spring boot

spring boot

配置文件：

格式一：

application.properties

例如：添加全局訪問路徑和修改 Tomcat 的端口號

server.context-path=/demo
server.port=8081

格式二：

  • 系統屬性 application.yml

    例如：添加全局訪問路徑 和 修改 Tomcat 的端口號

    server:
  context-path: /demo
  port: 8081

  • 自定義屬性：application.yml

    age: 18 # 自定義屬性
name: inke # 自定義屬性
content: "name:${name},age:${age}" #配置引用配置

    在代碼中引用 HelloController.java

    @Value("${age}")
private Integer age;//@value可以獲取application.yml配置的值

@RestController
public class HelloController {
}

  • 類和屬性關聯

    application.yml

    person:
  age: 18 # 自定義屬性
  name: inke # 自定義屬性

    Person.java

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

    public String getName() {
        return name;
    }

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

    public Integer getAge() {
        return age;
    }

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

    在代碼中引用 HelloController.java

    @RestController
public class HelloController {

//    @Value("${age}")
//    private Integer age;
//
//    @Value("${content}")
//    private String content;

    @Autowired
    private Person person;

    @RequestMapping(value = "/hello")
    public String sayHello() {
        return "hello world name:" + person.getName() + " , age:" + person.getAge();
    }
}

多個配置文件切換

application.yml 通過 active 指定的屬性的環(huán)境：dev 還是 prod

spring:
  profiles:
    active: prod

application-dev.yml

person:
  age: 18 # 自定義屬性
  name: dev001 # 自定義屬性

application-prod.yml

person:
  age: 18 # 自定義屬性
  name: prod001 # 自定義屬性

啟動的時候，會根據 active 指定的環(huán)境屬性文件進行加載。


Controller

示例：

HelloController

package com.example;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {

    @Value("${age}")
    private Integer age;//@value可以獲取application.yml配置的值

    @RequestMapping(value = "/hello")
    public String sayHello() {
        return "hello world age:" + age;
    }
}

application.yml

age: 18


常用注解

@RestController = @Controller + @ResponseBody
@Controller需要返回 template 模版，類似于 Django 的模板。
建議使用：@RestController


映射多個路徑

  • 單個映射：@RequestMapping(value = "/hello") 
@RequestMapping(value = "/hello")
public String sayHello() {
   return "hello world name:" + person.getName() + " , age:" + person.getAge();
}
  • 多個映射：@RequestMapping(value = {"hello", "hi"}) 
@RequestMapping(value = {"hello", "hi"})
public String sayHello() {
   return "hello world name:" + person.getName() + " , age:" + person.getAge();
}
  • 整個 controller 增加映射，在類上增加：@RequestMapping(value = "/demo") 
@RestController
@RequestMapping(value = "/demo")
public class HelloController {

    @Autowired
    private Person person;

    @RequestMapping(value = {"hello", "hi"})
    public String sayHello() {
        return "hello world name:" + person.getName() + " , age:" + person.getAge();
    }
}


訪問方式：

  • method = RequestMethod.GET
  • method = RequestMethod.POST
  • ...
  • 簡便方式：
    • @GetMapping(value = "hello")
    • @PostMapping(value = "hello")
@RestController
@RequestMapping(value = "/demo")
public class HelloController {

    @Autowired
    private Person person;

    @RequestMapping(value = {"hello", "hi"}, method = RequestMethod.GET)
    //@GetMapping(value = "hello")
    public String sayHello() {
        return "hello world name:" + person.getName() + " , age:" + person.getAge();
    }
}

注意：什么都不寫，默認是 get 和 post 都可以訪問，但是不建議這樣做，需要明確指定訪問方式。


獲取訪問參數

  • 獲取 GET 的 URL 的參數和 POST 的 請求 body 參數

    • 字段field映射
    @RequestMapping(value = "hello", method = RequestMethod.GET)
public String sayHello(@RequestParam(value = "id", required = false, defaultValue = "0") Integer id) {
   return "id:" + id;
}
    • 實體 model 映射
    @PostMapping(value = "/addPerson")
public Person addPerson(Person person) {
   return personRespository.save(person);
}
  • 獲取 restfully 參數
@RequestMapping(value = "hello/{id}", method = RequestMethod.GET)
public String sayHello(@PathVariable("id") Integer id) {
   return "id:" + id;
}


數據庫

  • 準備工作，加入數據庫的配置和依賴

    pom.xml

    <dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
</dependency>

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

    application.yml

    spring:
  profiles:
    active: prod
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/springboot
    username: root
    password: root
  jpa:
    hibernate:
      ddl-auto: create
    show-sql: true

    Person.java

    @Entity
public class Person {

    @Id
    @GeneratedValue
    private Integer id;
    private String name;
    private Integer age;

    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 Integer getAge() {
        return age;
    }

