Mybatis Generator 自定义注释

1.mybatis generator使用

1.1. 阅读官网文档 ，导入maven plugin

<plugin>
    <groupId>org.mybatis.generator</groupId>
    <artifactId>mybatis-generator-maven-plugin</artifactId>
    <version>1.3.7</version>
    <executions>
        <execution>
            <id>Generate MyBatis Artifacts</id>
            <goals>
                <goal>generate</goal>
            </goals>
        </execution>
    </executions>
    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.17</version>
        </dependency>
    </dependencies>
</plugin>

1.2. 在src/main/resources目录下创建generatorConfig.xml配置文件

文件模板在官网有提供

<?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="MysqlTables" targetRuntime="MyBatis3">
        <!--解决读取数据库中的comments中文乱码-->
        <property name="javaFileEncoding" value="UTF-8"/>
        <!--分页-->
        <plugin type="org.mybatis.generator.plugins.RowBoundsPlugin"/>
        <!--注释：课可通过type自动配置-->
        <commentGenerator type="cn.edu.nwafu.ssr.community.MyCommentGenerator">
            <property name="addRemarkComments" value="true"/>
        </commentGenerator>
        <!--jdbcConnection: 数据库连接的属性-->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/blog_community?serverTimezone=UTC"
                        userId="root"
                        password="123456">
        </jdbcConnection>

        <javaTypeResolver>
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>
        <!--javaModelGenerator: Java模型生成器的属性 此元素是<context>元素的必需子元素。-->
        <!--enableSubPackages: value为true时，包不存在会自动创建-->
        <javaModelGenerator targetPackage="cn.edu.nwafu.ssr.community.model" targetProject="src\main\java">
            <property name="enableSubPackages" value="true"/>
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>

        <!--Mapper.xml生成-->
        <sqlMapGenerator targetPackage="cn.edu.nwafu.ssr.community.xml" targetProject="src\main\resources">
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>

        <!--XXXMapper.java生成-->
        <javaClientGenerator type="XMLMAPPER" targetPackage="cn.edu.nwafu.ssr.community.mapper"
                             targetProject="src\main\java">
            <property name="enableSubPackages" value="true"/>
        </javaClientGenerator>

        <!--  useActualColumnNames:如果为true，则MBG将使用从数据库元数据返回的列名作为生成的域对象的属性。
                                   如果为false（默认），则MBG将尝试以驼峰式表示返回的名称。
                                   默认值为false。-->
        <table schema="DB2ADMIN" tableName="tb_user" domainObjectName="User">
            <!--<property name="useActualColumnNames" value="true"/>-->
        </table>

    </context>
</generatorConfiguration>

1.3. 使用一下命令运行创建

mvn -Dmybatis.generator.overwrite=true mybatis-generator:generate

注意：使用的mysql驱动如果很新，需要在url中加入?serverTimezone=UTC，即

        <!--jdbcConnection: 数据库连接的属性-->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/blog_community?serverTimezone=UTC"
                        userId="root"
                        password="123456">
        </jdbcConnection>

否则会执行不了，会ERROR

[ERROR] Failed to execute goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.7:generate (default-cli) on project blog_community: The
server time zone value '?й???????' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (
via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support. -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

1.4. 在springboot启动类 XXXApplication中添加注解

@MapperScan(basePackages = "test.dao") //包为mapper所在的包 

1.5. 上边@MapperScan注解，只是让springboot知道了Mapper.java文件的位置，但是不知道Mapper.xml文件的位置，此时需要在application.properties文件中配置

##mybatis配置 
##mybatis.mapper-locations：mapper.xml文件的位置 
##mybatis.type-aliases-package：实体类所在的包 
mybatis.mapper-locations=classpath*:/test/**/*Mapper.xml
mybatis.type-aliases-package=test.model  

