我的项目遇到麻烦,它涉及JDBC和MysqL连接.
当我执行以下操作时:
private Statement m_statement = null; // statement
private Connection m_connection = null; // connection
/**
* Constructor #1 of the Database class
* @throws ClassNotFoundException
*/
public Database() throws ClassNotFoundException
{
try
{
Class.forName("com.MysqL.jdbc.Driver");
MysqLDataSource ds = new MysqLConnectionPoolDataSource();
ds.setServerName("localhost");
ds.setPort(3306);
ds.setUser("root");
ds.setPassword("");
this.m_connection = ds.getConnection();
this.m_statement = this.m_connection.createStatement();
}
catch (sqlException s)
{
System.out.println("sql statement is not executed! 2!");
}
}
当我尝试连接以上代码时,连接不起作用,这是stacktrace:
java.sql.sqlException: Access denied for user 'root'@'localhost' (using password: NO)
at com.MysqL.jdbc.sqlError.createsqlException(sqlError.java:1074)
at com.MysqL.jdbc.MysqLIO.checkerrorPacket(MysqLIO.java:4074)
at com.MysqL.jdbc.MysqLIO.checkerrorPacket(MysqLIO.java:4006)
at com.MysqL.jdbc.MysqLIO.checkerrorPacket(MysqLIO.java:919)
at com.MysqL.jdbc.MysqLIO.proceedHandshakeWithPluggableAuthentication(MysqLIO.java:1694)
at com.MysqL.jdbc.MysqLIO.doHandshake(MysqLIO.java:1244)
at com.MysqL.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2397)
at com.MysqL.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2430)
at com.MysqL.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2215)
at com.MysqL.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:813)
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:411)
at com.MysqL.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)
at com.MysqL.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:334)
at com.MysqL.jdbc.jdbc2.optional.MysqLDataSource.getConnection(MysqLDataSource.java:443)
at com.MysqL.jdbc.jdbc2.optional.MysqLDataSource.getConnection(MysqLDataSource.java:141)
at com.MysqL.jdbc.jdbc2.optional.MysqLDataSource.getConnection(MysqLDataSource.java:111)
at db.Database.<init>(Database.java:99)
at controller.LoginPage.doGet(LoginPage.java:61)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1001)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(UnkNown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(UnkNown Source)
at java.lang.Thread.run(UnkNown Source)
我该如何解决?
问候
解决方法:
我像这样使用DriverManager类:
Class.forName("com.MysqL.jdbc.Driver");
Connection Hello = DriverManager.getConnection("jdbc:MysqL://YOUR-URL-HERE", "USERNAME", "PASSWORD");
就是这样.另外,在选择表时,建议将数据库名称放在第一位,例如:
"DB_NAME.TABLE_NAME".