1、JDBC

<dependency>
    <groupId>org.springframework.boot</groupId> 
    <artifactId>spring‐boot‐starter‐jdbc</artifactId> 
</dependency>
 <dependency>
     <groupId>mysql</groupId> 
    <artifactId>mysql‐connector‐java</artifactId>
     <scope>runtime</scope>
 </dependency>
spring: 
datasource: 
username: root 
password: 123456 
url: jdbc:mysql://192.168.15.22:3306/jdbc 
driver‐class‐name: com.mysql.jdbc.Driver
效果:
默认是用org.apache.tomcat.jdbc.pool.DataSource作为数据源;
数据源的相关配置都在DataSourceProperties里面;
自动配置原理:
org.springframework.boot.autoconfifigure.jdbc:
1、参考DataSourceConfifiguration,根据配置创建数据源,默认使用Tomcat连接池;
  可以使用spring.datasource.type指定自定义的数据源类型;
2、SpringBoot默认可以支持;
 
org.apache.tomcat.jdbc.pool.DataSource、HikariDataSource、BasicDataSource、
3、自定义数据源类型
/**
* Generic DataSource configuration. 
*/ 
@ConditionalOnMissingBean(DataSource.class) 
@ConditionalOnProperty(name = "spring.datasource.type") static class Generic {
  @Bean
  public DataSource dataSource(DataSourceProperties properties) {
  //使用DataSourceBuilder创建数据源,利用反射创建响应type的数据源,并且绑定相关属性
  return properties.initializeDataSourceBuilder().build();
  }
}
4、DataSourceInitializer:ApplicationListener;
作用:
1)、runSchemaScripts();运行建表语句;
2)、runDataScripts();运行插入数据的sql语句;
默认只需要将文件命名为:
schema‐*.sql、data‐*.sql 
默认规则:schema.sql,schema‐all.sql;
 可以使用
    schema:
     ‐ classpath:department.sql 
    指定位置    
5、操作数据库:自动配置了JdbcTemplate操作数据库

2、整合Druid数据源

导入druid数据源 
    @Configuration 
    public class DruidConfig { 
    @ConfigurationProperties(prefix = "spring.datasource") 
    @Bean 
    public DataSource druid(){ 
        return new DruidDataSource(); 
}
    //配置Druid的监控 
    //1、配置一个管理后台的Servlet 
    @Bean 
    public ServletRegistrationBean statViewServlet(){ 
    ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*"); 
    Map<String,String> initParams = new HashMap<>();
    initParams.put("loginUsername","admin");     
  initParams.put("loginPassword","123456");
   initParams.put("allow",""); //默认就是允许所有访问 initParams.put("deny","192.168.15.21"); bean.setInitParameters(initParams); return bean; } //2、配置一个web监控的filter @Bean public FilterRegistrationBean webStatFilter(){ FilterRegistrationBean bean = new FilterRegistrationBean();
bean.setFilter(new WebStatFilter());  Map<String,String> initParams = new HashMap<>();
  initParams.put("exclusions","*.js,*.css,/druid/*");
   bean.setInitParameters(initParams);
    bean.setUrlPatterns(Arrays.asList("/*"));
     return bean; } }

3、整合MyBatis

<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis‐spring‐boot‐starter</artifactId>
<version>1.3.1</version>
</dependency>

 

 

步骤:
1)、配置数据源相关属性(见上一节Druid)
2)、给数据库建表
3)、创建JavaBean

 

4)、注解版


//指定这是一个操作数据库的mapper

@Mapper
public interface DepartmentMapper {
   @Select("select * from department where id=#{id}")
  public Department getDeptById(Integer id);

   @Delete("delete from department where id=#{id}")
  public int deleteDeptById(Integer id);

  @Options(useGeneratedKeys = true,keyProperty = "id")
   @Insert("insert into department(departmentName) values(#{departmentName})")
  public int insertDept(Department department);

  @Update("update department set departmentName=#{departmentName} where id=#{id}")
  public int updateDept(Department department);
}
问题:
自定义MyBatis的配置规则;给容器中添加一个ConfifigurationCustomizer;
@org.springframework.context.annotation.Configuration
   public class MyBatisConfig {
     @Bean
    public ConfigurationCustomizer configurationCustomizer(){
    return new ConfigurationCustomizer(){

     @Override
     public void customize(Configuration configuration) {
     configuration.setMapUnderscoreToCamelCase(true);
}
};
}
}
使用MapperScan批量扫描所有的Mapper接口; 
@MapperScan(value = "com.atguigu.springboot.mapper")
@SpringBootApplication
public class SpringBoot06DataMybatisApplication {
public static void main(String[] args) {
    SpringApplication.run(SpringBoot06DataMybatisApplication.class, args);
}
}

5)、配置文件版

mybatis:
   config‐location: classpath:mybatis/mybatis‐config.xml 指定全局配置文件的位置
  mapper‐locations: classpath:mybatis/mapper/*.xml 指定sql映射文件的位置
更多使用参照

4、整合SpringData JPA

1)、SpringData简介

 

2)、整合SpringData JPA

JPA:ORM(Object Relational Mapping);
1)、编写一个实体类(bean)和数据表进行映射,并且配置好映射关系
//使用JPA注解配置映射关系 
@Entity
//告诉JPA这是一个实体类(和数据表映射的类)
@Table(name = "tbl_user")

//@Table来指定和哪个数据表对应;如果省略默认表名就是user;
public class User {
   @Id
//这是一个主键
   @GeneratedValue(strategy = GenerationType.IDENTITY)
//自增主键
  private Integer id;
  @Column(name = "last_name",length = 50)
//这是和数据表对应的一个列
   private String lastName;
  @Column
//省略默认列名就是属性名
  private String email;
2)、编写一个Dao接口来操作实体类对应的数据表(Repository)
//继承JpaRepository来完成对数据库的操作 
  public interface UserRepository extends JpaRepository<User,Integer> { }
3)、基本的配置JpaProperties
spring: 
  jpa:
  hibernate:
  # 更新或者创建数据表结构
    ddl‐auto: update
   # 控制台显示SQL
    show‐sql: true

 

 

 

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