我们都知道mybatis generator自动生成的注释没什么实际作用，而且还增加了代码量。如果能将注释从数据库中捞取到，不仅能很大程度上增加代码的可读性，而且减少了后期手动加注释的工作量。
1、首先定义注释生成插件
MyCommentGenerator.java
package com.ilovey.mybatis.comment;
import org.mybatis.generator.api.IntrospectedColumn;
import org.mybatis.generator.api.IntrospectedTable;
import org.mybatis.generator.api.dom.java.Field;
import org.mybatis.generator.api.dom.java.InnerClass; import org.mybatis.generator.api.dom.java.Method; import org.mybatis.generator.internal.DefaultCommentGenerator; import java.text.SimpleDateFormat; import java.util.Date; import java.util.Properties; /** * mybatis generator生成注释插件 * <p> * Created by huhaichao on 2017/5/15. */ public class MyCommentGenerator extends DefaultCommentGenerator { private Properties properties; private Properties systemPro; private boolean suppressDate; private boolean suppressAllComments; private String currentDateStr; public MyCommentGenerator() { super(); properties = new Properties(); systemPro = System.getProperties(); suppressDate = false; suppressAllComments = false; currentDateStr = (new SimpleDateFormat("yyyy-MM-dd")).format(new Date()); } public void addFieldComment(Field field, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) { if (suppressAllComments) { return; } StringBuilder sb = new StringBuilder(); field.addJavaDocLine("/**"); sb.append(" * "); sb.append(introspectedColumn.getRemarks()); field.addJavaDocLine(sb.toString().replace("\n", " ")); field.addJavaDocLine(" */"); } public void addFieldComment(Field field, IntrospectedTable introspectedTable) { } public void addGeneralMethodComment(Method method, IntrospectedTable introspectedTable) { } public void addGetterComment(Method method, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) { } public void addSetterComment(Method method, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) { } public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable, boolean markAsDoNotDelete) { } public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable) { } }
2、然后为mybatisgenerator配置插件
<?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"> <plugin type="org.mybatis.generator.plugins.SerializablePlugin"/> <!-- 使用自定义的插件 --> <commentGenerator type="com.ilovey.mybatis.comment.MyCommentGenerator"> </commentGenerator> <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF8" userId="root" password="123456"> </jdbcConnection> <javaModelGenerator targetPackage="com.ilovey.biz.entity.base" targetProject="ilovey.biz/src/main/java"/> <sqlMapGenerator targetPackage="com.ilovey.biz.mapper.base" targetProject="ilovey.biz/src/main/resources"/> <javaClientGenerator targetPackage="com.ilovey.biz.mapper.base" targetProject="ilovey.biz/src/main/java" type="XMLMAPPER"/> <table tableName="us_user_info" domainObjectName="UsUserInfo"> <generatedKey column="id" sqlStatement="MySql" identity="true"/> </table> </context> </generatorConfiguration>3、使用mybatis generator自动生成代码
由于使用的是maven项目，而且使用了了自定义的插件，所以采用 main方法启动，适用场景更对，而且能将代码生成到对应的工程目录下，免去拷贝的过程（当然也可以用maven插件、控制台、eclipse插件等多种方式启动）。
注意：当前类所在的工程要添加mybatis generator的依赖包
启动类如下
package com.ilovey.mybatis;
import org.mybatis.generator.api.MyBatisGenerator;
import org.mybatis.generator.config.Configuration;
import org.mybatis.generator.config.xml.ConfigurationParser;
import org.mybatis.generator.internal.DefaultShellCallback; import java.io.InputStream; import java.util.ArrayList; import java.util.List; /** * 运行此方法生成mybatis代码 * 生成代码自动放入对应目录 * 配置文件targetProject应从项目名称开始到要生成到的classpath * Created by huhaichao on 2017/5/15. */ public class MyBatisGeneratorRun { public static void main(String[] args) throws Exception{ MyBatisGeneratorRun app = new MyBatisGeneratorRun(); System.out.println(app.getClass().getResource("/").getPath()); app.generator(); System.out.println(System.getProperty("user.dir")); } public void generator() throws Exception{ List<String> warnings = new ArrayList<String>(); boolean overwrite = true; InputStream resourceAsStream = this.getClass().getClassLoader().getResourceAsStream("generatorConfig.xml"); ConfigurationParser cp = new ConfigurationParser(warnings); Configuration config = cp.parseConfiguration(resourceAsStream); DefaultShellCallback callback = new DefaultShellCallback(overwrite); MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings); myBatisGenerator.generate(null); for(String warning:warnings){ System.out.println(warning); } } } 再贴下项目的maven依赖，有需要的可以看下
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>party.lovey</groupId> <artifactId>generator</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <dependencies> <dependency> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-core</artifactId> <version>1.3.6</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.29</version> </dependency> </dependencies> </project>4、生成效果
package com.ilovey.biz.entity.base;
import java.io.Serializable;
import java.util.Date;
public class UsUserInfo implements Serializable {
/**
*
*/
private Integer id;
/**
* 用户id
*/
private Integer userId;
/**
* 昵称
*/
private String nickName;
/**
* 头像
*/
private String headImage;
/**
* 手机号码
*/
private String mobile;
/**
* 性别（0保密，1男，2女）
*/
private Integer sex;
/**
* 地区
*/
private Integer region;
/**
* 个性签名
*/
private String signature;
/**
* 创建时间
*/
private Date createTime;
/**
* 更新时间
*/
private Date updateTime;
//setter 和 getter方法省略
}此外，mybatis的插件还有着更强大的功能，比如支持分页功能，修复因别名造成的delete语句错误等，需要这些插件的朋友可以在底部留言。
原文地址：https://www.cnblogs.com/cblogs/p/9432129.html