java - 在Apache Karaf 3.0.4中获取BasicDataSource时发生ClassCastException

我在Apache Karaf 3.0.4中工作，我的问题是，当我尝试从数据源（我有一个数据源列表）获取属性时遇到错误，我正在使用此代码

    BundleContext bundleContext = FrameworkUtil.getBundle(MyController.class).getBundleContext();
    ServiceReference[] serviceReferences =bundleContext.getAllServiceReferences("javax.sql.DataSource", null);

     //and in this part

     for (ServiceReference serviceReference : serviceReferences) {
            Object jndi = serviceReference.getProperty("osgi.jndi.service.name");
            if (jndi != null) {
                serviceReferenceDataSources.add(serviceReference);
                Object service = bundleContext.getService(serviceReference);
                //here the code fails
                BasicDataSource basicDataSource = (BasicDataSource) service;

             }
      }

这是堆栈跟踪

java.lang.ClassCastException: Proxyfcb4dd22_6103_4978_b41b_0bacfb118a66 cannot be cast to org.apache.commons.dbcp2.BasicDataSource

我需要BasicDataSource对象来获取其属性（maxTotal，用户名，URL，validationQuery，initialSize，maxWaitMillis）

最后，当我尝试转换为“ javax.sql.DataSource”时，此代码有效，但我需要此对象BasicDataSource。

编辑1

这是我的蓝图

<?xml version="1.0" encoding="UTF-8"?>
<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:cm="http://aries.apache.org/blueprint/xmlns/blueprint-cm/v1.0.0"
     xsi:schemaLocation="
        http://aries.apache.org/blueprint/xmlns/blueprint-cm/v1.0.0 http://aries.apache.org/schemas/blueprint-cm/blueprint-cm-1.0.0.xsd
        http://www.osgi.org/xmlns/blueprint/v1.0.0 http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd">

  <bean id="dataSource" class="org.apache.commons.dbcp2.BasicDataSource">
      <property name="driverClassName" value="${jdbc.driverClassName}" />
      <property name="url" value="${jdbc.url}" />
      <property name="username" value="${jdbc.username}" />
      <property name="password" value="${jdbc.password}" />
      <property name="initialSize" value="${jdbc.initialSize}" />
      <property name="maxTotal" value="${jdbc.maxTotal}" />
      <property name="maxWaitMillis" value="${jdbc.maxWaitMillis}" />
      <property name="validationQuery" value="${jdbc.validationQuery}"/>
      <property name="minEvictableIdleTimeMillis" value="${jdbc.minEvictableIdleTimeMillis}"/>
      <property name="timeBetweenEvictionRunsMillis" value="${jdbc.timeBetweenEvictionRunsMillis}"/>
  </bean>

  <service interface="javax.sql.DataSource" ref="dataSource">
    <service-properties>
        <entry key="osgi.jndi.service.name" value="jdbc/ejemplodb"/>
     <entry key="datasource" value="ejemplodb"/>
    </service-properties>
  </service>

如果我在控制台中打印此代码

  ...
    Object service = bundleContext.getService(serviceReference);
    logger.debug("Service getClass() ", service.getClass());
    System.out.println("Service in println" + service);
  ...

我懂了

  Service getClass() Proxy79d23ceb_cee2_4031_bdc3_13fd572cdf8c
  Service in println org.apache.commons.dbcp2.BasicDataSource@7f753504

希望您能帮助我，谢谢。

最佳答案

根据您的请求，返回的服务将为javax.sql.DataSource类型。在那里，投射到apache的基本数据源无效。但是，只要您只需要数据库连接，就可以使用javax.sql.Datasource吗？

javax.sql.DataSource basicDataSource = (javax.sql.DataSource) service;

如果您需要该服务的类型为BasicDataSource，则可能最终会更改bundleContext.getAllServiceReferences("javax.sql.DataSource", null);来查找BasicDatSource，然后将BasicDataSource的声明更改为BasicDataSource类型，而不是javax.sql.DataSource类型。 。