使用IDEA 從零開始搭建一個 Spring Boot + JPA + Swagger入門項目

我的gitee項目位址：https://gitee.com/hgqstudy/hgqstudy.git

文章目錄

- - - 1. 建立一個Spring Boot 項目
    - 2. 建立資料庫
    - 3. 在pom.xml檔案中引入maven依賴
    - 4. 編寫application.properties檔案
    - 5. 配置Swagger
    - 6. 編寫Json工具類,主要是把資料轉為json格式
    - 7. 編寫WebMvcConfig
    - 8. 主啟動類編寫
    - 9. 使用者實體類(CUserEntity)
    - 10. 位址實體類(CAddressEntity)
    - 11. 編寫CUserEntityRepository
    - 12. 編寫CAddressEntityRepository
    - 13. 編寫UserMessageWebController
    - 14. 編寫UserAddressWebController
    - 15. 最後測試一下
    - 16. 總結

1. 建立一個Spring Boot 項目

File -> New -> Project -> Spring Initializr -> Next -> Next -> Next ->Finish

2. 建立資料庫

CREATE DATABASE test;
USE test;

DROP TABLE IF EXISTS `c_user`;
CREATE TABLE `c_user`  (
  `id` int(0) NOT NULL AUTO_INCREMENT,
  `username` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL,
  `phone` varchar(18) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL,
  `create_at` date NULL DEFAULT NULL,
  `update_at` datetime(0) NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 5 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;

DROP TABLE IF EXISTS `c_address`;
CREATE TABLE `c_address`  (
  `id` int(0) NOT NULL AUTO_INCREMENT,
  `uid` int(0) NULL DEFAULT NULL,
  `address` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL,
  `create_at` date NULL DEFAULT NULL,
  `update_at` datetime(0) NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 1 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;

SET FOREIGN_KEY_CHECKS = 1;

3. 在pom.xml檔案中引入maven依賴

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

<dependency>
	<groupId>io.springfox</groupId>
	<artifactId>springfox-swagger-ui</artifactId>
	<version>2.7.0</version>
</dependency>

<dependency>
	<groupId>io.springfox</groupId>
	<artifactId>springfox-swagger2</artifactId>
	<version>2.7.0</version>
</dependency>

<dependency>
	<groupId>com.google.code.gson</groupId>
	<artifactId>gson</artifactId>
	<version>2.8.6</version>
</dependency>

<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<!--<scope>runtime</scope>-->
</dependency>

4. 編寫application.properties檔案

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2b8
spring.datasource.username=root
spring.datasource.password=123456

server.port=8081
spring.jpa.hibernate.ddl-auto=none
#是否會列印sql語句,true為列印
spring.jpa.show-sql=true

5. 配置Swagger

@Configuration
@EnableSwagger2
public class Swagger2 {

    final String host = "localhost";

    @Bean
    public Docket api() {
        return new Docket(DocumentationType.SWAGGER_2)
                .host(host)
                .select()
                .apis(RequestHandlerSelectors.any())
                .paths(PathSelectors.any())
                .build();
    }
}

6. 編寫Json工具類,主要是把資料轉為json格式

public class JsonCode<T> {

    public static class ResponseBean<T>{
        private Integer status;
        private Integer error_code;
        private String error_message;
        private T data;

        public Integer getStatus() {
            return status;
        }

        public void setStatus(Integer status) {
            this.status = status;
        }

        public Integer getError_code() {
            return error_code;
        }

        public void setError_code(Integer error_code) {
            this.error_code = error_code;
        }

        public String getError_message() {
            return error_message;
        }

        public void setError_message(String error_message) {
            this.error_message = error_message;
        }

        public T getData() {
            return data;
        }

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

    public String ResponseFail(int ErrorCode, String ErrorMessage) {
        ResponseBean<T> responseBean = new ResponseBean<T>();
        responseBean.setError_code(ErrorCode);
        responseBean.setError_message(ErrorMessage);
        Gson gson = new GsonBuilder().setDateFormat("yyyy-MM-dd HH:mm").create();
        return gson.toJson(responseBean);
    }

    public String ResponseSuccess(T data) {
        ResponseBean<T> responseBean = new ResponseBean<T>();
        responseBean.setData(data);
        responseBean.setError_code(0);
        responseBean.setError_message("");
        Gson gson = new GsonBuilder().setDateFormat("yyyy-MM-dd HH:mm").create();
        return gson.toJson(responseBean);
    }

    public String ResponseSuccess() {
        ResponseBean<T> responseBean = new ResponseBean<T>();
        responseBean.setData(null);
        responseBean.setError_code(0);
        responseBean.setError_message("");
        Gson gson = new GsonBuilder().setDateFormat("yyyy-MM-dd HH:mm").create();
        return gson.toJson(responseBean);
    }

