A.9 自定义MBG插件和注释生成器

用 IEDA 的 New Project 创建一个新的空的 Maven 类型的项目 JDK 选择 11

下面是添加依赖和相关设置的完整的 pom.xml （在Mac OS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>com.longser.mybatis</groupId>
    <artifactId>generatorr</artifactId>
    <version>1.0</version>
    <properties>
        <java.version>1.11</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.mybatis.generator</groupId>
            <artifactId>mybatis-generator-core</artifactId>
            <version>1.4.0</version>
        </dependency>
    </dependencies>
    <build>
        <pluginManagement>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>11</source>
                    <target>11</target>
                </configuration>
            </plugin>
            <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-deploy-plugin</artifactId>
                    <version>3.0.0-M1</version>
            </plugin>
        </plugins>
        </pluginManagement>
    </build>
    <distributionManagement>
        <repository>
            <id>localRepository</id>
            <url>file:~/.m2/Repository</url>
        </repository>
    </distributionManagement>
</project>

下面是注释生成器和插件的代码

package com.longser.mybatis.generator;

import static org.mybatis.generator.internal.util.StringUtility.isTrue;

import java.text.SimpleDateFormat;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Date;
import java.util.List;
import java.util.Optional;
import java.util.Properties;
import java.util.Set;

import org.mybatis.generator.api.CommentGenerator;
import org.mybatis.generator.api.IntrospectedColumn;
import org.mybatis.generator.api.IntrospectedTable;
import org.mybatis.generator.api.MyBatisGenerator;
import org.mybatis.generator.api.dom.java.CompilationUnit;
import org.mybatis.generator.api.dom.java.Field;
import org.mybatis.generator.api.dom.java.FullyQualifiedJavaType;
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.Parameter;
import org.mybatis.generator.api.dom.java.TopLevelClass;
import org.mybatis.generator.api.dom.kotlin.KotlinFile;
import org.mybatis.generator.api.dom.xml.TextElement;
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;

/**
 *
 * <p>自定义的MyBatis Generator注释生成器</p>
 * <p>内容是在官方代码基础上修改的</p>
 *
 * @see org.mybatis.generator.api.CommentGenerator
 * @see org.mybatis.generator.internal.DefaultCommentGenerator
 * @see "https://github.com/mybatis/generator/blob/master/core/mybatis-generator-core/src/main/java/org/mybatis/generator/internal/DefaultCommentGenerator.java"
 *
 * @author David
 * @version 1.0.0
 * @since 2021年6月11日
 */
@SuppressWarnings("unused")
public class MyCommentGenerator implements CommentGenerator {

    private final Properties properties;

    /**
     * 抑制日期  默认false：不抑制
     */
    private boolean suppressDate;
    /**
     * 抑制注释 默认false：不抑制
     */
    private boolean suppressAllComments;

    /**
     * 显示数据库comments 默认false：不显示
     * 如果suppressAllComments是true, 这个选项被忽略
     */
    private boolean addRemarkComments;
    /**
     * 日期格式
     */
    private SimpleDateFormat dateFormat;

    /**
     * 当前用户的名字
     */
    private final String userName;

    public MyCommentGenerator() {
        super();
        properties = new Properties();
        suppressDate = false;
        suppressAllComments = false;
        addRemarkComments = false;
        userName = System.getProperty("user.name");
    }

    @Override
    public void addJavaFileComment(CompilationUnit compilationUnit) {
        // add no file level comments by default
    }

    /**
     * @param xmlElement the xml element
     */
    @Override
    public void addComment(XmlElement xmlElement) {
        if (suppressAllComments) {
            return;
        }

        xmlElement.addElement(new TextElement("<!-- " + MergeConstants.NEW_ELEMENT_TAG + " -->"));

    }

    @Override
    public void addRootComment(XmlElement rootElement) {
        // add no document level comments by default
    }

    /**
     * 读取配置文件
     */
    @Override
    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);
        }
    }

    /**
     * This method adds the custom javadoc tag for. You may do nothing if you do not
     * wish to include the Javadoc tag - however, if you do not include the Javadoc
     * tag then the Java merge capability of the eclipse plugin will break.
     *
     * @param javaElement       the java element
     * @param markAsDoNotDelete the mark as do not delete
     */
    protected void addJavadocTag(JavaElement javaElement, boolean markAsDoNotDelete) {
        javaElement.addJavaDocLine(" *");
        String sb = " * " +
                MergeConstants.NEW_ELEMENT_TAG;
        javaElement.addJavaDocLine(sb);
    }

