集成mybatis

[toc]
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mybatis 注解方式

• 第一步：引入依赖包： build.gradle

  buildscript {
      ext {
          springBootVersion = '1.5.4.RELEASE'
      }
      repositories {
          mavenCentral()
      }
      dependencies {
          classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
      }
  }
  
  apply plugin: 'java'
  apply plugin: 'eclipse'
  apply plugin: 'org.springframework.boot'
  
  version = '0.0.1-SNAPSHOT'
  sourceCompatibility = 1.8
  
  repositories {
      mavenCentral()
  }
  
  dependencies {
      compile('org.springframework.boot:spring-boot-starter')
      testCompile('org.springframework.boot:spring-boot-starter-test')
      
      compile 'mysql:mysql-connector-java'
      
      //配置mybatis 数据源
      compile("org.mybatis.spring.boot:mybatis-spring-boot-starter:1.3.0")
      testCompile('org.mybatis.spring.boot:mybatis-spring-boot-starter-test:1.3.0')
      
      //使用 Controller 的时候需要引入 web 包
      compile('org.springframework.boot:spring-boot-starter-web')
  }
  

• 第二步：数据库连接配置 application.yml

  spring:
    datasource:
      url: jdbc:mysql://localhost:3306/test?characterEncoding=utf8
      username: root
      password: root
  

• 第三步：增加包扫描 Mapper 文件，也可以在 xml 文件中配置，以下使用注解。

  @SpringBootApplication
  @MapperScan("com.example.demo.dao.mapper")
  public class App {
      public static void main(String[] args) {
          SpringApplication.run(App.class, args);
      }
  }
  

• 第四步：写 Mapper 接口，使用 mybatis 的注解

  public interface UserMapper {
  
      @Select("select * from person where id = #{id}")
      Person findByID(Integer id);
  
      //返回的Integer值是变化的行数，@Options()会填充到实体 person 中。
      @Insert("insert into person(name, age) values(#{name}, #{age})")
      @Options(useGeneratedKeys = true, keyProperty = "id")
      Integer addPerson(Person person);
  
  //    @Insert("insert into person(name, age) values(#{name}, #{age})")
  //    Integer addPerson(@Param("name") String name, @Param("age") Integer age);
  
      @Update("update person set name = #{name}, age = #{age} where id = #{id}")
      Integer updatePerson(@Param("name") String name, @Param("age") Integer age, @Param("id") int id);
  
      @Delete("delete from person where id = #{id}")
      Integer deletePerson(Integer id);
  
      @Select("select * from person")
      List<Person> findAllPage();
  
  }
  

---

mybatis xml方式

• 第一步：引入依赖包： build.gradle

  buildscript {
      ext {
          springBootVersion = '1.5.4.RELEASE'
      }
      repositories {
          mavenCentral()
      }
      dependencies {
          classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
      }
  }
  
  apply plugin: 'java'
  apply plugin: 'eclipse'
  apply plugin: 'org.springframework.boot'
  
  version = '0.0.1-SNAPSHOT'
  sourceCompatibility = 1.8
  
  repositories {
      mavenCentral()
  }
  
  dependencies {
      compile('org.springframework.boot:spring-boot-starter')
      testCompile('org.springframework.boot:spring-boot-starter-test')
      
      compile 'mysql:mysql-connector-java'
      
      //配置mybatis 数据源
      compile("org.mybatis.spring.boot:mybatis-spring-boot-starter:1.3.0")
      testCompile('org.mybatis.spring.boot:mybatis-spring-boot-starter-test:1.3.0')
      
      //使用 Controller 的时候需要引入 web 包
      compile('org.springframework.boot:spring-boot-starter-web')
  }
  

• 第二步：数据库连接配置 application.yml

  spring:
    datasource:
      url: jdbc:mysql://localhost:3306/test?characterEncoding=utf8
      username: root
      password: root
      
  mybatis:
      type-aliases-package: org.larry.springboot.entity
      mapper-locations: classpath:mapper/**/*.xml
      check-config-location: true
  