}

7. 編寫WebMvcConfig

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("swagger-ui.html")
                .addResourceLocations("classpath:/META-INF/resources/");

        registry.addResourceHandler("/webjars/**")
                .addResourceLocations("classpath:/META-INF/resources/webjars/");

    }

    @Bean
    public PageableHandlerMethodArgumentResolverCustomizer customize() {
        return p -> p.setOneIndexedParameters(true);
    }

    static final String ORIGINS[] = new String[] { "GET", "POST", "PUT", "DELETE" };
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**").allowedOrigins("*").allowCredentials(true).allowedMethods(ORIGINS)
                .maxAge(3600);
    }
}

8. 主啟動類編寫

@EnableJpaAuditing
@EnableSwagger2
@SpringBootApplication
@Configuration
public class TestApplication {

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

9. 使用者實體類(CUserEntity)

@Entity
@EntityListeners(AuditingEntityListener.class)
@Table(name = "c_user",schema = "",catalog =  "")
public class CUserEntity {
    private int id;
    private String username;
    private String phone;

    @CreatedDate
    @DateTimeFormat(pattern = "yyyy-MM-dd HH-mm-ss")
    private Timestamp createAt;

    @LastModifiedDate
    @DateTimeFormat(pattern = "yyyy-MM-dd HH-mm-ss")
    private Timestamp updateAt;

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    @Basic
    @Column(name = "username")
    public String getUsername() {
        return username;
    }

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

    @Basic
    @Column(name = "phone")
    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    @Basic
    @Column(name = "create_at")
    public Timestamp getCreateAt() {
        return createAt;
    }

    public void setCreateAt(Timestamp createAt) {
        this.createAt = createAt;
    }

    @Basic
    @Column(name = "update_at")
    public Timestamp getUpdateAt() {
        return updateAt;
    }

    public void setUpdateAt(Timestamp updateAt) {
        this.updateAt = updateAt;
    }
}

10. 位址實體類(CAddressEntity)

@Entity
@EntityListeners(AuditingEntityListener.class)
@Table(name = "c_address")
public class CAddressEntity {

    private int id;
    private int uid;
    private String address;

    @CreatedDate
    @DateTimeFormat(pattern = "yyyy-MM-dd HH-mm-ss")
    private Timestamp createAt;

    @LastModifiedDate
    @DateTimeFormat(pattern = "yyyy-MM-dd HH-mm-ss")
    private Timestamp updateAt;

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    @Basic
    @Column(name = "uid")
    public int getUid() {
        return uid;
    }

    public void setUid(int uid) {
        this.uid = uid;
    }

    @Basic
    @Column(name = "address")
    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    @Basic
    @Column(name = "create_at")
    public Timestamp getCreateAt() {
        return createAt;
    }

    public void setCreateAt(Timestamp createAt) {
        this.createAt = createAt;
    }

    @Basic
    @Column(name = "update_at")
    public Timestamp getUpdateAt() {
        return updateAt;
    }

    public void setUpdateAt(Timestamp updateAt) {
        this.updateAt = updateAt;
    }
}

11. 編寫CUserEntityRepository

public interface CUserEntityRepository extends JpaRepository<CUserEntity,Integer>, JpaSpecificationExecutor<CUserEntity> {

    //簡單的查詢隻需要根據JPA命名規則來命名方法,就可以直接使用了，不需要編寫SQL語句，非常友善
    CUserEntity findFirstById(int id);
    CUserEntity findFirstByUsername(String username);
    CUserEntity findFirstByPhone(String phone);
}

12. 編寫CAddressEntityRepository

public interface CAddressEntityRepository extends JpaRepository<CAddressEntity, Integer>, JpaSpecificationExecutor<CAddressEntity> {
    
    //複雜的查詢則需要自己編寫SQL語句
    @Query(value = "SELECT c_user.username,c_user.phone,c_address.* FROM c_address LEFT JOIN c_user ON c_user.id = c_address.uid " +
            "WHERE c_user.id = ?1",
            nativeQuery = true)
    List<Map<String,Object>> NativeFindByUserId(int id);

    @Query(value = "SELECT c_user.username,c_user.phone,c_address.* FROM c_address LEFT JOIN c_user " +
            "ON c_user.id = c_address.uid WHERE IF(IFNULL(?1,'') !='',c_user.id = ?1,1 = 1) AND IF(?2 != '',c_user.username = ?2,1 = 1) AND " +
            "IF(?3 != '',c_user.phone = ?3,1 = 1) ",
    nativeQuery = true)
    Page<Map<String,Object>> NativeFindAllByUsernameOrPhone(Integer id,String username, String phone, Pageable pageable);
}

13. 編寫UserMessageWebController

@RestController
@RequestMapping("/api")
public class UserMessageWebController {

    //使用者資訊
    //檢視/添加/删除/修改
    
    @Autowired
    CUserEntityRepository cUserEntityRepository;

