小编典典

自动将org.mysql更改为org.sqlite

java

连接类别:

public class ConectaSiscart { 
        static Connection connection = null;
        Statement stm = null;
        static String serverName = "192.168.0.222";    //caminho do servidor do BD  
        static String mydatabase ="risabel";        //nome do seu banco de dados  
        static String url = "jdbc:mysql://" + serverName + "/" + mydatabase;  
        static String username = "siscart";        //nome de um usuário de seu BD        
        static String password = "progsis";      //sua senha de acesso





        public static Connection getConexao() {
            try {  
                // Carregando o JDBC Driver padrão  
                Class.forName("com.mysql.jdbc.Driver");  
                // Configurando a nossa conexão com um banco de dados//


                ResultSet results = null;
               // connection = DriverManager.getConnection("jdbc:mysql://192.168.0.222/risabel?user=siscart&password=progsis");
                connection = DriverManager.getConnection(url, username, password);  
                System.out.println("Connection é " + connection);
                return connection;  
            }  catch (ClassNotFoundException e) {  //Driver não encontrado  
                System.out.println("O driver especificado nao foi encontrado.");  
                return null;  
            } catch (SQLException e) {  
                //Não conseguindo se conectar ao banco  
                System.out.println("Nao foi possivel conectar ao Banco de Dados.");  
                e.printStackTrace();
                return null;

            }
}

}

进行连接的方法,此方法附加了一个鼠标lostfocus事件,并从数据库中返回我想要的项目:

private void puxaemailsiscart()  {
                ConectaSiscart puxaemail = new ConectaSiscart();
                Connection conectadomysql = ConectaSiscart.getConexao();
                String servico = null;
                    if(cboxservico.getSelectedItem() == "Registro de Imóveis") {
                    servico = "reg_cab";
                }
                Statement stm = null;
                ResultSet results = null;  
                 try {
                    stm = conectadomysql.createStatement ();
                } catch (SQLException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }


                                try {
                    System.out.println();
                    results = stm.executeQuery ("SELECT * FROM  " + servico + " WHERE protocolo =" + tfProtocolo.getText());
                    if(results.next()) {

                    tfEmailParte.setText(results.getString("Email").toString());

                    } else { 
                        System.out.println("Protocolo nao encontrado");


                    }
                    results.close();
                    stm.close();






                } catch (SQLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();

                } finally {
    System.out.println("Closing the connection.");
    if (conectadomysql != null) try { conectadomysql.close(); } catch (SQLException ignore) {}
}



            }
        });

但是由于某种原因,在第二次尝试中,它将org.mysql更改为org.sqlite.JDBC

java.sql.SQLException:无效的数据库地址:
org.sqlite.JDBC.createConnection(JDBC.java:110)处的*
jdbc:mysql://192.168.0.222/risabel
*

