关于 mybatis-generator自定义注释生成 使用DefaultCommentGenerator重写来完成

项目里新建表时model,mapper以及mapper.xml基本都是用Mybatis Generator(以下简称为MBG)自动生成的,但是MBG自动生成的model的注释实在有点非人类,至少中国人是完全接受不了的,在配置中禁用掉注释吧,倒是简单了,可是生成的model类光秃秃的,啥都没有,字段方法没有注释,使用很不方便,别人看也不知道这个字段是啥含义,到最后还是要自己添加,一张表多点几十个字段,特么添加累死了,不能这么干,得想法子,百度了一下网上,基本有两种方法,第一种,就是直接修改MGB的源代码,第二种就是自己写一个类实现CommentGenerator接口,先说自己写一个新类实现CommentGenerator接口的方法来使自动生成的model类含有中文注释吧.

一：首先你得有一个maven项目，这个我就不多踢

二：通过mybatis generator实现自动生产model,mapper以及mapper.xml，具体参考 Intellij IDEA 14中使用MyBatis-generator 自动生成MyBatis代码 

三：通过查看你会发现，注解类是在mybatis-generator-core jar包中  org.mybatis.generator.internal包下的DefaultCommentGenerator类。那么这里有两种方法，一种是重写DefaultCommentGenerator类，另外一种中修改jar包中的源码，但很明显第一种方法比较简单，这里也只介绍第一种方法的写法。

3.1在源代码中新建一个类MyCommentGenerator,实现CommentGenerator接口,类的代码如下:

package org.mybatis.generator;

/**
 * Created by 草帽boy on 2017/2/16.
 * mybatis generator 自定义comment生成器.
 * 基于MBG 1.3.2.
 * @author ZhangAY 2016-02-19
 */
import java.text.SimpleDateFormat;
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.*;
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 {

    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 addJavaFileComment(CompilationUnit compilationUnit) {
        // add no file level comments by default
        return;
    }

    /**
     * Adds a suitable comment to warn users that the element was generated, and
     * when it was generated.
     */
    public void addComment(XmlElement xmlElement) {
        return;
    }

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

    public void addConfigurationProperties(Properties properties) {
        this.properties.putAll(properties);

        suppressDate = StringUtility.isTrue(properties.getProperty(PropertyRegistry.COMMENT_GENERATOR_SUPPRESS_DATE));

        suppressAllComments = StringUtility.isTrue(properties.getProperty(PropertyRegistry.COMMENT_GENERATOR_SUPPRESS_ALL_COMMENTS));
    }

    /**
     * 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
     */
    protected void addJavadocTag(JavaElement javaElement, boolean markAsDoNotDelete) {
        javaElement.addJavaDocLine(" *");
        StringBuilder sb = new StringBuilder();
        sb.append(" * ");
        sb.append(MergeConstants.NEW_ELEMENT_TAG);
        if (markAsDoNotDelete) {
            sb.append(" do_not_delete_during_merge");
        }
        String s = getDateString();
        if (s != null) {
            sb.append(' ');
            sb.append(s);
        }
        javaElement.addJavaDocLine(sb.toString());
    }

    /**
     * This method 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() {
        String result = null;
        if (!suppressDate) {
            result = currentDateStr;
        }
        return result;
    }

    public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable) {
        if (suppressAllComments) {
            return;
        }
        StringBuilder sb = new StringBuilder();
        innerClass.addJavaDocLine("/**");
        sb.append(" * ");
        sb.append(introspectedTable.getFullyQualifiedTable());
        sb.append(" ");
        sb.append(getDateString());
        innerClass.addJavaDocLine(sb.toString());
        innerClass.addJavaDocLine(" */");
    }

    public void addEnumComment(InnerEnum innerEnum, IntrospectedTable introspectedTable) {
        if (suppressAllComments) {
            return;
        }

        StringBuilder sb = new StringBuilder();

        innerEnum.addJavaDocLine("/**");
        //      addJavadocTag(innerEnum, false);
        sb.append(" * ");
        sb.append(introspectedTable.getFullyQualifiedTable());
        innerEnum.addJavaDocLine(sb.toString());
        innerEnum.addJavaDocLine(" */");
    }

    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());

        //      addJavadocTag(field, false);

        field.addJavaDocLine(" */");
    }

    public void addFieldComment(Field field, IntrospectedTable introspectedTable) {
        if (suppressAllComments) {
            return;
        }

        StringBuilder sb = new StringBuilder();

        field.addJavaDocLine("/**");
        sb.append(" * ");
        sb.append(introspectedTable.getFullyQualifiedTable());
        field.addJavaDocLine(sb.toString());
        field.addJavaDocLine(" */");
    }

    public void addModelClassComment(TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {

