Call Stored Procedure with JPA 2.1

JPA 2.1 introduces APIs to call Stored Procedure. It has similar programming pattern as executing a common CRUD sql statement.

@NamedStoredProcedureQuery: defines details of the stored proc to call
@StoredProcedureParameter: defines IN/OUT parameters of the stored proc
StoredProcedureQuery: Interface used to control stored procedure query execution

-- create a function
CREATE OR REPLACE FUNCTION test1.process_upload(p1 text, p2 integer) RETURNS integer AS 
$$
DECLARE
	arow record;
    counter integer := 0;
BEGIN
	FOR arow IN (SELECT * FROM test1.buffer_table)
    LOOP
    	-- process this row
    	counter = counter + 1;
    END LOOP;
    
    RETURN counter;
END;
$$ LANGUAGE plpgsql;

-- test the function
select test1.process_upload('jwang', 10);

import javax.persistence.*;
import java.io.Serializable;
import java.util.Date;

@Entity
@Table(name = "buffer_table", schema = "test1")
@NamedStoredProcedureQueries({
    @NamedStoredProcedureQuery(
        name="processUpload", // query name used in your app
        procedureName = "process_upload", // name of stored proc in db
        //resultClasses = {BufferTable.class},
        parameters = {
          @StoredProcedureParameter(name="p1", type=String.class, mode=ParameterMode.IN),
          @StoredProcedureParameter(name="p2", type=Integer.class, mode=ParameterMode.IN)
        }
    )
})
public class BufferTable implements Serializable {

    @Id
    @Column(name="id")
    private Integer id;

    @Column(name="name")
    private String name;

    @Column(name="created")
    private Date created;

    @Column(name="department_name")
    private String departmentName;

    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Date getCreated() {
        return created;
    }
    public void setCreated(Date created) {
        this.created = created;
    }
    public String getDepartmentName() {
        return departmentName;
    }
    public void setDepartmentName(String departmentName) {
        this.departmentName = departmentName;
    }
}

public int processUpload() {
    StoredProcedureQuery spQuery = em.createNamedStoredProcedureQuery("processUpload");
    // use named param - positional param can be used as well.
    spQuery.setParameter("p1", "jwang");
    spQuery.setParameter("p2", 10);

    List results = spQuery.getResultList();
    Integer result = results.size() > 0 ? (Integer) results.get(0) : null;
    log.info("Result from executing stored proc: " + result);

    return result != null ? result.intValue() : 0;
}

For more example: http://www.baeldung.com/jpa-stored-procedures