1.建maven工程（傻子都会）如下图：
2.pom文件内容：jar包就这几个
3.两 个类分别如下：
MyCommentGenerator.java和RunClass.java(随你放哪个位置)
**第一个类*******************************************************
/**
* Copyright 2006-2016 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package mybatis_generator.mybatis_generator;
import static org.mybatis.generator.internal.util.StringUtility.isTrue;
import java.text.SimpleDateFormat;
import java.time.LocalDateTime;
import java.util.Date;
import java.util.Properties;
import org.mybatis.generator.api.CommentGenerator;
import org.mybatis.generator.api.IntrospectedColumn;
import org.mybatis.generator.api.IntrospectedTable;
import org.mybatis.generator.api.dom.java.CompilationUnit;
import org.mybatis.generator.api.dom.java.Field;
import org.mybatis.generator.api.dom.java.InnerClass;
import org.mybatis.generator.api.dom.java.InnerEnum;
import org.mybatis.generator.api.dom.java.JavaElement;
import org.mybatis.generator.api.dom.java.Method;
import org.mybatis.generator.api.dom.java.TopLevelClass;
import org.mybatis.generator.api.dom.xml.XmlElement;
import org.mybatis.generator.config.MergeConstants;
import org.mybatis.generator.config.PropertyRegistry;
import org.mybatis.generator.internal.util.StringUtility;
public class MyCommentGenerator implements CommentGenerator {
/** The properties. */
private Properties properties;
/** The suppress date. */
private boolean suppressDate;
/** The suppress all comments. */
private boolean suppressAllComments;
/** The addition of table remark's comments.
* If suppressAllComments is true, this option is ignored*/
private boolean addRemarkComments;
private SimpleDateFormat dateFormat;
public MyCommentGenerator() {
super();
properties = new Properties();
suppressDate = false;
suppressAllComments = false;
addRemarkComments = false;
}
public void addJavaFileComment(CompilationUnit compilationUnit) {
}
/**
* 实体类对应的mapper.xml注释，mapper类不加注释，如有需要参考 DefaultCommentGenerator
*/
public void addComment(XmlElement xmlElement) {
if (suppressAllComments) {
return;
}
}
public void addRootComment(XmlElement rootElement) {
}
public void addConfigurationProperties(Properties properties) {
this.properties.putAll(properties);
suppressDate = isTrue(properties
.getProperty(PropertyRegistry.COMMENT_GENERATOR_SUPPRESS_DATE));
suppressAllComments = isTrue(properties
.getProperty(PropertyRegistry.COMMENT_GENERATOR_SUPPRESS_ALL_COMMENTS));
addRemarkComments = isTrue(properties
.getProperty(PropertyRegistry.COMMENT_GENERATOR_ADD_REMARK_COMMENTS));
String dateFormatString = properties.getProperty(PropertyRegistry.COMMENT_GENERATOR_DATE_FORMAT);
if (StringUtility.stringHasValue(dateFormatString)) {
dateFormat = new SimpleDateFormat(dateFormatString);
}
}
protected void addJavadocTag(JavaElement javaElement,
boolean markAsDoNotDelete) {
javaElement.addJavaDocLine(" *"); //$NON-NLS-1$
StringBuilder sb = new StringBuilder();
sb.append(" * "); //$NON-NLS-1$
sb.append(MergeConstants.NEW_ELEMENT_TAG);
if (markAsDoNotDelete) {
sb.append(" do_not_delete_during_merge"); //$NON-NLS-1$
}
String s = getDateString();
if (s != null) {
sb.append(' ');
sb.append(s);
}
javaElement.addJavaDocLine(sb.toString());
}
protected String getDateString() {
if (suppressDate) {
return null;
} else if (dateFormat != null) {
return dateFormat.format(new Date());
} else {
return new Date().toString();
}
}
public void addClassComment(InnerClass innerClass,
IntrospectedTable introspectedTable) {
if (suppressAllComments) {
return;
}
StringBuilder sb = new StringBuilder();
innerClass.addJavaDocLine("/**"); //$NON-NLS-1$
sb.append(" * This class corresponds to the database table "); //$NON-NLS-1$
sb.append(introspectedTable.getFullyQualifiedTable());
innerClass.addJavaDocLine(sb.toString());
addJavadocTag(innerClass, false);
innerClass.addJavaDocLine(" */"); //$NON-NLS-1$
}
// public void addModelClassComment(TopLevelClass topLevelClass,
// IntrospectedTable introspectedTable) {
// if (suppressAllComments || !addRemarkComments) {
// return;
// }
//