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

    創(chuàng)建接口繼承JpaRepository，泛型使用的是

    public interface PersonRespository extends JpaRepository<Person, Integer> {
}

  • 單表簡單查詢

    HelloController.java

    @RestController
public class HelloController {

    @Autowired
    private PersonRespository personRespository;

    @PostMapping(value = "/addPerson")
    public Person addPerson(@RequestParam(value = "name") String name, @RequestParam(value = "age") Integer age) {
        Person person = new Person();
        person.setName(name);
        person.setAge(age);
        return personRespository.save(person);
    }
    
        @DeleteMapping(value = "/delPerson/{id}")
    public void delPerson(@PathVariable(value = "id") Integer id) {
        personRespository.delete(id);
    }

    @PutMapping(value = "/updatePerson")
    public Person updatePerson(@RequestParam(value = "id") Integer id, @RequestParam(value = "name") String name, @RequestParam(value = "age") Integer age) {
        Person person = new Person();
        person.setId(id);
        person.setName(name);
        person.setAge(age);
        return personRespository.save(person);
    }

    @GetMapping(value = "/findPerson/{id}")
    public Person findPerson(@PathVariable(value = "id") Integer id) {
        return personRespository.findOne(id);
    }

    @GetMapping(value = "/findPersons")
    public List<Person> findPerson() {
        return personRespository.findAll();
    }
}

  • 單表根據年齡查詢

    PersonRespository.java

    增加一個根據年齡查詢的抽象方法

    public interface PersonRespository extends JpaRepository<Person, Integer> {
    Person findByAge(Integer age);
}

    HelloController.java

    @RestController
public class HelloController {

    @Autowired
    private PersonRespository personRespository;

    @GetMapping(value = "/findPersonByAge/{age}")
    public Person findPersonByAge(@PathVariable(value = "age") Integer age) {
        return personRespository.findByAge(age);
    }
}


事務管理

在方法名稱上增加@Transactional，該方法就有事務管理了。

@Service
public class PersonService {

    @Autowired
    private PersonRespository personRespository;

    @Transactional
    public void insertTwo() {
        Person person = new Person();
        person.setName("jack");
        person.setAge(40);
        personRespository.save(person);

        Person person1 = new Person();
        person1.setName("rose");
        person1.setAge(30000);
        int a = 1 / 0;
        personRespository.save(person1);

    }
}


校驗

在 model 增加注解 @Min(value = 18,message = "不能小于18歲")

@Entity
public class Person {

    @Id
    @GeneratedValue
    private Integer id;
    private String name;
    
    @Min(value = 18,message = "不能小于18歲")
    private Integer age;

    。。。set、get 方法
}

在 controller 的 model 增加@Valid注解，同時可以BindingResult獲取校驗的信息。

@PostMapping(value = "/addPerson")
public Person addPerson(@Valid Person person, BindingResult bindingResult) {
   if (bindingResult.hasErrors()) {
       //輸出錯誤信息:不能小于18歲
       System.out.print(bindingResult.getFieldError().getDefaultMessage());
   }
   return personRespository.save(person);
}


AOP

  • 創(chuàng)建切面方式一：

    @Aspect
@Component
public class HttpAspect {


    @Before("execution(public * com.example.HelloController.*(..))")
    public void logBefore() {
        System.out.print("logBefore");
    }


    @After("execution(public * com.example.HelloController.*(..))")
    public void logAfter() {
        System.out.print("logAfter");
    }
}

  • 創(chuàng)建切面方式二：(抽取切點出來，減少重復代碼)

    @Aspect
@Component
public class HttpAspect {

    @Pointcut("execution(public * com.example.HelloController.*(..))")
    public void log() {

    }

    @Before("log()")
    public void logBefore() {
        System.out.print("logBefore");
    }


    @After("log()")
    public void logAfter() {
        System.out.print("logAfter");
    }
}

@Aspect
@Component
public class HttpAspect {

    public static Logger logger = LoggerFactory.getLogger(HttpAspect.class);

    @Pointcut("execution(public * com.example.HelloController.*(..))")
    public void log() {

    }

    @Before("log()")
    public void logBefore(JoinPoint joinPoint) {
        logger.info("logBefore");
        ServletRequestAttributes servletRequestAttributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        HttpServletRequest request = servletRequestAttributes.getRequest();
        logger.info("url={}", request.getRequestURL());
        logger.info("method={}", request.getMethod());
        logger.info("ip={}", request.getRemoteAddr());
        logger.info("class.method={}", joinPoint.getSignature().getDeclaringTypeName() + "." + joinPoint.getSignature().getName());
        logger.info("args={}", joinPoint.getArgs());
    }


    @After("log()")
    public void logAfter() {
        logger.info("logAfter");
    }

    @AfterReturning(returning = "object", pointcut = "log()")
    public void logAfterReturning(Object object) {
        logger.info("response={}", object.toString());
    }
}