• 第三步：配置包扫描 Mapper 文件 Application.java

  @SpringBootApplication
  @MapperScan("com.example.demo.mapper")
  public class Application {
      public static void main(String[] args) {
          SpringApplication.run(Application.class, args);
      }
  }
  

• 第四步：测试代码

  创建model 和 Mapper 文件用于测试，但是可以使用 generator 自动生成。

  public class User {
      private Integer id;
  
      private String name;
  
      public User(Integer id, String name) {
          this.id = id;
          this.name = name;
      }
  
      public User() {
          super();
      }
  
      public Integer getId() {
          return id;
      }
  
      public void setId(Integer id) {
          this.id = id;
      }
  
      public String getName() {
          return name;
      }
  
      public void setName(String name) {
          this.name = name == null ? null : name.trim();
      }
  }
  

  public interface UserMapper {
      long countByExample(UserExample example);
  
      int deleteByExample(UserExample example);
  
      int deleteByPrimaryKey(Integer id);
  
      int insert(User record);
  
      int insertSelective(User record);
  
      List<User> selectByExample(UserExample example);
  
      User selectByPrimaryKey(Integer id);
  
      int updateByExampleSelective(@Param("record") User record, @Param("example") UserExample example);
  
      int updateByExample(@Param("record") User record, @Param("example") UserExample example);
  
      int updateByPrimaryKeySelective(User record);
  
      int updateByPrimaryKey(User record);
  
      @Select("select * from user")
      List<User> findAll();
  }
  

  @RestController
  public class UserContorller {
  
      @Autowired
      private UserMapper userMapper;
  
      @RequestMapping("/insert")
      public User insertUser() {
          User user = new User(null, "inke");
          userMapper.insert(user);
          return user;
      }
  
      @RequestMapping("/findAll")
      public List<User> findAll() {
          return userMapper.findAll();
      }
  }
  

---

分页查询 pagehelper

• 第一步：引入依赖包： build.gradle

  dependencies {
      compile('org.springframework.boot:spring-boot-starter')
      testCompile('org.springframework.boot:spring-boot-starter-test')
      compile 'org.springframework.boot:spring-boot-devtools'
   
      compile 'mysql:mysql-connector-java'
      
      //配置mybatis 数据源
      compile("org.mybatis.spring.boot:mybatis-spring-boot-starter:1.3.0")
      testCompile('org.mybatis.spring.boot:mybatis-spring-boot-starter-test:1.3.0')
      //pagehelper
      compile("com.github.pagehelper:pagehelper-spring-boot-starter:1.1.1")
      //mapper 使用 xml 的 mybatis 方式，需要引入下面的包，不然 dev-tools 会报错
      //compile("tk.mybatis:mapper-spring-boot-starter:1.1.1")
  }
  

• 第二步：数据库连接配置 application.yml

  server:
    port: 9010
  
  spring:
    datasource:
      url: jdbc:mysql://localhost:3306/test?characterEncoding=utf8
      username: root
      password: root
  
  mybatis:
      type-aliases-package: tk.mybatis.springboot.model
      mapper-locations: classpath:mapper/*.xml
  
  #mapper:
  #    mappers:
  #        - tk.mybatis.springboot.util.MyMapper
  #    not-empty: false
  #    identity: MYSQL
  
  pagehelper:
      helperDialect: mysql
      reasonable: true
      supportMethodsArguments: true
      params: count=countSql
  

• 第三步：测试代码

  @Test
  public void testFindAllPage() {
     // startPage(pageNum, pageSize);
     PageHelper.startPage(1, 3);
     List<Person> persons = userMapper.findAllPage();
     System.out.println("findAllPage:" + persons);
     PageInfo<Person> pageInfo = new PageInfo<>(persons);
     System.out.println("pageInfo:" + pageInfo);
     //获取返回的数据
     List<Person> lists = pageInfo.getList();
     for (Person person : lists) {
         System.out.println("person:" + person);
     }
  }
  

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