MyBatis Generator 逆向工程根据表字段注释生成实体类属性注释、序列化、toString

目录

一、文章前言

二、取消自动生成注释

三、自动生成序列化

四、自动生成toString

五、生成自定义注释

六、结果演示

七、工程源码

---

一、文章前言

    本篇文章讲述的是MyBatis Generator 逆向工程生成自定义注释、序列化、toString配置，在看到这篇文章之前，希望读者对MyBatis Generator 基本使用已经没有问题，因为本篇文章并不会讲述如何搭建MyBatis Generator环境

二、取消自动生成注释

    1.自动生成的注释很烦，而且一点用都没有，所以我们需要取消自动生成的注释

    2.在context节点下配置

    3.参考代码

三、自动生成序列化

    1.当我们生成实体类以后，发现默认是没有toString和序列化，但是很多时候需要序列化对象，从而方便在网络上传输

    2.生成序列化只需要在context节点下加入 插件即可  

    3.参考代码

四、自动生成toString

    1.生成toString和生成序列化一样，同样在context节点下加入 插件即可

    2.参考代码

五、生成自定义注释

    注意：在数据表中一定要有注释字段，以下以MySQL为例，因为会将comment字段注释提取为实体类的注释信息

    1.MyBatis逆向工程默认使用的是org.mybatis.generator.api.CommentGenerator类的org.mybatis.generator.internal.DefaultCommentGenerator子类生成的注释，所以我们可以自己实现一个注释类

   2.新建一个类，实现CommentGenerator接口

    3.从org.mybatis.generator.internal.DefaultCommentGenerator把所有代码拷贝出来，复制到更改新建的类中，注意其中有一个@Override的类会报错，把@Override去掉即可，以下是拷贝过来的代码部分截图

    4.我们生成注释的主要有以下几个地方：实体类属性、实体类getter方法、实体类setter方法、实体类静态常量属性、mapper.xml注释

   5.实体类属性注释是addFieldComment(Field field,IntrospectedTable introspectedTable,IntrospectedColumn introspectedColumn) 这个方法

    6.实体类静态属性字段的方法名和上一个方法名一样，只是参数不同

    7.实体类toString方法是addGeneralMethodComment(Method method, IntrospectedTable introspectedTable)，这里没有选择生成任何代码，因为没有必要

    8.实体类getter方法注释是addGetterComment方法

    9.实体类setter注释是addSetterComment方法

    10.实体类对应的mapper.xml注释是addComment(XmlElement xmlElement)方法，这里没有加入任何注释，如有需要参考 DefaultCommentGenerator

六、结果演示

    1.序列化和属性字段注释，如账户ID是从数据库comment字段中提取出来的

    2.静态字段

   3.getter和setter方法

   4.toString

   5.mapper

七、工程源码

    1.maven依赖

	
	
		mysql
		mysql-connector-java
		5.1.44
	

	
	
		org.mybatis.generator
		mybatis-generator-core
		1.3.5
	

	
	
		org.mybatis
		mybatis
		3.4.6
	

    2.MyBatis逆向工程配置文件generatorConfig.xml

    3.自定义注释类 MyCommentGenerator

/**
 *    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 com.codecoord.config;

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(" */"); //$NON-NLS-1$
    }

    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(" */"); 
    }

    /**
     * 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(" */"); //$NON-NLS-1$
    }
}

    4.逆向工程启动类

package com.codecoord.main;

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 warnings = new ArrayList();
            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();
        }
    }
}

    5.工程结构