Mon, 09 Aug 2021 15:50:37 +0200
#105 fixes wrong font for form controls
1 /*
2 * Copyright 2021 Mike Becker. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 *
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
15 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
20 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
21 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
22 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
26 package de.uapcore.lightpit
28 import java.sql.SQLException
29 import javax.naming.Context
30 import javax.naming.InitialContext
31 import javax.naming.NamingException
32 import javax.servlet.ServletContextEvent
33 import javax.servlet.ServletContextListener
34 import javax.servlet.annotation.WebListener
35 import javax.sql.DataSource
37 /**
38 * Provides access to the database.
39 */
40 @WebListener
41 class DataSourceProvider : ServletContextListener, LoggingTrait {
43 enum class Dialect {
44 Postgres
45 }
47 /**
48 * The database dialect to use.
49 * May be overridden by context parameter.
50 *
51 * @see Constants.CTX_ATTR_DB_DIALECT
52 */
53 var dialect = Dialect.Postgres; private set
55 /**
56 * The data source, if available.
57 */
58 var dataSource: DataSource? = null
60 companion object {
61 /**
62 * The attribute name in the Servlet context under which an instance of this class can be found.
63 */
64 const val SC_ATTR_NAME = "lightpit.service.DataSourceProvider"
66 /**
67 * Timeout in seconds for the validation test.
68 */
69 private const val DB_TEST_TIMEOUT = 10
71 /**
72 * The default schema to test against when validating the connection.
73 * May be overridden by context parameter.
74 *
75 * @see Constants.CTX_ATTR_DB_SCHEMA
76 */
77 private const val DB_DEFAULT_SCHEMA = "lightpit"
79 /**
80 * The JNDI resource name for the data source.
81 */
82 private const val DS_JNDI_NAME = "jdbc/lightpit/app"
83 }
85 private fun checkConnection(ds: DataSource, testSchema: String) {
86 try {
87 ds.connection.use { conn ->
88 if (!conn.isValid(DB_TEST_TIMEOUT)) {
89 throw SQLException("Validation check failed.")
90 }
91 if (conn.isReadOnly) {
92 throw SQLException("Connection is read-only and thus unusable.")
93 }
94 if (conn.schema != testSchema) {
95 throw SQLException(
96 String.format(
97 "Connection is not configured to use the schema %s.",
98 testSchema
99 )
100 )
101 }
102 val metaData = conn.metaData
103 logger().info(
104 "Connections as {} to {}/{} ready to go.",
105 metaData.userName,
106 metaData.url,
107 conn.schema
108 )
109 }
110 } catch (ex: SQLException) {
111 logger().error("Checking database connection failed", ex)
112 }
113 }
115 private fun retrieveDataSource(ctx: Context): DataSource? {
116 return try {
117 val ret = ctx.lookup(DS_JNDI_NAME) as DataSource
118 logger().info("Data source retrieved.")
119 ret
120 } catch (ex: NamingException) {
121 logger().error("Data source {} not available.", DS_JNDI_NAME)
122 logger().error("Reason for the missing data source: ", ex)
123 null
124 }
125 }
127 override fun contextInitialized(sce: ServletContextEvent?) {
128 val sc = sce!!.servletContext
130 val dbSchema = sc.getInitParameter(Constants.CTX_ATTR_DB_SCHEMA) ?: DB_DEFAULT_SCHEMA
131 sc.getInitParameter(Constants.CTX_ATTR_DB_DIALECT)?.let { dbDialect ->
132 try {
133 dialect = Dialect.valueOf(dbDialect)
134 } catch (ex: IllegalArgumentException) {
135 logger().error(
136 "Unknown or unsupported database dialect {}. Defaulting to {}.",
137 dbDialect,
138 dialect
139 )
140 }
141 }
143 dataSource = try {
144 logger().debug("Trying to access JNDI context ...")
145 val initialCtx: Context = InitialContext()
146 val ctx = initialCtx.lookup("java:comp/env") as Context
147 retrieveDataSource(ctx)
148 } catch (ex: NamingException) {
149 logger().error("Cannot access JNDI resources.", ex)
150 null
151 } catch (ex: ClassCastException) {
152 logger().error("Cannot access JNDI resources.", ex)
153 null
154 }
156 dataSource?.let { checkConnection(it, dbSchema) }
158 sc.setAttribute(SC_ATTR_NAME, this)
159 logger().info("Database facade injected into ServletContext.")
160 }
162 override fun contextDestroyed(sce: ServletContextEvent?) {
163 dataSource = null
164 }
165 }