Java connecting JDBC to Dynamic Web App - java

I have run into a problem that I have been trying to figure out for days:
I added my driver: mysql-connector-java-5.1.40.jar to build path.
web-inf lib folder, apache tomcat lib folder. And also I have it in web app libaries.
However when I just run a main class and run it works, it is something to do with the web app?
This is my code:
This is the servlet class, that I use to connect to my database
package sql;
import java.io.IOException;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class RegisterServlet
*/
#WebServlet("/register")
public class RegisterServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private DbUtil sql = new DbUtil();
/**
* #see HttpServlet#HttpServlet()
*/
public RegisterServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* #see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String email = request.getParameter("email");
String username = request.getParameter("username");
String password = request.getParameter("password");
if (sql.addToAccountToDatabase(username, password, email)) {
System.out.println("Gongratz");
} else {
System.out.println("mhhh ?");
}
}
/**
* #see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
}
this is the second class how i make connection
package sql;
import java.sql.*;
public class DbUtil {
public Connection getConnection() {
Connection connect = null;
try {
String url = "jdbc:mysql://hidden:3306/hidden";
connect = DriverManager.getConnection(url, "hidden", "hidden");
return connect;
} catch (Exception e) {
System.out.println("Cannot connect to database");
e.printStackTrace();
}
return connect;
}
public boolean addToAccountToDatabase(String username, String password, String email) {
try {
String query = "INSERT INTO Account (username, password, email) VALUES (?, ?,?)";
PreparedStatement pStat = getConnection().prepareStatement(query);
pStat.setString(1, username);
pStat.setString(2, password);
pStat.setString(3, email);
pStat.executeUpdate();
return true;
} catch (Exception e) {
System.out.println("User already exists");
e.printStackTrace();
return false;
}
}
}
And I get this error:
Cannot connect to database
java.sql.SQLException: No suitable driver found for jdbc:mysql://192.185.227.214:3306/ratekas9_illegalminds
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at sql.DbUtil.getConnection(DbUtil.java:15)
at sql.DbUtil.addToAccountToDatabase(DbUtil.java:34)
at sql.RegisterServlet.doPost(RegisterServlet.java:40)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:108)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:784)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:802)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
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)
User already exists
java.lang.NullPointerException
at sql.DbUtil.addToAccountToDatabase(DbUtil.java:34)
at sql.RegisterServlet.doPost(RegisterServlet.java:40)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:108)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:784)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:802)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
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)
mhhh ?

Because the String "jdbc:mysql" doesn't declare the driver Class itself, but only the name registered by a potential driver. You have to force the JVM to load the Driver class with a :
Class.forName("com.mysql.jdbc.Driver").newInstance();
before starting the JDBC connection.

You need 3 steps to solve your problem:
Add this code before connection Class.forName("com.mysql.jdbc.Driver");
Add 'JConnector.jar' into your project and build path.
Don't try enter same person because there is error in stack trace "User all ready exist ".

Adding the JAR file into your CLASSPATH (for compilation needs) / project's BUILDPATH and also under your project's WEB-INF/lib folder (for runtime references, i.e., when you deploy your application to an application server). For further reference, please go through this link
Class.forName("com.mysql.jdbc.Driver");
This is no longer required as per Official Java documentation here, but it is a mandatory step if you are using prior versions of JDBC 4.0.
This question can provide you lot many details on this regards.
Hope all these details help you resolve your issue!

Related

My servelet runs without any problem but the data is not inserted into the database. Why?

Servlet
package com.reservation;
import java.io.IOException;
import java.sql.Date;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
#WebServlet("/reservationservlet")
public class reservationservlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public reservationservlet() {
super();
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String clientid = request.getParameter("clientid");
String reservationid = request.getParameter("resid");
String reservationdate = request.getParameter("resdate");
String paymethod = request.getParameter("paymentmethod");
String ecat = request.getParameter("category");
String packg = request.getParameter("package");
boolean isTrue;
isTrue = reservationDBUtil.insertreservation(clientid, reservationid, reservationdate, paymethod, ecat, packg);
if(isTrue == true) {
RequestDispatcher dis = request.getRequestDispatcher("services2.jsp");
dis.forward(request, response);
}
else {
RequestDispatcher dis2 = request.getRequestDispatcher("reservation.jsp");
dis2.forward(request, response);
}
}
}
DBUtil
package com.reservation;
import java.sql.Connection;
import java.sql.DriverManager;
import java.util.List;
import com.mysql.jdbc.Statement;
public class reservationDBUtil {
public static boolean insertreservation(String clientid,String reservationid,String reservationdate,String paymethod,String ecat,String packg) {
boolean isSuccess = false;
//database connection
String url = "jdbc:mysql://localhost:3306/reservations";
String user = "root";
String pass = "6334";
try {
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection(url, user, pass);
Statement stmt = (Statement) con.createStatement();
String sql = "insert into reservation values ('"+clientid+"','"+reservationid+"','"+reservationdate+"','"+paymethod+"','"+packg+"')";
int res = stmt.executeUpdate(sql);
if(res > 0) {
isSuccess = true;
} else {
isSuccess = false;
}
}
catch (Exception e) {
e.printStackTrace();
}
return isSuccess;
}
}
Mon Apr 27 15:30:24 IST 2020 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'reservations.reservation' doesn't exist
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500)
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:481)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.Util.getInstance(Util.java:408)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:944)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3933)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3869)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2524)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2675)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2465)
at com.mysql.jdbc.StatementImpl.executeUpdateInternal(StatementImpl.java:1536)
at com.mysql.jdbc.StatementImpl.executeLargeUpdate(StatementImpl.java:2585)
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1464)
at com.reservation.reservationDBUtil.insertreservation(reservationDBUtil.java:27)
at com.reservation.reservationservlet.doPost(reservationservlet.java:36)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.base/java.lang.Thread.run(Thread.java:832)
I think your problem is that you don't have the table reservation in your database. Try creating it.

