Discussion :

[toztoztoze]

bonjour je viens de créer mon application elle est toujours vide je mets juste une classe qui permet de se connecter à ma base de données sql mais quand je lance mon application j'obtiens l'erreur suivante:

AVERTISSEMENT: com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@17460bca -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception:
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:832)
at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:456)
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:207)
at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:175)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:220)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:206)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:203)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1138)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1125)
at com.mchange.v2.resourcepool.BasicResourcePool.access$700(BasicResourcePool.java:44)
at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1870)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.GeneratedConstructorAccessor34.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151)
at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167)
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:91)
at com.mysql.cj.NativeSession.connect(NativeSession.java:152)
at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:952)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:822)
... 12 more
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:173)
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:65)
... 15 more

voici le code que j'ai fait:

Code Java :

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package com.luv2code.testdb;
 
import java.io.IOException;
import java.io.PrintWriter;
 
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 java.sql.*;
/**
 * Servlet implementation class TestDbServlet
 */
@WebServlet("/TestDbServlet")
public class TestDbServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
 
	/**
         * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
         */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 
		// établir la connexion à mysql :
 
		String user="springstudent";
		String password="springstudent";
		String jdbcUrl="jdbc:mysql://localhost:3309/web_customer_tracker?useSSL=false&serverTimezone=UTC";
		String driver="com.mysql.jdbc.Driver";
 
		try {
 
			PrintWriter out= response.getWriter();
			out.println("Connection à  la base de donnée :"+jdbcUrl);
 
			Class.forName(driver);
			Connection cnx;
			cnx=DriverManager.getConnection(jdbcUrl, user, password);
 
			out.println("Success !!!!!!!!!");
 
			cnx.close();
		}
 
		catch(Exception ex) {
			ex.printStackTrace();
			throw new ServletException(ex);
		}
	}
 
}

J'ai mis le port 3309 au lieu de 3306 car le port 3306 ne fonctionne pas dans mon mysqlworkbench cela me donne l'erreur suivante:



et même lorsque je veux créer une nouvelle base de données avec le port 3306, cela me donne l'erreur suivante:



Je ne sais pas si c'est ce problème de port qui me donne cette erreur.

aidez-moi s'il vous plaît !!