Mybatis Generator's bug: configuration items should be ordered? - mybatis

Question

If I put "<commentGenerator>" after "<jdbcConnection>", MBG proposed an error that context content should match: blablabla...
But when I put "<commentGenerator>" before "<jdbcConnection>", everything is ok. Here I have something to complain to the official website that if the order of these items is need, why you do not tell us! What an important thing! You r kidding the freshmen. Maybe it is some where I do not know, but this is a key point to build the MBG's configuration file successfully, why not put this NOTE on the top of the tutorial or somewhere eye-catching?
<generatorConfiguration >
<classPathEntry location="D:\mariadb-java-client-1.1.7.jar" />
<context id="db" >
<commentGenerator>
<property name="suppressAllComments" value="true" />
<property name="suppressDate" value="true" />
</commentGenerator>
<jdbcConnection driverClass="org.mariadb.jdbc.Driver"
connectionURL="jdbc:mariadb://localhost:3306/dbname"
userId="root"
password="password"
/>
<javaTypeResolver >
<property name="forceBigDecimals" value="false" />
</javaTypeResolver>
<!-- Model Class -->
<javaModelGenerator targetPackage="org.infrastructure.model" targetProject="infrastructure\src\main\java">
<property name="enableSubPackages" value="false" />
<property name="trimStrings" value="true" />
</javaModelGenerator>
<!-- XML Files -->
<sqlMapGenerator targetPackage="sqlMap" targetProject="infrastructure\src\main\config">
<property name="enableSubPackages" value="false" />
</sqlMapGenerator>
<!-- DAO -->
<javaClientGenerator type="XMLMAPPER" targetPackage="org.infrastructure.dao" targetProject="infrastructure\src\main\java">
<property name="enableSubPackages" value="false" />
</javaClientGenerator>
<!-- Tables -->
<table tableName="user" domainObjectName="User" ></table>
</context>
</generatorConfiguration>

Answer 1

First of all, in your xml configuration file, it doesn't contains a valid root element, which always should be like <!DOCTYPE .../>. About how to add a correct root element of mybatis generator configuration file, please see example from MyBatis GeneratorXML Configuration File Reference.
If you correctly specified root element such as following:
<!DOCTYPE generatorConfiguration PUBLIC
"-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
"http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd"
>
This root element contains a typical DTD declaration located at http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd. This is the definition of the order of these items is need. And we are going to see what it looks like.
From line 47 of this document type definition, it defines element named context. The content is as following:
<!--
The context element is used to describe a context for generating files, and the source tables.
-->
<!ELEMENT context (property*, plugin*, commentGenerator?, jdbcConnection, javaTypeResolver?,javaModelGenerator, sqlMapGenerator?, javaClientGenerator?, table+)>
Which obviously defined the order of the element in context, that is:
property*, plugin*, commentGenerator?, jdbcConnection,
javaTypeResolver?,javaModelGenerator, sqlMapGenerator?,
javaClientGenerator?, table+
In this element, all children must occurs as following rules:
+ for specifying that there must be one or more occurrences of the item — the effective content of each occurrence may be different;
* for specifying that any number (zero or more) of occurrences is allowed — the item is optional and the effective content of each occurrence may be different;
? for specifying that there must not be more than one occurrence — the item is optional;
If there is no quantifier, the specified item must occur exactly one time at the specified position in the content of the element.
After we understanding its real meaning, why you could not change the order of commentGenerator and jdbcConnection should be clear.
Maybe you want to know how to make the element out of order, question How to define DTD without strict element order could be useful.
Wish it helpful.