SpringDataJPA之Base抽象类+范型快速实现增删查改

基本配置

pom.xml

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

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

application.yml

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://xxx:3306/mall?serverTimezone=GMT%2b8
    username: xxxx
    password: xxxx
  jpa:
    hibernate:
      ddl-auto: update
      naming:
        physical-strategy: org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
    show-sql: true

数据库基本配置
自动更新数据库表
使用驼峰命名方式
显示sql

实体类

BaseEntity.java

@Getter
@Setter
@DynamicUpdate
@DynamicInsert
@MappedSuperclass
@EntityListeners(AuditingEntityListener.class)
public abstract class BaseEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    protected Long id;

    @CreatedDate
    @Column(updatable = false)
    private Long createTime;

    @LastModifiedDate
    @Column
    private Long updateTime;

    @CreatedBy
    @Column(name = "created_by", updatable = false, length = 64)
    private String createdBy;

    @LastModifiedBy
    @Column(name = "updated_by", length = 64)
    private String updatedBy;

    @Column(columnDefinition = "tinyint(1) default 0")
    private Boolean deleted=false;

}

用法

@Getter
@Setter
@Entity
@Table(name = "user_info")
@Where(clause = "deleted<>1")
public class User extends BaseEntity {
	...
}

数据访问层

BaseRepository.java

1 2	`public interface BaseRepository<Entity extends BaseEntity> extends JpaRepository<Entity,Long>, JpaSpecificationExecutor<Entity> { }`

用法

@Repository
public interface UserRepository extends BaseRepository<User> {
	...
}

服务层

BaseService.java

public abstract class BaseService<Entity extends BaseEntity>{
    private final BaseRepository<Entity> repository;

    protected BaseService(BaseRepository<Entity> repository) {
        this.repository = repository;
    }

    public CommonResult save(Entity entity) {
        return CommonResult.success(repository.save(entity));
    }
    public CommonResult saveAll(List<Entity> entities) {
            if (((boolean) FieldUtil.getFieldValueByName("deleted", entities.get(0)))) {
              repository.deleteAll(entities);
              return CommonResult.success("删除成功");
            }
        return CommonResult.success(repository.saveAll(entities));
    }
    public CommonResult list() {
        return CommonResult.success(repository.findAll());
    }
    public CommonResult page(int pageNumber, int pageSize, Entity entity) {
        return CommonResult.success(repository.findAll((Specification<Entity>) (root, criteriaQuery, criteriaBuilder) -> {
            List<Predicate> predicateList = new ArrayList<>();
            List<Map<String,Object>> fieldList = FieldUtil.getFiledsInfo(entity);
            fieldList.stream().filter(field-> field.get("value")!=null ).forEach(field->{
                String name = field.get("name").toString();
                Object value = field.get("value");
                Class<?> type = (Class<?>) field.get("type");
                if (!Collection.class.isAssignableFrom(type) && !type.cast(value).toString().isEmpty()) {
                    if (String.class.isAssignableFrom(type)) {
                        predicateList.add(criteriaBuilder.like(root.get(name), "%" + value + "%"));
                    }else {
                        predicateList.add(criteriaBuilder.equal(root.get(name),type.cast(value)));
                    }
                }

            });
            return criteriaQuery.where(predicateList.toArray(new Predicate[predicateList.size()])).getRestriction();
        }, PageRequest.of(pageNumber - 1, pageSize)));
    }


}

FieldUtil.java

public class FieldUtil {
    public static final Logger log = LoggerFactory.getLogger(FieldUtil.class);

    /**
     * 根据属性名获取属性值
     */
    public static Object getFieldValueByName(String fieldName, Object o) {
        try {
            String firstLetter = fieldName.substring(0, 1).toUpperCase();
            String getter = "get" + firstLetter + fieldName.substring(1);
            Method method = o.getClass().getMethod(getter, new Class[]{});
            Object value = method.invoke(o, new Object[]{});
            return value;
        } catch (Exception e) {
            log.error(e.getMessage(), e);
            return null;
        }
    }

    /**
     * 获取属性名数组
     */
    public static String[] getFiledName(Object o) {
        Field[] fields = o.getClass().getDeclaredFields();
        String[] fieldNames = new String[fields.length];
        for (int i = 0; i < fields.length; i++) {
            System.out.println(fields[i].getType());
            fieldNames[i] = fields[i].getName();
        }
        return fieldNames;
    }