    }

    public void addGeneralMethodComment(Method method, IntrospectedTable introspectedTable) {
        if (suppressAllComments) {
            return;
        }
        //      method.addJavaDocLine("/**");
        //      addJavadocTag(method, false);
        //      method.addJavaDocLine(" */");
    }

    public void addGetterComment(Method method, IntrospectedTable introspectedTable,
                                 IntrospectedColumn introspectedColumn) {
        if (suppressAllComments) {
            return;
        }

        method.addJavaDocLine("/**");

        StringBuilder sb = new StringBuilder();
        sb.append(" * ");
        sb.append(introspectedColumn.getRemarks());
        method.addJavaDocLine(sb.toString());

        sb.setLength(0);
        sb.append(" * @return ");
        sb.append(introspectedColumn.getActualColumnName());
        sb.append(" ");
        sb.append(introspectedColumn.getRemarks());
        method.addJavaDocLine(sb.toString());

        //      addJavadocTag(method, false);

        method.addJavaDocLine(" */");
    }

    public void addSetterComment(Method method, IntrospectedTable introspectedTable,
                                 IntrospectedColumn introspectedColumn) {
        if (suppressAllComments) {
            return;
        }


        method.addJavaDocLine("/**");
        StringBuilder sb = new StringBuilder();
        sb.append(" * ");
        sb.append(introspectedColumn.getRemarks());
        method.addJavaDocLine(sb.toString());

        Parameter parm = method.getParameters().get(0);
        sb.setLength(0);
        sb.append(" * @param ");
        sb.append(parm.getName());
        sb.append(" ");
        sb.append(introspectedColumn.getRemarks());
        method.addJavaDocLine(sb.toString());

        //      addJavadocTag(method, false);

        method.addJavaDocLine(" */");
    }

    public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable, boolean markAsDoNotDelete) {
        if (suppressAllComments) {
            return;
        }

        StringBuilder sb = new StringBuilder();

        innerClass.addJavaDocLine("/**");
        sb.append(" * ");
        sb.append(introspectedTable.getFullyQualifiedTable());
        innerClass.addJavaDocLine(sb.toString());

        sb.setLength(0);
        sb.append(" * @author ");
        sb.append(systemPro.getProperty("user.name"));
        sb.append(" ");
        sb.append(currentDateStr);

        //      addJavadocTag(innerClass, markAsDoNotDelete);

        innerClass.addJavaDocLine(" */");
    }
}

3.2.再新建一个类StartUp,用于运行项目,也就是运行StartUp类 就会直接生成model,mapper以及mapper.xml，类的代码如下:

package org.mybatis.generator;

/**
 * Created by 草帽boy on 2017/2/16.
 * 启动文件，只需要点击运行就行
 */
import java.io.File;
import java.io.IOException;
import java.net.URISyntaxException;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import org.mybatis.generator.api.MyBatisGenerator;
import org.mybatis.generator.config.Configuration;
import org.mybatis.generator.config.xml.ConfigurationParser;
import org.mybatis.generator.exception.InvalidConfigurationException;
import org.mybatis.generator.exception.XMLParserException;
import org.mybatis.generator.internal.DefaultShellCallback;

public class StartUp {
    public static void main(String[] args) throws URISyntaxException {
        try {
            List<String> warnings = new ArrayList<String>();
            boolean overwrite = true;
            //直接获取generatorConfig.xml的文件路径 根据具体情况查看
            File configFile = new File("E:\\IDEAWorkPlace\\GraduationDesign\\CourseDesignManageSystem\\20170122\\CourseDesignManage\\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 (SQLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (InvalidConfigurationException e) {
            e.printStackTrace();
        } catch (XMLParserException e) {
            e.printStackTrace();
        }
    }
}

3.3 另外需要简单修改一下generatorConfig.xml中的注释配置

  <commentGenerator type="org.mybatis.generator.MyCommentGenerator">
           <!-- <property name="suppressDate" value="true"/>
            &lt;!&ndash; 是否去除自动生成的注释 true：是 ： false:否 &ndash;&gt;
            <property name="suppressAllComments" value="false"/>-->
        </commentGenerator>

commentGenerator 的type是你刚刚重构的MyCommentGenerator类的位置

3.4其中我的文件结构如下：

四：点击运行StartUp，你会发现model,mapper以及mapper.xml都已经产生，其中实体类的 运行的结果如下

更多参考：

mybatis-generator自定义注释生成

Mybatis Generator的model生成中文注释,支持oracle和mysql(通过实现CommentGenerator接口的方法来实现)