QueryResultVisitor.java

package com.avaje.ebean;

/**
 * Used to process a query result one bean at a time via a callback to this
 * visitor.
 * <p>
 * If you wish to stop further processing return false from the accept method.
 * </p>
 * <p>
 * Unlike findList() and findSet() using a QueryResultVisitor does not require
 * all the beans in the query result to be held in memory at once. This makes
 * QueryResultVisitor useful for processing large queries.
 * </p>
 * 
 * <pre class="code">
 * 
 * Query<Customer> query = server.find(Customer.class)
 *     .fetch("contacts", new FetchConfig().query(2))
 *     .where().gt("id", 0)
 *     .orderBy("id")
 *     .setMaxRows(2);
 * 
 * query.findVisit(new QueryResultVisitor<Customer>() {
 * 
 *   public boolean accept(Customer customer) {
 *     // do something with customer
 *     System.out.println("-- visit " + customer);
 *     return true;
 *   }
 * });
 * </pre>
 * 
 * @author rbygrave
 * 
 * @param <T>
 *          the type of entity bean being queried.
 */
public interface QueryResultVisitor<T> {

  /**
   * Process the bean and return true if you want to continue processing more
   * beans. Return false if you want to stop processing further.
   * 
   * @param bean
   *          the entity bean to process
   * @return true to continue processing or false to stop.
   */
  public boolean accept(T bean);
}