Tomcat的连接池问题？？？在线等待。。。。。

Question

Context ctx = new InitialContext();
DataSource ds = (DataSource)ctx.lookup("java:comp/env/jdbc/pdb");
Connection conn = ds.getConnection();
Statement stmt = conn.createStatement();ResultSet rst = null;
String sql=null;
sql="select * from XZQH";
rst=stmt.executeQuery(sql);那行是79行，看看哪个是null,是ds，conn还是stmt??

Answer 1

我测了一下，是ds 为null，怎么解决？

Answer 2

那就是你的server.xml配置的有问题
server.xml里面有
<ResourceParams name="jdbc/pdb"> 
吗？

Answer 3

这是server.xml里的配置，请帮忙诊断，谢谢 <!-- Tomcat Root Context -->
        <Context path="/pstat" docBase="pstat" debug="0">          
           <Resource name="jdbc/pdb" auth="Container"  type="javax.sql.DataSource"/>       
            <ResourceParams name="jdbc/pdb">
             <parameter>  
               <name>user</name>
               <value>patent</value>
             </parameter>
             <parameter>
               <name>password</name>
               <value>patent</value>
             </parameter>
             <parameter>
              <name>maxActive</name>
              <value>100</value>
             </parameter>
            <parameter>
              <name>maxWait</name>
              <value>5000</value>
            </parameter>
             <parameter>
               <name>driverClassName</name>
               <value>oracle.jdbc.driver.OracleDriver</value>
             </parameter>
             <parameter>
               <name>driverName</name>
               <value>jdbc:oracle:thin:@192.168.3.30:1521:o8i</value>
             </parameter>
            </ResourceParams>
          </Context>

Answer 4

改成这样
<!-- Tomcat Root Context --> 
<Context path="/pstat" docBase="pstat" debug="0"> 
<Resource name="jdbc/pdb" auth="Container" type="javax.sql.DataSource"/>
<ResourceParams name="jdbc/pdb"> 
<parameter> 
<name>factory</name> 
<value>org.apache.commons.dbcp.BasicDataSourceFactory</value> 
</parameter> 
<parameter> 
<name>driverClassName</name> 
<value>oracle.jdbc.driver.OracleDriver</value> 
</parameter> 
<parameter> 
<name>url</name> 
<value>jdbc:oracle:thin:@192.168.3.30:1521:o8i</value> 
</parameter> 
<parameter> 
<name>username</name> 
<value>patent</value> 
</parameter> 
<parameter> 
<name>password</name> 
<value>patent</value>
</parameter> 
<parameter> 
<name>maxActive</name> 
<value>20</value> 
</parameter> 
<parameter> 
<name>maxIdle</name> 
<value>10</value> 
</parameter> 
<parameter> 
<name>maxWait</name> 
<value>-1</value> 
</parameter> 
</ResourceParams> 
</Context>

Answer 5

@ DataSource ds = (DataSource)ctx.lookup("java:comp/env/jdbc/pdb");web.xml
<resource-ref>
        <description>hiber example</description>
@       <res-ref-name>jdbc/pdb</res-ref-name>
        <res-type>javax.sql.DataSource</res-type>
        <res-auth>Container</res-auth>
</resource-ref>
server.xml
<Context path="/pstat" docBase="pstat" debug="0"> 
<Resource name="jdbc/pdb" auth="Container" type="javax.sql.DataSource"/>
@<ResourceParams name="jdbc/pdb"> 
....以上标@处 naming 是否一致？！

Answer 6

to cricketlj(蟋蟀) :我用你的试了，但报了两个错javax.servlet.ServletException: Cannot create resource instance
at org.apache.jasper.runtime.PageContextImpl.handlePageException(Unknown Source)
at org.apache.jsp.test$jsp._jspService(test$jsp.java:105)
at org.apache.jasper.runtime.HttpJspBase.service(Unknown Source)
。
javax.naming.NamingException: Cannot create resource instance
at org.apache.naming.NamingContext.lookup(Unknown Source)
at org.apache.naming.NamingContext.lookup(Unknown Source)
at org.apache.naming.NamingContext.lookup(Unknown Source)
at org.apache.naming.NamingContext.lookup(Unknown Source)

Answer 7

Tomcat的数据库连接池配置 http://www.csdn.net/Develop/Read_Article.asp?Id=19013我昨天刚看了，一配就成功！

Answer 8

Context ctx = new InitialContext();
System.out.println("1111111111111");
DataSource ds = (DataSource)ctx.lookup("java:comp/env/jdbc/pdb");
System.out.println("2222222222222");
Connection conn = ds.getConnection();
System.out.println("3333333333333");
Statement stmt = conn.createStatement();
System.out.println("4444444444444");
ResultSet rst = null;
String sql=null;
sql="select * from XZQH";
rst=stmt.executeQuery(sql);
System.out.println("5555555555555");看看能打到哪？