实习小结（四）--- MyBatis Generator使用

第一次听闻MyBatis Generator插件很是惊讶，已经有这么便捷方式的工具通过数据库表来自动生成实体类，映射文件，接口以及帮助类，而且可以通过自己写方法来增加中文注释，遂来学习一波。首先先建一个Maven的java项目

项目的目录结构

1、首先是pom.xml中的配置

<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.sysystem</groupId>
  <artifactId>mybatisgenerator</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>mybatisgenerator</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>

    <dependency>
     <groupId>org.mybatis.generator</groupId>
     <artifactId>mybatis-generator-core</artifactId>
     <version>1.3.2</version>
    </dependency>

    <dependency>
         <groupId>mysql</groupId>
         <artifactId>mysql-connector-java</artifactId>
         <version>5.1.9</version>
    </dependency>

  </dependencies>
</project>

2、MyCommentGenerator.java为生成中文注释的方法

package com.mybatis.generator;

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

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.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.Parameter;
import org.mybatis.generator.api.dom.xml.XmlElement;
import org.mybatis.generator.config.MergeConstants;
import org.mybatis.generator.config.PropertyRegistry;

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

        suppressAllComments = 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().replace("\n", " "));
        innerClass.addJavaDocLine(" */");
    }

    public void addEnumComment(InnerEnum innerEnum, IntrospectedTable introspectedTable) {
        if (suppressAllComments) {
            return;
        }
        StringBuilder sb = new StringBuilder();
        innerEnum.addJavaDocLine("/**");
        sb.append(" * ");
        sb.append(introspectedTable.getFullyQualifiedTable());
        innerEnum.addJavaDocLine(sb.toString().replace("\n", " "));
        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().replace("\n", " "));
        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().replace("\n", " "));
        field.addJavaDocLine(" */");
    }

    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().replace("\n", " "));
        sb.setLength(0);
        sb.append(" * @return ");
        sb.append(introspectedColumn.getActualColumnName());
        sb.append(" ");
        sb.append(introspectedColumn.getRemarks());
        method.addJavaDocLine(sb.toString().replace("\n", " "));
        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().replace("\n", " "));
        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().replace("\n", " "));
        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().replace("\n", " "));
        sb.setLength(0);
        sb.append(" * @author ");
        sb.append(systemPro.getProperty("user.name"));
        sb.append(" ");
        sb.append(currentDateStr);
        innerClass.addJavaDocLine(" */");
    }
}

3、在resources下增加配置信息generatorConfig.xml

<?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="context1" targetRuntime="MyBatis3">

    <!-- 指定生成的java文件的编码,没有直接生成到项目时中文可能会乱码 -->
    <property name="javaFileEncoding" value="UTF-8"/>

    <!-- 生成的pojo，将implements Serializable-->
    <plugin type="org.mybatis.generator.plugins.SerializablePlugin"></plugin>

    <!-- 注释, 这里的type里写的是你的实现类的类全路径 -->
    <commentGenerator type="com.mybatis.generator.MyCommentGenerator"></commentGenerator>

    <!-- 数据库连接 mysql配置 -->
    <jdbcConnection driverClass="com.mysql.jdbc.Driver"
        connectionURL="jdbc:mysql://localhost:3306/studentmanager" userId="root" password="root">
        <property name="useInformationSchema" value="true"></property>
    </jdbcConnection>

    <!--
     默认false，把JDBC DECIMAL 和 NUMERIC 类型解析为 Integer
         true，把JDBC DECIMAL 和 NUMERIC 类型解析为java.math.BigDecimal
    -->
    <javaTypeResolver>
        <property name="forceBigDecimals" value="false" />
    </javaTypeResolver>

    <!--  生成model模型，对应的包路径，以及文件存放路径(targetProject)，targetProject可以指定具体的路径
                   也可以使用“MAVEN”来自动生成，这样生成的代码会在target/generatord-source目录下      -->
    <javaModelGenerator targetPackage="model"
        targetProject="I:/test">
        <property name="enableSubPackages" value="true" />
        <!-- 从数据库返回的值被清理前后的空格  -->
        <property name="trimStrings" value="true" />
    </javaModelGenerator>

    <!--对应的mapper.xml文件  -->
    <sqlMapGenerator targetPackage="mapper"
        targetProject="I:/test">
        <property name="enableSubPackages" value="true" />
    </sqlMapGenerator>

    <!-- 对应的Mapper接口类文件 -->
    <javaClientGenerator type="XMLMAPPER"
        targetPackage="dao" targetProject="I:/test">
        <property name="enableSubPackages" value="true" />
    </javaClientGenerator>

    <!-- 生成哪些些表，tableName对应数据库表，domainObjectName对应实体类名 -->
    <table schema="" tableName="emp" domainObjectName="Emp"
        enableCountByExample="true" enableUpdateByExample="true"
        enableDeleteByExample="true" enableSelectByExample="true"
        selectByExampleQueryId="true">
    </table>

  </context>
</generatorConfiguration>

4、最后编写一个mian方法用来生成需要的文件

package com.mybatis.generator;

import java.io.IOException;
import java.io.InputStream;
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;
            ClassLoader classloader = Thread.currentThread().getContextClassLoader();
            InputStream is = classloader.getResourceAsStream("generatorConfig.xml");
            ConfigurationParser cp = new ConfigurationParser(warnings);
            Configuration config = cp.parseConfiguration(is);
            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();
        }
    }
}

运行StartUp就会生成所需要的实体类，映射文件等

分享GitHub上找到的一个web 形式的mybatis 生成器：

https://github.com/huzhicheng/kite-mybatis-builder

参考博客

[1]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)

http://www.cnblogs.com/NieXiaoHui/p/6094144.html

[2]MyBatis Generator 配置详解

https://blog.csdn.net/testcs_dn/article/details/79295065