org.grouplens.lenskit.util.io

Interface DescriptionWriter

All Known Implementing Classes:

AbstractDescriptionWriter, HashDescriptionWriter, StringDescriptionWriter

public interface DescriptionWriter

Accumulate a description of an object (or objects). Object descriptions should reflect the complete identity of an object - enough to uniquely distinguish it from non-equivalent objects - but are not (usually) a full serialization. They are more verbose than Object.toString(), and are used for things like generating deterministic keys for naming cache files.

Descriptions are composed of fields with values.

Since:

2.1

Method Summary

Modifier and Type	Method and Description
DescriptionWriter	putField(String name, byte[] value) Put a byte array field.
DescriptionWriter	putField(String name, double value) Put a floating-point field.
DescriptionWriter	putField(String name, long value) Put an integer field.
DescriptionWriter	putField(String name, Object value) Put an object field into the description.
DescriptionWriter	putField(String name, String value) Put a field into the description.
<T> DescriptionWriter	putField(String name, T value, Describer<? super T> describer) Put an object field into the description.
DescriptionWriter	putList(String name, Iterable<?> objects) Put a field with a list of values, using the default describer.
<T> DescriptionWriter	putList(String name, Iterable<T> objects, Describer<? super T> describer) Put a field with a list of values.

Method Detail

putField

DescriptionWriter putField(String name,
                           String value)

Put a field into the description.

Parameters:

name - The field name. It cannot begin with an underscore.

value - The field value.

putField

DescriptionWriter putField(String name,
                           long value)

Put an integer field.

Parameters:

name - The field name.

value - The field value.

See Also:

putField(String, String)

putField

DescriptionWriter putField(String name,
                           double value)

Put a floating-point field.

Parameters:

name - The field name.

value - The field value.

See Also:

putField(String, String)

putField

DescriptionWriter putField(String name,
                           byte[] value)

Put a byte array field.

Parameters:

name - The field name.

value - The field value.

See Also:

putField(String, String)

putField

DescriptionWriter putField(String name,
                           Object value)

Put an object field into the description.

Parameters:

name - The field name. It cannot begin with an underscore.

value - The field value. It is described with Descriptions.defaultDescriber()}.

putList

DescriptionWriter putList(String name,
                          Iterable<?> objects)

Put a field with a list of values, using the default describer.

Parameters:

name - The field name.

objects - The list of objects.

Returns:

The description writer (for chaining).

putList

<T> DescriptionWriter putList(String name,
                              Iterable<T> objects,
                              Describer<? super T> describer)

Put a field with a list of values.

Parameters:

name - The field name.

objects - The list of objects.

describer - A describer for the objects.

T - The type of objects in the list.

Returns:

The description writer (for chaining).

putField

<T> DescriptionWriter putField(String name,
                               T value,
                               Describer<? super T> describer)

Put an object field into the description.

Parameters:

name - The field name. It cannot begin with an underscore.

value - The field value. If it implements Describable, then it is asked to write its description; otherwise, some default behavior is used.

describer - A describer to describe the value.