Springboot学习笔记

最新推荐文章于 2023-07-06 09:35:31 发布

多啦不能没有梦

最新推荐文章于 2023-07-06 09:35:31 发布

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文章标签： spring boot 学习 java

本文链接：https://blog.youkuaiyun.com/qq_52117632/article/details/125048441

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六、用lombok插件获取get，set和toString方法

一、Hello Spring boot

1.1pom包

  <properties>
        <java.version>1.8</java.version>
    </properties>
    <parent>
        <artifactId>spring-boot-starter-parent</artifactId>
        <groupId>org.springframework.boot</groupId>
        <version>2.1.5.RELEASE</version>
    </parent>
    <dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    </dependencies>

1.2启动类

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

1.3Controller层

@RestController
public class HelloController {
    @GetMapping("hello")
    public String hello(){
        return "hello spring boot";
    }
}

二、连接数据库（方法一）

2.1pom包

在一的pom包中增添如下内容：

    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>1.1.6</version>
    </dependency>

2.2配置类

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/test
jdbc.username=root
jdbc.password=xxxxxx

2.3配置文件

@Configuration //声明是配置类
@PropertySource("classpath:jdbc.properties")
public class JdbcConfig {
    @Value("${jdbc.url}")
    String url;
    @Value("${jdbc.driverClassName}")
    String driverClassName;
    @Value("${jdbc.username}")
    String username;
    @Value("${jdbc.password}")
    String password;
    @Bean
    public DataSource dataSource(){
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driverClassName);
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        return dataSource;
    }
}

3.3Controller层

@RestController
public class HelloController {
    @Autowired
    private DataSource dataSource;
    @GetMapping("hello")
    public String hello(){
        System.out.println("dataSource"+dataSource);
        return "hello spring boot";
    }
}

三、连接数据库（方法二，相对简洁）

3.1配置类

3.2配置文件

@Configuration //声明是配置类
public class JdbcConfig {
    @Bean
    @ConfigurationProperties(prefix = "jdbc")
    public DataSource dataSource(){
          return new DruidDataSource();
    }
}

四、连接数据库（方法三）

4.1JdbcProperties

@ConfigurationProperties(prefix = "jdbc")
public class JdbcProperties {
    private String url;
    private String driverClassName;
    private String username;
    private String password;

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    public String getDriverClassName() {
        return driverClassName;
    }

    public void setDriverClassName(String driverClassName) {
        this.driverClassName = driverClassName;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

4.2JdbcConfig

@Configuration //声明是配置类
@EnableConfigurationProperties(JdbcProperties.class)
public class JdbcConfig {

    @Bean
    public DataSource dataSource(JdbcProperties jdbc){
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(jdbc.getDriverClassName());
        dataSource.setUrl(jdbc.getUrl());
        dataSource.setUsername(jdbc.getUsername());
        dataSource.setPassword(jdbc.getPassword());
        return dataSource;
    }
}

五、配置多个yml文件

5.1yml文件

5.2Controller层：

@RestController
public class HelloController {

    @Value("${duobaoyu.url}")
    private String yuUrl;
    @Value("${zhashutiao.url}")
    private String shutiaoUrl;
    @GetMapping("hello")

     public String hello(){
        System.out.println("duobaoyuurl="+yuUrl);
        System.out.println("shutiaourl="+shutiaoUrl);
        return "hello spring boot";
     }
}

六、用lombok插件获取get，set和toString方法

6.1安装插件

6.2导入pom坐标

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

6.3实体类

@Data
public class User {
    private Long id;
    // 用户名
    private String userName;
    // 密码
    private String password;
    // 姓名
    private String name;
    // 年龄
    private Integer age;
    // 性别，1男性，2女性
    private Integer sex;
    // 出生日期
    private Date birthday;
    // 创建时间
    private Date created;
    // 更新时间
    private Date updated;
    // 备注
    private String note;
    // getter和setter省略
}

加了@Data注解，实体类就无需添加get，set和toString方法，用的时候lombox插件会自动生成。

七、设置拦截器

@Slf4j
public class MyInterceptor implements HandlerInterceptor  {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        log.debug("这是MyInterceptor拦截器的preHandle方法");
        return HandlerInterceptor.super.preHandle(request, response, handler);
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        log.debug("这是MyIntercepor拦截器的postHandle方法");
        HandlerInterceptor.super.postHandle(request, response, handler, modelAndView);
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        log.debug("这是MyIntercepor拦截器的afterCompletion方法");
        HandlerInterceptor.super.afterCompletion(request, response, handler, ex);
    }
}

@Configuration
public class MvcConfig implements WebMvcConfigurer {

    /*
    将拦截器注册到Spirng ioc容器里
     */
    @Bean
    public MyInterceptor myInterceptor(){
        return new MyInterceptor();
    }

    @Override
    public void addInterceptors(InterceptorRegistry registry){
        registry.addInterceptor(myInterceptor()).addPathPatterns("/*");
    }
}

yml：

logging:
  level:
    com.bukaedu: debug
    org.springframework: info

八、查询操作

8.1配置文件

application.properties:

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/test
jdbc.username=root
jdbc.password=xxxxxx

application.yml:

spring:
  profiles:
    active: abc,def
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/test
    username: root
    password: xxxxxx
  redis:
    host: localhost
    port: 6379

server:
  port: 80
logging:
  level:
    com.bukaedu: debug
    org.springframework: info
mybatis:
  type-aliases-package: com.bukaedu.pojo
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

8.2pojo

@Data
@Table(name="tb_user")
public class User {
    @Id
    @KeySql(useGeneratedKeys = true)
    private Long id;
    // 用户名
    private String userName;
    // 密码
    private String password;
    // 姓名
    private String name;
    // 年龄
    private Integer age;
    // 性别，1男性，2女性
    private Integer sex;
    // 出生日期
    private Date birthday;
    // 创建时间
    private Date created;
    // 更新时间
    private Date updated;
    // 备注
    private String note;
    // getter和setter省略
}

8.3Mapper

public interface UserMapper extends Mapper<User> {
}

8.4Service

@Service
public class UserService {
    @Autowired
    private UserMapper userMapper;
    public User queryById(Long id){
        return userMapper.selectByPrimaryKey(id);

    }
    @Transactional
    public void savaUser(User user){
        userMapper.insertSelective(user);
        System.out.println("新增用户");
    }
}

8.5Controller

@RestController
public class HelloController {

   @Autowired
   private UserService userService;

   @GetMapping("/user/{id}")
     public User hello(@PathVariable Long id){
       return userService.queryById(id);
     }
}

8.6启动类

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

九、单元测试

@RunWith(SpringRunner.class)
@SpringBootTest
public class UserTest {
    @Autowired
    private UserService userService;
    @Test
    public void queryById(){
        User user=userService.queryById(1L);
        System.out.println("user="+user);
    }
    @Test
    public void saveUser(){
        User user=new User();
        user.setUserName("test");
        userService.savaUser(user);
    }
}