com._4dconcept.springframework.data.marklogic.datasource.SessionHolder.java Source code

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Here is the source code for com._4dconcept.springframework.data.marklogic.datasource.SessionHolder.java

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/*
 * Copyright 2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com._4dconcept.springframework.data.marklogic.datasource;

import com.marklogic.xcc.Session;
import org.springframework.transaction.support.ResourceHolderSupport;
import org.springframework.util.Assert;

/**
 * Session holder, wrapping a XDBC Session.
 * {@link ContentSourceTransactionManager} binds instances of this class
 * to the thread, for a specific ContentSource.
 *
 * <p>Inherits rollback-only support for nested XDBC transactions
 * and reference count functionality from the base class.
 *
 * <p>Note: This is an SPI class, not intended to be used by applications.
 *
 * @author Stephane Toussaint
 * @author Juergen Hoeller
 *
 * @see ContentSourceTransactionManager
 * @see ContentSourceUtils
 */
public class SessionHolder extends ResourceHolderSupport {

    private SessionHandle sessionHandle;

    private Session currentSession;

    private boolean transactionActive = false;

    /**
     * Create a new SessionHolder for the given SessionHandle.
     * @param sessionHandle the SessionHandle to hold
     */
    public SessionHolder(SessionHandle sessionHandle) {
        Assert.notNull(sessionHandle, "SessionHandle must not be null");
        this.sessionHandle = sessionHandle;
    }

    /**
     * Create a new SessionHolder for the given XDBC Session,
     * wrapping it with a {@link SimpleSessionHandle},
     * assuming that there is no ongoing transaction.
     * @param session the XDBC Session to hold
     * @see SimpleSessionHandle
     * @see #SessionHolder(Session, boolean)
     */
    public SessionHolder(Session session) {
        this.sessionHandle = new SimpleSessionHandle(session);
    }

    /**
     * Create a new SessionHolder for the given XDBC Session,
     * wrapping it with a {@link SimpleSessionHandle}.
     * @param session the XDBC Session to hold
     * @param transactionActive whether the given Session is involved
     * in an ongoing transaction
     * @see SimpleSessionHandle
     */
    public SessionHolder(Session session, boolean transactionActive) {
        this(session);
        this.transactionActive = transactionActive;
    }

    /**
     * @return the SessionHandle held by this SessionHolder.
     */
    public SessionHandle getSessionHandle() {
        return this.sessionHandle;
    }

    /**
     * @return whether this holder currently has a Session.
     */
    protected boolean hasSession() {
        return (this.sessionHandle != null);
    }

    /**
     * @return whether this holder represents an active, XDBC-managed transaction.
     */
    protected boolean isTransactionActive() {
        return this.transactionActive;
    }

    /**
     * @param transactionActive whether this holder represents an active, XDBC-managed transaction.
     * @see ContentSourceTransactionManager
     */
    protected void setTransactionActive(boolean transactionActive) {
        this.transactionActive = transactionActive;
    }

    /**
     * Return the current Session held by this SessionHolder.
     * <p>This will be the same Session until {@code released}
     * gets called on the SessionHolder, which will reset the
     * held Session, fetching a new Session on demand.
     * @see SessionHandle#getSession()
     * @see #released()
     * @return the current session
     */
    public Session getSession() {
        Assert.notNull(this.sessionHandle, "Active Session is required");
        if (this.currentSession == null) {
            this.currentSession = this.sessionHandle.getSession();
        }
        return this.currentSession;
    }

    /**
     * Override the existing Session handle with the given Session.
     * Reset the handle if given {@code null}.
     * <p>Used for releasing the Session on suspend (with a {@code null}
     * argument) and setting a fresh Session on resume.
     *
     * @param session the new session to be handled
     */
    protected void setSession(Session session) {
        if (this.currentSession != null) {
            this.sessionHandle.releaseSession(this.currentSession);
            this.currentSession = null;
        }
        if (session != null) {
            this.sessionHandle = new SimpleSessionHandle(session);
        } else {
            this.sessionHandle = null;
        }
    }

    /**
     * Releases the current Session held by this SessionHolder.
     * <p>This is necessary for SessionHandles that expect "Session borrowing",
     * where each returned Session is only temporarily leased and needs to be
     * returned once the data operation is done, to make the Session available
     * for other operations within the same transaction.
     */
    @Override
    public void released() {
        super.released();
        if (!isOpen() && this.currentSession != null) {
            this.sessionHandle.releaseSession(this.currentSession);
            this.currentSession = null;
        }
    }

    @Override
    public void clear() {
        super.clear();
        this.transactionActive = false;
    }

}