    //查詢使用者資訊
    @GetMapping(value = "/userMessage")
    public String userMessage(HttpServletRequest request,
                  @RequestParam(value = "username",required = true) String username
    ){

        CUserEntity cUserEntity = cUserEntityRepository.findFirstByUsername(username);
        if(cUserEntity == null){
            return new JsonCode<>().ResponseFail(99,"log_out");
        }

        return new JsonCode<>().ResponseSuccess(cUserEntity);
    }

    //添加使用者資訊
    @PostMapping(value = "/userMessage")
    public String addUserMessage(HttpServletRequest request,
                  @RequestParam(value = "username",required = true) String username,
                  @RequestParam(value = "phone",required = true) String phone
    ){

        CUserEntity cUserEntity = new CUserEntity();
        cUserEntity.setUsername(username);
        cUserEntity.setPhone(phone);
        cUserEntityRepository.saveAndFlush(cUserEntity);

        return new JsonCode<>().ResponseSuccess();
    }

    //修改使用者資訊
    @PutMapping(value = "/userMessage")
    public String changeUserMessage(HttpServletRequest request,
                  @RequestParam(value = "username",required = true) String username,
                  @RequestParam(value = "phone",required = true) String phone
    ){

        CUserEntity cUserEntity = cUserEntityRepository.findFirstByUsername(username);
        if(cUserEntity == null){
            return new JsonCode<>().ResponseFail(99,"log_out");
        }

        cUserEntity.setPhone(phone);
        cUserEntityRepository.save(cUserEntity);
        return new JsonCode<>().ResponseSuccess();
    }

    //删除使用者資訊
    @DeleteMapping(value = "/userMessage")
    public String deleteUserMessage(HttpServletRequest request,
                  @RequestParam(value = "username",required = true) String username
    ){

        CUserEntity cUserEntity = cUserEntityRepository.findFirstByUsername(username);
        if(cUserEntity == null){
            return new JsonCode<>().ResponseFail(99,"log_out");
        }

        cUserEntityRepository.delete(cUserEntity);
        return new JsonCode<>().ResponseSuccess();
    }
}

14. 編寫UserAddressWebController

@RestController
@RequestMapping("/api")
public class UserAddressWebController {

    @Autowired
    CAddressEntityRepository cAddressEntityRepository;

    @Autowired
    CUserEntityRepository cUserEntityRepository;


    @GetMapping(value = "/userAddress1")
    public String userAddress(HttpServletRequest request,
                  @RequestParam(value = "username",required = true) String username
    ){

        CUserEntity cUserEntity = cUserEntityRepository.findFirstByUsername(username);
        if(cUserEntity == null){
            return new JsonCode<>().ResponseFail(99,"log_out");
        }

        List<Map<String, Object>> address = cAddressEntityRepository.NativeFindByUserId(cUserEntity.getId());
        return new JsonCode<>().ResponseSuccess(address);
    }

    @GetMapping(value = "/userAddress2")
    public String userAddress(HttpServletRequest request,
                  @RequestParam(value="page", required=true) int page,
                  @RequestParam(value = "id",required = false) int id,
                  @RequestParam(value = "username",required = false) String username,
                  @RequestParam(value = "phone",required = false) String phone
   ){

        Pageable firstPageWithTwoElements = PageRequest.of(page, 10);
        Page<Map<String, Object>> address = cAddressEntityRepository.NativeFindAllByUsernameOrPhone(id,username,phone,firstPageWithTwoElements);

        return new JsonCode<>().ResponseSuccess(address);
    }
}

15. 最後測試一下

Swagger文檔的位址: http://localhost:8081/swagger-ui.html#/

測試接口位址: http://localhost:8081/api/userMessage?username=張三

使用IDEA 從零開始搭建一個 Spring Boot + JPA + Swagger入門項目

16. 總結

這是一個Spring Boot + JPA + Swagger的入門項目，主要是介紹一下如何在Spring Boot中使用JPA和Swagger，如果想要更加了解JPA的使用，還是需要自己更加深入地去學習一下的。

使用IDEA 從零開始搭建一個 Spring Boot + JPA + Swagger入門項目

文章目錄

1. 建立一個Spring Boot 項目

2. 建立資料庫

3. 在pom.xml檔案中引入maven依賴

4. 編寫application.properties檔案

5. 配置Swagger

6. 編寫Json工具類,主要是把資料轉為json格式

7. 編寫WebMvcConfig

8. 主啟動類編寫

9. 使用者實體類(CUserEntity)

10. 位址實體類(CAddressEntity)

11. 編寫CUserEntityRepository

12. 編寫CAddressEntityRepository

13. 編寫UserMessageWebController

14. 編寫UserAddressWebController

15. 最後測試一下

16. 總結

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