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Version 1.1 by christoph_lechleitner@iteg_at on 2013-07-09 02.32:04
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1 = {{id name="Multi-DataSourcepoolingwithJDBC-Provider-Introduction"/}}Introduction =
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3 Many OSGi bundles require a pool of database connections, and usually the implementing it themselfes.
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5 In larger multi-package projects resp. OSGi container installations, a whole list of bundles require access to one and the same data source.
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7 This not only is a configuration nightmare, it also produces an unnecessary large number of unnecessary large pools.
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9 The new OSGi bundle {{code language="none"}}org.clazzes.util.jdbc-provider{{/code}} allows to configure multiple datasources, which are exported as OSGi services implementing the interface {{code language="none"}}javax.sql.DataSource{{/code}}.
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11 = {{id name="Multi-DataSourcepoolingwithJDBC-Provider-ConfiguringJDBC-ProviderDataSources"/}}Configuring JDBC-Provider DataSources =
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13 This package uses the configuration PID org.clazzes.jdbc.provider and may be configured with keys using the following pattern:
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15 |=(((
16 (% class="tablesorter-header-inner" %)
17 (((
18 Key
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20 )))|=(((
21 (% class="tablesorter-header-inner" %)
22 (((
23 Description
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25 )))
26 |(((
27 {{code language="none"}}
28 datasource.<datasourcename>.url
29 {{/code}}
30 )))|(((
31 JDBC URL
32 )))
33 |(((
34 datasource.<datasourcename>.user
35 )))|(((
36 JDBC User
37 )))
38 |(((
39 datasource.<datasourcename>.password
40 )))|(((
41 JDBC Password
42 )))
43 |(((
44 datasource.<datasourcename>.validationQuery
45 )))|(((
46 Validation query, executed to ensure the application receives a valid connection
47 )))
48 |(((
49 datasource.<datasourcename>.maxActive
50 )))|(((
51 Optional
52 )))
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54 For more supported key patterns take a look at the JavaDoc of the [[org.clazzes.util.jdbc.provider.JdbcProvider>>url:http://svn.clazzes.org/svn/util/trunk/jdbc-provider/src/main/java/org/clazzes/util/jdbc/provider/JdbcProvider.java||shape="rect"]] class.
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56 == {{id name="Multi-DataSourcepoolingwithJDBC-Provider-Configurationexample"/}}Configuration example ==
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58 (((
59 Sample configuration file {{code language="none"}}/etc/apache-karaf/org.clazzes.jdbc.provider.cfg{{/code}}:
60 )))
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64 {{code language="none"}}
65 datasource.JPTEST.url = jdbc:mysql://localhost/JPTEST
66 datasource.JPTEST.username = jptest
67 datasource.JPTEST.password = jptest321
68 datasource.JPTEST.validationQuery = SELECT 1
69 datasource.SPECTRUM.url = jdbc:oracle:thin:@10.1.2.3:1521:XE
70 datasource.SPECTRUM.maxActive = 8
71 datasource.SPECTRUM.username = FOO
72 datasource.SPECTRUM.password = bar
73 datasource.SPECTRUM.validationQuery = select SYSDATE from DUAL
74 {{/code}}
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76
77
78 = {{id name="Multi-DataSourcepoolingwithJDBC-Provider-DeveloperSnippets"/}}Developer Snippets =
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80 == {{id name="Multi-DataSourcepoolingwithJDBC-Provider-pom.xmlSnippets"/}}pom.xml Snippets ==
81
82 It's important for the maven-bundle-plugin to import the Package {{code language="none"}}javax.sql{{/code}}:
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84 {{code language="none"}}
85 ...
86 <build>
87 <plugins>
88 <plugin>
89 <groupId>org.apache.felix</groupId>
90 <artifactId>maven-bundle-plugin</artifactId>
91 <configuration>
92 <instructions>
93 ...
94 <Import-Package>*,javax.sql</Import-Package>
95 </instructions>
96 </configuration>
97 </plugin>
98 ...
99 </plugin>
100 ...
101 </build>
102 {{/code}}
103
104 But that's all you need!
105
106 == {{id name="Multi-DataSourcepoolingwithJDBC-Provider-BlueprintSnippets"/}}Blueprint Snippets ==
107
108 {{code language="none"}}
109 <bp:bean id="configProps" class="org.clazzes.util.osgi.ConfigPropertyAccessor" init-method="createDefaultConfig">
110 ...
111 <bp:property name="defaultValues">
112 <bp:map>
113 <bp:entry key="datasourceName" value="MYDATASOURCE"/>
114 ...
115 </bp:map>
116 </bp:property>
117 </bp:bean>
118 ...
119 <bp:bean id="datasourceName" factory-ref="configProps" factory-method="getProperty">
120 <bp:argument value="datasourceName" />
121 </bp:bean>
122 ...
123 <bp:bean id="datasourceMap" class="org.clazzes.util.osgi.ServiceMap" init-method="initialize">
124 <bp:property name="bundle" ref="blueprintBundle"/>
125 <bp:property name="keyProperty" value="datasource.name"/>
126 <bp:property name="serviceInterface" value="javax.sql.DataSource"/>
127 </bp:bean>
128 <bp:bean id="dataSource" factory-ref="datasourceMap" factory-method="getServiceProxy">
129 <bp:argument ref="datasourceName"/>
130 </bp:bean>
131 ...
132 <bp:bean id="myDao" ...>
133 <bp:property name="dataSource" ref="dataSource" />
134 </bp:bean>
135 {{/code}}
136
137 The blueprint xml can and should be kept free from any other JDBC stuff like URLs, driver magic and the like.
138
139 (% class="syntaxhighlighter nogutter java" %)
140 (((
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