无法为连接URL'null'创建类''的JDBC驱动程序：Tomcat& SQL Server JDBC驱动程序 [英] Cannot create JDBC driver of class '' for connect URL 'null' : Tomcat & SQL Server JDBC driver

问题描述

我已经试过了一切我可以找到的，如果有人能够帮助我，我会永远感激（和更多的自由在我的时间）。

基本上，我有一个错误在Tomcat 7.0（当运行在Eclipse和通过startup.bat），这说明，一旦数据开始被我的动态Web应用程序访问：

无法为连接URL创建类''的JDBC驱动程序'null'
java.lang.NullPointerException
at sun.jdbc.odbc。 JdbcOdbcDriver.getProtocol（JdbcOdbcDriver.java:507）
at sun.jdbc.odbc.JdbcOdbcDriver.knownURL（JdbcOdbcDriver.java:476）
at sun.jdbc.odbc.JdbcOdbcDriver.acceptsURL（JdbcOdbcDriver.java： 307）


我在tomcat \lib目录中有sqljdbc4.jar文件。我也试过把它放在我的WEB-INF / lib，甚至我的JDK lib目录。我不认为sqljdbc.jar将工作，因为它是为我的老JDK / JRE安装。

我听说过context.xml和web。

web.xml片段：

 < resource-ref> 
< description> LBI DB连接< / description> 
< res-ref-name> jdbc / LBIDB< / res-ref-name> 
< res-type> javax.sql.DataSource< / res-type> 
< res-auth>容器< / res-auth> 
< res-sharing-scope>可共享< / res-sharing-scope> 
< / resource-ref> 
< resource-ref> 
< description>或数据库连接< / description> 
< res-ref-name> jdbc / ORDB< / res-ref-name> 
< res-type> javax.sql.DataSource< / res-type> 
< res-auth>容器< / res-auth> 
< res-sharing-scope>可共享< / res-sharing-scope> 
< / resource-ref> 
  
 
 
 
 context.xml 
 < Context> 
<！ - 默认的受监视资源集 - > 
< WatchedResource> WEB-INF / web.xml< / WatchedResource> 
< Resource name =jdbc / LBIDBauth =Container
 type =javax.sql.DataSourceusername =***password =***driverClassName =com .microsoft.sqlserver.jdbc.SQLServerDriver
 url =jdbc：sqlserver：localhost; DatabaseName = YYBackOffice; SelectMethod = cursor; 
 maxActive =8maxIdle =4/> 
 
< Resource name =jdbc / ORDBauth =Container
 type =javax.sql.DataSourceusername =***password =*** driverClassName =com.microsoft.sqlserver.jdbc.SQLServerDriver
 url =jdbc：sqlserver：localhost; DatabaseName = XXBackOffice; SelectMethod = cursor; 
 maxActive =8maxIdle =4/> 
  
上下文选项卡最终有一个关闭选项卡。
 
 
 
请帮忙！如果您需要任何更多的信息，请让我知道。此外，我不知道应该修改哪个context.xml，Tomcat目录中有2个，/ conf文件夹中有一个，webapps / appname / META-INF文件夹中有一个。对不起，如果它听起来像我有点新手，这是因为我是！
 
 
 
此外，我看到了许多不同的例子的url =.. 。是context.xml的一部分，一些包括端口号。我已经尝试了几个在线，但没有什么似乎工作（不帮助没有在线是我的确切的数据环境，我想这是有挑战性的，这个应用程序查询两个不同的DB在给定的时间）。
 
 
 
想法？
解决方案
 
 
 
 
 <$ c $您的web应用程序的 META-INF 文件夹中的c> context.xml 将优先于/ conf目录中的，通用默认值。
 
 
 
 
开源 JTDS SQL Server 驱动程序比Microsoft的方式更好。除非有一个最重要的原因，否则改用它。把它放在你的tomcat / lib文件夹中的唯一原因是如果你声明一个 
 
 
 
 
 
 > JTDS的JDBC URL为： jdbc：jtds：sqlserver：// hostname / databasename  
  
 
 
 JTDS的连接驱动程序类是： net.sourceforge.jtds.jdbc.Driver  
 
 
 
 
I've tried just about everything I can find out there, if someone is able to help me out, I will be eternally grateful (and a lot more free in my time).


Basically, I have an error in Tomcat 7.0 (both when running within Eclipse and via startup.bat) that says this once data begins to be accessed by my dynamic web application:
Cannot create JDBC driver of class '' for connect URL 'null'
java.lang.NullPointerException
at sun.jdbc.odbc.JdbcOdbcDriver.getProtocol(JdbcOdbcDriver.java:507)
at sun.jdbc.odbc.JdbcOdbcDriver.knownURL(JdbcOdbcDriver.java:476)
at sun.jdbc.odbc.JdbcOdbcDriver.acceptsURL(JdbcOdbcDriver.java:307)
I have the sqljdbc4.jar file in my tomcat\lib directory. I have also tried putting this in my WEB-INF/lib, and even my JDK lib directories. I don't think sqljdbc.jar will work, as it is intended for older JDK/JRE installs than mine.

I've heard the context.xml and web.xml files are crucial in getting this to work.

web.xml snippet:
<resource-ref>
<description>LBI DB Connection</description>
<res-ref-name>jdbc/LBIDB</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
<res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>
<resource-ref>
<description>OR DB Connection</description>
<res-ref-name>jdbc/ORDB</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
<res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>
context.xml
<Context>
<!-- Default set of monitored resources -->
<WatchedResource>WEB-INF/web.xml</WatchedResource>
<Resource name="jdbc/LBIDB" auth="Container"
type="javax.sql.DataSource" username="***" password="***"   driverClassName="com.microsoft.sqlserver.jdbc.SQLServerDriver" 
url="jdbc:sqlserver:localhost;DatabaseName=YYBackOffice;SelectMethod=cursor;"
maxActive="8" maxIdle="4"/>

<Resource name="jdbc/ORDB" auth="Container"
type="javax.sql.DataSource" username="***" password="***"   driverClassName="com.microsoft.sqlserver.jdbc.SQLServerDriver" 
url="jdbc:sqlserver:localhost;DatabaseName=XXBackOffice;SelectMethod=cursor;"
maxActive="8" maxIdle="4"/>
The Context tab does have a closing tab, eventually.

Please help! If you need any more information, please let me know. Also, I'm not sure which context.xml ought to be modified, there are 2 in the Tomcat directories, one in the /conf folder, and one in the webapps/appname/META-INF folder. Sorry if it sounds like I'm a bit of a rookie, that's because I am!

Also, I've seen many different examples of the url="..." part of the context.xml, some including port numbers. I have tried several things out online, but nothing seems to work (doesn't help nothing online is my exact data environment, also I suppose it's challenging that this app queries two different DBs at given times).

Thoughts?
解决方案

The context.xml in your web application's META-INF folder will take precedence over the one in the /conf directory, which is really just a generic default.
The open-source JTDS SQL Server driver is way better than Microsoft's.  Unless there's an overriding reason, use it instead.  The only reason to put it in your tomcat/lib folder is if you're declaring a GlobalNamingResource for the database in your server.xml, otherwise you can just put it in your application's /lib folder.
The JDBC URL for JTDS is: jdbc:jtds:sqlserver://hostname/databasename
The connection driver class for JTDS is: net.sourceforge.jtds.jdbc.Driver


                        
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