// StringBuilder sb = new StringBuilder();
//
// topLevelClass.addJavaDocLine("/**"); //$NON-NLS-1$
//
// String remarks = introspectedTable.getRemarks();
// if (addRemarkComments && StringUtility.stringHasValue(remarks)) {
// topLevelClass.addJavaDocLine(" * Database Table Remarks:");
// String[] remarkLines = remarks.split(System.getProperty("line.separator")); //$NON-NLS-1$
// for (String remarkLine : remarkLines) {
// topLevelClass.addJavaDocLine(" * " + remarkLine); //$NON-NLS-1$
// }
// }
// topLevelClass.addJavaDocLine(" *"); //$NON-NLS-1$
//
// topLevelClass
// .addJavaDocLine(" * This class was generated by MyBatis Generator."); //$NON-NLS-1$
//
// sb.append(" * This class corresponds to the database table "); //$NON-NLS-1$
// sb.append(introspectedTable.getFullyQualifiedTable());
// topLevelClass.addJavaDocLine(sb.toString());
//
// addJavadocTag(topLevelClass, true);
//
// topLevelClass.addJavaDocLine(" */"); //$NON-NLS-1$
// }
@Override
public void addModelClassComment(TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {
String author = "wmd";
// String dateFormat = properties.getProperty("dateFormat", "yyyy-MM-dd");
// SimpleDateFormat dateFormatter = new SimpleDateFormat(dateFormat);
// 获取表注释
String remarks = introspectedTable.getRemarks();
topLevelClass.addJavaDocLine("/**");
topLevelClass.addJavaDocLine(" * " + remarks);
topLevelClass.addJavaDocLine(" *");
topLevelClass.addJavaDocLine(" * @author " + author);
// topLevelClass.addJavaDocLine(" * @date " + dateFormatter.format(new Date()));
topLevelClass.addJavaDocLine(" */");
}
public void addEnumComment(InnerEnum innerEnum,
IntrospectedTable introspectedTable) {
if (suppressAllComments) {
return;
}
StringBuilder sb = new StringBuilder();
innerEnum.addJavaDocLine("/**"); //$NON-NLS-1$
innerEnum
.addJavaDocLine(" * This enum was generated by MyBatis Generator."); //$NON-NLS-1$
sb.append(" * This enum corresponds to the database table "); //$NON-NLS-1$
sb.append(introspectedTable.getFullyQualifiedTable());
innerEnum.addJavaDocLine(sb.toString());
addJavadocTag(innerEnum, false);
innerEnum.addJavaDocLine(" */"); //$NON-NLS-1$
}
/**
* 实体类字段注释
*/
public void addFieldComment(Field field,
IntrospectedTable introspectedTable,
IntrospectedColumn introspectedColumn) {
if (suppressAllComments) {
return;
}
field.addJavaDocLine("/**"); //$NON-NLS-1$
// 核心代码 introspectedColumn.getRemarks() 就是获取字段注释
StringBuilder sb = new StringBuilder();
sb.append(" * " + introspectedColumn.getRemarks());
sb.append("\n\t * [email protected]");
sb.append("\n\t * " + LocalDateTime.now());
field.addJavaDocLine(sb.toString());
field.addJavaDocLine(" */");
}
// @Override
// public void addFieldComment(Field field, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) {
// // 获取列注释
// String remarks = introspectedColumn.getRemarks();
// field.addJavaDocLine("/**");
// field.addJavaDocLine(" * " + remarks);
// field.addJavaDocLine(" */");
// }
/**
* 实体类的静态字段
*/
public void addFieldComment(Field field, IntrospectedTable introspectedTable) {
if (suppressAllComments) {
return;
}
StringBuilder sb = new StringBuilder();
field.addJavaDocLine("/**");
sb.append(" * [email protected]");
sb.append("\n\t * " + LocalDateTime.now());
field.addJavaDocLine(sb.toString());
field.addJavaDocLine(" */");
}
/**
* 实体类toString方法
*/
public void addGeneralMethodComment(Method method,
IntrospectedTable introspectedTable) {
if (suppressAllComments) {
return;
}
/* StringBuilder sb = new StringBuilder();
method.addJavaDocLine("/**"); //$NON-NLS-1$
method.addJavaDocLine(" * toString."); //$NON-NLS-1$
sb.append(introspectedTable.getFullyQualifiedTable());
method.addJavaDocLine(sb.toString());
addJavadocTag(method, false);*/
//method.addJavaDocLine(" */");
}
/**
* 实体类getter方法注释
*/
public void addGetterComment(Method method,
IntrospectedTable introspectedTable,
IntrospectedColumn introspectedColumn) {
if (suppressAllComments) {
return;
}
StringBuilder sb = new StringBuilder();
method.addJavaDocLine("/**"); //$NON-NLS-1$
