Values and types

The input and output to and from a procedure or a function must be one of the supported types, as described in Cypher Manual → Values and types.

Composite types are supported via:

List<T>, where T is one of the supported types, and
Map<String, Object>, where the values in the map must have one of the supported types.

The use of Object is supported for the case where the type is not known beforehand. Note, however, that the actual value must still have one of the aforementioned types.

Table 1. Supported Cypher types and their equivalents in Java
Cypher type	Java type
`String`	`String`
`Integer`	`Long`
`Float`	`Double`
`Boolean`	`Boolean`
`Point`	`org.neo4j.graphdb.spatial.Point`
`Date`	`java.time.LocalDate`
`Time`	`java.time.OffsetTime`
`LocalTime`	`java.time.LocalTime`
`DateTime`	`java.time.ZonedDateTime`
`LocalDateTime`	`java.time.LocalDateTime`
`Duration`	`java.time.temporal.TemporalAmount`
`Node`	`org.neo4j.graphdb.Node`
`Relationship`	`org.neo4j.graphdb.Relationship`
`Path`	`org.neo4j.graphdb.Path`

For more details, see the Neo4j Javadocs org.neo4j.procedure.Procedure.

There are two cases where more than one Java type is mapped to a single Cypher type. When this happens, type information is lost. If the following objects are returned from procedures, the original types cannot be recreated:

A Cypher Duration is created when either java.time.Duration or java.time.Period is provided. If Duration is returned, only the common interface java.time.temporal.TemporalAmount remains.
A Cypher DateTime is created when java.time.OffsetDateTime is provided. If DateTime is returned, it is converted into java.time.ZonedDateTime.