完成

1.小课堂讲了debug

第一行从左到右图标的意思分别是:

定位指针位置；

不进入方法体；

进入方法体，包括嵌套方法；

能进入源码；

跳出方法，并且该方法已被执行；

提前结束方法调用，方法没有被执行；

跳到鼠标指针处，指针不能在两个断点范围外，不能在已执行语句前；

计算：可以在debug过程中修改参数值，获得自己想要的结果。

左边列表显示断点分布，包括异常断点；

右边是断点属性，可以设置触发条件，日志输出，断点连接以及过滤器；

过滤器分三种：instance过滤一个ID，就是像这样的@后面的数，

class是过滤一个方法，pass count表示该断点前几次被过滤掉。

以上是一个智能步入方法，即可以选择你想进入的方法

在这里调用：

问题

还是之前的问题，这里再详细记录一下

被拦截器拦截的页面时而能打开时而打不开，打不开几率比较大（本地问题，在服务器没问题）

参考（http://blog.csdn.net/cynhafa/article/details/19676865）

我把本地数据库的my.ini文件多加了一句wait_timeout，仍旧未解决

报错页面大致如下：

Type Exception Report

Message Request processing failed; nested exception is org.springframework.dao.RecoverableDataAccessException:

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.dao.RecoverableDataAccessException: 
### Error querying database.  Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 45 milliseconds ago.  The last packet sent successfully to the server was 44 milliseconds ago.
### The error may exist in class path resource [mapper.xml]
### The error may involve defaultParameterMap
### The error occurred while setting parameters
### SQL: SELECT count(*) FROM student WHERE major =1 AND status=0
### Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 45 milliseconds ago.  The last packet sent successfully to the server was 44 milliseconds ago.
; SQL []; Communications link failure

The last packet successfully received from the server was 45 milliseconds ago.  The last packet sent successfully to the server was 44 milliseconds ago.; nested exception is com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 45 milliseconds ago.  The last packet sent successfully to the server was 44 milliseconds ago.

Root Cause

org.springframework.dao.RecoverableDataAccessException: 
### Error querying database.  Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 45 milliseconds ago.  The last packet sent successfully to the server was 44 milliseconds ago.
### The error may exist in class path resource [mapper.xml]
### The error may involve defaultParameterMap
### The error occurred while setting parameters
### SQL: SELECT count(*) FROM student WHERE major =1 AND status=0
### Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 45 milliseconds ago.  The last packet sent successfully to the server was 44 milliseconds ago.
; SQL []; Communications link failure

The last packet successfully received from the server was 45 milliseconds ago.  The last packet sent successfully to the server was 44 milliseconds ago.; nested exception is com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 45 milliseconds ago.  The last packet sent successfully to the server was 44 milliseconds ago.

Root Cause

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 45 milliseconds ago.  The last packet sent successfully to the server was 44 milliseconds ago.

Root Cause

java.net.SocketException: Software caused connection abort: recv failed

收获

稍微熟练debug

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