LightPIT: src/main/kotlin/de/uapcore/lightpit/DataSourceProvider.kt@0a2ad22ac656 (annotated)

src/main/kotlin/de/uapcore/lightpit/DataSourceProvider.kt@0a2ad22ac656 (annotated)

src/main/kotlin/de/uapcore/lightpit/DataSourceProvider.kt

Thu, 13 May 2021 18:01:56 +0200

author: Mike Becker <universe@uap-core.de>
date: Thu, 13 May 2021 18:01:56 +0200
changeset 197: 0a2ad22ac656
parent 184: e8eecee6aadf
child 247: e71ae69c68c0
permissions: -rw-r--r--

removes useless guard

 /*
  * Copyright 2021 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.SQLException
 import javax.naming.Context
 import javax.naming.InitialContext
 import javax.naming.NamingException
 import javax.servlet.ServletContextEvent
 import javax.servlet.ServletContextListener
 import javax.servlet.annotation.WebListener
 import javax.sql.DataSource
 /**
  * Provides access to the database.
  */
 @WebListener
 class DataSourceProvider : ServletContextListener, LoggingTrait {
     enum class Dialect {
         Postgres
     }
     /**
      * The database dialect to use.
      * May be overridden by context parameter.
      *
      * @see Constants.CTX_ATTR_DB_DIALECT
      */
     var dialect = Dialect.Postgres; private set
     /**
      * The data source, if available.
      */
     var dataSource: DataSource? = null
     companion object {
         /**
          * The attribute name in the Servlet context under which an instance of this class can be found.
          */
         const val SC_ATTR_NAME = "lightpit.service.DataSourceProvider"
         /**
          * Timeout in seconds for the validation test.
          */
         private const val DB_TEST_TIMEOUT = 10
         /**
          * The default schema to test against when validating the connection.
          * May be overridden by context parameter.
          *
          * @see Constants.CTX_ATTR_DB_SCHEMA
          */
         private const val DB_DEFAULT_SCHEMA = "lightpit"
         /**
          * The JNDI resource name for the data source.
          */
         private const val DS_JNDI_NAME = "jdbc/lightpit/app"
     }
     private fun checkConnection(ds: DataSource, testSchema: String) {
         try {
             ds.connection.use { conn ->
                 if (!conn.isValid(DB_TEST_TIMEOUT)) {
                     throw SQLException("Validation check failed.")
                 }
                 if (conn.isReadOnly) {
                     throw SQLException("Connection is read-only and thus unusable.")
                 }
                 if (conn.schema != testSchema) {
                     throw SQLException(
                         String.format(
                             "Connection is not configured to use the schema %s.",
                             testSchema
                         )
                     )
                 }
                 val metaData = conn.metaData
                 logger().info(
                     "Connections as {} to {}/{} ready to go.",
                     metaData.userName,
                     metaData.url,
                     conn.schema
                 )
             }
         } catch (ex: SQLException) {
             logger().error("Checking database connection failed", ex)
         }
     }
     private fun retrieveDataSource(ctx: Context): DataSource? {
         return try {
             val ret = ctx.lookup(DS_JNDI_NAME) as DataSource
             logger().info("Data source retrieved.")
             ret
         } catch (ex: NamingException) {
             logger().error("Data source {} not available.", DS_JNDI_NAME)
             logger().error("Reason for the missing data source: ", ex)
             null
         }
     }
     override fun contextInitialized(sce: ServletContextEvent?) {
         val sc = sce!!.servletContext
         val dbSchema = sc.getInitParameter(Constants.CTX_ATTR_DB_SCHEMA) ?: DB_DEFAULT_SCHEMA
         sc.getInitParameter(Constants.CTX_ATTR_DB_DIALECT)?.let { dbDialect ->
             try {
                 dialect = Dialect.valueOf(dbDialect)
             } catch (ex: IllegalArgumentException) {
                 logger().error(
                     "Unknown or unsupported database dialect {}. Defaulting to {}.",
                     dbDialect,
                     dialect
                 )
             }
         }
         dataSource = try {
             logger().debug("Trying to access JNDI context ...")
             val initialCtx: Context = InitialContext()
             val ctx = initialCtx.lookup("java:comp/env") as Context
             retrieveDataSource(ctx)
         } catch (ex: NamingException) {
             logger().error("Cannot access JNDI resources.", ex)
             null
         } catch (ex: ClassCastException) {
             logger().error("Cannot access JNDI resources.", ex)
             null
         }
         dataSource?.let { checkConnection(it, dbSchema) }
         sc.setAttribute(SC_ATTR_NAME, this)
         logger().info("Database facade injected into ServletContext.")
     }
     override fun contextDestroyed(sce: ServletContextEvent?) {
         dataSource = null
     }
 }

Mercurial > hg > LightPIT / annotate

src/main/kotlin/de/uapcore/lightpit/DataSourceProvider.kt@0a2ad22ac656 (annotated)

src/main/kotlin/de/uapcore/lightpit/DataSourceProvider.kt