我的项目遇到了麻烦,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!");
}
}
当我尝试连接上面的代码时,连接不起作用,这里是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?
此致
答案 0 :(得分:3)
我遇到同样的错误,这就是我修复它的方法:
我像这样使用了DriverManager类:
Class.forName("com.mysql.jdbc.Driver");
Connection Hello = DriverManager.getConnection("jdbc:mysql://YOUR-URL-HERE", "USERNAME", "PASSWORD");
就是这样。此外,在选择表时,请先将数据库名称放在首位,如:
"DB_NAME.TABLE_NAME".
答案 1 :(得分:2)
要检查mysql是否有密码,请转到安装mysql的目录,并在bin目录中尝试使用
调出mysql提示符./ mysql -u root mysql
如果登录没有任何问题,则表示没有设置密码 您可以使用mysqadmin脚本来设置/重置密码。
./ mysqladmin -u root password&#34; password string&#34;
答案 2 :(得分:2)
看起来你刚刚安装了mysql。运行mysql_secure_installation
。除其他外,它会提示您输入root密码。
答案 3 :(得分:0)
用户名/密码错误或用户缺少访问架构/表的权限。使用
授予权限在上授予所有权限。根目录&#39; @&#39; localhost&#39; WITH GRANT OPTION