详解使用MyBatis Generator逆向工程生成代码

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#Mybatis #Generator #逆向工程

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本文详细介绍了如何使用MyBatis代码生成器插件，从配置Maven pom.xml文件到创建并运行自定义注解类，实现数据库表的代码自动生成。包括依赖和插件的添加、配置文件的设置、自定义注解类的编写等关键步骤。

一、配置Maven pom.xml 文件

在pom.xml增加以下插件：

1.添加依赖：

    <!--mybatis核心-->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.4.1</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis.generator</groupId>
      <artifactId>mybatis-generator-core</artifactId>
      <version>1.3.6</version>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.21</version>
    </dependency>

2.增加插件：

<build>
   <finalName>test</finalName>
   <pluginManagement>
      <plugins>
        <plugin>
          <groupId>org.mybatis.generator</groupId>
          <artifactId>mybatis-generator-maven-plugin</artifactId>
          <version>1.3.2</version>
          <configuration>
            <verbose>true</verbose>
            <overwrite>true</overwrite>
          </configuration>
        </plugin>
      </plugins>
   </pluginManagement>
</build>

配置好Maven插件，下面需要配置插件需要的配置文件

二、在maven项目下的src/main/resources 目录下建立名为Maven的项目配置文件存放路径如下图：generatorConfig.xml和config.properties配置文件，

1.Maven的项目配置文件存放路径如下图：

2.generatorConfig.xml代码如下：

<?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>
        <!--导入属性配置-->
        <properties resource="config.properties"></properties>

        <!--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">
                <property name="javaFileEncoding" value="UTF-8"/>
                <!--<commentGenerator>-->
            	<!-- 是否去除自动生成的注释 -->
                <!--<property name="suppressDate" value="false"/>-->
                <!--<property name="suppressAllComments" value="false"/>-->
                <!--</commentGenerator>-->
                <!-- ①.type为自定义注释类，需要自己创建，代码下面贴出。旨在创建class时，对注释进行控制 
                     ②.也可以不使用这种方式，注释掉就好，使用上边的<commentGenerator>标签-->
                <commentGenerator type="com.zc.ssm_market.common.MyCommentGenerator">
                </commentGenerator>

                <!--jdbc的数据库连接 -->
                <jdbcConnection
                        driverClass="${jdbc.driver}"
                        connectionURL="${jdbc.url}"
                        userId="${jdbc.username}"
                        password="${jdbc.password}">
                </jdbcConnection>
                
                <!-- 非必需，类型处理器，在数据库类型和java类型之间的转换控制-->
                <javaTypeResolver>
                        <property name="forceBigDecimals" value="false"/>
                </javaTypeResolver>
                
                <!-- Model模型生成器,用来生成含有主键key的类，记录类 以及查询Example类
                    targetPackage     指定生成的model生成所在的包名
                    targetProject     指定在该项目下所在的路径
                -->
                <javaModelGenerator targetPackage="com.zc.ssm_market.entity"
                                    targetProject="src/main/java">
                        <!-- 是否允许子包，即targetPackage.schemaName.tableName -->
                        <property name="enableSubPackages" value="false"/>
                        <!-- 是否对model添加 构造函数 -->
                        <property name="constructorBased" value="true"/>
                        <!-- 是否对类CHAR类型的列的数据进行trim操作 -->
                        <property name="trimStrings" value="true"/>
                        <!-- 建立的Model对象是否 不可改变  即生成的Model对象不会有 setter方法，只有构造方法 -->
                        <property name="immutable" value="false"/>
                </javaModelGenerator>

                <!--Mapper映射文件生成所在的目录 为每一个数据库的表生成对应的SqlMap文件 -->
                <sqlMapGenerator targetPackage="/mapper"
                                 targetProject="src/main/resources">
                        <property name="enableSubPackages" value="false"/>
                </sqlMapGenerator>

                <!-- 客户端代码，生成易于使用的针对Model对象和XML配置文件 的代码
                        type="ANNOTATEDMAPPER",生成Java Model 和基于注解的Mapper对象
                        type="MIXEDMAPPER",生成基于注解的Java Model 和相应的Mapper对象
                        type="XMLMAPPER",生成SQLMap XML文件和独立的Mapper接口
                -->
                <javaClientGenerator targetPackage="com.zc.ssm_market.mapper"
                                     targetProject="src/main/java" type="XMLMAPPER">
                        <property name="enableSubPackages" value="true"/>
                </javaClientGenerator>


                <table tableName="user" domainObjectName="User"
                enableCountByExample="false" enableUpdateByExample="false"
                enableDeleteByExample="false" enableSelectByExample="false"
                selectByExampleQueryId="true">
                </table>
                <table tableName="vip" domainObjectName="Vip"
                enableCountByExample="false" enableUpdateByExample="false"
                enableDeleteByExample="false" enableSelectByExample="false"
                selectByExampleQueryId="false">
                </table>

             <!--根据自己的表添加和修改table标签 -->
              
                
        </context>
</generatorConfiguration>

3.config.propertites代码如下：

#JDBC
#驱动jar包所在的本地位置
jdbc.driverLocation=F:\\javasoft\\repository-maven\\repository-maven\\mysql\\mysql-connector-java\\5.1.21\\mysql-connector-java-5.1.21.jar
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/market?useUnicode=true&characterEncoding=UTF-8
jdbc.username=root
jdbc.password=root
c3p0.maxPoolSize=30
c3p0.minPoolSize=10
c3p0.autoCommitOnClose=false
c3p0.checkoutTimeout=10000
c3p0.acquireRetryAttempts=2

4.创建启动类Startup 和自定义注解类MyCommentGenerator

5.启动类Startup 代码：

package com.zc.ssm_market.common;


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;

import java.io.IOException;
import java.io.InputStream;
import java.net.URISyntaxException;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

/**
 * @Author:
 * @Date:2018-11-26
 */
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");//配置文件地址
            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();
        }
    }
}

6.自定义注解类MyCommentGenerator代码：（若配置为默认注解方式直接可以省略这步）

package com.zc.ssm_market.common;


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

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

/**
 * mybatis自动生成获取数据库的注释
 */
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());
    }
    @Override
    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.
     */
    @Override
    public void addComment(XmlElement xmlElement) {
        return;
    }

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

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

    }

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

    }

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

    }

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

    }

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

    }

    @Override
    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(" */");
    }

    @Override
    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().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(" */");
    }
}