@orpha
In PostgreSQL, the bit(24)
data type is used to store a fixed-length bit string of 24 bits. To map this column type with Hibernate, you can use the @Type
annotation along with a custom BitStringType
class that implements the org.hibernate.usertype.UserType interface.
First, create a custom BitStringType
class that converts the 24-bit String to a byte array and vice versa:
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import org.hibernate.HibernateException; import org.hibernate.engine.spi.SharedSessionContractImplementor; import org.hibernate.usertype.UserType; import java.io.Serializable; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Types; public class BitStringType implements UserType { @Override public int[] sqlTypes() { return new int[]{Types.VARBINARY}; } @Override public Class returnedClass() { return String.class; } @Override public boolean equals(Object x, Object y) throws HibernateException { return x.equals(y); } @Override public int hashCode(Object x) throws HibernateException { return x.hashCode(); } @Override public Object nullSafeGet(ResultSet rs, String[] names, SharedSessionContractImplementor session, Object owner) throws HibernateException, SQLException { byte[] bytes = rs.getBytes(names[0]); if (bytes == null) { return null; } return bytes.toString(); } @Override public void nullSafeSet(PreparedStatement st, Object value, int index, SharedSessionContractImplementor session) throws HibernateException, SQLException { if (value == null) { st.setNull(index, Types.VARBINARY); } else { byte[] bytes = ((String) value).getBytes(); st.setBytes(index, bytes); } } @Override public Object deepCopy(Object value) throws HibernateException { return value; } @Override public boolean isMutable() { return false; } @Override public Serializable disassemble(Object value) throws HibernateException { return (Serializable) value; } @Override public Object assemble(Serializable cached, Object owner) throws HibernateException { return cached; } @Override public Object replace(Object original, Object target, Object owner) throws HibernateException { return original; } } |
Next, annotate the column in your entity class with @Type
and specify the BitStringType
class:
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import org.hibernate.annotations.Type; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; @Entity public class YourEntity { @Id @GeneratedValue private long id; @Column @Type(type = "com.example.BitStringType") private String yourBitStringColumn; // getters/setters } |
With this setup, Hibernate will use the custom BitStringType
class to map the bit(24)
column in PostgreSQL to a Java String in your entity class.