--- a/src/java/de/uapcore/lightpit/DatabaseFacade.java Sun Apr 08 16:51:15 2018 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,178 +0,0 @@
-/*
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
- *
- * Copyright 2018 Mike Becker. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- *
- */
-package de.uapcore.lightpit;
-
-import java.sql.Connection;
-import java.sql.DatabaseMetaData;
-import java.sql.SQLException;
-import java.util.Optional;
-import javax.naming.Context;
-import javax.naming.InitialContext;
-import javax.naming.NamingException;
-import javax.servlet.ServletContext;
-import javax.servlet.ServletContextEvent;
-import javax.servlet.ServletContextListener;
-import javax.servlet.annotation.WebListener;
-import javax.sql.DataSource;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-/**
- * Provides access to different privilege layers within the database.
- */
-@WebListener
-public final class DatabaseFacade implements ServletContextListener {
-
- private static final Logger LOG = LoggerFactory.getLogger(DatabaseFacade.class);
-
- /**
- * Timeout in seconds for the validation test.
- */
- private static final int DB_TEST_TIMEOUT = 10;
-
- public static enum Dialect {
- Postgres;
- }
-
- /**
- * The database dialect to use.
- *
- * May be override by context parameter.
- *
- * @see Constants#CTX_ATTR_DB_DIALECT
- */
- private Dialect dialect = Dialect.Postgres;
-
- /**
- * The default schema to test against when validating the connection.
- *
- * May be overridden by context parameter.
- *
- * @see Constants#CTX_ATTR_DB_SCHEMA
- */
- private static final String DB_DEFAULT_SCHEMA = "lightpit";
-
- /**
- * The attribute name in the Servlet context under which an instance of this class can be found.
- */
- public static final String SC_ATTR_NAME = DatabaseFacade.class.getName();
- private ServletContext sc;
-
- private static final String DS_JNDI_NAME = "jdbc/lightpit/app";
- private Optional<DataSource> dataSource;
-
- /**
- * Returns the data source.
- *
- * The Optional returned should never be empty. However, if something goes
- * wrong during initialization, the data source might be absent.
- * Hence, users of this data source are forced to check the existence.
- *
- * @return a data source
- */
- public Optional<DataSource> getDataSource() {
- return dataSource;
- }
-
- public Dialect getSQLDialect() {
- return dialect;
- }
-
- private static void checkConnection(DataSource ds, String testSchema, String errMsg) {
- try (Connection conn = ds.getConnection()) {
- if (!conn.isValid(DB_TEST_TIMEOUT)) {
- throw new SQLException("Validation check failed.");
- }
- if (conn.isReadOnly()) {
- throw new SQLException("Connection is read-only and thus unusable.");
- }
- if (!conn.getSchema().equals(testSchema)) {
- throw new SQLException(String.format("Connection is not configured to use the schema %s.", testSchema));
- }
- DatabaseMetaData metaData = conn.getMetaData();
- LOG.info("Connections as {} to {}/{} ready to go.", metaData.getUserName(), metaData.getURL(), conn.getSchema());
- } catch (SQLException ex) {
- LOG.error(errMsg, ex);
- }
- }
-
- private static Optional<DataSource> retrieveDataSource(Context ctx) {
- DataSource ret = null;
- try {
- ret = (DataSource)ctx.lookup(DS_JNDI_NAME);
- LOG.info("Data source retrieved.");
- } catch (NamingException ex) {
- LOG.error("Data source {} not available.", DS_JNDI_NAME);
- LOG.error("Reason for the missing data source: ", ex);
- }
- return Optional.ofNullable(ret);
- }
-
- @Override
- public void contextInitialized(ServletContextEvent sce) {
- sc = sce.getServletContext();
-
- dataSource = null;
-
- final String contextName = Optional
- .ofNullable(sc.getInitParameter(Constants.CTX_ATTR_JNDI_CONTEXT))
- .orElse("java:comp/env");
- final String dbSchema = Optional
- .ofNullable(sc.getInitParameter(Constants.CTX_ATTR_DB_SCHEMA))
- .orElse(DB_DEFAULT_SCHEMA);
- final String dbDialect = sc.getInitParameter(Constants.CTX_ATTR_DB_DIALECT);
- if (dbDialect != null) {
- try {
- dialect = Dialect.valueOf(dbDialect);
- } catch (IllegalArgumentException ex) {
- LOG.error("Unknown or unsupported database dialect {}. Defaulting to {}.", dbDialect, dialect);
- }
- }
-
- try {
- LOG.debug("Trying to access JNDI context {}...", contextName);
- Context initialCtx = new InitialContext();
- Context ctx = (Context) initialCtx.lookup(contextName);
-
- dataSource = retrieveDataSource(ctx);
-
- dataSource.ifPresent((ds) -> checkConnection(ds, dbSchema, "Checking database connection failed"));
- } catch (NamingException | ClassCastException ex) {
- LOG.error("Cannot access JNDI resources.", ex);
- }
-
- sc.setAttribute(SC_ATTR_NAME, this);
- LOG.info("Database facade injected into ServletContext.");
- }
-
- @Override
- public void contextDestroyed(ServletContextEvent sce) {
- dataSource = null;
- }
-}