    /**
     * Returns a formated date string to include in the Javadoc tag and XML
     * comments. You may return null if you do not want the date in these
     * documentation elements.
     *
     * @return a string representing the current timestamp, or null
     */
    protected String getDateString() {
        if (suppressDate) {
            return null;
        } else if (dateFormat != null) {
            return dateFormat.format(new Date());
        } else {
            return new Date().toString();
        }
    }

    @Override
    public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable) {
        if (suppressAllComments) {
            return;
        }
        innerClass.addJavaDocLine("/**");
        innerClass.addJavaDocLine(" * ");
        String remarks = introspectedTable.getRemarks();
        if (addRemarkComments && StringUtility.stringHasValue(remarks)) {
            String[] remarkLines = remarks.split(System.getProperty("line.separator"));
            for (String remarkLine : remarkLines) {
                innerClass.addJavaDocLine(" * <p>" + remarkLine);
            }
        }
        innerClass.addJavaDocLine(" * ");
        innerClass.addJavaDocLine(" * @author " + userName);
        innerClass.addJavaDocLine(" * @date " + getDateString());


        innerClass.addJavaDocLine(" */");
    }

    @Override
    public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable, boolean markAsDoNotDelete) {
        addClassComment(innerClass, introspectedTable);
    }

    /**
     * 创建的数据表对应的类添加的注释
     */
    @Override
    public void addModelClassComment(TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {
        if (suppressAllComments) {
            return;
        }
        topLevelClass.addJavaDocLine("/**");
        topLevelClass.addJavaDocLine(" * ");
        String remarks = introspectedTable.getRemarks();
        if (addRemarkComments && StringUtility.stringHasValue(remarks)) {
            String[] remarkLines = remarks.split(System.getProperty("line.separator"));
            for (String remarkLine : remarkLines) {
                topLevelClass.addJavaDocLine(" * " + remarkLine);
            }
        }
        topLevelClass.addJavaDocLine(" * ");
        topLevelClass.addJavaDocLine(" * @author " + userName);
        topLevelClass.addJavaDocLine(" * @version 1.0");
        topLevelClass.addJavaDocLine(" * @since " + getDateString());
        topLevelClass.addJavaDocLine(" * ");
        topLevelClass.addJavaDocLine(" * Copyright by Longser Technologies Ltd. ");
        topLevelClass.addJavaDocLine(" */");
    }

    @Override
    public void addEnumComment(InnerEnum innerEnum, IntrospectedTable introspectedTable) {
        if (suppressAllComments) {
            return;
        }
        innerEnum.addJavaDocLine("/**");
        innerEnum.addJavaDocLine(" * ");
        String remarks = introspectedTable.getRemarks();
        if (addRemarkComments && StringUtility.stringHasValue(remarks)) {
            String[] remarkLines = remarks.split(System.getProperty("line.separator"));
            for (String remarkLine : remarkLines) {
                innerEnum.addJavaDocLine(" * " + remarkLine);
            }
        }

        innerEnum.addJavaDocLine(" * @author " + userName);
        innerEnum.addJavaDocLine(" * @date " + getDateString());


        innerEnum.addJavaDocLine(" */");
    }

    /**
     * <p>生成xx.java文件（model）属性的注释</p>
     */
    @Override
    public void addFieldComment(Field field, IntrospectedTable introspectedTable,
                                IntrospectedColumn introspectedColumn) {
        if (suppressAllComments) {
            return;
        }

        field.addJavaDocLine("/**");

        // 获取列注释并加入到注解中
        String remarks = introspectedColumn.getRemarks();
        if (addRemarkComments && StringUtility.stringHasValue(remarks)) {
            String[] remarkLines = remarks.split(System.getProperty("line.separator"));
            for (String remarkLine : remarkLines) {
                field.addJavaDocLine(" * " + remarkLine);
            }
        }

        field.addJavaDocLine(" */");
    }

    @Override
    public void addFieldComment(Field field, IntrospectedTable introspectedTable) {
    }

