How to use Spring Data / JPA to insert into a Postgres Array type column?

You need to create your own type and implement the UserType interface. Based in next response I've written a Generic UserType to use in all arrays and it works but you must use non primitive data types (Integer, Long, String,...). Otherwise see the above update with Boolean type.

public class GenericArrayUserType<T extends Serializable> implements UserType {    protected static final int[] SQL_TYPES = { Types.ARRAY };    private  Class<T> typeParameterClass;    @Override    public Object assemble(Serializable cached, Object owner) throws HibernateException {        return this.deepCopy(cached);    }    @Override    public Object deepCopy(Object value) throws HibernateException {        return value;    }    @SuppressWarnings("unchecked")    @Override    public Serializable disassemble(Object value) throws HibernateException {        return (T) this.deepCopy(value);    }    @Override    public boolean equals(Object x, Object y) throws HibernateException {        if (x == null) {            return y == null;        }        return x.equals(y);    }    @Override    public int hashCode(Object x) throws HibernateException {        return x.hashCode();    }    @Override    public boolean isMutable() {        return true;    }    @Override    public Object nullSafeGet(ResultSet resultSet, String[] names, SessionImplementor session, Object owner)            throws HibernateException, SQLException {        if (resultSet.wasNull()) {            return null;        }        if (resultSet.getArray(names[0]) == null) {            return new Integer[0];        }        Array array = resultSet.getArray(names[0]);        @SuppressWarnings("unchecked")        T javaArray = (T) array.getArray();        return javaArray;    }    @Override    public void nullSafeSet(PreparedStatement statement, Object value, int index, SessionImplementor session)            throws HibernateException, SQLException {        Connection connection = statement.getConnection();        if (value == null) {            statement.setNull(index, SQL_TYPES[0]);        } else {            @SuppressWarnings("unchecked")            T castObject = (T) value;            Array array = connection.createArrayOf("integer", (Object[]) castObject);            statement.setArray(index, array);        }    }    @Override    public Object replace(Object original, Object target, Object owner) throws HibernateException {        return original;    }    @Override    public Class<T> returnedClass() {        return typeParameterClass;    }    @Override    public int[] sqlTypes() {        return new int[] { Types.ARRAY };    }}

Then the array properties would be same type of data base with same dimension:

• integer[] -> Integer[]
• text[][]-> String[][]

And in this special cases put the GenericType class above the properties

@Type(type = "packageofclass.GenericArrayUserType")

Then your entity would be:

@Entity@Table(name="sal_emp")public class SalEmp {    @Id    private String name;    @Column(name="pay_by_quarter")    @Type(type = "packageofclass.GenericArrayUserType")    private Integer[] payByQuarter;    @Column(name="schedule")    @Type(type = "packageofclass.GenericArrayUserType")    private String[][] schedule;    //Getters, Setters, ToString, equals, and so on}

If you don't want to use this Generic UserType the Integer[] type and write the String[][] type. You need to write your own types, in your case there would be as next:

• integer[]

  public class IntArrayUserType implements UserType {protected static final int[] SQL_TYPES = { Types.ARRAY };@Overridepublic Object assemble(Serializable cached, Object owner) throws HibernateException {    return this.deepCopy(cached);}@Overridepublic Object deepCopy(Object value) throws HibernateException {    return value;}@Overridepublic Serializable disassemble(Object value) throws HibernateException {    return (Integer[]) this.deepCopy(value);}@Overridepublic boolean equals(Object x, Object y) throws HibernateException {    if (x == null) {        return y == null;    }    return x.equals(y);}@Overridepublic int hashCode(Object x) throws HibernateException {    return x.hashCode();}@Overridepublic boolean isMutable() {    return true;}@Overridepublic Object nullSafeGet(ResultSet resultSet, String[] names, SessionImplementor session, Object owner)        throws HibernateException, SQLException {    if (resultSet.wasNull()) {        return null;    }    if (resultSet.getArray(names[0]) == null) {        return new Integer[0];    }    Array array = resultSet.getArray(names[0]);    Integer[] javaArray = (Integer[]) array.getArray();    return javaArray;}@Overridepublic void nullSafeSet(PreparedStatement statement, Object value, int index, SessionImplementor session)        throws HibernateException, SQLException {    Connection connection = statement.getConnection();    if (value == null) {        statement.setNull(index, SQL_TYPES[0]);    } else {        Integer[] castObject = (Integer[]) value;        Array array = connection.createArrayOf("integer", castObject);        statement.setArray(index, array);    }}@Overridepublic Object replace(Object original, Object target, Object owner) throws HibernateException {    return original;}@Overridepublic Class<Integer[]> returnedClass() {    return Integer[].class;}@Overridepublic int[] sqlTypes() {    return new int[] { Types.ARRAY };}}

