean hasDefaultValue)
{
Throw.whenNull(id, "Id may not be null.");
Throw.whenNull(description, "Description may not be null.");
Throw.whenNull(valueClass, "Value class may not be null.");
if (hasDefaultValue)
{
Throw.whenNull(defaultValue, "Default values of parameter types may not be null.");
}
this.id = id;
this.description = description;
this.valueClass = valueClass;
this.defaultValue = defaultValue;
this.constraint = constraint;
if (this.defaultValue != null)
{
try
{
checkConstraint(this.defaultValue);
}
catch (ParameterException pe)
{
throw new RuntimeException(
"Default value of parameter '" + this.id + "' does not comply with default constraints.", pe);
}
try
{
// Forward empty set of parameters. At creation time of parameter types, values cannot be checked with values of
// other parameter types.
check(defaultValue, new ParameterSet());
}
catch (ParameterException pe)
{
throw new RuntimeException(
"Default value of parameter '" + getId() + "' does not comply with custom constraints.", pe);
}
}
}
/**
* Retrieve the id of this AbstractParameterType.
* @return the id of this AbstractParameterType
*/
@Override
public final String getId()
{
return this.id;
}
/**
* Retrieve the description of this AbstractParameterType.
* @return the description of this AbstractParameterType
*/
public final String getDescription()
{
return this.description;
}
/**
* Retrieve the class of the value of this AbstractParameterType.
* @return the class of the value of this AbstractParameterType
*/
public final Class<T> getValueClass()
{
return this.valueClass;
}
/**
* Returns whether this parameter type has a default value.
* @return true if this AbstractParameterType type has a default value; false if it does not have a default value
*/
public final boolean hasDefaultValue()
{
return this.defaultValue != null;
}
/**
* Retrieve the the default value of this AbstractParameterType.
* @return the default value of this AbstractParameterType
* @throws ParameterException if this AbstractParameterType does not have a default value
*/
public final T getDefaultValue() throws ParameterException
{
Throw.when(null == this.defaultValue, ParameterException.class, "No default value was set for '%s'.", getId());
return this.defaultValue;
}
/**
* Check that a value complies with the constraint of this AbstractParameterType.
* @param value the value to check
* @throws ParameterException if the value does not comply with constraints
*/
public final void checkConstraint(final T value) throws ParameterException
{
if (this.constraint == null)
{
return;
}
Throw.when(!this.constraint.accept(value), ParameterException.class, this.constraint.failMessage(), this.getId());
}
/**
* Default implementation of check method. This default implementation will never throw any Exception.
* @param value the value to check
* @param params Set of parameters to check
* @throws ParameterException If the value does not comply with constraints.
*/
public void check(final T value, final Parameters params) throws ParameterException
{
// Default implementation does nothing
}
/**
* Print the given value from the map in Parameters in a presentable format. The default implementation simply returns the
* output of toString().
* @param parameters Parameters to get the value from
* @return readable representation of the value
* @throws ParameterException If the parameter is not present
*/
public String printValue(final Parameters parameters) throws ParameterException
{
return parameters.getParameter(this).toString();
}
@Override
public final int hashCode()
{
final int prime = 31;
int result = 1;
result = prime * result + ((this.defaultValue == null) ? 0 : this.defaultValue.hashCode());
result = prime * result + this.description.hashCode();
result = prime * result + this.id.hashCode();
result = prime * result + this.valueClass.hashCode();
return result;
}
@Override
public final boolean equals(final Object obj)
{
if (this == obj)
{
return true;
}
if (obj == null)
{
return false;
}
if (getClass() != obj.getClass())
{
return false;
}
ParameterType<?> other = (ParameterType<?>) obj;
if (!this.id.equals(other.id))
{
return false;
}
if (!this.description.equals(other.description))
{
return false;
}
if (!this.valueClass.equals(other.valueClass))
{
return false;
}
if (this.defaultValue == null)
{
if (other.defaultValue != null)
{
return false;
}
}
else if (!this.defaultValue.equals(other.defaultValue))
{
return false;
}
return true;
}
/**
* Retrieve the constraint.
* @return the constraint of this AbstractParameterType
*/
public final Constraint<? super T> getConstraint()
{
return this.constraint;
}
@Override
public String toString()
{
return "ParameterType [id=" + this.id + ", description=" + this.description + ", valueClass=" + this.valueClass + "]";
}
}