    /**
     * xxxMapper接口和xxxExample类方法注解
     */
    @Override
    public void addGeneralMethodComment(Method method, IntrospectedTable introspectedTable) {
        if (suppressAllComments) {
            return;
        }

        method.addJavaDocLine("/**");

        List<Parameter> parameters = method.getParameters();
        for(Parameter parameter : parameters) {
            String sb = " * @param " +
                    parameter.getName();
            method.addJavaDocLine(sb);
        }

        Optional<FullyQualifiedJavaType> returnType = method.getReturnType();
        returnType.ifPresent(x -> method.addJavaDocLine(" * @return " + x.getShortName()));

        method.addJavaDocLine(" */");
    }

    @Override
    public void addGetterComment(Method method, IntrospectedTable introspectedTable,
                                 IntrospectedColumn introspectedColumn) {
    }

    @Override
    public void addSetterComment(Method method, IntrospectedTable introspectedTable,
                                 IntrospectedColumn introspectedColumn) {
    }

    @Override
    public void addGeneralMethodAnnotation(Method method, IntrospectedTable introspectedTable,
                                           Set<FullyQualifiedJavaType> imports) {
        addGeneralMethodComment(method, introspectedTable);
    }

    @Override
    public void addGeneralMethodAnnotation(Method method, IntrospectedTable introspectedTable,
                                           IntrospectedColumn introspectedColumn, Set<FullyQualifiedJavaType> imports) {
        addGeneralMethodComment(method, introspectedTable);
    }

    @Override
    public void addFieldAnnotation(Field field, IntrospectedTable introspectedTable,
                                   Set<FullyQualifiedJavaType> imports) {
        addFieldComment(field, introspectedTable);
    }

    @Override
    public void addFieldAnnotation(Field field, IntrospectedTable introspectedTable,
                                   IntrospectedColumn introspectedColumn, Set<FullyQualifiedJavaType> imports) {
        addFieldComment(field, introspectedTable, introspectedColumn);
    }

    @Override
    public void addClassAnnotation(InnerClass innerClass, IntrospectedTable introspectedTable,
                                   Set<FullyQualifiedJavaType> imports) {
    }

    @SuppressWarnings("unused")
    private String getGeneratedAnnotation(String comment) {
        StringBuilder buffer = new StringBuilder();
        buffer.append("@Generated(");
        if (suppressAllComments) {
            buffer.append('\"');
        } else {
            buffer.append("value=\"");
        }

        buffer.append(MyBatisGenerator.class.getName());
        buffer.append('\"');

        if (!suppressDate && !suppressAllComments) {
            buffer.append(", date=\"");
            buffer.append(DateTimeFormatter.ISO_OFFSET_DATE_TIME.format(ZonedDateTime.now()));
            buffer.append('\"');
        }

        if (!suppressAllComments) {
            buffer.append(", comments=\"");
            buffer.append(comment);
            buffer.append('\"');
        }

        buffer.append(')');
        return buffer.toString();
    }

    @Override
    public void addFileComment(KotlinFile kotlinFile) {
    }
}

package com.longser.mybatis.generator.plugins;

import org.mybatis.generator.api.IntrospectedColumn;
import org.mybatis.generator.api.IntrospectedTable;
import org.mybatis.generator.api.PluginAdapter;
import org.mybatis.generator.api.dom.java.FullyQualifiedJavaType;
import org.mybatis.generator.api.dom.java.Interface;
import org.mybatis.generator.api.dom.java.Method;
import org.mybatis.generator.api.dom.java.TopLevelClass;
import org.mybatis.generator.config.PropertyRegistry;
import org.mybatis.generator.internal.util.StringUtility;

import java.text.SimpleDateFormat;
import java.util.*;

import static org.mybatis.generator.internal.util.StringUtility.isTrue;

/**
 * @author Sin
 * @date 2019/04/04/11:15
 */
@SuppressWarnings("unused")
public class LombokPlugin extends PluginAdapter {

    private final Collection<Annotations> annotations;

    /**
     * 抑制日期  默认false：不抑制
     */
    private final boolean suppressDate;
    /**
     * 抑制注释 默认false：不抑制
     */
    private final boolean suppressAllComments;

    /**
     * 日期格式
     */
    private SimpleDateFormat dateFormat;