org.sqlite.JDBC.connect(JDBC.java:87)在

java.sql.DriverManager.getConnection(未知源)(位于ConectaSiscart.getConexao(ConectaSiscart.java:30)在telaprincipal
$
3处的java.sql.DriverManager.getConnection(未知源).puxaemailsiscart(telaprincipal.java:359)在telaprincipal
$ 3处。
focusLost(telaprincipal.java:350),java.awt.AWTEventMulticaster.focusLost(未知源),java.awt.Component.processFocusEvent(未知源),java.awt.Component.processEvent(未知源),java.awt.Container
java.awt.Component.dispatchEventImpl的.processEvent(未知源)java.awt.Component.dispatchEventImpl的java.awt.Component.dispatchEventImpl(java.awt.KeyboardFocusManager.redispatchEvent的Unknown
Source) (java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(Unknown
Source)中的(未知源)。java.awt.Component.dispatchEventImpl的awt.DefaultKeyboardFocusManager.dispatchEvent(未知源)java.awt.Container.dispatchEventImpl的java.awt.Component.dispatchEventImpl(未知源)
EventQueue.dispatchEventImpl(来源未知)java.awt.EventQueue.access $
200(来源未知)java.awt.EventQueue $ 3.run(来源未知)java.awt.EventQueue $
3.run(来源未知)java.security
Java的.AccessController.doPrivileged(本机方法),java.security.ProtectionDomain $
1.doIntersectionPrivilege(未知源),java.awt.EventQueue $
4.run(未知源),java.security.ProtectionDomain $ 1.doIntersectionPrivilege(未知源)。
java.security.AccessController上的awt.EventQueue $
4.run(未知源)。java.security.ProtectionDomain $
1.doIntersectionPrivilege(本地方法)处的doPrivileged(本机方法)java.awt.EventQueue.dispatchEvent(未知源)处的java.awt.EventDispatchThread.pumpOneEventForFilters(未知源)处的java.awt.EventDispatchThread.pumpEventsForFilters(未知源)
(未知源)java.awt.EventDispatchThread.pumpEventsForHierarchy(未知源)java.awt.EventDispatchThread.pumpEvents(未知源)java.awt.EventDispatchThread.pumpEvents(未知源)java.awt.EventDispatchThread.run(未知源)源)线程“
AWT-EventQueue-0”中的异常telaprincipal $
3.puxaemailsiscart(telaprincipal.java:367)处telaprincipal $
3.focusLost(telaprincipal.java:350)处java.awt.AWTEventMulticaster.focusLost(未知来源),网址为java.awt。Component.processFocusEvent(未知源),java.awt.Component.processEvent(未知源),java.awt.Container.processEvent(未知源),java.awt.Component.dispatchEventImpl(java.awt.Container,未知源)。
java.awt.Component.dispatchEvent中的dispatchEventImpl(Unknown
Source)(java.awt.KeyboardFocusManager.redispatchEvent中的java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(Unknown
Source)中的java.awt.DefaultKeyboardFocusManager.dispatchEvent(Unknown Source)
java.awt.Component.dispatchEventImpl上的未知源(java.awt.Container.dispatchEventImpl上的java.awt.Component.dispatchEventImpl的未知源(java.awt.EventQueue.dispatchEventImpl上的未知源)
),java.awt.EventQueue.access $ 200(未知源)。awt.EventQueue $
3.run(未知源)在java.awt.EventQueue $
3.run(未知源)在java.security.AccessController.doPrivileged(本机方法)在java.security.ProtectionDomain
$ 1.doIntersectionPrivilege(未知源) .security.ProtectionDomain $
1.doIntersectionPrivilege(未知源)在java.awt.EventQueue $
4.run(未知源)在java.awt.EventQueue $
4.run(在java.security.AccessController.doPrivileged(本机方法)
java.awt.EventDispatchThread.pumpOneEventForFilters(未知源)java.awt.EventDispatchThread.pumpOneEventForFilters(未知源)java.awt.EventQueue.dispatchEvent(未知源)java.awt.EventDispatchThread.pumpEventsForFilter(未知源)java.security.ProtectionDomain
$ 1.doIntersectionPrivilege(未知源)
java中的.awt.EventDispatchThread.pumpEventsForHierarchy(未知来源)。java.awt.EventDispatchThread.pumpEvents(未知源)处的awt.EventDispatchThread.pumpEvents(未知源)。java.awt.EventDispatchThread.run中的awt.EventDispatchThread.pumpEvents(未知源)

whyyyy我听不懂,我在另一个.java文件中有另一个类来与sql
lite数据库建立连接,但是此刻它在任何时候都没有被调用,为什么eclipse会犯此错误?!他认为:“首先,我在org.mysql上工作良好,现在在第二个中,我将尝试使用org.sqlite”。

:|


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2020-11-30

共1个答案

小编典典

我想我知道发生了什么事。当您调用DriverManager.getConnection时,它将一一尝试所有可用的驱动程序,直到一个成功。在驱动程序上调用connect时,如果驱动程序错误,则可以返回null;如果失败,则引发异常;如果成功,则返回Connection对象。当所有驱动程序均发生故障时,DriverManager会抛出它获得的第一个异常(如果有),否则将创建并引发“找不到合适的驱动程序”异常。

这可能是您的情况:
-DriverManager首先尝试sqlite驱动程序;它应该返回null,因为它是错误的url驱动程序,但是它引发了异常(这是sqlite驱动程序实现中的错误!)
-接下来,DriverManager正在尝试mysql驱动程序,该驱动程序无法连接某些其他原因(例如,服务器未运行或密码错误)
-DriverManager看到所有驱动程序均无法连接,因此抛出了第一个异常,这是来自sqlite的异常(由于该实现错误)

您可以做什么:
-暂时从类路径中删除sqlite驱动程序,以解决mysql连接问题
-更好地,使用数据源而不是DriverManager。MySQL的例子:

MysqlDataSource ds = new MysqlDataSource();
ds.setServerName(serverName);
ds.setDatabaseName(mydatabase);
ds.setUser(username);
ds.setPassword(password);
connection = ds.getConnection();

或者您可以使用数据库库为您处理

2020-11-30