1.6. 官方文档

1.6.1. mybatis generator

1.6.2. spring-boot-starter

1.7.可实现CommentGenerator 类，从而自动配置添加的注释

1.7.1. 实现CommentGenerator 类

package cn.edu.nwafu.ssr.community;

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.internal.util.StringUtility;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.Properties;
import java.util.Set;


/**
 * @author shensr
 * @version V1.0
 * @description mybatis generator自定义生成注释插件类
 * @create 2019/10/4
 **/
public class MyCommentGenerator implements CommentGenerator {

    private Properties properties = new Properties();
    /**
     * 抑制日期  默认false：不抑制
     */
    private boolean suppressDate = false;
    /**
     * 抑制注释 默认false：不抑制
     */
    private boolean suppressAllComments = false;

    /**
     * 显示数据库comments 默认false：不显示
     */
    private boolean addRemarkComments = false;
    /**
     * 日期格式
     */
    private SimpleDateFormat dateFormat;

    public MyCommentGenerator() {
        super();
        dateFormat = new SimpleDateFormat("yyyy/MM/dd");
    }


    /**
     * 读取配置文件
     *
     * @param properties
     */
    @Override
    public void addConfigurationProperties(Properties properties) {
        this.properties.putAll(properties);
        this.suppressDate = StringUtility.isTrue(properties.getProperty("suppressDate"));
        this.suppressAllComments = StringUtility.isTrue(properties.getProperty("suppressAllComments"));
        this.addRemarkComments = StringUtility.isTrue(properties.getProperty("addRemarkComments"));
        String dateFormatString = properties.getProperty("dateFormat");
        if (StringUtility.stringHasValue(dateFormatString)) {
            this.dateFormat = new SimpleDateFormat(dateFormatString);
        }

    }

    /**
     * 日期格式化
     *
     * @return 格式化后的日期
     */
    protected String getDateString() {
        if (this.suppressDate) {
            return null;
        } else {
            return this.dateFormat != null ? this.dateFormat.format(new Date()) : (new Date()).toString();
        }
    }

    /**
     * 创建的数据表对应的类添加的注释
     *
     * @param topLevelClass
     * @param introspectedTable
     */
    @Override
    public void addModelClassComment(TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {
        if (!this.suppressAllComments) {
            topLevelClass.addJavaDocLine("/**");
            topLevelClass.addJavaDocLine(" * @author shensr");
            topLevelClass.addJavaDocLine(" * @version V1.0 ");
            topLevelClass.addJavaDocLine(" * @description MyBatis Generator 自动创建,对应数据表为：" + introspectedTable.getFullyQualifiedTable());
            topLevelClass.addJavaDocLine(" * @create " + this.getDateString());
            topLevelClass.addJavaDocLine(" */");
        }
    }

    /**
     * <p>生成xx.java文件（model）属性的注释</p>
     *
     * @param field
     * @param introspectedTable
     * @param introspectedColumn
     */
    @Override
    public void addFieldComment(Field field, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) {
        if (!this.suppressAllComments) {
            // 注释开始的地方
            field.addJavaDocLine("/**");
            String remarks = introspectedColumn.getRemarks();
            // 开启注释，并且数据库中comment有值
            if (this.addRemarkComments && StringUtility.stringHasValue(remarks)) {
                // 通过换行符分割 System.getProperty("line.separator")：换行符 ，屏蔽了 Windows和Linux的区别
                String[] remarkLines = remarks.split(System.getProperty("line.separator"));
                int length = remarkLines.length;
                // 如果有多行，就换行显示
                for (int i = 0; i < length; i++) {
                    String remarkLine = remarkLines[i];
                    field.addJavaDocLine(" * " + remarkLine);
                }
            }
            // 注释结束
            field.addJavaDocLine(" */");
        }
    }

