SpringBoot+Mybatis-Plus 簡單樣例

下面是Mybatis-plus 的官方文檔,建議大家去參考官方文檔.
http://mp.baomidou.com/guide

1.引入依賴:

		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<scope>provided</scope>
		</dependency>

		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>mybatis-plus-boot-starter</artifactId>
			<version>3.0.6</version>
		</dependency>
		
		<dependency>
			<groupId>org.freemarker</groupId>
			<artifactId>freemarker</artifactId>
		</dependency>

本文中引入了lombok來簡化代碼,數據庫源爲mysql.

2.新建SpringBoot項目,在初始化的時候,引入Web和Mysql模塊.

3.配置application.properties

#mysql
spring.datasource.url=jdbc:mysql://localhost:3306/raynor?useUnicode=true&characterEncoding=utf8
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

4.測試

編寫Mapper類

package com.demo.mapper;
import com.demo.entity.User;
import org.apache.ibatis.annotations.Mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
@Mapper
public interface UserMapper extends BaseMapper<User> {
}

編寫實體類:

package com.demo.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import java.time.LocalDate;
import com.baomidou.mybatisplus.annotation.TableId;
import java.io.Serializable;
import lombok.Data;
import lombok.EqualsAndHashCode;
import lombok.experimental.Accessors;

@Data
@EqualsAndHashCode(callSuper = false)
@Accessors(chain = true)
public class User implements Serializable {
      private static final long serialVersionUID = 1L;
      @TableId(value = "u_id", type = IdType.AUTO)
       private Integer uId; 
	private String uAccount;
	private String uPassword;
	private LocalDate uCreatetime;
	private Integer uState;
}

編寫測試類(直接繼承SpringBoot初始的XXApplicationTests即可)

package com.demo;
import java.util.List;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;
import com.demo.entity.User;
import com.demo.mapper.UserMapper;
public class SampleTest extends  MybatisPlusApplicationTests{
    @Autowired
    private UserMapper userMapper;
    @Test
    public void testSelect() {
        System.out.println(("----- selectAll method test ------"));
        List<User> userList = userMapper.selectList(null);
        userList.forEach(System.out::println);
    }
}

Junit運行:

5.代碼生成器

package com.demo.generator;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import com.baomidou.mybatisplus.core.exceptions.MybatisPlusException;
import com.baomidou.mybatisplus.core.toolkit.StringPool;
import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.InjectionConfig;
import com.baomidou.mybatisplus.generator.config.DataSourceConfig;
import com.baomidou.mybatisplus.generator.config.FileOutConfig;
import com.baomidou.mybatisplus.generator.config.GlobalConfig;
import com.baomidou.mybatisplus.generator.config.PackageConfig;
import com.baomidou.mybatisplus.generator.config.StrategyConfig;
import com.baomidou.mybatisplus.generator.config.TemplateConfig;
import com.baomidou.mybatisplus.generator.config.po.TableInfo;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;

//演示例子，執行 main 方法控制檯輸入模塊表名回車自動生成對應項目目錄中
public class CodeGenerator {

 /**
  * <p>
  * 讀取控制檯內容
  * </p>
  */
 public static String scanner(String tip) {
     @SuppressWarnings("resource")
	Scanner scanner = new Scanner(System.in);
     StringBuilder help = new StringBuilder();
     help.append("請輸入" + tip + "：");
     System.out.println(help.toString());
     if (scanner.hasNext()) {
         String ipt = scanner.next();
         if (StringUtils.isNotEmpty(ipt)) {
             return ipt;
         }
     }
     throw new MybatisPlusException("請輸入正確的" + tip + "！");
 }

 public static void main(String[] args) {
     // 代碼生成器
     AutoGenerator mpg = new AutoGenerator();

     // 全局配置
     GlobalConfig gc = new GlobalConfig();
     String projectPath = System.getProperty("user.dir");
     gc.setOutputDir(projectPath + "/src/main/java");
     gc.setAuthor("Raynor");
     gc.setOpen(false);
     mpg.setGlobalConfig(gc);

