如何从tomcat webapp中的context.xml文件获取资源？

Question

这是我的context.xml文件:

...
<Resource auth="Container"
          driverClass="net.sourceforge.jtds.jdbc.Driver"
          type="com.jolbox.bonecp.BoneCPDataSource"
          idleMaxAge="240"
          idleConnectionTestPeriod="60"
          partitionCount="3"
          acquireIncrement="1"
          maxConnectionsPerPartition="10"
          minConnectionsPerPartition="3"
          statementsCacheSize="50"
          releaseHelperThreads="4"

          name="jdbc/MyDatasource"
          username="my_username"
          password="my_password"
          factory="org.apache.naming.factory.BeanFactory"
          jdbcUrl="jdbc:jtds:sqlserver://localhost:12345/my_database"
/>
...

我已经尝试使用ServletContext.getResource(java.lang.String)和资源名称("jdbc/MyDatasource"),但Tomcat抱怨该名称不以'/'开头.我也试过"/ jdbc/MyDatasource",但这次它返回null.

我主要需要jdbcUrl与数据库服务器进行连接检查(查看服务器是否在线且可操作).

Answer 1

关键字是:JNDI.其中的资源context.xml不是"系统资源",而是JNDI资源.试试这个:

InitialContext ic = new InitialContext();
// that's everything from the context.xml and from the global configuration
Context xmlContext = (Context) ic.lookup("java:comp/env");
DataSource myDatasource = (DataSource) xmlContext.lookup("jdbc/MyDatasource");

// now get a connection to see if everything is fine.
Connection con = ds.getConnection();
// reaching this point means everything is fine.
con.close();

Answer 2

您应该能够使用以下代码访问数据源:

Context initialContext = new InitialContext();
Context envContext  = (Context)initialContext.lookup("java:/comp/env");
DataSource ds = (DataSource)envContext.lookup("jdbc/MyDatasource");