mysql+eclipse+tomcat问题

[ianley]

tomcat、MYSQL安装正常，mysql_connector配置正常，eclipse下运行jsp页面，却出现如下报错，请仁兄指点，谢谢！


信息: Server startup in 505 ms
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

Last packet sent to the server was 0 ms ago.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:506)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2104)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:729)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
……
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
……
严重: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.jsp.index_jsp._jspService(index_jsp.java:148)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)

[zharrisl]

Caused by: java.net.ConnectException: Connection refused: connect
还是连接数据库的问题

[lgq_0714]

Caused by: java.net.ConnectException: Connection refused: connect 

检查数据库连接密码是否正确、mysql服务是否启动

java.lang.NullPointerException 

index.jsp中空指向异常

[gengwanshanreally]

解决了连接问题就不空指针了

[lvfeng19806001]

没有正确连接数据库，看数据库服务是否启动，连接字符串，uid,pwd等是否正确！

[ytsmtxxi]

连接mysql的问题。你现在是没有连接上。检查你的mysql的JDBC驱动能不能。如果可以用的话，那就看一下你的连接的时候的用户名跟密码会不会有错误。应该就是这两个的问题了。

[ytsmtxxi]

哦。对了，还有Mysql的服务有没有启动。没有的话，也会报这个错误的。