SpringBoot學習筆記_ZenDei技術網路在線

這次的學習以一個簡單的Student Demo為示例。 1、代碼：主程式類DemoApplication.java。 1 package com.julion.demo; 2 3 import org.springframework.boot.SpringApplication; 4 import ...

這次的學習以一個簡單的Student Demo為示例。

1、代碼：

主程式類DemoApplication.java。

 1 package com.julion.demo;
 2 
 3 import org.springframework.boot.SpringApplication;
 4 import org.springframework.boot.autoconfigure.SpringBootApplication;
 5 
 6 @SpringBootApplication
 7 public class DemoApplication {
 8 
 9     public static void main(String[] args) {
10 
11         SpringApplication.run(DemoApplication.class, args);
12 
13     }
14 }

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實體類Student.java。

 1 package com.julion.demo.domain;
 2 
 3 import javax.persistence.Entity;
 4 import javax.persistence.GeneratedValue;
 5 import javax.persistence.Id;
 6 import javax.validation.constraints.Min;
 7 
 8 @Entity
 9 public class Student {
10 
11     @Id
12     @GeneratedValue
13     private int id;
14 
15     @Min(value = 10, message = "未滿10歲不來塞")
16     private int age;
17 
18     private String name;
19 
20     public Student(){
21 
22     }
23 
24     public int getId() {
25         return id;
26     }
27 
28     public void setId(int id) {
29         this.id = id;
30     }
31 
32     public int getAge() {
33         return age;
34     }
35 
36     public void setAge(int age) {
37         this.age = age;
38     }
39 
40     public String getName() {
41         return name;
42     }
43 
44     public void setName(String name) {
45         this.name = name;
46     }
47 }

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結果類Result.java。

 1 package com.julion.demo.domain;
 2 
 3 public class Result<T> {
 4 
 5     private int code;
 6 
 7     private String message;
 8 
 9     private T data;
10 
11     public int getCode() {
12         return code;
13     }
14 
15     public void setCode(int code) {
16         this.code = code;
17     }
18 
19     public String getMessage() {
20         return message;
21     }
22 
23     public void setMessage(String message) {
24         this.message = message;
25     }
26 
27     public T getData() {
28         return data;
29     }
30 
31     public void setData(T data) {
32         this.data = data;
33     }
34 }

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數據相關類StudentRepository.java。

 1 package com.julion.demo.repository;
 2 
 3 import com.julion.demo.domain.Student;
 4 import org.springframework.data.jpa.repository.JpaRepository;
 5 
 6 import java.util.List;
 7 
 8 public interface StudentRepository extends JpaRepository<Student, Integer> {
 9 
10     public List<Student> findByAge(int age);
11 
12 }

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控制類StudentController.java。

 1 package com.julion.demo.controller;
 2 
 3 import com.julion.demo.domain.Result;
 4 import com.julion.demo.domain.Student;
 5 import com.julion.demo.repository.StudentRepository;
 6 import com.julion.demo.util.ResultUtil;
 7 import org.springframework.beans.factory.annotation.Autowired;
 8 import org.springframework.validation.BindingResult;
 9 import org.springframework.web.bind.annotation.*;
10 
11 import javax.validation.Valid;
12 import java.util.List;
13 
14 @RestController
15 public class StudentController {
16 
17     @Autowired
18     private StudentRepository studentRepository;
19 
20     @GetMapping(value = "/student")
21     public List<Student> getList(){
22         return studentRepository.findAll();
23     }
24 
25     @PostMapping(value = "/student")
26     public Result<Student> insert(@Valid Student student, BindingResult bindingResult){
27         if (bindingResult.hasErrors()){
28             return ResultUtil.error(1, bindingResult.getFieldError().getDefaultMessage());
29         }
30 
31         return ResultUtil.success(studentRepository.save(student));
32     }
33 
34     @GetMapping(value = "/student/{id}")
35     public Student getOne(@PathVariable("id") int id){
36         return studentRepository.findOne(id);
37     }
38 
39     @PutMapping(value = "/student/{id}")
40     public Student updateOne(@PathVariable("id") int id,
41                              @RequestParam("age") int age,
42                              @RequestParam("name") String name){
43         Student student = new Student();
44         student.setName(name);
45         student.setId(id);
46         student.setAge(age);
47 
48         return studentRepository.save(student);
49     }
50 
51     @DeleteMapping(value = "/student/{id}")
52     public void deleteOne(@PathVariable("id") int id){
53         studentRepository.delete(id);
54     }
55 
56     @GetMapping(value = "student/age/{age}")
57     public List<Student> getOneByAge(@PathVariable("age") int age){
58         return studentRepository.findByAge(age);
59     }
60 
61 }

