access database (newbie)
hi all, first time servelt and it's going ok.
I just have this minor problem when trying to connect the db:
import java.io.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import javax.servlet.http.*;
import javax.servlet.*;
publicclass HelloServletextends HttpServlet
{
private String url;
private Connection con;
publicvoid doGet (HttpServletRequest req, HttpServletResponse res)throws ServletException, IOException
{
PrintWriter out = res.getWriter();
out.println("Hello, Brave new World 3 3523!");
try{
Class.forName("com.mysql.jdbc.Driver").newInstance();
url ="jdbc:mysql://"+getHost()+"/usgroups_db";
con = DriverManager.getConnection(url,"root","topsecret");
out.println("i'm done");
}catch(SQLException sqlex)
{
out.println("err 1");
}catch(Exception ex)
{
out.println("the value of getHost is: "+this.getHost());
out.println("err 2:"+ex.getMessage());
}
out.println("done!");
out.close();
}
public String getHost()
{
return"localhost";
}
}
the result is:
Hello, Brave new World 3 5423!
the value of getHost is: localhost
err 2:com.mysql.jdbc.Driver
done!
can someone guide me why the conn fails?
I added the mysql jar file to the project (using eclipse)
thanks
peter
thanks
>> make sure db driver jar file under WEB-INF/ lib
yes, now i get an sql exception:
Hello, Brave new World 20xbx!
Hello, Brave 22
err 1:
Unable to connect to any hosts due to exception: java.security.AccessControlException: access denied (java.net.SocketPermission 127.0.0.1:3306 connect,resolve)
** BEGIN NESTED EXCEPTION **
java.security.AccessControlException
MESSAGE: access denied (java.net.SocketPermission 127.0.0.1:3306 connect,resolve)
STACKTRACE:
java.security.AccessControlException: access denied (java.net.SocketPermission 127.0.0.1:3306 connect,resolve)
at java.security.AccessControlContext.checkPermission(Unknown Source)
at java.security.AccessController.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkConnect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:124)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:225)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1783)
at com.mysql.jdbc.Connection.<init>(Connection.java:450)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:411)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at HelloServlet.doGet(HelloServlet.java:23)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:98)
at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:176)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:172)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2417)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:193)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:781)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:549)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:589)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:666)
at java.lang.Thread.run(Unknown Source)
** END NESTED EXCEPTION **
done!