輸出日志：

logBefore
url=http://localhost:8080/updatePerson
method=PUT
ip=0:0:0:0:0:0:0:1
class.method=com.example.HelloController.updatePerson
args=10
m person person0_ where person0_.id=?
logAfter
response=com.example.Person@34b98c82


日志

public static Logger logger = LoggerFactory.getLogger(HttpAspect.class);

    @Pointcut("execution(public * com.example.HelloController.*(..))")
    public void log() {

    }

    @Before("log()")
    public void logBefore() {
        logger.info("logBefore");
    }


    @After("log()")
    public void logAfter() {
        logger.info("logAfter");
    }


異常處理

定義常量枚舉：ResultEnum.java

public enum ResultEnum {

    UNKNOW(-1, "未知錯誤"),
    OKKK(100, "小于18歲"),
    NOOO(101, "大于50歲"),;

    private Integer code;
    private String msg;

    ResultEnum(Integer code, String mag) {
        this.code = code;
        this.msg = mag;
    }

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }

    public String getMag() {
        return msg;
    }

    public void setMag(String mag) {
        this.msg = mag;
    }
}

自定義異常類：PersonException.java

public class PersonException extends Exception {
    private Integer code;
    private String msg;

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public PersonException(ResultEnum resultEnum) {
        this.code = resultEnum.getCode();
        this.msg = resultEnum.getMag();
    }
}

定義返回結果類：ResultInfo.java

public class ResultInfo<T> implements Serializable {
    private int code;
    private String msg;
    private T data;

    public ResultInfo(int code, String msg) {
        this.code = code;
        this.msg = msg;
    }

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public T getData() {
        return data;
    }

    public void setData(T data) {
        this.data = data;
    }
}

全局異常處理類：ResultExceptionHandle.java

@ControllerAdvice
public class ResultExceptionHandle {

    @ExceptionHandler(value = Exception.class)
    @ResponseBody
    public ResultInfo handleException(Exception e) {
        if (e instanceof PersonException) {
            PersonException personException = (PersonException) e;
            return new ResultInfo(personException.getCode(), personException.getMsg());
        }
        return new ResultInfo(-1, "未知錯誤");
    }
}

Controller 正常調用，全局 Exception 會自動攔截處理 HelloController.java

@RestController
public class HelloController {
    @Autowired
    private PersonRespository personRespository;

    @PostMapping(value = "/addPerson")
    public Person addPerson(@Valid Person person, BindingResult bindingResult) throws Exception {
        if (bindingResult.hasErrors()) {
            //輸出錯誤信息
            System.out.print(bindingResult.getFieldError().getDefaultMessage());
        }
        return personService.save(person);
    }
}


單元測試

需要模擬 http 請求進行單元測試，類上要添加注解（@RunWith(SpringRunner.class)、@SpringBootTest、@AutoConfigureMockMvc），方法上也要添加注解（@Test），使用MockMvc進行請求模擬。

@RunWith(SpringRunner.class)
@SpringBootTest
@AutoConfigureMockMvc
public class PersonControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @Test
    public void findPerson() throws Exception {
        mockMvc.perform(MockMvcRequestBuilders.get("/findPersons")).andExpect(MockMvcResultMatchers.status().isOk()).andExpect(MockMvcResultMatchers.content().string("hello"));
    }
}

打包默認會運行所有單元測試，可以通過參數跳過單元測試。

最后編輯于 ：
?著作權歸作者所有,轉載或內容合作請聯系作者
【社區(qū)內容提示】社區(qū)部分內容疑似由AI輔助生成，瀏覽時請結合常識與多方信息審慎甄別。
平臺聲明：文章內容（如有圖片或視頻亦包括在內）由作者上傳并發(fā)布，文章內容僅代表作者本人觀點，簡書系信息發(fā)布平臺，僅提供信息存儲服務。

相關閱讀更多精彩內容

  • Spring Cloud為開發(fā)人員提供了快速構建分布式系統中一些常見模式的工具（例如配置管理，服務發(fā)現，斷路器，智...
    卡卡羅2017閱讀 136,578評論 19贊 139
  • 1. Java基礎部分 基礎部分的順序：基本語法，類相關的語法，內部類的語法，繼承相關的語法，異常的語法，線程的語...
    子非魚_t_閱讀 34,734評論 18贊 399
  • 集成mybatis [toc]簡書不支持目錄，截圖。 mybatis 注解方式 第一步：引入依賴包： build....
    inke閱讀 7,859評論 1贊 6
  • 朋友圈有一張圖片，說是一個人減肥的心理歷程。 她特別想減肥，整天羨慕別人細胳膊細腿的，，于是她就不停滴收集關于減肥...
    何耳閱讀 222評論 0贊 3
  • 莫扎特：第二十三鋼琴協奏曲 MOZART: Piano Concerto No.23 這首《第二十三鋼琴協奏曲》，...
    MU心閱讀 728評論 0贊 2

友情鏈接更多精彩內容