Java的generator工具类，数据库生成实体类和映射文件

Posted 2021-09-28 明金同学

首先需要几个jar包：

freemarker-2.3.23.jar

log4j-1.2.16.jar

mybatis-3.2.3.jar

mybatis-generator-core-1.3.2.jar

mysql-connector-java-5.1.28-bin.jar

ojdbc14.jar

这些jar包网上都有下载的地方

xml配置文件：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">
<!-- 配置生成器 -->
<generatorConfiguration>
	<!-- 生成复杂的xml文件 -->
	<context id="MySQLContext" targetRuntime="MyBatis3Simple" defaultModelType="flat">
		<!-- 配置前置分隔符和后置分隔符 -->
		<property name="beginningDelimiter" value="`"/>
		<property name="endingDelimiter" value="`"/>
		<!-- 配置注释信息 -->
		<commentGenerator>
			<!-- 不生成注释 -->
			<property name="suppressAllComments" value="true"/>
			<property name="suppressDate" value="true"/>
			<property name="addRemarkComments" value="true"/>
		</commentGenerator>
		<!-- 数据库连接配置 -->
		<jdbcConnection driverClass="com.mysql.jdbc.Driver" 
				connectionURL="jdbc:mysql://localhost:3306/logisticsDB"
				userId="root" password="123456">
		</jdbcConnection>
		
		<!-- targetPackage：生成实体类存放的包名， targetProject：指定目标项目路径，可以使用相对路径或绝对路径 -->
		<javaModelGenerator targetPackage="com.entity" targetProject="src">
			<property name="trimStrings" value="true"/>
		</javaModelGenerator>
		
		<!-- 配置SQL映射器Mapper.xml文件的属性 -->
		<sqlMapGenerator targetPackage="com.dao" targetProject="src"/>
		
		<!-- type="XMLMAPPER"：所有的方法都在XML中，接口调用依赖XML文件 -->
		<javaClientGenerator targetPackage="com.dao" type="XMLMAPPER" 
								targetProject="src"/>
								
		<!-- 生成所有表的映射 -->
		<table tableName="%"></table>		
	</context>
</generatorConfiguration>

Java：Generator类

package generator;

import java.io.IOException;
import java.io.InputStream;
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 Generator {
	/*
	 * targetRuntime="MyBatis3Simple", 不生成Example
	 */
	public void generateMyBatis() {
		// MBG执行过程中的警告信息
		List<String> warnings = new ArrayList<String>();
		// 当生成的代码重复时，覆盖原代码
		boolean overwrite = true;
		String generatorFile = "/generatorConfig.xml";
		// String generatorFile = "/generator/generatorConfigExample.xml";
		// 读取MBG配置文件
		InputStream is = Generator.class.getResourceAsStream(generatorFile);

		ConfigurationParser cp = new ConfigurationParser(warnings);
		Configuration config;
		try {
			config = cp.parseConfiguration(is);
			DefaultShellCallback callback = new DefaultShellCallback(overwrite);
			// 创建MBG
			MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
			// 执行生成代码
			myBatisGenerator.generate(null);
		} catch (IOException e) {
			e.printStackTrace();
		} catch (XMLParserException e) {
			e.printStackTrace();
		} catch (InvalidConfigurationException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
		for (String warning : warnings) {
			System.out.println(warning);
		}
	}

	public static void main(String[] args) {
		Generator generator = new Generator();
		generator.generateMyBatis();
	}
}