RL System - Escola Online para Programadores

Curso de JSP e Servlets Online (Java EE) - Não consigo acessar o banco:

- Kelvio Wallisson Cavalcante da Silva

Criei um banco no phpmyadmin do Xampp, chamado: "chamados". Porque no arquivo "mysql.exe" abre o monitor do MariaDB e não do MySQL. Código do arquivo NovoChamadoServlet.java.




import java.io.IOException;

import java.io.PrintWriter;
import java.sql.DriverManager;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

//import com.mysql.jdbc.Connection;
//import com.mysql.jdbc.Statement;

/**
 * Servlet implementation class NovoChamadoServlet
 */
public class NovoChamadoServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	private java.sql.Statement stm;
	private String sQL;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
	/*
    public NovoChamadoServlet() {
        super();
        // TODO Auto-generated constructor stub
    }
	*/
	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
		// TODO Auto-generated method stub
		try {
			PrintWriter out = res.getWriter();
			out.println("<html>");
			out.println("<head>");
			out.println("<title>Novo Chamado</title>");
			out.println("</head>");
			out.println("<body>");
			out.println("<h1>Preencha as Informaçoes do chamado</h1>");
			out.println("</hr>"); 
			out.println("<form method='POST'>");
			out.println("Titulo: <br><input type='text' name='txtTitulo'");
			out.println("<br>");
			out.println("<br>");
			out.println("Conteudo: <br><textarea name='txtConteudo' rows='10' cols='40'></textarea>");
 
			out.println("<br>");
			out.println("<input type='submit' value='Abrir Chamado'>");
			out.println("</form>");
			out.println("<br>");
			out.println("<a href='http://localhost:8080/Chamados/ListarChamados'>Listar Chamados</a>");
			out.println("<br>");
			out.println("<a href='http://localhost:8080/Chamados/Logoff'>Sair</a>");
			out.println("</body>");
			out.println("</html>");
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		 
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		PrintWriter out = response.getWriter();
		String titulo = request.getParameter("txtTitulo");
		String conteudo = request.getParameter("txtConteudo");
		if(titulo.trim().length()<4) {
			out.println("Preencha nome do Titulo");
		}else if(conteudo.trim().length()<4) {
			out.println("Preencha o campo Conteudo");
		}else {
			try {
			Class.forName("com.mysql.jdbc.Driver");
			sQL = "INSERT INTO chamados (titulo, conteudo) VALUES(";
			sQL += "'"+titulo+"', '"+conteudo+"')";
				try {
					java.sql.Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/chamados", "root", "");
					stm = conn.createStatement();
					stm.execute(sQL);
					stm.close();
					conn.close();
				}catch(SQLException e) {
					e.printStackTrace();
					out.println("Problema na conexao com o banco");
				}
			}catch(ClassNotFoundException ex) {
				out.println("Problema ao carregar o driver de conexao");
			}
		}
	}

ERRO:

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.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:425)

at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:990)

at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:342)

at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2188)

at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2221)

at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2016)

at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:776)

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:425)

at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386)

at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)

at java.sql.DriverManager.getConnection(Unknown Source)

at NovoChamadoServlet.doPost(NovoChamadoServlet.java:88)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)

at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:498)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)

at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:1025)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)

at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1115)

at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)

at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)

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.net.SocketException: Permission denied: connect

at java.net.DualStackPlainSocketImpl.connect0(Native Method)

at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)

at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)

at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)

at java.net.AbstractPlainSocketImpl.connect(Unknown Source)

at java.net.PlainSocketImpl.connect(Unknown Source)

at java.net.SocksSocketImpl.connect(Unknown Source)

at java.net.Socket.connect(Unknown Source)

at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:211)

at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:301)

Preciso de ajuda para fazer essa conexão funcionar para continuar o curso.

Obrigado.

- José Carlos Sarinho Tavares

Testa esse código: Obs.:Modifique o nome da tabela e dos campos, que eu coloquei diferente.




import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.Date;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.Statement;
import java.text.SimpleDateFormat;


import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class NovoChamadoServlet
 */
public class NovoChamadoServlet extends HttpServlet {
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		try {
			PrintWriter out = response.getWriter();
			out.println(\"<html>\");
			out.println(\"<head>\");
			out.println(\"<title>Novo Chamado</title>\");
			out.println(\"</head>\");
			out.println(\"<body>\");
			out.println(\"<h1>Preencha as informações do Chamado</h1>\");
			out.println(\"<hr/>\");
			out.println(\"<form method=\'POST\'>\");
			out.println(\"Título:<br> <input type=\'text\' name=\'txtTitulo\'>\");
			out.println(\"<br>\");
			out.println(\"Conteúdo:<br> <textarea name=\'txtConteudo\' rows=\'10\' cols=\'40\'></textarea>\");
			out.println(\"<br>\");
			out.println(\"<input type=\'submit\' value=\'Abrir Camado\'>\");
			out.println(\"</form>\");
			out.println(\"<br>\");
			out.println(\"<a href=\'http://localhost:8080/Chamados/ListarChamado\'>Listar Chamados<a/>\");
			out.println(\"<br>\");
			out.println(\"<a href=\'http://localhost:8080/Chamados/Logoff\'>Sair<a/>\");
			out.println(\"</body>\");
			out.println(\"</html>\");
		} catch (IOException e) {
			
		}
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		PrintWriter out = response.getWriter();
		
		String titulo = request.getParameter(\"txtTitulo\");
		String conteudo = request.getParameter(\"txtConteudo\");		
			
		if(titulo.trim().length() < 4) {
			out.println(\"Preencha o título\");
		} else if(conteudo.trim().length() < 4) {
			out.println(\"Preencha o conteúdo\");
		} else {
			try {
				//Class.forName(\"com.mysql.cj.jdbc.Driver\");
			    Class.forName(\"com.mysql.jdbc.Driver\");//Caminho do driver de conexão
			    String SQL = \"INSERT INTO tbl_chamado(titulo, conteudo, data) VALUES(?, ?, ?)\";
					   
					   try {						   
							Connection conn = DriverManager.getConnection(\"jdbc:mysql://localhost:3306/chamados\", \"root\", \"\");
							PreparedStatement pstm = conn.prepareStatement(SQL);
							
							Date dataSQL = new Date(new java.util.Date().getTime());
							//SimpleDateFormat dt = new SimpleDateFormat(\"yyy-MM-dd\");//\"yyy-MM-dd\" padrão da data no mysql
							//dt.format(data);
							
							pstm.setString(1, titulo);
							pstm.setString(2, conteudo);
							pstm.setDate(3, dataSQL);
							
							pstm.execute();
							pstm.close();
							conn.close();
							response.sendRedirect(\"http://localhost:8080/Chamados/ListarChamado\");
							
					} catch (Exception e) {
						out.println(\"Problema no banco de dados! \" + e.getMessage());
					}				
					   
			} catch (ClassNotFoundException e) {
				out.println(\"Problema ao carregar o driver de conexão! \" + e.getMessage());
			}
		}
	}
}

Fórum

Curso de JSP e Servlets Online (Java EE) - Não consigo acessar o banco:

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