Mybatis反向生成模型带中文注释

mybatis可以通过数据库表直接替我们生成模型类和mappper文件。

这里说一下怎么配置，尤其是如何加上中文注释。当前前提是数据表和字段有中文注释。

比如这样的：

下面配置自动生成模型类和mapper类还有mapper的xml文件。

网上关于如何使用mybatis-generator生成Java对象的文章很多，这里不详细说了。大家可以到百度上so一下，比如http://www.cnblogs.com/smileberry/p/4145872.html，http://www.cnblogs.com/yjmyzz/p/4210554.html

假设我们已经设计好了表结构，表和字段都有自己的注释（其实中英文倒无所谓）。

下面是反向生成的过程：

在类路径下新建generatorConfig.xml，配置如下

<?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>
    <!--指定特定数据库的jdbc驱动jar包的位置-->
    <classPathEntry location="${jdbc.driverLocation}"/>

    <context id="default" targetRuntime="MyBatis3">

        <!--jdbc的数据库连接 -->
        <jdbcConnection
                driverClass="${jdbc.driverClass}"
                connectionURL="${jdbc.connectionURL}"
                userId="${jdbc.userId}"
                password="${jdbc.password}">
        </jdbcConnection>

        <javaTypeResolver>
            <property name="forceBigDecimals" value="true"/>
        </javaTypeResolver>
        <javaModelGenerator targetPackage="comxxx.model"
                            targetProject="src/main/java">
            <property name="enableSubPackages" value="false"/>
            <property name="constructorBased" value="true"/>
            <property name="trimStrings" value="true"/>
           <property name="immutable" value="false"/>
        </javaModelGenerator>

        <sqlMapGenerator targetPackage="com.xxx.mapper"
                         targetProject="src/main/resources">
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>

        <javaClientGenerator targetPackage="com.xxx.mapper"
                             targetProject="src/main/java"
                             type="XMLMAPPER">
            <property name="enableSubPackages" value="false"/>
        </javaClientGenerator>

        <table tableName="import_goods_quantity"
               enableCountByExample="false" enableUpdateByExample="false"
               enableDeleteByExample="false" enableSelectByExample="false"
               selectByExampleQueryId="false">
            <!--<generatedKey identity="true" sqlStatement="MySql" column="id"/>-->
        </table>
     </context>
</generatorConfiguration>

 generatorConfiguration 有一个子标签

<properties resource="xxx.properties"></properties>

可以引入配置变量。

配置好以后就可以使用插件mybatis-generator-maven-plugin生成了。

<plugin>
   <groupId>org.mybatis.generator</groupId>
   <artifactId>mybatis-generator-maven-plugin</artifactId>
   <version>1.3.5</version>
   <configuration>
      <verbose>true</verbose>
      <overwrite>true</overwrite>
   </configuration>
</plugin>

我们这里使用的是1.3.5版本。

 现在用mybatis-generator:generate就可以生成Java类和xml文件到指定目录了。

这样生成的类注释是自动的、毫无意义的时间描述，类似于

@mbg.generated

我们希望数据库里的注释能够拿过来，怎么搞呢？

新建一个maven工程，坐标比如是

<groupId>com.xxx</groupId>
<artifactId>comment_generator</artifactId>
<version>1.0-SNAPSHOT</version>

 引入依赖

<dependency>
    <groupId>org.mybatis.generator</groupId>
    <artifactId>mybatis-generator-core</artifactId>
    <version>1.3.5</version>
</dependency>

 新建注释配置类

public class MybatisCommentGenerator implements CommentGenerator {
    private Properties properties;
    private Properties systemPro;
    private boolean suppressDate;
    private boolean suppressAllComments;
    private String currentDateStr;

    public MybatisCommentGenerator() {
        super();
        properties = new Properties();
        systemPro = System.getProperties();
        suppressDate = false;
        suppressAllComments = false;
        currentDateStr = (new SimpleDateFormat("yyyy-MM-dd")).format(new Date());
    }

