Spring boot text tutorial series article directory

1. Spring boot picture and text tutorial 1 "concept + case mind map" and "basic chapter I"
2. Spring boot graphic tutorial 2 - use of log "logback" and "log4j"
3. Spring boot graphic tutorial 3 - "first love complex" integration
4. Spring boot picture and text tutorial 4 - spring boot implementation file upload and download
5. Spring boot graphic tutorial 5 - using Aop in spring boot
6. Spring boot picture and text tutorial 6 - use of filters in spring boot
7. Spring boot graphic tutorial 7 - the usage posture of spring boot interceptor

Preface

When using Mybatis for project development, the most tedious thing is to write entity class, dao interface and mapper.xml file. Almost every table needs to write a corresponding set, and most of the workload is in the most basic addition, deletion, modification and query. If the fields in the table are modified, the entity class, mapper file and even dao interface will be modified.

The world has been struggling with mapper files for a long time, so the official recommendation of Mybatis is a Mybatis code generator (MBG) to save people in the water and fire.

Mybatis code generator

MBG

MBG, the full name of MyBatis Generator, can be used to generate Mybatis development related code, including basic add, delete, modify and query entity classes, dao interfaces and mapper files. And the MBG tool supports all versions of Mybatis.

SpringBoot integrated MBG

1. Import dependency

To use MBG in spring boot, you need to import the startup plug-ins of MBG while importing MBG dependencies. MBG dependence

<!--MybatisGenerator Dependence jar package-->
<dependency>
			<groupId>org.mybatis.generator</groupId>
			<artifactId>mybatis-generator-core</artifactId>
			<version>1.3.2</version>
		</dependency>

Start plug-in of MBG

<!--MybatisGenerator Start plug-in for-->
			<plugin>
				<groupId>org.mybatis.generator</groupId>
				<artifactId>mybatis-generator-maven-plugin</artifactId>
				<version>1.3.2</version>
				<!--jar Package to generate corresponding class needs to connect to database data connection version consistent with that in project-->
				<dependencies>
					<dependency>
						<groupId>mysql</groupId>
						<artifactId>mysql-connector-java</artifactId>
						<version>5.1.38</version>
					</dependency>
				</dependencies>
				
				<configuration>
					<!--MBG Path to profile -->
					<configurationFile>${basedir}/src/main/resources/generatorConfig.xml</configurationFile>
					<overwrite>true</overwrite>
				</configuration>
			</plugin>

2. Import and write MBG configuration file

After importing dependencies, you need to import the configuration file generatorConfig.xml of MBG in the SpringBoot resources directory

Here are all the contents and comments of the configuration file

<?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="test" targetRuntime="MyBatis3">
        <plugin type="org.mybatis.generator.plugins.EqualsHashCodePlugin"></plugin>  
        <plugin type="org.mybatis.generator.plugins.SerializablePlugin"></plugin> 
        <plugin type="org.mybatis.generator.plugins.ToStringPlugin"></plugin>

        <commentGenerator>
            <!-- This element is used to remove the generated date from the specified generated comment false:Representation includes -->
            <!-- If a date is generated, even if a field is modified, all properties of the entire entity class will change, which is not conducive to version control. Therefore, it is set to true -->
            <property name="suppressDate" value="true" />
            <!-- Remove automatically generated comments or not true: Yes, false:no -->
            <property name="suppressAllComments" value="true" />

        </commentGenerator>

        <!--Database links URL，User name, password -->
        <jdbcConnection
                driverClass="com.mysql.jdbc.Driver"
                connectionURL="jdbc:mysql://localhost/demo"
                userId="root"
                password="123456">
        </jdbcConnection>

        <javaTypeResolver>
            <property name="forceBigDecimals" value="false" />
        </javaTypeResolver>

        <!-- Package name and location of the generated entity class -->
        <javaModelGenerator targetPackage="com.lu.entity"
            targetProject="src/main/java">
            <property name="enableSubPackages" value="true" />
            <property name="trimStrings" value="true" />
        </javaModelGenerator>

        <!--Package name and location of the build mapping file  com/lu/mapper-->
        <sqlMapGenerator targetPackage="mapper"
            targetProject="src/main/resources">
            <property name="enableSubPackages" value="true" />
        </sqlMapGenerator>

        <!-- generate DAO Package name and location for mybatis Two development models xml Annotation-->
        <javaClientGenerator type="XMLMAPPER"
            targetPackage="com.lu.dao" targetProject="src/main/java">
            <property name="enableSubPackages" value="true" />
        </javaClientGenerator>
        
        <!-- Which tables to generate -->
        <table tableName="user" domainObjectName="User"
               enableCountByExample="false" enableUpdateByExample="false"
               enableDeleteByExample="false" enableSelectByExample="false"
               selectByExampleQueryId="false">
        </table>

     

    </context>
</generatorConfiguration>

Key configuration!!!

In the configuration file, users need to configure according to their own conditions

1. Modify database connection parameters to their own database connection parameters

2. Configuration of location package structure for generating mapper file of dao interface entity class

1. Configure the entity class dao interface and mapper file corresponding to which tables to generate

3. Code can be generated by plug-in startup

Run the plug-in and generate the code as follows:

• Entity class

• dao interface

• mapper file

summary

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