如何快速生成指定类的resultMap

要快速生成指定类的resultMap，可以使用MyBatis Generator插件自动生成。步骤如下：

1. 在pom.xml文件中添加MyBatis Generator插件的依赖：

<dependency>
    <groupId>org.mybatis.generator</groupId>
    <artifactId>mybatis-generator-core</artifactId>
    <version>1.4.0</version>
</dependency>

2. 在pom.xml文件中添加MyBatis Generator插件的配置：

<build>
    <plugins>
        <plugin>
            <groupId>org.mybatis.generator</groupId>
            <artifactId>mybatis-generator-maven-plugin</artifactId>
            <version>1.4.0</version>
            <dependencies>
                <dependency>
                    <groupId>mysql</groupId>
                    <artifactId>mysql-connector-java</artifactId>
                    <version>8.0.19</version>
                </dependency>
            </dependencies>
            <executions>
                <execution>
                    <id>generate</id>
                    <phase>generate-sources</phase>
                    <goals>
                        <goal>generate</goal>
                    </goals>
                </execution>
            </executions>
            <configuration>
                <verbose>true</verbose>
                <overwrite>true</overwrite>
                <configurationFile>src/main/resources/generatorConfig.xml</configurationFile>
            </configuration>
        </plugin>
    </plugins>
</build>

3. 在src/main/resources目录下创建generatorConfig.xml文件，配置要生成的resultMap和对应的数据库表和Java类：

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

<generatorConfiguration>
    <context id="context1">
        <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/test?useUnicode=true&amp;characterEncoding=utf8&amp;serverTimezone=GMT%2B8"
                        userId="root"
                        password="123456">
        </jdbcConnection>

        <javaTypeResolver>
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>

        <javaModelGenerator targetPackage="com.example.model" targetProject="src/main/java">
            <property name="enableSubPackages" value="true"/>
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>

        <sqlMapGenerator targetPackage="mapper" targetProject="src/main/resources">
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>

        <javaClientGenerator type="XMLMAPPER" targetPackage="com.example.mapper" targetProject="src/main/java">
            <property name="enableSubPackages" value="true"/>
        </javaClientGenerator>

        <table tableName="user" domainObjectName="User">
            <property name="useActualColumnNames" value="true"/>
            <generatedKey column="id" sqlStatement="JDBC"/>
        </table>

        <resultMap id="BaseResultMap" type="com.example.model.User">
            <id column="id" property="id" jdbcType="INTEGER"/>
            <result column="name" property="name" jdbcType="VARCHAR"/>
            <result column="age" property="age" jdbcType="INTEGER"/>
            <result column="phone" property="phone" jdbcType="VARCHAR"/>
        </resultMap>

    </context>
</generatorConfiguration>

4. 在项目根目录下执行命令：mvn mybatis-generator:generate，即可生成指定类的resultMap。

注意：在配置generatorConfig.xml文件时，需要根据具体的数据库和Java类进行配置。