找不到合適的驅動程序（但是驅動程序在那里！）
[英]No suitable driver found (but the driver is there!)
問題描述
好吧，我在這里苦於用eclipse在Java中制作我的第一個Web應用程序。 事實是，我擁有mysql驅動程序JDBC，並創建了與數據庫建立連接的類，我編寫了一本書以在數據庫中注冊一些聯系人，例如個人組織者，它在Java中效果很好，沒有錯誤。 但是在Java EE中，我無法將聯系人保存在數據庫中，因為出現了以下錯誤： java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost/bDados 。 好吧，它具有相同的類來進行連接，我已經將mysql JDBC驅動程序（例如build path-> add）構建到構建路徑中，我不知道為什么它在Java EE中不起作用！ 這里：
package br.com.caelum.servlet;
import java.sql.*;
public class ConnectionFactory {
public Connection getConnection(){
try{
return DriverManager.getConnection(
"jdbc:mysql://localhost/bDados", "gabrielDados","25120107");
}catch(SQLException e){
throw new RuntimeException(e);
}
}
}
import java.util.Calendar;
public class Contato {
private Long id;
private String nome;
private String email;
private String endereco;
private Calendar dataNascimento;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getNome() {
return nome;
}
public void setNome(String nome) {
this.nome = nome;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getEndereco() {
return endereco;
}
public void setEndereco(String endereco) {
this.endereco = endereco;
}
public Calendar getDataNascimento() {
return dataNascimento;
}
public void setDataNascimento(Calendar dataNascimento) {
this.dataNascimento = dataNascimento;
}
}
import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.SQLException;
public class ContatoDao {
private Connection connection;
public ContatoDao(){
this.connection = new ConnectionFactory().getConnection();
}
public void adiciona(Contato contato) {
String sql = "insert into contatos " +
"(nome,email,endereco,dataNascimento)" +
" values (?,?,?,?)";
try {
// prepared statement para inserção
PreparedStatement stmt = connection.prepareStatement(sql);
// seta os valores
stmt.setString(1,contato.getNome());
stmt.setString(2,contato.getEmail());
stmt.setString(3,contato.getEndereco());
stmt.setDate(4, new Date(
contato.getDataNascimento().getTimeInMillis()));
// executa
stmt.execute();
stmt.close();
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
}
import java.io.IOException;
import java.io.PrintWriter;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
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("/adicionaContato")
public class AdicionaContatoServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void service(HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException {
// busca o writer
PrintWriter out = response.getWriter();
// buscando os parâmetros no request
String nome = request.getParameter("nome");
String endereco = request.getParameter("endereco");
String email = request.getParameter("email");
String dataEmTexto = request
.getParameter("dataNascimento");
Calendar dataNascimento = null;
// fazendo a conversão da data
try {
Date date =
new SimpleDateFormat("dd/MM/yyyy")
.parse(dataEmTexto);
dataNascimento = Calendar.getInstance();
dataNascimento.setTime(date);
} catch (ParseException e) {
out.println("Erro de conversão da data");
return; //para a execução do método
}
// monta um objeto contato
Contato contato = new Contato();
contato.setNome(nome);
contato.setEndereco(endereco);
contato.setEmail(email);
contato.setDataNascimento(dataNascimento);
// salva o contato
ContatoDao dao = new ContatoDao();
dao.adiciona(contato);
// imprime o nome do contato que foi adicionado
out.println("<html>");
out.println("<body>");
out.println("Contato " + contato.getNome() +
" adicionado com sucesso");
out.println("</body>");
out.println("</html>");
}
}
<html>
<body>
<h1>Adiciona Contatos</h1>
<br/>
<form action="adicionaContato">
Nome: <input type="text" name="nome" /><br />
E-mail: <input type="text" name="email" /><br />
Endereço: <input type="text" name="endereco" /><br />
Data Nascimento: <input type="text" name="dataNascimento" /><br />
<input type="submit" value="Gravar" />
</form>
</body>
</html>
我是新來的，不知道我是否做對了，但是無論如何，對於冗長的代碼感到抱歉...