    /**
     * 当前用户的名字
     */
    private final String userName;

    /**
     * LombokPlugin constructor
     */
    public LombokPlugin() {
        super();

        annotations = new LinkedHashSet<>(Annotations.values().length);

        Properties properties = new Properties();

        suppressDate = isTrue(properties.getProperty(PropertyRegistry.COMMENT_GENERATOR_SUPPRESS_DATE));
        suppressAllComments = isTrue(properties.getProperty(PropertyRegistry.COMMENT_GENERATOR_SUPPRESS_ALL_COMMENTS));

        String dateFormatString = properties.getProperty(PropertyRegistry.COMMENT_GENERATOR_DATE_FORMAT);
        if (StringUtility.stringHasValue(dateFormatString)) {
            dateFormat = new SimpleDateFormat(dateFormatString);
        }

        userName = System.getProperty("user.name");
    }

    /**
     * Returns a formated date string to include in the Javadoc tag and XML
     * comments. You may return null if you do not want the date in these
     * documentation elements.
     *
     * @return a string representing the current timestamp, or null
     */
    protected String getDateString() {
        if (suppressDate) {
            return null;
        } else if (dateFormat != null) {
            return dateFormat.format(new Date());
        } else {
            return new Date().toString();
        }
    }

    /**
     * @param list  warnings list of warnings
     * @return always true
     */
    @Override
    public boolean validate(List<String> list) {
        return true;
    }

    /**
     * Intercepts base record class generation
     *
     * @param topLevelClass     the generated base record class
     * @param introspectedTable The class containing information about the table as
     *                          introspected from the database
     * @return always true
     */
    @Override
    public boolean modelBaseRecordClassGenerated(
            TopLevelClass topLevelClass,
            IntrospectedTable introspectedTable
    ) {
        addAnnotations(topLevelClass);

        //实体类的import
        //topLevelClass.addImportedType("java.io.Serializable");

        //接口
        //topLevelClass.addSuperInterface(new FullyQualifiedJavaType("java.io.Serializable"));
        return true;
    }


    /**
     * Intercepts primary key class generation
     *
     * @param topLevelClass     the generated primary key class
     * @param introspectedTable The class containing information about the table as
     *                          introspected from the database
     * @return always true
     */
    @Override
    public boolean modelPrimaryKeyClassGenerated(
            TopLevelClass topLevelClass,
            IntrospectedTable introspectedTable
    ) {
        addAnnotations(topLevelClass);
        return true;
    }

    /**
     * Intercepts "record with blob" class generation
     *
     * @param topLevelClass     the generated record with BLOBs class
     * @param introspectedTable The class containing information about the table as
     *                          introspected from the database
     * @return always true
     */
    @Override
    public boolean modelRecordWithBLOBsClassGenerated(
            TopLevelClass topLevelClass,
            IntrospectedTable introspectedTable
    ) {
        addAnnotations(topLevelClass);
        return true;
    }

    @Override
    public void setProperties(Properties properties) {
        super.setProperties(properties);

        //@Data is default annotation
        annotations.add(Annotations.DATA);

        for (String annotationName : properties.stringPropertyNames()) {
            if (annotationName.contains(".")) {
                // Not an annotation name
                continue;
            }
            String value = properties.getProperty(annotationName);
            if (!Boolean.parseBoolean(value)) {
                // The annotation is disabled, skip it
                continue;
            }
            Annotations annotation = Annotations.getValueOf(annotationName);
            if (annotation == null) {
                continue;
            }
            String optionsPrefix = annotationName + ".";
            for (String propertyName : properties.stringPropertyNames()) {
                if (!propertyName.startsWith(optionsPrefix)) {
                    // A property not related to this annotation
                    continue;
                }
                String propertyValue = properties.getProperty(propertyName);
                annotation.appendOptions(propertyName, propertyValue);
            }
            annotations.add(annotation);
            annotations.addAll(Annotations.getDependencies(annotation));
        }
    }

    @Override
    public boolean clientGenerated(Interface interfaze, IntrospectedTable introspectedTable) {
        //Mapper文件的注释
        if(!suppressAllComments) {
            interfaze.addJavaDocLine("/**");
            interfaze.addJavaDocLine(" * ");

