[Java][JPA] LOB example

User.java

import javax.persistence.*;

@Entity
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;
    private String name;
    @Lob
    private String avatar;

    ...

    @Override
    public String toString() {
        return String.format("Employee #%d: %s", id, name);
    }
}

A LOB is a Large OBject, such as a BLOB (Binary LOB), or a CLOB (Character LOB). It is a database type that can store a large binary or string value, as the normal VARCHAR or VARBINARY types typically have size limitations. A LOB is often stored as a locator in the database table, with the actual data stored outside of the table. In Java a CLOB will normally map to a String, and a BLOB will normally map to a byte[], although a BLOB may also represent some serialized object.

By default in JPA any Serializable attribute that is not a relationship or a basic type (String, Number, temporal, primitive), will be serialized to a BLOB field.

Source Wikibooks

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• String
• byte[]
• Serializable