java web http 500_[转载]JAVA-Web错误之“HTTP Status 500

具体报错如下：

HTTP Status 500 - Servlet execution threw an exception

type Exception report

message Servlet execution threw an exception

description The server encountered an internal error

that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: Servlet execution threw an exception

org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

root cause

java.lang.AbstractMethodError: com.mysql.jdbc.Connection.isValid(I)Z

org.apache.tomcat.dbcp.dbcp2.DelegatingConnection.isValid(DelegatingConnection.java:913)

org.apache.tomcat.dbcp.dbcp2.PoolableConnection.validate(PoolableConnection.java:226)

org.apache.tomcat.dbcp.dbcp2.PoolableConnectionFactory.validateConnection(PoolableConnectionFactory.java:302)

org.apache.tomcat.dbcp.dbcp2.BasicDataSource.validateConnectionFactory(BasicDataSource.java:2208)

org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:2191)

org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createDataSource(BasicDataSource.java:1945)

org.apache.tomcat.dbcp.dbcp2.BasicDataSource.getConnection(BasicDataSource.java:1412)

Dao.DBConnectionFromPool.(DBConnectionFromPool.java:16)

Dao.DBConnectionFromPool.(DBConnectionFromPool.java:10)

Dao.JdbcTools.getConnectionFromPool(JdbcTools.java:16)

Dao.UserDao.(UserDao.java:16)

Servlet.RegServlet.doPost(RegServlet.java:36)

javax.servlet.http.HttpServlet.service(HttpServlet.java:648)

javax.servlet.http.HttpServlet.service(HttpServlet.java:729)

org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

note The full stack trace of the root cause is

available in the Apache Tomcat/8.0.21 logs.

Apache Tomcat/8.0.21

出现错误场景：

在另外的电脑上测试过是可以正常运行的，但是，换到自己电脑上就出现此类错误，主要原因是Tomcat、mysql-connector-java、jdk几个之间的版本不匹配。

个人推测比较有可能是mysql-connector-java和tomacat版本不匹配，但是不能肯定。(更确切的原因目前也还是不知道)

我最初的配置是：

JDK：1.7.0.67

jre1.7

tomcat 8.0.21

mysql-connector-java 5.0.4

解决方法如下：

一、更改了tomcat的版本为apache-tomcat-7.0.64

二、更改mysql-connector-java版本为5.1.24

二者选其一即可。

ps:写入数据库的时候用到了数据连接池，如果不使用数据连接池的话不会有这个问题。