sb.append(" * " + introspectedColumn.getRemarks());
method.addJavaDocLine(sb.toString());
method.addJavaDocLine(" */"); //$NON-NLS-1$
}
/**
* 实体类setter注释
*/
public void addSetterComment(Method method,
IntrospectedTable introspectedTable,
IntrospectedColumn introspectedColumn) {
if (suppressAllComments) {
return;
}
StringBuilder sb = new StringBuilder();
method.addJavaDocLine("/**"); //$NON-NLS-1$
sb.append(" * " + introspectedColumn.getRemarks());
method.addJavaDocLine(sb.toString());
method.addJavaDocLine(" */"); //$NON-NLS-1$
}
public void addClassComment(InnerClass innerClass,
IntrospectedTable introspectedTable, boolean markAsDoNotDelete) {
if (suppressAllComments) {
return;
}
StringBuilder sb = new StringBuilder();
innerClass.addJavaDocLine("/**"); //$NON-NLS-1$
innerClass
.addJavaDocLine(" * This class was generated by MyBatis Generator."); //$NON-NLS-1$
sb.append(introspectedTable.getFullyQualifiedTable());
innerClass.addJavaDocLine(sb.toString());
addJavadocTag(innerClass, markAsDoNotDelete);
innerClass.addJavaDocLine(" */"); //$NON-NLS-1$
}
}```
**第二个类*****************************************************
package mybatis_generator.mybatis_generator;
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.File;
import java.util.ArrayList;
import java.util.List;
public class RunClass {
public static void main(String[] args) {
try {
List<String> warnings = new ArrayList<String>();
boolean overwrite = true;
File configFile = new File("src/main/resources/generatorConfig.xml");
ConfigurationParser cp = new ConfigurationParser(warnings);
Configuration config = cp.parseConfiguration(configFile);
DefaultShellCallback callback = new DefaultShellCallback(overwrite);
MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
myBatisGenerator.generate(null);
} catch (Exception e) {
e.printStackTrace();
}
}
}
4.项目结构
5.最后只要运行runclass就可以得到实体、dao层、mapper文件，具体的生成方式都在generatorConfig.xml文件中，如下图：
<?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>
<!-- 指定数据库驱动包 -->
<!-- <classPathEntry location="~\mysql\mysql-connector-java\5.1.46\mysql-connector-java-5.1.46.jar" /> -->
<context id="MySQLTables" targetRuntime="MyBatis3">
<!-- 配置生成pojo的序列化的插件 -->
<plugin type="org.mybatis.generator.plugins.SerializablePlugin" />
<!-- 配置生成pojo的toString()方法的插件 -->
<plugin type="org.mybatis.generator.plugins.ToStringPlugin" />
<!-- 取消生成的注释 -->
<!-- <commentGenerator>
<property name="suppressDate" value="false"/>
<property name="suppressAllComments" value="false"/>
</commentGenerator> -->
<!-- 通过type指定自定义的注释 -->
<commentGenerator type="mybatis_generator.mybatis_generator.MyCommentGenerator">
<!-- 不要开启，否则将不会使用自定义注释 -->
<!-- <property name="suppressAllComments" value="true"> -->
</commentGenerator>
<!-- 数据库连接参数 -->
<jdbcConnection driverClass="com.mysql.jdbc.Driver"
connectionURL="jdbc:mysql://localhost:3306/ssm"
userId="root"
password="123456">
</jdbcConnection>
<javaTypeResolver>
<property name="forceBigDecimals" value="false"/>
</javaTypeResolver>
<!-- 指定实体类 -->
<javaModelGenerator targetPackage="com.wmd.entity"
targetProject=".\src\main\java">
<property name="enableSubPackages" value="true"/>
<property name="trimStrings" value="true"/>
</javaModelGenerator>
<!-- 创建SQL的Mapper文件 -->
<sqlMapGenerator targetPackage="mapper"
targetProject=".\src\main\resources">
<property name="enableSubPackages" value="true"/>
</sqlMapGenerator>
<!-- 指定Mapper文件XMLMAPPER生成xml ANNOTATEDMAPPER为注解 -->
<javaClientGenerator type="XMLMAPPER" targetPackage="com.wmd.dao"
targetProject=".\src\main\java">
<property name="enableSubPackages" value="true"/>
</javaClientGenerator>
<!-- 指定数据库哪些表生成代码 -->
<table tableName="t_function" domainObjectName="function"
enableCountByExample="false" enableDeleteByExample="false"
enableUpdateByExample="false" enableSelectByExample="false">
</table>
</context>
</generatorConfiguration>
6.只要跟着我的步骤无脑操作，最终就会将数据库的表转换成实体、dao、mapper，而且实体字段的注释和类注释和getset注释都是可以在MyCommentGenerator.java中自由编写的，如下如： （万一最后你还是没有生成成功，不要着急，请把我的项目直接拿去，还是不行，我提头来见！）
补充：前提是数据库已经有现成的表哦！！！！！！！