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException Public Key Retrieval is not allowed

I'm presently learning Servlets and Jsp via a video tutorial, I am trying to connect to MySql database but its been difficult doing so, I have followed all steps taken in the tutorial but its still not connecting, at first the exception i was getting was the java.sql.SQLException: No suitable driver found for com.mysql.jdbc.Driver at java.sql.DriverManager
i have checked online for a possible solution but none is working for me, right now i added MySQL-connector-java-5.1.49-bin.jar to the lib and its bringing another type of exception.
java.sql.SQLException: Cannot create PoolableConnectionFactory (Public Key Retrieval is not allowed)
at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:669)
at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createDataSource(BasicDataSource.java:544)
at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.getConnection(BasicDataSource.java:753)
at com.luv2code.web.jdbc.TextSerlets.doGet(TextSerlets.java:43)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
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: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Public Key Retrieval is not allowed
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:403)
at com.mysql.jdbc.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:861)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:878)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:874)
at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1770)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1217)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2189)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2220)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2015)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:768)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:403)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:385)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:323)
at org.apache.tomcat.dbcp.dbcp2.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:55)
at org.apache.tomcat.dbcp.dbcp2.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:355)
at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.validateConnectionFactory(BasicDataSource.java:115)
at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:665)
... 27 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Public Key Retrieval is not allowed
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:403)
at com.mysql.jdbc.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:861)
at com.mysql.jdbc.authentication.CachingSha2PasswordPlugin.nextAuthenticationStep(CachingSha2PasswordPlugin.java:130)
at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1768)
... 44 more
I'm kinda getting frustrated as its affecting my learning progress,below is my context.xml file and i must also say that its now showing some kind of multiple annotation found at this line error which is in line 1.
<Context>
<Resource name="jdbc/web_student_tracker"
auth="Container" type="javax.sql.DataSource"
maxActive="20" maxIdle="5" maxWait="10000"
username="webstudent" password="webstudent"
driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/web_student_tracker?useSSL=false"/>
</Context>
My servlet code:
package com.luv2code.web.jdbc;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import javax.annotation.Resource;
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;
/**
* Servlet implementation class TextSerlets
*/
#WebServlet("/TextSerlets")
public class TextSerlets extends HttpServlet {
private static final long serialVersionUID = 1L;
#Resource(name="jdbc/web_student_tracker")
private DataSource dataSource;
/**
* #see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//step 1 : Set up print writer
PrintWriter out = response.getWriter();
response.setContentType("text/plain");
//step 2: Get a cinnection to the adatbase
Connection myConn = null;
Statement myStmt = null;
ResultSet myRs = null;
try {
myConn = dataSource.getConnection();
//Step 3 :Create a SQL statement
String sql = "select * from student";
myStmt = myConn.createStatement();
//step 4: Execute SQL query
myRs = myStmt.executeQuery(sql);
//step 5 : Process the result set
while (myRs.next()) {
String email = myRs.getString("email");
out.println(email);
}
}
catch (Exception exc) {
exc.printStackTrace();
}
}
}
This is my first time posting here so kindly ignore any error made on the post if there's any.
You should add allowPublicKeyRetrieval=true to allow the client to automatically request the public key from the server. Note that allowPublicKeyRetrieval=true is not recommended as it could allow a malicious proxy to perform a MITM attack to get the plaintext password. Change
url="jdbc:mysql://localhost:3306/web_student_tracker?useSSL=false"
to
url="jdbc:mysql://localhost:3306/web_student_tracker?allowPublicKeyRetrieval=true&useSSL=false;"
So i deleted the total web project an created a new one and it seems to be working fine now with this url="jdbc:mysql://localhost:3306/web_student_tracker?useSSL=false"

I am connecting to mysql database using JNDI but on execution it ends up on throwing exceptions

