How to Map PostgreSQL Arrays to Java Arrays Using Hibernate?

Mapping PostgreSQL Array to Java Array using Hibernate

When attempting to map a PostgreSQL numeric array to a numeric array in Java via Hibernate, you may encounter an exception. This can be resolved by following these steps:

Maven Dependency

Add the following dependency to your project's pom.xml configuration file:

<code class="xml"><dependency>
    <groupid>com.vladmihalcea</groupid>
    <artifactid>hibernate-types-52</artifactid>
    <version>${hibernate-types.version}</version>
</dependency></code>

Hibernate Types

Define custom Hibernate types for the array columns:

<code class="java">@TypeDefs({
    @TypeDef(
        name = "string-array", 
        typeClass = StringArrayType.class
    ),
    @TypeDef(
        name = "int-array", 
        typeClass = IntArrayType.class
    )
})</code>

Entity Mapping

Map the entity fields to the PostgreSQL array columns using these custom types:

<code class="java">@Type( type = "string-array" )
@Column(
    name = "sensor_names", 
    columnDefinition = "text[]"
)
private String[] sensorNames;

@Type( type = "int-array" )
@Column(
    name = "sensor_values", 
    columnDefinition = "integer[]"
)
private int[] sensorValues;</code>

Example

When inserting entities with array values, Hibernate will generate SQL statements similar to the following:

<code class="sql">INSERT INTO event (
    version, 
    sensor_names, 
    sensor_values, 
    id
) 
VALUES (
    0, 
    {"Temperature","Pressure"}, 
    {"12","756"}, 
    1
)</code>

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