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              Spring boot集成 MyBatis 通用Mapper
              2021-10-11 14:58:07

              Spring boot集成 MyBatis 通用Mapper

              配置

              POM文件

              <parent>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-parent</artifactId>
              <version>1.5.6.RELEASE</version>
              <relativePath />
              </parent>

              <properties>
              <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
              <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
              <java.version>1.8</java.version>
              </properties>

              <dependencies>
              <dependency>
              <groupId>tk.mybatis</groupId>
              <artifactId>mapper-spring-boot-starter</artifactId>
              <version>RELEASE</version>
              </dependency>
              <dependency>
              <groupId>com.github.pagehelper</groupId>
              <artifactId>pagehelper-spring-boot-starter</artifactId>
              <version>RELEASE</version>
              </dependency>
              <dependency>
              <groupId>mysql</groupId>
              <artifactId>mysql-connector-java</artifactId>
              </dependency>
              <dependency>
              <groupId>org.mybatis.spring.boot</groupId>
              <artifactId>mybatis-spring-boot-starter</artifactId>
              <version>1.3.1</version>
              </dependency>
              <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-jdbc</artifactId>
              </dependency>
              <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-test</artifactId>
              <scope>test</scope>
              </dependency>
              </dependencies>

              ?

              同一環(huán)境1.5.7.RELEASE版本的Spring-boot會拋Caused by: java.lang.IllegalStateException: Cannot load driver class: com.mysql.jdbc.Driver異常,1.5.6.RELEASE以及1.5.5.RELEASE版本親測沒問題



              application.properties配置文件

              #數(shù)據(jù)庫
              spring.datasource.url=jdbc:mysql://127.0.0.1:3306/test
              spring.datasource.username=root
              spring.datasource.password=741852
              spring.datasource.driver-class-name=com.mysql.jdbc.Driver

              #mybatis&&通用Mapper
              mybatis.type-aliases-package=com.karle.bean
              mybatis.mapper-locations=classpath:mapper/*.xml
              mapper.mappers=com.karle.tk.TkMapper
              mapper.identity=MYSQL

              #分頁插件
              pagehelper.helperDialect=mysql
              pagehelper.reasonable=true
              pagehelper.supportMethodsArguments=true
              pagehelper.params=count=countSql

              #log
              logging.file=logger.log
              logging.level.*=debug

              ?

              映射實體(省略字段get、set)

              import java.util.Date;

              import javax.persistence.Column;
              import javax.persistence.GeneratedValue;
              import javax.persistence.GenerationType;
              import javax.persistence.Id;
              import javax.persistence.Table;

              @Table(name = "user")
              public class User {

              @Id
              @GeneratedValue(strategy = GenerationType.IDENTITY)
              private Integer id;

              /**
              * 名稱
              */
              @Column(name = "name")
              private String name;

              /**
              * 年齡
              */
              @Column(name = "age")
              private Integer age;

              /**
              * 身份編號
              */
              @Column(name = "card_no")
              private Integer cardNo;

              /**
              * 生日
              */
              @Column(name = "birthday")
              private Date birthday;
              }

              ?

              本地通用Mapper接口(繼承通用Mapper接口)

              import tk.mybatis.mapper.common.Mapper;
              import tk.mybatis.mapper.common.MySqlMapper;

              public interface TkMapper<T> extends Mapper<T>, MySqlMapper<T> {

              }

              ?

              Mapper接口:基本的增、刪、改、查方法?

              MySqlMapper:針對MySQL的額外補充接口,支持批量插入

              業(yè)務接口(繼承“本地通用Mapper接口”)

              import org.apache.ibatis.annotations.Param;

              import com.karle.bean.User;
              import com.karle.tk.TkMapper;

              public interface UserMapper extends TkMapper<User> {

              public User selectByCardNo(@Param("cardNo") int cardNo);

              }

              ?

              Spring-boot啟動類,@MapperScan僅掃描業(yè)務接口包,不能掃描本地通用Mapper接口包,否則報java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class異常

              import org.mybatis.spring.annotation.MapperScan;
              import org.springframework.boot.SpringApplication;
              import org.springframework.boot.autoconfigure.SpringBootApplication;

              @SpringBootApplication
              @MapperScan(basePackages = { "com.karle.mapper" })
              public class SpringBootMyBatisApplication {

              public static void main(String[] args) {
              SpringApplication.run(SpringBootMyBatisApplication.class, args);
              }

              }

              ?

              通過使用@MapperScan可以指定要掃描的Mapper類的包的路徑,比如:

              Java代碼??

              1. @SpringBootApplication??
              2. @MapperScan("com.kfit.*.mapper")??
              3. public?class?App?{??
              4. ????public?static?void?main(String[]?args)?{??
              5. ???????SpringApplication.run(App.class,?args);??
              6. ????}??
              7. }??

              ?

              或者:

              Java代碼??