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AOP相關類HttpAspect.java。

 1 package com.julion.demo.aspect;
 2 
 3 
 4 import com.julion.demo.domain.Student;
 5 import org.aspectj.lang.JoinPoint;
 6 import org.aspectj.lang.annotation.*;
 7 import org.slf4j.Logger;
 8 import org.slf4j.LoggerFactory;
 9 import org.springframework.stereotype.Component;
10 import org.springframework.web.context.request.RequestContextHolder;
11 import org.springframework.web.context.request.ServletRequestAttributes;
12 
13 import javax.servlet.http.HttpServletRequest;
14 
15 @Aspect
16 @Component
17 public class HttpAspect {
18 
19     private static final Logger logger = LoggerFactory.getLogger(HttpAspect.class);
20 
21     @Pointcut("execution(public * com.julion.demo.controller.StudentController.*(..))")
22     public void log(){
23     }
24 
25     @Before("log()")
26     public void doBefore(JoinPoint joinPoint){
27         logger.info("i am before");
28         ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
29         HttpServletRequest request = attributes.getRequest();
30 
31         //url
32         logger.info("url={}", request.getRequestURL());
33 
34         //method
35         logger.info("method={}", request.getMethod());
36 
37         //ip
38         logger.info("ip={}",request.getRemoteAddr());
39 
40         //類方法
41         logger.info("class_method={}", joinPoint.getSignature().getDeclaringTypeName() + "." + joinPoint.getSignature().getName());
42 
43         //參數
44         logger.info("args={}", joinPoint.getArgs());
45     }
46 
47     @After("log()")
48     public void doAfter(){
49         logger.info("i am after");
50     }
51 
52     @AfterReturning(returning = "object", pointcut = "log()")
53     public void doAfterReturning(Object object){
54         logger.info("response={}", object.toString());
55     }
56 
57 }

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結果工具類ResultUtil.java。

 1 package com.julion.demo.util;
 2 
 3 import com.julion.demo.domain.Result;
 4 
 5 public class ResultUtil {
 6 
 7     public static Result success(Object object){
 8         Result result = new Result();
 9         result.setCode(0);
10         result.setMessage("成功");
11         result.setData(object);
12         return result;
13     }
14 
15     public static Result success(){
16         return success(null);
17     }
18 
19     public static Result error(int code, String message){
20         Result result = new Result();
21         result.setCode(code);
22         result.setMessage(message);
23         result.setData(null);
24         return result;
25     }
26 
27 }

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配置文件application.properties。

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

spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/dbdemo
spring.datasource.username=root
spring.datasource.password=root

spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true

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2、關於註解：

1) @Entity：註明是實體類。

2) @Aspect：註明是切麵。

@PointCut：標註controller的切點。

@Before：在controller切點前進行。

@After：在controller切點後進行。

@AfterReturning：在controller返回後進行。

3) @RestController：註明是controller。與@Controller和@ResponseBody同時註解的功能相當。

@Autowired：註入。

@GetMapping：註明是Get方法。用以查詢。

@PostMapping：註明是Post方法。用以增加。

@PutMapping：註明是Put方法。用以更新。

@DeleteMapping：註明是Delete方法。用以刪除。

@RequestMapping：註明是請求。

@PathVairable：用以獲取形如/xxx/value格式中的value。

@RequestParam：用以獲取形如?key=value中的value。

4) @Service：註明是Service。

@Component：註明是Component。