org.eclipse.persistence.queries.ScrollableCursorPolicy Maven / Gradle / Ivy
Show all versions of eclipselink Show documentation
/*
* Copyright (c) 1998, 2020 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Oracle - initial API and implementation from Oracle TopLink
package org.eclipse.persistence.queries;
import org.eclipse.persistence.internal.databaseaccess.*;
import org.eclipse.persistence.sessions.remote.*;
/**
* PUBLIC:
* ScrollableCursorPolicy allows for additional options to be specified for ReadAllQuery or DataReadQuery.
* These options are passed through to the JDBC result set,
* the JDBC driver must support JDBC2 scrolling cursors and the options used.
* Example:
* ScrollableCursorPolicy policy = new ScrollableCursorPolicy()
* policy.setResultSetType(ScrollableCursorPolicy.TYPE_SCROLL_INSENSITIVE);
* query.useScrollableCursor(policy);
*/
public class ScrollableCursorPolicy extends CursorPolicy {
protected int resultSetType;
protected int resultSetConcurrency;
/** RESULT SET TYPES **/
/** JDBC 2.0 The rows in a result set will be processed in a forward direction; first-to-last. */
public static final int FETCH_FORWARD = 1000;
/** JDBC 2.0 The rows in a result set will be processed in a reverse direction; last-to-first. */
public static final int FETCH_REVERSE = 1001;
/** JDBC 2.0 The order in which rows in a result set will be processed is unknown. */
public static final int FETCH_UNKNOWN = 1002;
/** JDBC 2.0 The type for a ResultSet object whose cursor may move only forward. */
public static final int TYPE_FORWARD_ONLY = 1003;
/** JDBC 2.0 The type for a ResultSet object that is scrollable but generally not sensitive to changes made by others. */
public static final int TYPE_SCROLL_INSENSITIVE = 1004;
/** JDBC 2.0 The type for a ResultSet object that is scrollable and generally sensitive to changes made by others. */
public static final int TYPE_SCROLL_SENSITIVE = 1005;
/** RESULT SET CONCURRENCY */
/** JDBC 2.0 The concurrency mode for a ResultSet object that may NOT be updated. */
public static final int CONCUR_READ_ONLY = 1007;
/** JDBC 2.0 The concurrency mode for a ResultSet object that may be updated. */
public static final int CONCUR_UPDATABLE = 1008;
/**
* PUBLIC:
* Create a new scrollable cursor policy.
*/
public ScrollableCursorPolicy() {
super();
setResultSetType(TYPE_SCROLL_INSENSITIVE);
setResultSetConcurrency(CONCUR_UPDATABLE);
}
/**
* INTERNAL:
* Create a cursor policy with the pagesize.
*/
public ScrollableCursorPolicy(ReadQuery query, int pageSize) {
super(query, pageSize);
setResultSetType(TYPE_SCROLL_INSENSITIVE);
setResultSetConcurrency(CONCUR_UPDATABLE);
}
/**
* INTERNAL:
* Execute the cursored select and build the stream.
*/
@Override
public Object execute() {
DatabaseCall call = getQuery().getQueryMechanism().cursorSelectAllRows();
// Create cursored stream
ScrollableCursor cursor = new ScrollableCursor(call, this);
return cursor;
}
/**
* PUBLIC:
* The ResultSetConcurrency specifies if the resultset is updatable.
* It is one of,
* CONCUR_READ_ONLY,
* CONCUR_UPDATABLE
*/
public int getResultSetConcurrency() {
return resultSetConcurrency;
}
/**
* PUBLIC:
* The ResultSetType specifies if the resultset is sensitive to changes made by others.
* It is one of,
* TYPE_SCROLL_INSENSITIVE,
* TYPE_SCROLL_SENSITIVE
*/
public int getResultSetType() {
return resultSetType;
}
@Override
public boolean isScrollableCursorPolicy() {
return true;
}
/**
* INTERNAL:
* Execute the cursored select and build the stream.
*/
@Override
public Object remoteExecute() {
return ((DistributedSession)getQuery().getSession()).cursorSelectObjects(this);
}
/**
* PUBLIC:
* The ResultSetConcurrency specifies if the resultset is updatable.
* It is one of,
* CONCUR_READ_ONLY,
* CONCUR_UPDATABLE
*/
public void setResultSetConcurrency(int resultSetConcurrency) {
this.resultSetConcurrency = resultSetConcurrency;
}
/**
* PUBLIC:
* The ResultSetType specifies if the resultset is sensitive to changes made by others.
* It is one of,
* TYPE_SCROLL_INSENSITIVE,
* TYPE_SCROLL_SENSITIVE
*/
public void setResultSetType(int resultSetType) {
this.resultSetType = resultSetType;
}
}