I am trying to implement the concept of ConnectionPooling in Oracle using Jetty server. I have tried the following that I saw on a tutorial. It is working if I deploy using Tomcat server, but Jetty seems to be giving me an unusual error. Details are below -
I have a class called TestServlet.java defined as -
import java.io.IOException;
import java.sql.*;
import javax.naming.*;
import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import javax.sql.DataSource;
@SuppressWarnings("serial")
@WebServlet("/TestServlet")
public class TestServlet extends HttpServlet {
public TestServlet() throws ServletException{
System.out.println("Constructor");
init();
}
public DataSource dataSource;
private Connection con;
private Statement statement;
public void init() throws ServletException {
System.out.println("inside init method");
try {
// Get DataSource
Context initContext = new InitialContext();
System.out.println("Before envcontext");
Context envContext = (Context)initContext.lookup("java:comp/env");
System.out.println("After envcontext");
dataSource = (DataSource)envContext.lookup("jdbc/DSTest");
System.out.println(dataSource.toString());
} catch (NamingException e) {
System.out.println("Exception in try");
e.printStackTrace();
}
}
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
System.out.println("Request: "+req+"\tResponse: "+resp);
int i=0;
ResultSet resultSet = null;
try {
// Get Connection and Statement
con = dataSource.getConnection();
statement = con.createStatement();
String query = "SELECT * FROM USER";
resultSet = statement.executeQuery(query);
while (resultSet.next()) {
++i;
System.out.println(i+":\nID:"+resultSet.getString("ID") +"\nEmail:"+ resultSet.getString("UEMAIL") +"\nPassword:" + resultSet.getString("PASSWORD")+"\nFlag:"+resultSet.getShort("FLAG")
+"\n");
}
} catch (SQLException e) {
System.out.println("EXCEPTIOn");
e.printStackTrace();
}finally {
try { if(null!=resultSet)resultSet.close();} catch (SQLException e)
{e.printStackTrace();System.out.println("1");}
try { if(null!=statement)statement.close();} catch (SQLException e)
{e.printStackTrace();System.out.println("2");}
try { if(null!=con)con.close();} catch (SQLException e)
{e.printStackTrace();System.out.println("3");}
}
}
}
And my Jetty-web.xml is as -
<?xml version="1.0" encoding="UTF-8"?>
<Configure class="org.eclipse.jetty.webapp.WebAppContext">
<New id="DSTest" class="org.eclipse.jetty.plus.jndi.Resource">
<Arg>java:comp/env</Arg>
<Arg>jdbc/DSTest</Arg>
<Arg>
<New class="org.apache.commons.dbcp.BasicDataSource">
<Set name="driverClassName">oracle.jdbc.OracleDriver</Set>
<Set name="url">ConnectionUrl</Set>
<Set name="username">app_user</Set>
<Set name="password">abcd</Set>
</New>
</Arg>
</New>
</Configure>
When I run the servlet class I get an error that says -
java.lang.NoClassDefFoundError: org/apache/commons/pool/impl/GenericObjectPool
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2658)
at java.lang.Class.getConstructors(Class.java:1638)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.newObj(XmlConfiguration.java:748)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.itemValue(XmlConfiguration.java:1078)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.value(XmlConfiguration.java:993)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.newObj(XmlConfiguration.java:741)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.configure(XmlConfiguration.java:383)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.configure(XmlConfiguration.java:317)
at org.eclipse.jetty.xml.XmlConfiguration.configure(XmlConfiguration.java:276)
at org.eclipse.jetty.webapp.JettyWebXmlConfiguration.configure(JettyWebXmlConfiguration.java:100)
at org.eclipse.jetty.webapp.WebAppContext.configure(WebAppContext.java:427)
at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1207)
at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:610)
at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:453)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59)
at org.eclipse.jetty.server.handler.HandlerWrapper.doStart(HandlerWrapper.java:89)
at org.eclipse.jetty.server.Server.doStart(Server.java:262)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59)
at runjettyrun.Bootstrap.main(Bootstrap.java:80)
Caused by:
java.lang.ClassNotFoundException: org.apache.commons.pool.impl.GenericObjectPool
at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at org.eclipse.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:415)
at runjettyrun.ProjectClassLoader.loadClass(ProjectClassLoader.java:92)
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2658)
at java.lang.Class.getConstructors(Class.java:1638)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.newObj(XmlConfiguration.java:748)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.itemValue(XmlConfiguration.java:1078)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.value(XmlConfiguration.java:993)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.newObj(XmlConfiguration.java:741)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.configure(XmlConfiguration.java:383)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.configure(XmlConfiguration.java:317)
at org.eclipse.jetty.xml.XmlConfiguration.configure(XmlConfiguration.java:276)
at org.eclipse.jetty.webapp.JettyWebXmlConfiguration.configure(JettyWebXmlConfiguration.java:100)
at org.eclipse.jetty.webapp.WebAppContext.configure(WebAppContext.java:427)
at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1207)
at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:610)
at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:453)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59)
at org.eclipse.jetty.server.handler.HandlerWrapper.doStart(HandlerWrapper.java:89)
at org.eclipse.jetty.server.Server.doStart(Server.java:262)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59)
at runjettyrun.Bootstrap.main(Bootstrap.java:80)
2015-10-30 14:22:51.172:INFO:oejs.AbstractConnector:Started SelectChannelConnector@0.0.0.0:8081 STARTING
2015-10-30 14:22:51.172:WARN:oejuc.AbstractLifeCycle:FAILED org.eclipse.jetty.server.Server@7857fe2: java.lang.NoClassDefFoundError: org/apache/commons/pool/impl/GenericObjectPool
