I am trying to implement connection pooling using servlet. I know there are lots of similar questions has been asked but none is able to help.
Here is exception :
java.sql.SQLException: Cannot create JDBC driver of class for connect URL null at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createConnectionFactory(BasicDataSource.java:2160) at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createDataSource(BasicDataSource.java:2032) at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.getConnection(BasicDataSource.java:1532) at connection.CityInfoServlet.showCityInformation(CityInfoServlet.java:104) at connection.CityInfoServlet.doGet(CityInfoServlet.java:76) at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:521) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1096) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:674) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Unknown Source) Caused by: java.sql.SQLException: No suitable driver at java.sql.DriverManager.getDriver(Unknown Source) at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createConnectionFactory(BasicDataSource.java:2144) ... 27 more
I don't know why this exception show :
Caused by: java.sql.SQLException: No suitable driver.
I added jar file in WEB-INF/lib folder.
Here is my Servlet Code :
package connection;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;
@WebServlet("/CityInfoServlet")
public class CityInfoServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
DataSource dataSource = null;
public void init( ServletConfig config ) {
try{
Context initContext = new InitialContext();
Context envContext = (Context) initContext.lookup("java:/comp/env");
dataSource = (DataSource) envContext.lookup("jdbc/worldDB");
}
catch( Exception exe )
{
exe.printStackTrace();
}
}
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String title = "City Information From Mysql Database";
out.print("<html><body bgcolor=\"#f0f0f0\">");
out.print("<h1 align=\"center\">" + title + "</h1>\n");
showCityInformation(out);
out.print("</body></html>");
}
private void showCityInformation( PrintWriter out )
{
Connection connection = null;
PreparedStatement preparedStatement = null;
try {
String sql = "select * from city limit ?";
connection = dataSource.getConnection();
preparedStatement = connection.prepareStatement(sql);
preparedStatement.setInt(1, 10);
ResultSet rs = preparedStatement.executeQuery();
while( rs.next() )
{
int id = rs.getInt(1);
String name = rs.getString(2);
String countryCode = rs.getString(3);
String district = rs.getString(4);
int population = rs.getInt(5);
out.print("ID: " + id + "<br>");
out.print("Name: " + name+ "<br>");
out.print("CountryCode: " + countryCode+ "<br>");
out.print("District: " + district+ "<br>");
out.println("Population: " + population+ "<br>");
out.println("--------------------------------------"+ "<br>");
}
rs.close();
}
catch( Exception e )
{
e.printStackTrace();
}
finally
{
try {
if( preparedStatement != null ) {
preparedStatement.close();
}
}
catch( SQLException sqlException ){
sqlException.printStackTrace();
}
try
{
if( connection != null )
{
connection.close();
}
}
catch( SQLException sqlException )
{
sqlException.printStackTrace();
}
}
}
}
This is context.xml file
<?xml version="1.0" encoding="UTF-8"?>
<Context>
<Resource name="jdbc/worldDB" auth="Container" type="javax.sql.DataSource"
maxTotal="100" maxIdle="30" maxWaitMillis="10000"
username="root" password="12345" driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/world"/>
</Context>
