怎么覆盖Mybatis 中的generator mapper原文件

<&#63;xml version="1.0" encoding="UTF-8"&#63;>
<!DOCTYPE generatorConfiguration
  PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
  "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">

<generatorConfiguration>
 <properties resource="generator.properties"/>
 <context id="MySqlContext" targetRuntime="MyBatis3" defaultModelType="flat">
  <property name="beginningDelimiter" value="`"/>
  <property name="endingDelimiter" value="`"/>
  <property name="javaFileEncoding" value="UTF-8"/>
  <!-- 为模型生成序列化方法-->
  <plugin type="org.mybatis.generator.plugins.SerializablePlugin"/>
  <!-- 为生成的Java模型创建一个toString方法 -->
  <plugin type="org.mybatis.generator.plugins.ToStringPlugin"/>
   <!--生成mapper.xml时覆盖原文件-->
  <plugin type="org.mybatis.generator.plugins.UnmergeableXmlMappersPlugin" />
 
  <!--配置数据库连接-->
  <jdbcConnection driverClass="${jdbc.driverClass}"
      connectionURL="${jdbc.connectionURL}"
      userId="${jdbc.userId}"
      password="${jdbc.password}">
  </jdbcConnection>
  <!--指定生成model的路径-->
  <javaModelGenerator targetPackage="com.sw.model" targetProject="src/main/java"/>
  <!--指定生成mapper.xml的路径-->
  <sqlMapGenerator targetPackage="com.sw.mbg.mapper" targetProject="src/main/resources"/>
  <!--指定生成mapper接口的的路径-->
  <javaClientGenerator type="XMLMAPPER" targetPackage="com.sw.mbg.mapper"
        targetProject="src/main/java"/>
  <!--生成全部表tableName设为%-->
  <table tableName="user">
   <generatedKey column="id" sqlStatement="MySql" identity="true"/>
  </table>
 </context>
</generatorConfiguration>

<!-- MyBatis 生成器 -->
  <dependency>
   <groupId>org.mybatis.generator</groupId>
   <artifactId>mybatis-generator-core</artifactId>
   <!--依赖的版本要在1.3.5以上-->
   <version>1.3.7</version>
  </dependency>