              1. @SpringBootApplication??
              2. @MapperScan("com.kfit.mapper")??
              3. public?class?App?{??
              4. ????public?static?void?main(String[]?args)?{??
              5. ???????SpringApplication.run(App.class,?args);??
              6. ????}??
              7. }??

              ?

              ???????可以根據(jù)包的結(jié)構(gòu)指定不同的表達式。

              ?

              使用@MapperScan注解多個包

              可以使用如下的方式指定多個包:

              Java代碼??

              1. @SpringBootApplication??
              2. @MapperScan({"com.kfit.demo","com.kfit.user"})??
              3. public?class?App?{??
              4. ????public?static?void?main(String[]?args)?{??
              5. ???????SpringApplication.run(App.class,?args);??
              6. ????}??
              7. }??

              ?

              ???????如果mapper類沒有在Spring Boot主程序可以掃描的包或者子包下面,可以使用如下方式進行配置:

              Java代碼??

              1. @SpringBootApplication??
              2. @MapperScan({"com.kfit.*.mapper","org.kfit.*.mapper"})??
              3. public?class?App?{??
              4. ????public?static?void?main(String[]?args)?{??
              5. ???????SpringApplication.run(App.class,?args);??
              6. ????}??
              7. } ?
              8. ?

              單元測試


              import java.util.ArrayList;
              import java.util.Date;
              import java.util.List;

              import org.junit.Test;
              import org.junit.runner.RunWith;
              import org.springframework.beans.factory.annotation.Autowired;
              import org.springframework.boot.test.context.SpringBootTest;
              import org.springframework.test.context.junit4.SpringRunner;

              import com.github.pagehelper.PageHelper;
              import com.karle.bean.User;
              import com.karle.mapper.UserMapper;

              @RunWith(SpringRunner.class)
              @SpringBootTest
              public class SpringBootMyBatisApplicationTests {

              @Autowired
              private UserMapper mapper;

              // 插入一條新記錄
              @Test
              public void insertOne() {
              User newUser = new User();
              int cardNo = (int) (Math.random() * 10000000);
              newUser.setAge(24);
              newUser.setBirthday(new Date());
              newUser.setName(cardNo + "用戶");
              newUser.setCardNo(cardNo);
              mapper.insertSelective(newUser);
              System.out.println("插入成功");
              }

              // 批量插入記錄
              @Test
              public void insertMore() {
              List<User> recordList = new ArrayList<User>();
              for (int i = 0; i < 2; i++) {
              User newUser = new User();
              int cardNo = (int) (Math.random() * 10000000);
              newUser.setAge(26);
              newUser.setBirthday(new Date());
              newUser.setName(cardNo + "批量插入用戶");
              newUser.setCardNo(cardNo);
              recordList.add(newUser);
              }
              mapper.insertList(recordList);
              System.out.println("批量插入成功");
              }

              // 根據(jù)唯一編號查詢用戶(通用Mapper查詢)
              @Test
              public void selectByCardNo() {
              User paramBean = new User();
              paramBean.setCardNo(6647403);
              User dbUser = mapper.selectOne(paramBean);
              if (dbUser != null) {
              System.out.println("數(shù)據(jù)庫用戶(通用Mapper查詢):" + dbUser.getName());
              return;
              }
              System.out.println("查無此用戶");
              }

              // 根據(jù)唯一編號查詢用戶(XML查詢)
              @Test
              public void selectByCardNoByXml() {
              User dbUser = mapper.selectByCardNo(6105967);
              if (dbUser != null) {
              System.out.println("數(shù)據(jù)庫用戶(XML查詢):" + dbUser.getName());
              return;
              }
              System.out.println("查無此用戶");
              }

              // 根據(jù)年齡查詢一組用戶
              @Test
              public void selectByAge() {
              User paramBean = new User();
              paramBean.setAge(24);
              List<User> dbUserList = mapper.select(paramBean);
              System.out.println("總共查詢數(shù):" + dbUserList.size());
              }

              // 分頁查詢用戶
              @Test
              public void selectByPage() {
              PageHelper.offsetPage(1, 5);
              List<User> dbUserList = mapper.select(null);
              for (User item : dbUserList) {
              System.out.println("分頁用戶:" + item.getName());
              }
              }

              // 更新用戶信息
              @Test
              public void updateOneInfo() {
              User paramBean = new User();
              paramBean.setId(1);
              paramBean.setAge(26);
              mapper.updateByPrimaryKeySelective(paramBean);
              System.out.println("更新成功");
              }

              }

              事物的使用

              spring Boot 使用事務非常簡單,首先使用注解???@EnableTransactionManagement??開啟事務支持后,然后在訪問數(shù)據(jù)庫的Service方法上添加注解???@Transactional???便可。

              ??@EnableTransactionManagement??放在啟動類上

              本文摘自 :https://blog.51cto.com/u

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