    /**
     * Adds properties for this instance from any properties configured in the
     * CommentGenerator configuration.
     * <p>     * This method will be called before any of the other methods.
     *
     * @param properties All properties from the configuration
     */
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));
    }

    /**     *
     * @param field              the field
     * @param introspectedTable  the introspected table
     * @param introspectedColumn
*/
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(" */");
    }

    /**
     * Adds the field comment.
     *
     * @param field             the field
     * @param introspectedTable
*/
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) {
        if (suppressAllComments) {
            return;
        }
        StringBuilder sb = new StringBuilder();
        topLevelClass.addJavaDocLine("/**");
        sb.append(" * ");
        sb.append(introspectedTable.getRemarks());
        sb.append(" ");
        sb.append(introspectedTable.getTableType());
        sb.append(" ");
        sb.append(getDateString());
        topLevelClass.addJavaDocLine(sb.toString());
        topLevelClass.addJavaDocLine(" */");
    }

    /**
     * Adds the inner class comment.
     *
     * @param innerClass        the inner class
     * @param introspectedTable
*/
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(" */");
    }

    /**
     * Adds the inner class comment.
     *
     * @param innerClass        the inner class
     * @param introspectedTable the introspected table
     * @param markAsDoNotDelete
*/
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(" */");
    }

    /**
     * Adds the enum comment.
     *
     * @param innerEnum         the inner enum
     * @param introspectedTable
*/
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(" */");
    }

    /**
     * Adds the getter comment.
     *
     * @param method             the method
     * @param introspectedTable  the introspected table
     * @param introspectedColumn
*/
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(" */");
    }

    /**
     * Adds the setter comment.
     *
     * @param method             the method
     * @param introspectedTable  the introspected table
     * @param introspectedColumn
*/
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(" */");
    }

    /**
     * Adds the general method comment.
     *
     * @param method            the method
     * @param introspectedTable
*/
public void addGeneralMethodComment(Method method, IntrospectedTable introspectedTable) {
        if (suppressAllComments) {
            return;
        }
        method.addJavaDocLine("/**");
//        addJavadocTag(method, false);
StringBuilder sb = new StringBuilder();
        sb.append(" * ");
        sb.append(MergeConstants.NEW_ELEMENT_TAG);
        String s = method.getName();
        sb.append(' ');
        sb.append(s);
        method.addJavaDocLine(sb.toString());
        method.addJavaDocLine(" */");
    }
public void addJavaFileComment(CompilationUnit compilationUnit) {

    }
public void addComment(XmlElement xmlElement) {

    }
public void addRootComment(XmlElement rootElement) {
    }

    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());
    }

    protected String getDateString() {
        String result = null;
        if (!suppressDate) {
            result = currentDateStr;
        }
        return result;
    }
}

 将这个工程install一下。（可以关闭了，除非你要继续修改）

回到前面需要反向生成的工程。

在generatorConfig.xml中，修改

commentGenerator

元素为

<commentGenerator type="com.xxx.mybatis.MybatisCommentGenerator">
    <property name="suppressDate" value="false"/>
    <property name="suppressAllComments" value="false"/>
</commentGenerator>

 其中type指向刚才工程里的注释配置类。suppressDate依个人喜好可有可无。

修改generator插件，引入刚才新建的工程依赖：

<plugin>
   <groupId>org.mybatis.generator</groupId>
   <artifactId>mybatis-generator-maven-plugin</artifactId>
   <version>1.3.5</version>
   <configuration>
      <verbose>true</verbose>
      <overwrite>true</overwrite>
   </configuration>
             <dependencies>
                 <dependency>
                     <groupId>com.xxx</groupId>
                     <artifactId>comment_generator</artifactId>
                     <version>1.0-SNAPSHOT</version>
                 </dependency>
             </dependencies>
</plugin>

 再次运行插件，可以看到模型类上有了我们在数据库里写好的注释。