Eclipse Kepler Tomcat 7 中的 MySQL jdbc 连接

Question

我安装了一个新的 Eclipse，但忘记备份我的 tomcat 上下文和服务器 xml(如果这确实是问题的话)。现在我无法建立 MySQL 数据库连接。

以下是文件的相关部分:

编辑:server.xml 没有上下文元素

上下文.xml

<?xml version="1.0" encoding="UTF-8"?>
<Context path="/ListenB" 
    debug="5" reloadable="true" crossContext="false">

  <Resource name="jdbc/LDB" auth="Container" type="javax.sql.DataSource"
     maxActive="100" maxIdle="30" maxWait="10000"
     username="student" password="password" driverClassName="com.mysql.jdbc.Driver"
     url="jdbc:mysql://localhost:3306/teacher" />
</Context>

我的 web.xml 有这个 block :

<resource-ref>
  <description>DB Connection</description>
  <res-ref-name>jdbc/LDB</res-ref-name>
  <res-type>javax.sql.DataSource</res-type>
  <res-auth>Container</res-auth>
</resource-ref>

我有以下驱动程序/ListenB/WebContent/WEB-INF/lib/mysql-connector-java-5.1.28-bin.jar它也在构建路径上:

当我通过 Eclipse 的数据库开发选项卡创建数据库时，我得到以下信息:

但是测试 ping 失败。原因有一页半，但其中只有一些有用的陈述，例如:“最后一次成功发送到服务器的数据包是在 0 毫秒前。驱动程序尚未收到来自服务器的任何数据包。”

如果您需要其余部分，请告诉我。

我喜欢 Tomcat，但是页面上的解释很清楚......好吧，有些东西不是很清楚。有什么建议吗？

编辑:应大众要求，ping错误信息:

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
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.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1015)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:989)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:975)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:920)
at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2395)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2316)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:834)
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:416)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:347)
at org.eclipse.datatools.connectivity.drivers.jdbc.JDBCConnection.createConnection(JDBCConnection.java:298)
at org.eclipse.datatools.connectivity.DriverConnectionBase.internalCreateConnection(DriverConnectionBase.java:105)
at org.eclipse.datatools.connectivity.DriverConnectionBase.open(DriverConnectionBase.java:54)
at org.eclipse.datatools.connectivity.drivers.jdbc.JDBCConnection.open(JDBCConnection.java:81)
at org.eclipse.datatools.enablement.internal.mysql.connection.JDBCMySQLConnectionFactory.createConnection(JDBCMySQLConnectionFactory.java:28)
at org.eclipse.datatools.connectivity.internal.ConnectionFactoryProvider.createConnection(ConnectionFactoryProvider.java:83)
at org.eclipse.datatools.connectivity.internal.ConnectionProfile.createConnection(ConnectionProfile.java:359)
at org.eclipse.datatools.connectivity.ui.PingJob.createTestConnection(PingJob.java:76)
at org.eclipse.datatools.connectivity.ui.PingJob.run(PingJob.java:59)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
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.SQLError.createCommunicationsException(SQLError.java:1129)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:358)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2489)
at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2334)
... 20 more
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.TwoStacksPlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:256)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:308)
... 22 more

Answer 1

理想情况下，您应该仅在 context.xml 文件中声明您的资源。

查找以“Caused By”开头的行，它应该会给您更清晰的解释。您很可能有:1)Mysql服务器没有启动。2) 连接 URL 中的端口号配置错误。

另外，请上传错误跟踪。如果我的两个假设都被证明是错误的，那将会有所帮助。