java.lang.NoClassDefFoundError: org/apache/commons/pool/impl/GenericObjectPool
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2658)
at java.lang.Class.getConstructors(Class.java:1638)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.newObj(XmlConfiguration.java:748)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.itemValue(XmlConfiguration.java:1078)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.value(XmlConfiguration.java:993)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.newObj(XmlConfiguration.java:741)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.configure(XmlConfiguration.java:383)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.configure(XmlConfiguration.java:317)
at org.eclipse.jetty.xml.XmlConfiguration.configure(XmlConfiguration.java:276)
at org.eclipse.jetty.webapp.JettyWebXmlConfiguration.configure(JettyWebXmlConfiguration.java:100)
at org.eclipse.jetty.webapp.WebAppContext.configure(WebAppContext.java:427)
at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1207)
at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:610)
at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:453)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59)
at org.eclipse.jetty.server.handler.HandlerWrapper.doStart(HandlerWrapper.java:89)
at org.eclipse.jetty.server.Server.doStart(Server.java:262)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59)
at runjettyrun.Bootstrap.main(Bootstrap.java:80)
Caused by:
java.lang.ClassNotFoundException: org.apache.commons.pool.impl.GenericObjectPool
at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at org.eclipse.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:415)
at runjettyrun.ProjectClassLoader.loadClass(ProjectClassLoader.java:92)
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2658)
at java.lang.Class.getConstructors(Class.java:1638)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.newObj(XmlConfiguration.java:748)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.itemValue(XmlConfiguration.java:1078)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.value(XmlConfiguration.java:993)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.newObj(XmlConfiguration.java:741)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.configure(XmlConfiguration.java:383)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.configure(XmlConfiguration.java:317)
at org.eclipse.jetty.xml.XmlConfiguration.configure(XmlConfiguration.java:276)
at org.eclipse.jetty.webapp.JettyWebXmlConfiguration.configure(JettyWebXmlConfiguration.java:100)
at org.eclipse.jetty.webapp.WebAppContext.configure(WebAppContext.java:427)
at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1207)
at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:610)
at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:453)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59)
at org.eclipse.jetty.server.handler.HandlerWrapper.doStart(HandlerWrapper.java:89)
at org.eclipse.jetty.server.Server.doStart(Server.java:262)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59)
at runjettyrun.Bootstrap.main(Bootstrap.java:80)
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/pool/impl/GenericObjectPool
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2658)
at java.lang.Class.getConstructors(Class.java:1638)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.newObj(XmlConfiguration.java:748)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.itemValue(XmlConfiguration.java:1078)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.value(XmlConfiguration.java:993)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.newObj(XmlConfiguration.java:741)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.configure(XmlConfiguration.java:383)
at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.configure(XmlConfiguration.java:317)
at org.eclipse.jetty.xml.XmlConfiguration.configure(XmlConfiguration.java:276)
at org.eclipse.jetty.webapp.JettyWebXmlConfiguration.configure(JettyWebXmlConfiguration.java:100)
at org.eclipse.jetty.webapp.WebAppContext.configure(WebAppContext.java:427)
at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1207)
at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:610)
at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:453)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59)
at org.eclipse.jetty.server.handler.HandlerWrapper.doStart(HandlerWrapper.java:89)
at org.eclipse.jetty.server.Server.doStart(Server.java:262)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59)
at runjettyrun.Bootstrap.main(Bootstrap.java:80)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.pool.impl.GenericObjectPool
at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at org.eclipse.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:415)
at runjettyrun.ProjectClassLoader.loadClass(ProjectClassLoader.java:92)
... 20 more
I have added the commons-dbcp-1.4.jar to my WEB-INF/lib folder in eclipse after looking at other stackoverflow threads. Even after doing that, I am getting the same error when I deploy on Jetty.
I am using jetty server version 8 integrated with eclipse luna 4.4.1.
Any help much appreciated.
You have 3 ways to do it:
- If you are using maven or gradle in your project simply add commons-pool dependency to your pom.xml or build.gradle file (recommended way)
- If you are not using one of the mentioned tools place correct jar in the WEB-INF/lib directory
- The last one is to place jar in ${jettyHome}/lib directory
Make sure that you are using correct version of the commons-pool for your current commons-dbcp implementation
you don't you just use tomcat instead. find it here http://tomcat.apache.org/ :)
Note that jetty is only well to be used when you need to make local app development easier.
https://tomcat.apache.org/tomcat-7.0-doc/jdbc-pool.html
I suggest you start reading up the basics for tomcat and as you begin to gain a basic understanding of how things work, you should start implementing Connection Pooling :)
Hope this helps.
来源：https://stackoverflow.com/questions/33430675/connection-pooling-using-jetty-in-oracle