• text[][]

  public class StringMultidimensionalArrayType implements UserType {protected static final int[] SQL_TYPES = { Types.ARRAY };@Overridepublic Object assemble(Serializable cached, Object owner) throws HibernateException {    return this.deepCopy(cached);}@Overridepublic Object deepCopy(Object value) throws HibernateException {    return value;}@Overridepublic Serializable disassemble(Object value) throws HibernateException {    return (String[][]) this.deepCopy(value);}@Overridepublic boolean equals(Object x, Object y) throws HibernateException {    if (x == null) {        return y == null;    }    return x.equals(y);}@Overridepublic int hashCode(Object x) throws HibernateException {    return x.hashCode();}@Overridepublic boolean isMutable() {    return true;}@Overridepublic Object nullSafeGet(ResultSet resultSet, String[] names, SessionImplementor session, Object owner)        throws HibernateException, SQLException {    if (resultSet.wasNull()) {        return null;    }    if (resultSet.getArray(names[0]) == null) {        return new String[0][];    }    Array array = resultSet.getArray(names[0]);    String[][] javaArray = (String[][]) array.getArray();    return javaArray;}@Overridepublic void nullSafeSet(PreparedStatement statement, Object value, int index, SessionImplementor session)        throws HibernateException, SQLException {    Connection connection = statement.getConnection();    if (value == null) {        statement.setNull(index, SQL_TYPES[0]);    } else {        String[][] castObject = (String[][]) value;        Array array = connection.createArrayOf("integer", castObject);        statement.setArray(index, array);    }}@Overridepublic Object replace(Object original, Object target, Object owner) throws HibernateException {    return original;}@Overridepublic Class<String[][]> returnedClass() {    return String[][].class;}@Overridepublic int[] sqlTypes() {    return new int[] { Types.ARRAY };}}

In this case your properties has different types:

@Column(name="pay_by_quarter")@Type(type = "packageofclass.IntArrayUserType")private Integer[] payByQuarter;@Column(name="schedule")@Type(type = "packageofclass.StringMultidimensionalArrayType")private String[][] schedule;

Update Hibernate UserType

With Boolean or boolean seems It doesn't works with GenericArrayUserType, so the solutions could be create in your CREATE DDL declare booleanof type bytea:

CREATE TABLE sal_emp (    name text,    pay_by_quarter  integer[],    schedule        text[][],    wow_boolean     bytea    );

And your property without any type:

private boolean[][][] wowBoolean;

It parses very good without any Typeor Converter. Output: wowBoolean=[[[true, false], [true, false]], [[true, true], [true, true]]])

Update With @Converter of JPA 2.1

I've tried an option with @Converterof JPA 2.1 with EclipseLinkand Hibernate. I've just tried integer[] (not text[][]) Converterlike this (*I've changed the property to a List<Integer> but it doesn't matter):

@Converterpublic class ConverterListInteger implements AttributeConverter<List<Integer>, Array>{    @Override    public Array convertToDatabaseColumn(List<Integer> attribute) {        DataSource source = ApplicationContextHolder.getContext().getBean(DataSource.class);        try {            Connection conn = source.getConnection();            Array array = conn.createArrayOf("integer", attribute.toArray());            return  array;        } catch (SQLException e) {            e.printStackTrace();        }        return null;    }    @Override    public List<Integer> convertToEntityAttribute(Array dbData) {        List<Integer> list = new ArrayList<>();        try {            for(Object object : (Object[]) dbData.getArray()){                list.add((Integer) object);            }        } catch (SQLException e) {            e.printStackTrace();        }        return list;    }}

Then, add the converter to the property in the Entity:

@Convert(converter=ConverterListInteger.class)private List<Integer> pay_by_quarter;

So the solution based on the JPA specification doesn't works. Why? Hibernate does not support database arrays (java.sql.Array)....

Then I've tried with EclipseLink (see how to configure here) and it works, but not always ...It seems there's a bug, It works the first time well but then next times it's not possible to update or query this row. Then just I've success add new rows but It's not possible to update or query after....

Conclusion

At the moment, It seems there is not supported by JPA vendors properly... Only the solution with Hibernate UserType works well but it's just for Hibernate.

Simple Approach will be

try to convert string[] to string and then in Entity class make

@Column(name = "nice_work" columnDefinition="text")

function for converting string[] to string and vice-versa

private static String stringArrayTOString(String[] input) {        StringBuffer sb =new StringBuffer("");        int i=0;        for(String value:input) {                        if(i!=0) {                sb.append(",");            }            sb.append(value);            i++;        }        return sb.toString();    }        private static String[] stringToStringArray(String input) {        String[] output = input.split(",");        return output;    }