These are exceptions I'm facing
java.sql.SQLException: Cannot create PoolableConnectionFactory (Public Key Retrieval is not allowed)
Caused by: java.sql.SQLNonTransientConnectionException: Public Key Retrieval is not allowed
Here is context.xml
<Context>
<Resource name="jdbc/project"
auth="Container" type="javax.sql.DataSource"
maxActive="25" maxIdle="5" maxWait="10000"
username="Shubham" password="1234abc"
driverClassName="com.mysql.cj.jdbc.Driver"
url="jdbc:mysql://127.0.0.1:3306/studyeasy_db?useSSL=false"/>
</Context>
This is servlet Demo2.java
package org.studyeasy;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.annotation.Resource;
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;
/**
* Servlet implementation class Demo2
*/
#WebServlet("/Demo2")
public class Demo2 extends HttpServlet {
private static final long serialVersionUID = 1L;
#Resource(name="jdbc/project")
private DataSource dataSource;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
PrintWriter out = response.getWriter();
Connection connect = null;
Statement stmt = null;
ResultSet rs = null;
try {
connect = dataSource.getConnection();
String query = "Select * from users";
stmt = connect.createStatement();
rs = stmt.executeQuery(query);
while(rs.next()) {
out.print(rs.getString("email"));
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
java.sql.SQLException: Cannot create PoolableConnectionFactory (Public Key Retrieval is not allowed)
at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:669)
at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createDataSource(BasicDataSource.java:544)
at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.getConnection(BasicDataSource.java:753)
at org.studyeasy.Demo.doGet(Demo.java:41)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:688)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1594)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
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.SQLNonTransientConnectionException: Public Key Retrieval is not allowed
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:110)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:836)
at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:456)
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:246)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:197)
at org.apache.tomcat.dbcp.dbcp2.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:55)
at org.apache.tomcat.dbcp.dbcp2.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:355)
at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.validateConnectionFactory(BasicDataSource.java:115)
at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:665)
... 27 more
I'm beginner please help me!
I'm glad that you joined stack overflow. This error has nothing to do with your Java code. The error code says:
java.sql.SQLException: Cannot create PoolableConnectionFactory (Public Key Retrieval is not allowed)
All you need to do is set up a username and password to connect to your database.

java.sql.SQLException: No suitable driver found for localhost [duplicate]

This question already has answers here:
Connect Java to a MySQL database
(14 answers)
Closed 5 years ago.
My Code
Connection conn = null;
Statement stmt;
String user = "test";
String password = "test1";
String url = "localhost;
public void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
response.setStatus(HttpServletResponse.SC_OK);
try {
try { Class.forName("com.mysql.jdbc.Driver");
} catch (Exception e) {
System.out.println(e);
}
conn = DriverManager.getConnection(url, user, password);
stmt = conn.createStatement();
String query = "select * from dataTable";
}........
The Errors i am getting
java.sql.SQLException: No suitable driver found for localhost
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.phidget22.ShowDatabase.doGet(ShowDatabase.java:47)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
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)
i have also got the mysql connector jar in my referenced library, WEB-INF folder and tomcat library folder. i am not sure why it is giving me these errors again and again.
In your code you have String url = "localhost; it must be edited as
String url = "localhost";
url = "jdbc:mysql://localhost/(your db name)";

Unable to execute jdbc query on a servlet [duplicate]

This question already has answers here:
How to add JAR libraries to WAR project without facing java.lang.ClassNotFoundException? Classpath vs Build Path vs /WEB-INF/lib
(5 answers)
Closed 6 years ago.
I am trying to create an html page which takes some input and saves that data in oracle database using jdbc and servlet.
This is the HTML file
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<form action="HelloServlet" method="post">
<input type="text" placeholder="ID" name="id">
<input type="text" placeholder="NAME" name="name">
<input type="text" placeholder="SALARY" name="salary">
<input type="submit" value="submit">
</form>
</body>
</html>
Here is javafile contains the servlet
package com.gaurav;
import java.sql.*;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
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 org.apache.jasper.tagplugins.jstl.core.Out;
#WebServlet("/HelloServlet")
public class HelloServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
#Override
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// Set response content type
// Actual logic goes here.
//String name=request.getParameter("name");
//out.println(name);
}
#Override
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String url="jdbc:oracle:thin:#localhost:1521:xe";
String user="system";
String pass="inception";
try{
int id=Integer.parseInt(request.getParameter("id"));
String name=request.getParameter("name");
int salary=Integer.parseInt(request.getParameter("salary"));
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con=DriverManager.getConnection(url,user,pass);
String query="INSERT INTO employee VALUES(?,?,?)";
PreparedStatement stm=con.prepareStatement(query);
stm.setInt(1, id);
stm.setString(2, name);
stm.setInt(3, salary);
stm.executeUpdate();
con.close();
}
catch(ClassNotFoundException e){
out.println("class not found ");
}
catch(SQLException e){
out.println("SQL Exception");
}
}
#Override
public void destroy() {
// resource release
super.destroy();
}
}
file hierarchy
whenever i tries to run the above program,it doesn't shows any error but when i write some data and press the submit button it thorws a ClassNotFound Exception.I don't have any idea whats happening.so someone help me.
Stack Trace:
java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1285)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1119)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at com.gaurav.HelloServlet.doPost(HelloServlet.java:50)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:108)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:789)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
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)
It looks like you are using Oracle 10g. From Oracle 9i onwards, support for oracle.jdbc.driver.OracleDriver is deprecated (documentation here). Could you try using oracle.jdbc.OracleDriver instead?
Check if you loaded the correct oracle jar driver on your project.

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