【SpringBoot】整合 - JDBC、Mybatis、JPA

10.1 整合JDBC

10.2 整合Mybatis

 <dependency>
            <groupId>org.mybatis.spring.bootgroupId>
            <artifactId>mybatis-spring-boot-starterartifactId>
            <version>2.1.3version>
        dependency>

        <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>druidartifactId>
            <version>1.1.8version>
        dependency>

druid 数据源配置，在主配置文件yml文件中编写如下配置

spring:
  datasource:
#   数据源基本配置
    username: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://192.168.40.132:3306/db01
    type: com.alibaba.druid.pool.DruidDataSource
#   数据源其他配置
    initialSize: 5
    minIdle: 5
    maxActive: 20
    maxWait: 60000
    timeBetweenEvictionRunsMillis: 60000
    minEvictableIdleTimeMillis: 300000
    validationQuery: SELECT 1 FROM DUAL
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    poolPreparedStatements: true
#   配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙
    filters: stat,wall,log4j
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

# 使用xml文件配置时使用下面的配置映射到mybatis的配置文件位置
mybatis:
  # 指定全局配置文件位置
  config-location: classpath:mybatis/mybatis-config.xml
  # 指定sql映射文件位置
  mapper-locations: classpath:mybatis/mapper/*.xml

# 会自动加载该路径下得sql
#    schema:
#      - classpath:sql/department.sql
#      - classpath:sql/employee.sql

编写druid配置类

@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;
    }
}

注解版

加入domain类

编写dao层

@Mapper
public interface BookDao {
     

    @Select("select * from tb_book")
    public List<Book> findAll();

    @Select("select * from tb_book where id=#{id}")
    public Book findById(int id);

    @Options(useGeneratedKeys = true,keyProperty = "id")//主键自增长
    @Insert("insert into tb_book(id,name)values(#{id},#{name})")
    public void insert(Book book);

    @Delete("delete from tb_book where id=#{id} and name=#{name}")
    public void delete(Book book);

    @Update("update tb_book set name=#{name} where id=#{id}")
    public void update(Book book);

}

编写service层，此处省略，自行添加

编写controller层

@RestController
public class BookController {
     
    @Autowired
    BookService bookService;


    @GetMapping("/book/{id}")
    public Book findById(@PathVariable("id") int id){
     
        return bookService.findById(1);
    }
    @GetMapping("/book")
    public Book insert(Book book){
     
        bookService.insert(book);
        return book;
    }

//    @GetMapping("/book")
//    public void delete(Book book){
     
//        bookService.delete(book);
//    }
}

启动服务器

踩坑

如果启动程序时有如下报错，说明缺少log4j，导入依赖即可

		<dependency>
		    <groupId>log4jgroupId>
		    <artifactId>log4jartifactId>
		    <version>1.2.17version>
		dependency>

导入依赖后还出现警告，那就自己手动在resources目录下创建一个 log4j。properties文件

log4j.rootLogger=DEBUG, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

xml版

mybatis-3的官方文档，找到全局配置文件：https://mybatis.org/mybatis-3/getting-started.html

由于数据库的驱动链接等配置信息在yml主配置文件中都写完了，这里的配置就不用加了

<configuration>
 <settings>
     驼峰命名法的配置开启
     <setting name="mapUnderscoreToCamelCase" value="true"/>
 settings>
configuration>

设置一个全局配置文件，和一个mapper映射配置文件

编写dao层接口，和对应接口的mapper映射配置文件

//@Mapper 或者 @MapperScan 将接口扫描并装配到容器中
public interface StudentDao {
     

    public Student findById(Integer id);

    public void  insert(Student student);

}

<mapper namespace="zy.code.springboot06mybatis.dao.StudentDao">
    <select id="findById" parameterType="int" resultType="zy.code.springboot06mybatis.domain.Student">
    select * from student where id = #{id}
  select>

    <insert id="insert" parameterType="zy.code.springboot06mybatis.domain.Student">
        insert into student(id,name) values (#{id},#{name})
    insert>
mapper>

编写测试controller层，直接调用dao层，测试是否能够操作数据库成功

@RestController
public class StudentController {
     

    @Autowired
    StudentDao studentDao;

    @GetMapping("/stu/{id}")
    public Student findById(@PathVariable("id") Integer id){
     
        Student stu = studentDao.findById(id);
        return stu;
    }
    @GetMapping("/stu")
    public Student insert(Student student){
     
        studentDao.insert(student);
        return student;
    }

}

10.3 整合SpringData-JPA