一、配置
<!-- Mybatis plus -->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.1.1</version>
</dependency>
<!-- 自动生成代码 -->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-generator</artifactId>
<version>3.1.1</version>
</dependency>
<!-- 模板引擎 -->
<dependency>
<groupId>org.apache.velocity</groupId>
<artifactId>velocity-engine-core</artifactId>
<version>2.1</version>
</dependency>
<!-- lombok -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.16.10</version>
</dependency>
二、生成代码类
package com.czhappy.wanmathapi.generate;
import com.baomidou.mybatisplus.core.toolkit.CollectionUtils;
import com.baomidou.mybatisplus.core.toolkit.StringPool;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.InjectionConfig;
import com.baomidou.mybatisplus.generator.config.*;
import com.baomidou.mybatisplus.generator.config.po.TableInfo;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import com.baomidou.mybatisplus.generator.engine.VelocityTemplateEngine;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.jdbc.core.JdbcOperations;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.SingleColumnRowMapper;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import javax.sql.DataSource;
import java.io.File;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class MysqlGenerator {
private static final String database = "wanmath";
private static final String url = "jdbc:mysql://localhost:3306/" + database
+ "?useUnicode=true&useSSL=false&characterEncoding=utf8&serverTimezone=UTC";
private static final String driverName = "com.mysql.jdbc.Driver";
private static final String userName = "root";
private static final String password = "root";
private static String basePath = "";
private static String mapperPath = "";
public static void main(String[] args) {
//生成代码，多张表用逗号分隔
generate("chenzheng","com.czhappy.wanmathapi", "tb_web_user");
}
/**
* 自动生成代码
* @param author 作者
* @param packageName 包名
* @param tableNames 表
*/
public static void generate(String author, String packageName, String... tableNames) {
// 全局配置
GlobalConfig gc = initGlobalConfig(author, packageName);
// 数据源配置
DataSourceConfig dsc = initDataSourceConfig();
// 包配置
PackageConfig pc = new PackageConfig().setParent(packageName);
// 模板引擎配置
VelocityTemplateEngine templateEngine = new VelocityTemplateEngine();
//每一个entity都需要单独设置InjectionConfig, StrategyConfig和TemplateConfig
Map<String, String> names = new JdbcRepository().getEntityNames(tableNames);
if (names == null || names.isEmpty()) {
return;
}
for (String tableName : names.keySet()) {
// 代码生成器
AutoGenerator mpg = new AutoGenerator();
mpg.setGlobalConfig(gc);
mpg.setDataSource(dsc);
mpg.setPackageInfo(pc);
mpg.setTemplateEngine(templateEngine);
// 自定义配置
InjectionConfig cfg = initInjectionConfig(packageName);
mpg.setCfg(cfg);
// 策略配置
StrategyConfig strategy = initStrategyConfig(tableName);
mpg.setStrategy(strategy);
// 模板配置
// mapper文件
String mapperFile = mapperPath
+ "/" + names.get(tableName) + "Mapper" + StringPool.DOT_XML;
TemplateConfig tc = initTemplateConfig(mapperFile);
mpg.setTemplate(tc);
//开始执行
mpg.execute();
}
}
/**
* 配置数据源
* @return
*/
private static DataSourceConfig initDataSourceConfig() {
return new DataSourceConfig()
.setUrl(url)
.setDriverName(driverName)
.setUsername(userName)
.setPassword(password);
}
/**
* 全局配置
* @return
*/
private static GlobalConfig initGlobalConfig(String author, String packageName) {
GlobalConfig gc = new GlobalConfig();
String tmp = MysqlGenerator.class.getResource("").getPath();
String codeDir = tmp.substring(0, tmp.indexOf("/target"));
basePath = codeDir + "/src/main/java";
mapperPath = codeDir + "/src/main/resources/mapper";
System.out.println("basePath = " + basePath + "\nmapperPath = " + mapperPath);
