Is there a solution about Gson “circular reference”?

Question

I have found many articles about the circular reference with Gson, but I can\'t find an elegant solution.

As I know, some solutions is:

• Set the propert

Answer 1

Since Gson doesn't properly handle circular references, and in some cases you may need to call the parent entity from its child, you can do this. Say we have:

@Entity
@Table(name = "servers_postgres")
public class PostgresServer implements Serializable {

    public PostgresServer() {
        this.tables = new ArrayList<>();
    }

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id_server")
    private Integer serverId;

    @OneToMany(orphanRemoval = true, mappedBy = "server", fetch = FetchType.EAGER)
    @Cascade(org.hibernate.annotations.CascadeType.ALL)
    private List tables;

    @Column(length = 250)
    private String serverAddress;

    @Column(length = 250)
    private String name;
}

and

@Entity
@Table(name = "postgres_tables")
    public class PostgresTable implements Serializable {

        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        @Column(name = "id_table")
        private Integer tableId;

        @Column(length = 250)
        private String name;

        @ManyToOne()
        @JoinColumn(name = "id_server", foreignKey = @ForeignKey(name = "fk_postgres_tables"))
        private PostgresServer server;
    }

In this case, you may need to get a PostgresServer reference from a PostgresTable entity. So, instead of excluding PostgresServer from serialization, you simply set its List of tables to null. For example:

//Assuming a List...
postgresTables.forEach(postgresTable -> postgresTable.getServer().setTables(null));

This is how i solve circular references with Gson. Hope that helps someone.