我在 Windows XP 上，使用 Tomcat 6（我要到月底才能升级到 7）。
我一直在尝试在 Oracle 11g 中实现 JNDI 数据库资源，但没有成功。
我计算机上的许多其他应用程序使用相同的数据库凭据连接得很好。我使用直接的 JDBC 制作了一个测试 JSP，并将其放入 Tomcat。它也连接得很好。
我修改了我的 conf/server.xml 的一部分，如下所示：
<!-- Global JNDI resources
Documentation at /docs/jndi-resources-howto.html
-->
<GlobalNamingResources>
<!-- Editable user database that can also be used by
UserDatabaseRealm to authenticate users
-->
<Resource name="jdbc/mydb"
auth="Container"
type="javax.sql.DataSource" driverClassName="oracle.jdbc.OracleDriver"
factory="oracle.jdbc.pool.OracleDataSourceFactory"
url="jdbc:oracle:thin:@apollo.abc.acme.com:2222:mydatabase"
user="joe"
password="blow"
maxActive="20"
maxIdle="30"
maxWait="-1"/>
<Resource name="UserDatabase" auth="Container"
type="org.apache.catalina.UserDatabase"
description="User database that can be updated and saved"
factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
pathname="conf/tomcat-users.xml"/>
</GlobalNamingResources>
我的 conf/context.xml：
<Context>
<!-- Default set of monitored resources -->
<WatchedResource>WEB-INF/web.xml</WatchedResource>
<ResourceLink global="jdbc/mydb" name="jdbc/mydb" type="javax.sql.DataSource"/>
<!-- Uncomment this to disable session persistence across Tomcat restarts -->
<!--
<Manager pathname="" />
-->
<!-- Uncomment this to enable Comet connection tacking (provides events
on session expiration as well as webapp lifecycle) -->
<!--
<Valve className="org.apache.catalina.valves.CometConnectionManagerValve" />
-->
</Context>
我的 conf/web.xml：
<resource-ref>
<res-ref-name>jdbc/mydb</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
这是测试 JSP 的摘录，它在获取 JNDI 资源的地方出现了一个空指针异常：
Connection conn = null;
ResultSet result = null;
Statement stmt = null;
String nsdtestcount = null;
InitialContext ctx = null;
Context envContext = null;
javax.sql.DataSource ds = null;
try
{
ctx = new InitialContext();
envContext = (Context)ctx.lookup("java:/comp/env");
ds = (DataSource)envContext.lookup("jdbc/mydb");
conn = ds.getConnection();
}
catch (Exception e)
{
System.out.println(nameJSP + "Failed to connect to the database: " +
"\n ctx = " + ctx +
"\n envContext = " + envContext +
"\n ds = " + ds +
"\n conn = " + conn );
e.printStackTrace();
}
我的日志摘录：：
INFO: Server startup in 675 ms
testJNDI2.jsp: Failed to connect to the database:
ctx = javax.naming.InitialContext@15356d5
envContext = org.apache.naming.NamingContext@69d02b
ds = null
conn = null
java.lang.NullPointerException
at org.apache.jsp.testJNDI_jsp._jspService(testJNDI_jsp.java:114)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:388)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:291)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:877)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:594)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1675)
at java.lang.Thread.run(Thread.java:595)
堆栈跟踪中的代码行：
at org.apache.jsp.testJNDI_jsp._jspService(testJNDI_jsp.java:114)
ctx = new InitialContext();
envContext = (Context)ctx.lookup("java:/comp/env");
ds = (DataSource)envContext.lookup("jdbc/mydb");
conn = ds.getConnection();
conn = ds.getConnection(); 是第 114 行
从我的 catalina 日志中：
May 1, 2012 4:17:48 PM org.apache.tomcat.util.modeler.Registry registerComponent
SEVERE: Null component Catalina:type=DataSource,class=javax.sql.DataSource,name="jdbc/mydb"
我的 CATALINA_HOME/lib 的内容：
C:\tomcat\lib>ls -l
annotations-api.jar
catalina-ant.jar
catalina-ha.jar
catalina-tribes.jar
catalina.jar
ecj-3.3.1.jar
el-api.jar
jasper-el.jar
jasper.jar
jsp-api.jar
log4j-1.2.16.jar
ojdbc14.jar
servlet-api.jar
tomcat-coyote.jar
tomcat-dbcp.jar
tomcat-i18n-es.jar
tomcat-i18n-fr.jar
tomcat-i18n-ja.jar
tomcat-juli-adapters.jar
tomcat-juli.jar
C:\tomcat\lib>
我的 JAVA/JDK jre/lib/ext 的内容：
C:\Program Files\Java\jdk1.5.0_22\jre\lib\ext>ls -l
activation.jar
dnsns.jar
localedata.jar
log4j-1.2.16.jar
mail.jar
nls_charset12.jar
sunjce_provider.jar
sunmscapi.jar
sunpkcs11.jar
C:\Program Files\Java\jdk1.5.0_22\jre\lib\ext>
关于我可以尝试什么的任何想法？我想让数据库资源可用于 Tomcat 中运行的所有内容（这是我的开发环境）
提前致谢。