1 個解決方案
解決方案1
1 2014-07-25 23:13:46
您沒有說如何部署此應用程序。 假設它是部署到Tomcat的正確構造的WAR文件。
Tomcat文檔說JDBC驅動程序需要添加到Tomcat / lib目錄。 嘗試將其放到那里，然后重新啟動Tomcat。
您的ConnectionFactory是個壞主意。 正確的做法是在Tomcat中設置池化的JNDI數據源。 該文檔向您展示了如何。
您可以在命令外殼中使用admin登錄MySQL嗎？
MySQL守護程序在監聽哪個端口？ 您沒有提供端口號，因此假定為3306。
數據庫偵聽器是否在本地計算機上運行？
嘗試在命令行上運行此獨立程序，以測試數據庫連接。 修改您的案例的連接字符串和憑據，編譯並運行它。 我正在為您提供的課程毫無疑問地有效。 現在將需要Eclipse，Tomcat，Web應用程序以及您不了解的所有其他功能。 看看是否可以連接； 正確選擇，然后繼續進行下一個級別。
package persistence;
import java.sql.*;
import java.util.*;
/**
* util.DatabaseUtils
* User: Michael
* Date: Aug 17, 2010
* Time: 7:58:02 PM
*/
public class DatabaseUtils {
/*
private static final String DEFAULT_DRIVER = "oracle.jdbc.driver.OracleDriver";
private static final String DEFAULT_URL = "jdbc:oracle:thin:@host:1521:database";
private static final String DEFAULT_USERNAME = "username";
private static final String DEFAULT_PASSWORD = "password";
*/
/*
private static final String DEFAULT_DRIVER = "org.postgresql.Driver";
private static final String DEFAULT_URL = "jdbc:postgresql://localhost:5432/party";
private static final String DEFAULT_USERNAME = "pgsuper";
private static final String DEFAULT_PASSWORD = "pgsuper";
*/
private static final String DEFAULT_DRIVER = "com.mysql.jdbc.Driver";
private static final String DEFAULT_URL = "jdbc:mysql://localhost:3306/party";
private static final String DEFAULT_USERNAME = "party";
private static final String DEFAULT_PASSWORD = "party";
public static void main(String[] args) {
long begTime = System.currentTimeMillis();
String driver = ((args.length > 0) ? args[0] : DEFAULT_DRIVER);
String url = ((args.length > 1) ? args[1] : DEFAULT_URL);
String username = ((args.length > 2) ? args[2] : DEFAULT_USERNAME);
String password = ((args.length > 3) ? args[3] : DEFAULT_PASSWORD);
Connection connection = null;
try {
connection = createConnection(driver, url, username, password);
DatabaseMetaData meta = connection.getMetaData();
System.out.println(meta.getDatabaseProductName());
System.out.println(meta.getDatabaseProductVersion());
} catch (Exception e) {
e.printStackTrace();
} finally {
close(connection);
long endTime = System.currentTimeMillis();
System.out.println("wall time: " + (endTime - begTime) + " ms");
}
}
public static Connection createConnection(String driver, String url, String username, String password) throws ClassNotFoundException, SQLException {
Class.forName(driver);
if ((username == null) || (password == null) || (username.trim().length() == 0) || (password.trim().length() == 0)) {
return DriverManager.getConnection(url);
} else {
return DriverManager.getConnection(url, username, password);
}
}
public static void close(Connection connection) {
try {
if (connection != null) {
connection.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void close(Statement st) {
try {
if (st != null) {
st.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void close(ResultSet rs) {
try {
if (rs != null) {
rs.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void rollback(Connection connection) {
try {
if (connection != null) {
connection.rollback();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public static List<Map<String, Object>> map(ResultSet rs) throws SQLException {
List<Map<String, Object>> results = new ArrayList<Map<String, Object>>();
try {
if (rs != null) {
ResultSetMetaData meta = rs.getMetaData();
int numColumns = meta.getColumnCount();
while (rs.next()) {
Map<String, Object> row = new HashMap<String, Object>();
for (int i = 1; i <= numColumns; ++i) {
String name = meta.getColumnName(i);
Object value = rs.getObject(i);
row.put(name, value);
}
results.add(row);
}
}
} finally {
close(rs);
}
return results;
}
public static List<Map<String, Object>> query(Connection connection, String sql, List<Object> parameters) throws SQLException {
List<Map<String, Object>> results = null;
PreparedStatement ps = null;
ResultSet rs = null;
try {
ps = connection.prepareStatement(sql);
int i = 0;
for (Object parameter : parameters) {
ps.setObject(++i, parameter);
}
rs = ps.executeQuery();
results = map(rs);
} finally {
close(rs);
close(ps);
}
return results;
}
public static int update(Connection connection, String sql, List<Object> parameters) throws SQLException {
int numRowsUpdated = 0;
PreparedStatement ps = null;
try {
ps = connection.prepareStatement(sql);
int i = 0;
for (Object parameter : parameters) {
ps.setObject(++i, parameter);
}
numRowsUpdated = ps.executeUpdate();
} finally {
close(ps);
}
return numRowsUpdated;
}
}
MySql-找不到合適的驅動程序
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