    /**
     * xxxMapper接口和xxxExample类方法注解
     *
     * @param method
     * @param introspectedTable
     */
    @Override
    public void addGeneralMethodComment(Method method, IntrospectedTable introspectedTable) {
        if (!this.suppressAllComments) {
            method.addJavaDocLine("/**");
            method.addJavaDocLine(" * " + method.getName());
            List<Parameter> parameters = method.getParameters();
            parameters.forEach(parameter -> method.addJavaDocLine(" * @param " + parameter.getName()));
            // 如果有返回类型，添加@return
            String returnType = "void";
            if (!returnType.equals(method.getReturnType())) {
                method.addJavaDocLine(" * @return ");
            }
            method.addJavaDocLine(" */");
        }

    }

    /**
     * 数据库对应实体类的Getter方法注解
     *
     * @param method
     * @param introspectedTable
     * @param introspectedColumn
     */
    @Override
    public void addGetterComment(Method method, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) {

    }

    /**
     * 数据库对应实体类的Setter方法注解
     *
     * @param method
     * @param introspectedTable
     * @param introspectedColumn
     */
    @Override
    public void addSetterComment(Method method, IntrospectedTable introspectedTable, IntrospectedColumn introspectedColumn) {

    }

    /**
     * 生成xxMapper.XML文件的注释
     *
     * @param xmlElement
     */
    @Override
    public void addComment(XmlElement xmlElement) {
    }

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

    }

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

    }

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

    }

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

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

    @Override
    public void addJavaFileComment(CompilationUnit compilationUnit) {
    }

    @Override
    public void addRootComment(XmlElement rootElement) {
    }

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

    }

    @Override
    public void addEnumComment(InnerEnum innerEnum, IntrospectedTable introspectedTable) {

    }

    @Override
    public void addClassComment(InnerClass innerClass, IntrospectedTable introspectedTable) {

    }

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

    }

}

1.7.2.在generatorConfig.xml配饰文件中添加

<!--注释：课可通过type自动配置-->
<commentGenerator type="cn.edu.nwafu.ssr.community.MyCommentGenerator">
    <property name="addRemarkComments" value="true"/>
</commentGenerator>

1.7.3. 通过java方式启动mbg ，maven会出现一些问题

package cn.edu.nwafu.ssr.community;

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;

/**
 * @author shensr
 * @version V1.0
 * @description 通过java方式启动mbg，实现自定配置注解，使用maven方式会出现问题
 * @create 2019/10/9
 **/

public class Generator {
    public static void main(String[] args)  {
        List<String> warnings = new ArrayList<>();
        // 覆盖
        boolean overwrite = true;
        // 给出generatorConfig.xml文件的位置
        File configFile = new File("D:\\IdeaProjects\\blog_community\\src\\main\\resources\\generatorConfig.xml");
        ConfigurationParser cp = new ConfigurationParser(warnings);
        try {
            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();
        }
    }
}

1.7.8. 生成效果

package cn.edu.nwafu.ssr.community.model;

/**
 * @author shensr
 * @version V1.0 
 * @description MyBatis Generator 自动创建,对应数据表为：tb_user
 * @create 2019/10/09
 */
public class User {
    /**
     * ID 
     */
    private Integer id;

    /**
     * 账户Id
     */
    private String accountId;

    /**
     * 用户名
     */
    private String name;

    /**
     * token
     */
    private String token;

    /**
     * 创建时间
     */
    private Long gmtCreate;

    /**
     * 更新时间
     */
    private Long gmtModified;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getAccountId() {
        return accountId;
    }

    public void setAccountId(String accountId) {
        this.accountId = accountId == null ? null : accountId.trim();
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name == null ? null : name.trim();
    }

    public String getToken() {
        return token;
    }

    public void setToken(String token) {
        this.token = token == null ? null : token.trim();
    }

    public Long getGmtCreate() {
        return gmtCreate;
    }

    public void setGmtCreate(Long gmtCreate) {
        this.gmtCreate = gmtCreate;
    }

    public Long getGmtModified() {
        return gmtModified;
    }

    public void setGmtModified(Long gmtModified) {
        this.gmtModified = gmtModified;
    }
}