            String remarks = introspectedTable.getRemarks();
            if (StringUtility.stringHasValue(remarks)) {
                String[] remarkLines = remarks.split(System.getProperty("line.separator"));
                for (String remarkLine : remarkLines) {
                    interfaze.addJavaDocLine(" * " + remarkLine + " 映射定义");
                }
            }
            interfaze.addJavaDocLine(" * ");
            interfaze.addJavaDocLine(" * @author " + userName);
            interfaze.addJavaDocLine(" * @version 1.0");
            interfaze.addJavaDocLine(" * @since " + getDateString());
            interfaze.addJavaDocLine(" * ");
            interfaze.addJavaDocLine(" * Copyright by Longser Technologies Ltd. ");

            interfaze.addJavaDocLine(" */");
        }
        return true;
    }

    @Override
    public boolean modelSetterMethodGenerated(Method method, TopLevelClass topLevelClass, IntrospectedColumn introspectedColumn, IntrospectedTable introspectedTable, ModelClassType modelClassType) {
        //不生成getter
        return false;
    }

    @Override
    public boolean modelGetterMethodGenerated(Method method, TopLevelClass topLevelClass, IntrospectedColumn introspectedColumn, IntrospectedTable introspectedTable, ModelClassType modelClassType) {
        //不生成setter
        return false;
    }

    /**
     * Adds the lombok annotations' imports and annotations to the class
     *
     * @param topLevelClass the partially implemented model class
     */
    private void addAnnotations(TopLevelClass topLevelClass) {
        for (Annotations annotation : annotations) {
            topLevelClass.addImportedType(annotation.javaType);
            topLevelClass.addAnnotation(annotation.asAnnotation());
        }
    }

    private enum Annotations {
        DATA("data", "@Data", "lombok.Data"),
        BUILDER("builder", "@Builder", "lombok.Builder"),
        ALL_ARGS_CONSTRUCTOR("allArgsConstructor", "@AllArgsConstructor", "lombok.AllArgsConstructor"),
        NO_ARGS_CONSTRUCTOR("noArgsConstructor", "@NoArgsConstructor", "lombok.NoArgsConstructor"),
        ACCESSORS("accessors", "@Accessors", "lombok.experimental.Accessors"),
        TO_STRING("toString", "@ToString", "lombok.ToString");


        private final String paramName;
        private final String name;
        private final FullyQualifiedJavaType javaType;
        private final List<String> options;


        Annotations(String paramName, String name, String className) {
            this.paramName = paramName;
            this.name = name;
            this.javaType = new FullyQualifiedJavaType(className);
            this.options = new ArrayList<>();
        }

        private static Annotations getValueOf(String paramName) {
            for (Annotations annotation : Annotations.values()) {
                if (String.CASE_INSENSITIVE_ORDER.compare(paramName, annotation.paramName) == 0) {
                    return annotation;
                }
            }

            return null;
        }

        private static Collection<Annotations> getDependencies(Annotations annotation) {
            if (annotation == ALL_ARGS_CONSTRUCTOR) {
                return Collections.singleton(NO_ARGS_CONSTRUCTOR);
            } else {
                return Collections.emptyList();
            }
        }

        // A trivial quoting.
        // Because Lombok annotation options type is almost String or boolean.
        private static String quote(String value) {
            if (Boolean.TRUE.toString().equals(value) || Boolean.FALSE.toString().equals(value)) {
                // case of boolean, not passed as an array.
                return value;
            }
            return value.replaceAll("[\\w]+", "\"$0\"");
        }

        private void appendOptions(String key, String value) {
            String keyPart = key.substring(key.indexOf(".") + 1);
            String valuePart = value.contains(",") ? String.format("{%s}", value) : value;
            this.options.add(String.format("%s=%s", keyPart, quote(valuePart)));
        }

        private String asAnnotation() {
            if (options.isEmpty()) {
                return name;
            }
            StringBuilder sb = new StringBuilder();
            sb.append(name);
            sb.append("(");
            boolean first = true;
            for (String option : options) {
                if (first) {
                    first = false;
                } else {
                    sb.append(", ");
                }
                sb.append(option);
            }
            sb.append(")");
            return sb.toString();
        }
    }

}

执行 Maven 项目的 package 和 deploy，就可以在你本地的依赖库中部署好生成器的 jar 文件

下面是在Mac OS 系统中部署后的情况