    /**
     * 获取属性类型(type)，属性名(name)，属性值(value)的map组成的list
     */
    public static List<Map<String,Object>> getFiledsInfo(Object o) {
        Field[] fields1 = o.getClass().getDeclaredFields();
        Field[] fields2 = o.getClass().getSuperclass().getDeclaredFields();
        Field[] fields = new Field[fields1.length + fields2.length];
        fields = ArrayUtil.append(fields1, fields2);
        String[] fieldNames = new String[fields.length];
        List<Map<String, Object>> list = new ArrayList<>();
        Map<String, Object> infoMap = null;
        for (Field field : fields) {
            infoMap = new HashMap<>();
            infoMap.put("type", field.getType());
            infoMap.put("name", field.getName());
            infoMap.put("value", getFieldValueByName(field.getName(), o));
            list.add(infoMap);
        }
        return list;
    }

    /**
     * 获取对象的所有属性值，返回一个对象数组
     */
    public static Object[] getFiledValues(Object o) {
        String[] fieldNames = getFiledName(o);
        Object[] value = new Object[fieldNames.length];
        for (int i = 0; i < fieldNames.length; i++) {
            value[i] = getFieldValueByName(fieldNames[i], o);
        }
        return value;
    }
}

用法

@Service
public class UserService extends BaseService<User>{
    
    protected UserService(UserRepository repository) {
        super(repository);
    }
    ...
}

Web服务层

BaseController.java

public class BaseController<Entity extends BaseEntity> {
    private final BaseService<Entity> service;
    private final Class<?> clazz;

    public BaseController(BaseService<Entity> service, Class<?> clazz) {
        this.service = service;
        this.clazz = clazz;
    }
    @GetMapping("page")
    public CommonResult page(int pageNumber, int pageSize, String contain,Entity entity) {
        return service.page(pageNumber, pageSize, entity) ;
    }
    @GetMapping("list")
    public CommonResult list() {
        return service.list();
    }
    @PostMapping("saveAll")
    public CommonResult saveAll(String data) {
        return service.saveAll(JSONUtil.toList(JSONUtil.parseArray(data), (Class<Entity>) clazz));
    }
}

用法

@RestController
@RequestMapping("/user")
public class UserController extends BaseController<User>{
    @Autowired
    UserService userService;

    public UserController(UserService service) {
        super(service, User.class);
    }
    ...
}

扩展：树形数据

TreeEntity.java

@Getter
@Setter
@MappedSuperclass
@EntityListeners(AuditingEntityListener.class)
public abstract class TreeEntity<T> extends BaseEntity{

    private int sort;
    @Column(columnDefinition = "boolean default false")
    private Boolean hidden;
    @ManyToOne
    @JsonIgnoreProperties("children")
    private T parent;

    @OneToMany(mappedBy = "parent")
    @OrderBy("sort asc")
    @JsonInclude(JsonInclude.Include.NON_EMPTY)
    private Set<T> children;
}

TreeService.java

public abstract class TreeService<Entity extends TreeEntity<Entity>>
        extends BaseService<Entity> {

    private final BaseRepository<Entity> repository;
    protected TreeService(BaseRepository<Entity> repository) {
        super(repository);
        this.repository = repository;
    }

    @Override
    public CommonResult saveAll(List<Entity> entities) {
        entities.forEach(entity -> {
            if (entity.getDeleted()) {
                deleteChildren(entity);
            }
        });
        return super.saveAll(entities);
    }
    private void deleteChildren(Entity entity) {
        if (entity == null) {
            return;
        }
        entity.setDeleted(true);
        if (entity.getChildren() == null) {
            return;
        }
        entity.getChildren().forEach(this::deleteChildren);
    }

    public CommonResult listTree() {
        Specification<Entity> specification = (root, criteriaQuery, criteriaBuilder) -> {
            criteriaQuery.where(
                    criteriaBuilder.isNull(root.get("parent"))
            );
            criteriaQuery.orderBy(criteriaBuilder.asc(root.get("sort")));
            return criteriaQuery.getRestriction();
        };
        List<Entity> list = repository.findAll(specification);
        return CommonResult.success(list);
    }


}

TreeController.java

public class TreeController<Entity extends TreeEntity<Entity>>
        extends BaseController<Entity>{

    private final TreeService<Entity> service;
    public TreeController(TreeService<Entity> service, Class<?> clazz) {
        super(service, clazz);
        this.service = service;
    }
    @Override
    @GetMapping("list")
    public CommonResult list() {
        return service.listTree();
    }
}

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