gc.setOutputDir(basePath);
gc.setAuthor(author);
gc.setOpen(false);
gc.setServiceName("%sService");
gc.setFileOverride(true);
return gc;
}
/**
* 自定义配置
* @param packageName
* @return
*/
private static InjectionConfig initInjectionConfig(String packageName) {
InjectionConfig cfg = new InjectionConfig() {
@Override
public void initMap() {
// to do nothing
}
};
List<FileOutConfig> focList = new ArrayList<>();
focList.add(new FileOutConfig("/templates/mapper.xml.vm") {
@Override
public String outputFile(TableInfo tableInfo) {
//自定义输入文件名称
return mapperPath
+ "/" + tableInfo.getEntityName() + "Mapper" + StringPool.DOT_XML;
}
});
cfg.setFileOutConfigList(focList);
return cfg;
}
/**
* 策略配置
* @param tableName 数据库表名
* @return
*/
private static StrategyConfig initStrategyConfig(String tableName) {
StrategyConfig strategy = new StrategyConfig();
strategy.setNaming(NamingStrategy.underline_to_camel);
strategy.setColumnNaming(NamingStrategy.underline_to_camel);
strategy.setEntityLombokModel(true);
//strategy.setTablePrefix("tb");
strategy.setInclude(tableName);
strategy.setRestControllerStyle(true);
return strategy;
}
/**
* 覆盖Entity以及xml
* @param mapperFile
* @return
*/
private static TemplateConfig initTemplateConfig(String mapperFile) {
TemplateConfig tc = new TemplateConfig();
tc.setXml(null);
//如果当前Entity已经存在,那么仅仅覆盖Entity
File file = new File(mapperFile);
System.out.println("file.exists()="+file.exists());
if (file.exists()) {
tc.setController(null);
tc.setMapper(null);
tc.setService(null);
tc.setServiceImpl(null);
tc.setEntityKt(null);
}
return tc;
}
public static class JdbcRepository {
private static Pattern linePattern = Pattern.compile("_(\\w)");
private JdbcOperations jdbcOperations;
public JdbcRepository() {
DataSource dataSource = DataSourceBuilder.create()
//如果不指定类型，那么默认使用连接池，会存在连接不能回收而最终被耗尽的问题
.type(DriverManagerDataSource.class)
.driverClassName(driverName)
.url(url)
.username(userName)
.password(password)
.build();
this.jdbcOperations = new JdbcTemplate(dataSource);
}
/**
* 获取所有实体类的名字,实体类由数据库表名转换而来.
* 例如: 表前缀为auth,完整表名为auth_first_second,那么entity则为FirstSecond
* @param tableNameArray 数据库表名,可能为空
* @return
*/
public Map<String, String> getEntityNames(String... tableNameArray) {
//该sql语句目前支持mysql
String sql = "SELECT table_name FROM INFORMATION_SCHEMA.TABLES WHERE table_schema = '" + database + "'";
if (tableNameArray != null && tableNameArray.length != 0) {
sql += " and (";
for (String name : tableNameArray) {
sql += " or table_name = '" + name + "'";
}
sql += ")";
}
sql = sql.replaceFirst("or", "");
List<String> tableNames = jdbcOperations.query(sql, SingleColumnRowMapper.newInstance(String.class));
if (CollectionUtils.isEmpty(tableNames)) {
return new HashMap<>();
}
Map<String, String> result = new HashMap<>();
tableNames.forEach(
tableName -> {
String entityName = underlineToCamel(tableName);
// String prefix = "tb";
// //如果有前缀,需要去掉前缀
// if (tableName.startsWith(prefix)) {
// String tableNameRemovePrefix = tableName.substring((prefix + "_").length());
// entityName = underlineToCamel(tableNameRemovePrefix);
// System.out.println("******"+entityName+"******");
// }
result.put(tableName, entityName);
}
);
return result;
}
/**
* 下划线转驼峰
*
* @param str
* @return
*/
private static String underlineToCamel(String str) {
if (null == str || "".equals(str)) {
return str;
}
str = str.toLowerCase();
Matcher matcher = linePattern.matcher(str);
StringBuffer sb = new StringBuffer();
while (matcher.find()) {
matcher.appendReplacement(sb, matcher.group(1).toUpperCase());
}
matcher.appendTail(sb);
str = sb.toString();
str = str.substring(0, 1).toUpperCase() + str.substring(1);
return str;
}
}
}
