org.taverna.server.master.utils.WebappAwareDataSource.java Source code

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Here is the source code for org.taverna.server.master.utils.WebappAwareDataSource.java

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/*
 * Copyright (C) 2010-2011 The University of Manchester
 * 
 * See the file "LICENSE.txt" for license terms.
 */
package org.taverna.server.master.utils;

import static org.taverna.server.master.utils.Contextualizer.SUBSTITUAND;

import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

import javax.annotation.PreDestroy;

import org.apache.commons.dbcp.BasicDataSource;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.Required;

import edu.umd.cs.findbugs.annotations.SuppressWarnings;

/**
 * Add some awareness of the context so that we can locate databases internally
 * to the webapp.
 * 
 * @author Donal Fellows
 */
@SuppressWarnings("IS2_INCONSISTENT_SYNC")
public class WebappAwareDataSource extends BasicDataSource {
    Log log = LogFactory.getLog("Taverna.Server.Utils");
    private transient boolean init;
    private Contextualizer ctxt;
    private String shutdownUrl;

    @Required
    public void setContextualizer(Contextualizer ctxt) {
        this.ctxt = ctxt;
    }

    /**
     * A JDBC connection URL to use on shutting down the database. If not set,
     * do nothing special.
     * 
     * @param url
     */
    public void setShutdownUrl(String url) {
        shutdownUrl = url;
    }

    private void doInit() {
        synchronized (this) {
            if (!init) {
                String url = getUrl();
                if (url.contains(SUBSTITUAND)) {
                    String newurl = ctxt.contextualize(url);
                    setUrl(newurl);
                    log.info("mapped " + url + " to " + newurl);
                } else {
                    log.info("did not find " + SUBSTITUAND + " in " + url);
                }
                init = true;
            }
        }
    }

    // -=-=-=-=-=-=-=-=-=-=- HOOKS -=-=-=-=-=-=-=-=-=-=-

    @Override
    public Connection getConnection() throws SQLException {
        doInit();
        return super.getConnection();
    }

    @Override
    public void setLogWriter(PrintWriter pw) throws SQLException {
        doInit();
        super.setLogWriter(pw);
    }

    @Override
    public void setLoginTimeout(int num) throws SQLException {
        doInit();
        super.setLoginTimeout(num);
    }

    @Override
    public PrintWriter getLogWriter() throws SQLException {
        doInit();
        return super.getLogWriter();
    }

    @Override
    public int getLoginTimeout() throws SQLException {
        doInit();
        return super.getLoginTimeout();
    }

    @PreDestroy
    void realClose() {
        try {
            close();
        } catch (SQLException e) {
            log.warn("problem shutting down DB connection", e);
        }
        try {
            if (shutdownUrl != null)
                DriverManager.getConnection(ctxt.contextualize(shutdownUrl));
        } catch (SQLException e) {
            // Expected; ignore it
        }
        log = null;
    }
}