6.4. 使用 OSGi JDBC 服务

使用 pax-jdbc （或 pax-jdbc-mysql,pax-jdbc-oracle, …​）捆绑包时，您可以注册 org.osgi.service.jdbc.DataSourceFactory 服务，可用于获取给定数据库的数据源（请参阅 第 6.2.1 节 “特定于数据库和通用数据源”）。但是还没有实际的数据源。

mvn:org.ops4j.pax.jdbc/pax-jdbc-config/1.3.0 捆绑包提供了一个受管服务工厂，它有两个操作：

以下是从全新的 Fuse 安装开始的详细 规范 逐步指南。

您现在有一个特定于数据库的实际（还没有池）数据源。您可以已经注入需要它的位置。例如，您可以使用 Karaf 命令查询数据库：

karaf@root()> feature:install -v jdbc
Adding features: jdbc/[4.2.0.fuse-000237-redhat-1,4.2.0.fuse-000237-redhat-1]
...
karaf@root()> jdbc:ds-list
Mon May 14 08:46:22 CEST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Name    │ Product │ Version │ URL                                  │ Status
────────┼─────────┼─────────┼──────────────────────────────────────┼───────
mysqlds │ MySQL   │ 5.7.21  │ jdbc:mysql://localhost:3306/reportdb │ OK

karaf@root()> jdbc:query mysqlds 'select * from incident'
Mon May 14 08:46:46 CEST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
date                  │ summary    │ name   │ details                       │ id │ email
──────────────────────┼────────────┼────────┼───────────────────────────────┼────┼─────────────────
2018-02-20 08:00:00.0 │ Incident 1 │ User 1 │ This is a report incident 001 │ 1  │ user1@redhat.com
2018-02-20 08:10:00.0 │ Incident 2 │ User 2 │ This is a report incident 002 │ 2  │ user2@redhat.com
2018-02-20 08:20:00.0 │ Incident 3 │ User 3 │ This is a report incident 003 │ 3  │ user3@redhat.com
2018-02-20 08:30:00.0 │ Incident 4 │ User 4 │ This is a report incident 004 │ 4  │ user4@redhat.com

在上例中，您可以看到 MySQL 警告。这不是一个问题。可以提供任何属性（不仅是 OSGi JDBC 特定属性）：

karaf@root()> config:property-set --pid org.ops4j.datasource.a7941498-9b62-4ed7-94f3-8c7ac9365313 useSSL false

karaf@root()> jdbc:ds-list
Name    │ Product │ Version │ URL                                  │ Status
────────┼─────────┼─────────┼──────────────────────────────────────┼───────
mysqlds │ MySQL   │ 5.7.21  │ jdbc:mysql://localhost:3306/reportdb │ OK

admin factory PID 配置中的属性传递给相关的 org.osgi.service.jdbc.DataSourceFactory 实现。

pax-jdbc-config 捆绑包处理前缀为 jdbc 的属性。所有这些属性都将删除这个前缀，剩余的名称将被传递。

下面是一个全新的 Fuse 安装开始的示例：

karaf@root()> install -s mvn:mysql/mysql-connector-java/5.1.34
Bundle ID: 223
karaf@root()> install -s mvn:org.osgi/org.osgi.service.jdbc/1.0.0
Bundle ID: 224
karaf@root()> install -s mvn:org.ops4j.pax.jdbc/pax-jdbc-mysql/1.3.0
Bundle ID: 225
karaf@root()> install -s mvn:org.ops4j.pax.jdbc/pax-jdbc/1.3.0
Bundle ID: 226
karaf@root()> install -s mvn:org.ops4j.pax.jdbc/pax-jdbc-pool-common/1.3.0
Bundle ID: 227
karaf@root()> install -s mvn:org.ops4j.pax.jdbc/pax-jdbc-config/1.3.0
Bundle ID: 228

karaf@root()> config:edit --factory --alias mysql org.ops4j.datasource
karaf@root()> config:property-set osgi.jdbc.driver.name mysql
karaf@root()> config:property-set dataSourceName mysqlds
karaf@root()> config:property-set dataSourceType DataSource
karaf@root()> config:property-set jdbc.url jdbc:mysql://localhost:3306/reportdb
karaf@root()> config:property-set jdbc.user fuse
karaf@root()> config:property-set jdbc.password fuse
karaf@root()> config:property-set jdbc.useSSL false
karaf@root()> config:update

karaf@root()> config:list '(service.factoryPid=org.ops4j.datasource)'
----------------------------------------------------------------
Pid:            org.ops4j.datasource.7c3ee718-7309-46a0-ae3a-64b38b17a0a3
FactoryPid:     org.ops4j.datasource
BundleLocation: ?
Properties:
   dataSourceName = mysqlds
   dataSourceType = DataSource
   felix.fileinstall.filename = file:/data/servers/7.8.0.fuse-780038-redhat-00001/etc/org.ops4j.datasource-mysql.cfg
   jdbc.password = fuse
   jdbc.url = jdbc:mysql://localhost:3306/reportdb
   jdbc.useSSL = false
   jdbc.user = fuse
   osgi.jdbc.driver.name = mysql
   service.factoryPid = org.ops4j.datasource
   service.pid = org.ops4j.datasource.7c3ee718-7309-46a0-ae3a-64b38b17a0a3

karaf@root()> service:list javax.sql.DataSource
[javax.sql.DataSource]
----------------------
 dataSourceName = mysqlds
 dataSourceType = DataSource
 felix.fileinstall.filename = file:${karaf.etc}/org.ops4j.datasource-mysql.cfg
 jdbc.password = fuse
 jdbc.url = jdbc:mysql://localhost:3306/reportdb
 jdbc.user = fuse
 jdbc.useSSL = false
 osgi.jdbc.driver.name = mysql
 osgi.jndi.service.name = mysqlds
 pax.jdbc.managed = true
 service.bundleid = 228
 service.factoryPid = org.ops4j.datasource
 service.id = 246
 service.pid = org.ops4j.datasource.7c3ee718-7309-46a0-ae3a-64b38b17a0a3
 service.scope = singleton
Provided by :
 OPS4J Pax JDBC Config (228)

pax-jdbc-config 捆绑包需要这些属性：

查找并调用相关的 org.osgi.service.jdbc.DataSourceFactory 方法。前缀为 jdbc. 的属性会被传递（在删除前缀后），例如 org.osgi.service.jdbc.DataSourceFactory.createDataSource (properties)。但是，会添加这些属性，而不删除前缀，如 javax.sql.DataSource OSGi 服务的属性。