Spring Boot 必備註解

Spring Boot常用註解

項目配置

@Value(“${變量名}”)

變量名：配置文件中的全局變量

@Value("${name}")
private String name;
@Value("${desc}")
private String desc;

yml配置文件中的配置

name: 維吉爾
desc: 你好，${name}！

@ConfigurationProperties(prefix = “對象名”)

@ConfigurationProperties(prefix = “person”)註解要和@Component一起用

@Component
@ConfigurationProperties(prefix = "person")
public class Person {
    private String name;
    private int age;
    private String sex;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    @Override
    public String toString() {
        final StringBuffer sb = new StringBuffer("Person{");
        sb.append("name='").append(name).append('\'');
        sb.append(", age=").append(age);
        sb.append(", sex='").append(sex).append('\'');
        sb.append('}');
        return sb.toString();
    }
}

yml配置文件中的對象配置

person:
  name: Vigilr
  age: 23
  sex: 男

調用方式，會用到@Autowired和@GetMapping("/person")

@Autowired
private Person person;

@GetMapping("/person")
public String printPerson() {
    return this.person.toString();
}

請求方式

代碼	說明	舉例
@GetMapping("/url")	get請求	@GetMapping("/user/{id}")
@PostMapping("/url")	post請求	@PostMapping("/user")
@PutMapping("/url")	put請求	@PutMapping("/user/{id}")

Controller相關注解

@Controller

@Controller
public class HelloController {
    @GetMapping("/index")
    public String printIndex() {
        return "index";
    }
}

直接用可解析HTML

@ResponseBody

與@Controller配合使用

@Controller
public class HelloController {
    @GetMapping({"/hello", "hi"})
    @ResponseBody
    public String sayHello() {
        return desc;
    }
}

@RestController

@RestController=@Controller+@ResponseBody

@RestController
public class HelloController {
    @GetMapping({"/hello", "hi"})
    public String sayHello() {
        return desc;
    }
}

獲取參數

@PathVariable(“參數名”)

@GetMapping("/user/{id}")
public UserEntity findId(@PathVariable("id") Integer id) {
    return repository.findById(id).orElse(null);
}

@RequestParam(“參數名”)

@PostMapping("/user")
public UserEntity create(@RequestParam("age") Integer age,
                         @RequestParam("name") String name, @RequestParam("sex") String sex) {
    UserEntity userEntity = new UserEntity();
    userEntity.setAge(age);
    userEntity.setName(name);
    userEntity.setSex(sex);
    return repository.save(userEntity);
}

數據庫相關

@Entity

表的定義

@Id

設置主鍵

@GeneratedValue

設置自增

@Entity
public class UserEntity {
    @Id
    @GeneratedValue
    private Integer id;
    private String name;
    private String sex;
    private Integer age;

    public UserEntity() {
    }

    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;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

在IDEA中聲明@Entity後，左側會有數據庫的標誌

@Transactional

@Transactional
public void createTwo() {
    UserEntity userEntity1 = new UserEntity();
    userEntity1.setAge(12);
    userEntity1.setName("wasd");
    userEntity1.setSex("sssss");
    repository.save(userEntity1);

    UserEntity userEntity2 = new UserEntity();
    userEntity2.setAge(1314);
    userEntity2.setName("zxcvbnm");
    userEntity2.setSex("ddddddd");
    repository.save(userEntity2);
}

數據庫表的引擎必須爲INNODB纔可進行事務管理