     // 數據源配置
     DataSourceConfig dsc = new DataSourceConfig();
     dsc.setUrl("jdbc:mysql://localhost:3306/raynor?useUnicode=true&useSSL=false&characterEncoding=utf8");
     // dsc.setSchemaName("public");
     dsc.setDriverName("com.mysql.jdbc.Driver");
     dsc.setUsername("root");
     dsc.setPassword("123456");
     mpg.setDataSource(dsc);

     // 包配置
     PackageConfig pc = new PackageConfig();
     //pc.setModuleName(scanner("模塊名"));//不必要使用模塊名.
     pc.setParent("com.demo");
     mpg.setPackageInfo(pc);

     // 自定義配置
     InjectionConfig cfg = new InjectionConfig() {
         @Override
         public void initMap() {
             // to do nothing
         }
     };
     List<FileOutConfig> focList = new ArrayList<>();
     focList.add(new FileOutConfig("/templates/mapper.xml.ftl") {
         @Override
         public String outputFile(TableInfo tableInfo) {
             // 自定義輸入文件名稱
             return projectPath + "/src/main/resources/mapper/" + pc.getModuleName()
                     + "/" + tableInfo.getEntityName() + "Mapper" + StringPool.DOT_XML;
         }
     });
     cfg.setFileOutConfigList(focList);
     mpg.setCfg(cfg);
     mpg.setTemplate(new TemplateConfig().setXml(null));

     // 策略配置
     StrategyConfig strategy = new StrategyConfig();
     strategy.setNaming(NamingStrategy.underline_to_camel);
     strategy.setColumnNaming(NamingStrategy.underline_to_camel);
    // strategy.setSuperEntityClass("com.baomidou.ant.common.BaseEntity");
     strategy.setEntityLombokModel(true);
     strategy.setRestControllerStyle(true);
    // strategy.setSuperControllerClass("com.baomidou.ant.common.BaseController");
     strategy.setInclude(scanner("表名"));
     strategy.setSuperEntityColumns("id");
     strategy.setControllerMappingHyphenStyle(true);
     strategy.setTablePrefix(pc.getModuleName() + "_");
     mpg.setStrategy(strategy);
     mpg.setTemplateEngine(new FreemarkerTemplateEngine());//使用Freemarker模板引擎
     mpg.execute();
 }

}

如下鏈接中有更詳細的代碼生產配置的詳細內容
https://mp.baomidou.com/config/generator-config.html

運行以上main方法,會直接生成下述文件.

Mapper CRUD 接口

@Mapper
public interface UserMapper extends BaseMapper<User> {

}

Service CRUD 接口

@Service
public interface IUserService extends IService<User> {

}

編寫測試Controler類

package com.demo.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import com.demo.entity.User;
import com.demo.mapper.UserMapper;
import com.demo.service.IUserService;
@RestController
public class UserController {

	@Autowired
	IUserService  userServiceImpl;
	@Autowired
	UserMapper userMapper;
	@RequestMapping("/user")
	public User Sel() {
		User user =userServiceImpl.getById(1);
		return user;
	}
	
	
	@RequestMapping("/user2")
	public User Sel2() {
		User user = userMapper.selectById(1);
		return user;
	}
}

6.遇到的問題
Eclipse中使用lombok有個小小的BUG,引入依賴,並且增加註解@Data等編譯後的.class中沒有對應的代碼,比如set/get 方法.網上查到的更改org.apache.maven.plugins爲3.3版本,仍然不能生效,所幸查到 下述方法.
1.找到maven本地倉庫的org.projectlombok目錄,在該目錄下按住shift右鍵選擇在此處打開PowerShell或者CMD,執行 如下:

然後出現安裝程序

選擇你要安裝的Eclipse/STS的目錄的EXE文件,點擊Install/Update

重啓IDE即可.
在IDE中OutLine視圖中見到get/set等即可.