Spring JDBC - 无法连接到数据库答案

【问题标题】：Spring JDBC - Can't connect to databaseSpring JDBC - 无法连接到数据库
【发布时间】：2025-11-22 00:45:07
【问题描述】：

这对我来说似乎是一个奇怪的问题。即使看起来 jdbcTemplate 配置正确，jdbcTemplate.queryForObject 也失败了

o.a.tomcat.jdbc.pool.ConnectionPool      : Unable to create initial connections of pool.
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Access denied for user ''@'localhost' to database

就在调用queryForObject 之前，我正在打印jdbcTemplate.getDataSource().toString()，它确实正确显示了用户名（如下所示：

...; url=jdbc:mysql://localhost/mydb; username=test; validationQuery=SELECT 1; ...)。

代码：

public class JdbcLookupDao implements UserDao, OrderDao {

    private final JdbcTemplate jdbcTemplate;

    public JdbcLookupDao(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }

    @Override
    public User findUser(String phone) {
        System.out.println(jdbcTemplate.getDataSource().toString());

        return jdbcTemplate.queryForObject( //this line throws the exception
                "SELECT * FROM users WHERE phonenumber = ?",
                new Object[]{phone},
                new UserMapper()
        );
    }
....
}

弹簧配置文件：

...
       <bean id="dataSource" class="org.apache.commons.dbcp2.BasicDataSource" destroy-method="close">
              <property name="driverClassName" value="${spring.datasource.driver-class-name}" />
              <property name="url" value="${spring.datasource.url}"/>"
              <property name="username" value="${spring.datasource.username}"/>
              <property name="password" value="${spring.datasource.password}"/>
              <property name="validationQuery" value="${spring.datasource.validation-query}"/>
       </bean>

       <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
              <property name="dataSource" ref="dataSource"/>
       </bean>

       <context:property-placeholder location="application.properties"/>
...

异常和堆栈跟踪：

2015-08-15 23:00:16.123 ERROR 45791 --- [nio-8080-exec-1] o.a.tomcat.jdbc.pool.ConnectionPool      : Unable to create initial connections of pool.

com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Access denied for user ''@'localhost' to database 'lookup'
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:400)
    at com.mysql.jdbc.Util.getInstance(Util.java:383)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:980)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3847)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3783)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:871)
    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1665)
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1207)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2249)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2280)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2079)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:794)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:400)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325)
    at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:307)
    at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:200)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:699)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:633)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:484)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:142)
    at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:115)
    at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:102)
    at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:126)
    at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111)
    at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77)
    at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:630)
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:695)
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:727)
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:737)
    at org.springframework.jdbc.core.JdbcTemplate.queryForObject(JdbcTemplate.java:805)
    at com.lookup.aws.dao.JdbcLookupDao.findUser(JdbcLookupDao.java:36)
    at com.lookup.aws.TestController.getUser(TestController.java:35)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:776)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:705)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:857)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:85)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1521)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1478)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)

希望有人能帮我调试。谢谢！

【问题讨论】：

标签： java mysql spring jdbc

【解决方案1】：

问题在于 MySQL 中设置的权限。代码中使用的用户名无权访问数据库。

我认为错误消息Access denied for ''@'localhost' 具有误导性——如果显示的是实际用户名而不是''，那将是有意义的。

【讨论】：

如果它能够正确解析 xml，它将显示该用户名，请参阅我的答案。

【解决方案2】：

看起来像是数据库访问权限问题。您需要在 MYSQL Admin 中为用户授予数据库访问权限。

【讨论】：

【解决方案3】：

你的 spring 配置有一个错位的双引号

<bean id="dataSource" class="org.apache.commons.dbcp2.BasicDataSource" destroy-method="close">
          <property name="driverClassName" value="${spring.datasource.driver-class-name}" />
          <property name="url" value="${spring.datasource.url}"/>"
          <property name="username" value="${spring.datasource.username}"/>
          <property name="password" value="${spring.datasource.password}"/>
          <property name="validationQuery" value="${spring.datasource.validation-query}"/>
   </bean>

在 'url' 属性的末尾有一个无关的 "，将其删除，然后 spring 将正确获取用户名并将其注入数据源。

即

<bean id="dataSource" class="org.apache.commons.dbcp2.BasicDataSource" destroy-method="close">
          <property name="driverClassName" value="${spring.datasource.driver-class-name}" />
          <property name="url" value="${spring.datasource.url}"/>
          <property name="username" value="${spring.datasource.username}"/>
          <property name="password" value="${spring.datasource.password}"/>
          <property name="validationQuery" value="${spring.datasource.validation-query}"/>
   </bean>

【讨论】：

是的！我没注意到。

【解决方案4】：

检查属性中定义的数据库是否存在于MySql上或检查属性文件中的url。出现此错误时：-

Connection con = DriverManager.getConnection(url);

因为此时与数据库的连接是使用具有用户名、密码和数据库或架构 (Oracle) 的 url 创建的。所以你需要正确检查网址。如果它存在于 MySql 服务器上，则 URL 或数据库名称存在一些问题。可能是您更改了数据库上的用户名，但在从代码连接时仍使用旧用户名。

【讨论】：