springMVC+mybatis框架报错

这些错误很多时候都不细心引起的,如果大家也有出现些问题,希望能给大家一下提示,同时也提醒自己不要再犯相同的错误了.

使用eclipse编译项目的时候一直在报这个错误,但是项目都是可以通过编译的,到网上找的,说jdk换成1.8的,换了这后还是没有用

com/mysql/jdbc/JDBC42ResultSet : Unsupported major.minor version 52.0

----最后解决------- 我的tomcat里面有一个jdbc的驱动,比我自己项目下的jar包版本要高.把tomcat那个驱动删除即可.

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下面是部分ssm框架的错误

Caught exception while allowing TestExecutionListener [org.springframework.test.context.support.DependencyInjectionTestExecutionListener@e03bd6] to prepare test instance [org.seckill.dao.SeckillDaoTest1@6a776719] java.lang.IllegalStateException: Failed to load ApplicationContext

解决 其中user写成username

Bean property 'checkoutTimeOut' is not writable or has an invalid setter method. Did you mean 'checkoutTimeout'?

解决: name写错了checkoutTimeOut … nested exception is

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java.io.FileNotFoundException: class path resource [classPath:mybatis-config.xml] cannot be opened because it does not exist

解决: classPath 改成小写就可以了

com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@7edeaabc -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (2). Last acquisition attempt exception:

解决: 数据库,表名不对

runtime name="com.genuitec.runtime.generic.jee60

解决: 别人项目,打开报错,删除setting文件中runtime即可

org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException: ### Error querying database. Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is java.sql.SQLException: An attempt by a client to checkout a Connection has timed out.

解决: jdbc.properties 跟.xml的连接账号没对上

org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): org.seckill.dao.SeckillDao.queryAll

解决: 程序包org.junit.runner不存在 junit 换为4.x版本即可

maven项目运行注意 http://www.tuicool.com/articles/fm6nay

Servlet.init() for servlet seckill-dispacherServlet threw exception

原因: web.xml配置不对

Allocate exception for servlet seckill-dispacherServlet

原因: springmvc.xml的转发路径不对

org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): select id

原因: 上在是方法不对,ALl All 由于字体原因一直没看出来

元素类型 "set" 必须后跟属性规范 ">" 或 "/>"。 Nested exception: 元素类型 "set" 必须后跟属性规范 ">" 或 "/>"。

原因: 配置文件set位置没有加空格

A different object with the same identifier value was already associated with the session : [cn.entity.Employee#1]

原因: 主键重复

org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException: ### Error querying database. Cause: java.lang.UnsupportedOperationException ### The error may exist in file [C:\Users\Administrator.USER-20160618MA\seckill\target\classes\mapper\SeckillDao.xml] ### The error may involve org.seckill.dao.SeckillDao.queryAll ### The error occurred while handling results ### SQL: select seckill_id,name,number,start_time,end_time,create_time from seckill order by create_time desc limit ?,?;

原因: dao的映射mapping.xml中,resultType类型的问题:dao接口里写的方法返回是一个List集合,这个resultType类型是直接表示返回类型的(对应着我们的model对象中的实体)

引入js文件,访问资源时还提示404

先创建resources这个文件夹,名字不对的话mvc:default-servlet-handler/ 就算配置文件都对了,页面也是引不进来的