1. Why this configuration, the main purpose of this configuration is what, mainly for what mybatis XML map configuration SQL statement Example_where_clause This is just a SQL statement? <trim the meaning of the use and expression of the label here Test= "Condition.userid" How does this label come about and what does it mean?
Why is the red line so written, what's the point? What is the use of this <trim tag, the equivalent of a SQL sentence? The first red line box is the query statement ID: is the identity that labels this seletct, RESULTMAP is the ID tag identifier that calls Resultmap, Parametertyep is the type of parameter passed in the second Red line box what does it mean?? Distinct is unique and different is the only meaning.
<selectKey> This tag is mainly used when inserting the primary key to set the application. Select Replace (UUID (), '-', ') is the generation of a unique UUID code converted into an SQL statement what should it look like? Why is it a.xxx? Is this a an alias? And where did you get this nickname? Look closely at from Base_modules A, this is the definition of this database alias is a what does this mean? Why write ${condition.dynamicsql} What is this condition and what does dynamicsql mean? Why not write #{conditon.dynamicsql}?
What does this resultmap mean? Resultmap is the unique identifier for the ID label of the import Resultmap. But Resultmap cannot be used with Resulttype at the same time. The following is a configuration issue with Web. Xml. Callout 1: This is a welcome interface, when users visit the site, the first to see this page. is the first page of views 2: That action is Com.netbirdtech.framework.dispatcher.ActionController alias (listen to good, easy to write). When actually executing, everything that is action type is com.netbirdtech.framework.dispatcher.ActionController to execute. What is the action type? Just Mark 3. Callout 3: This means that all the ***.action that appear under the path are the action type Callout 4: Label 2 as 5:the Context-param element is used to set the environment parameter of the Web site, which contains two child elementsParam-name and Param-value.<param-name> parameter name </param-value>Set the context name<param-value> Values </param-value>set the value of the context name<display-name> platform name </display-name> define the name of the platform<description> Platform Description </description> description of platformExample:<context-param><param-name>param_name</param-name><param-value>param_value</param-value></context-param>The parameters that are set in the JSP Web page can be obtained using the following methods:${initparam.param_name}if the servlet can use the following methods to obtainString Param_name=getservletcontext (). Getinitparamter ("Param_name");
Callout 9:
In Java Web Development, the session provides a lot of convenience for us, the session is maintained between the browser and the server. The session timeout is understood as: A session is created between the browser and the server, because the client does not interact with the server for a long time (sleep time), the server destroys the session, and the client again interacts with the server before the session does not exist.
To set the session time-out mode:
Example:
set the Session-config in Web. Xml as follows:
<session-config>
<session-timeout>2</session-timeout>
</session-config>
that is, the client interacts twice with the server for a maximum of 2 minutes, and after 2 minutes, the value of Session.getattribute () is empty.
API Information:
Session.getcreationtime () Gets the session creation time
Session.getlastaccessedtime () Gets the last interaction time with the server
Session.getmaxinactiveinterval () Gets the maximum inactivity interval of the session, in seconds 120 seconds
Analysis of problems and problems encountered in MyBatis configuration
