利用java8 + Jpa写出流畅的代码示例（参考）

╰半夏微凉° 2024-04-18 09:49 33阅读 0赞

### 利用java8 + Jpa写出流畅的代码示例（参考） ###

*   *   *  一、新增
         *  二、修改(可适当调整，利用BeanUtil.copy)
         *  三、删除
         *  四、查询,需要在构造对象DTO的时候，合适的构造方法即可

### 一、新增 ###

### 二、修改(可适当调整，利用BeanUtil.copy) ###

*  2.1

public Optional<UserDTO> updateUser(UserDTO userDTO) { 
            return Optional.of(userRepository
                    .findById(userDTO.getId()))
                    .filter(Optional::isPresent)
                    .map(Optional::get)
                    .map(user -> { 
                        this.clearUserCaches(user);
                        user.setLogin(userDTO.getLogin().toLowerCase());
                        user.setFirstName(userDTO.getFirstName());
                        user.setLastName(userDTO.getLastName());
                        user.setEmail(userDTO.getEmail().toLowerCase());
                        user.setImageUrl(userDTO.getImageUrl());
                        user.setActivated(userDTO.isActivated());
                        user.setLangKey(userDTO.getLangKey());
                        Set<String> managedAuthorities = user.getAuthorities();
                        managedAuthorities.clear();
                        this.clearUserCaches(user);
                        log.debug("Changed Information for User: {}", user);
                        return user;
                    })
                    .map(user1 -> new UserDTO(user1));
        }

*  2.2

public void changePassword(String currentClearTextPassword, String newPassword) { 
            SecurityUtils.getCurrentUserLogin()
                .flatMap(userRepository::findOneByLogin)
                .ifPresent(user -> { 
                    String currentEncryptedPassword = user.getPassword();
                    if (!passwordEncoder.matches(currentClearTextPassword, currentEncryptedPassword)) { 
                        throw new InvalidPasswordException();
                    }
                    String encryptedPassword = passwordEncoder.encode(newPassword);
                    user.setPassword(encryptedPassword);
                    this.clearUserCaches(user);
                    log.debug("Changed password for User: {}", user);
                });
        }

### 三、删除 ###

*  3.1 方式1

public void deleteUser(String login) { 
            userRepository.findOneByLogin(login).ifPresent(user -> { 
                userRepository.delete(user);
                this.clearUserCaches(user);
                log.debug("Deleted User: {}", user);
            });
        }

*  3.2 方式2

@Scheduled(cron = "0 0 1 * * ?")
        public void removeNotActivatedUsers() { 
        userRepository   
           .findAllByActivatedIsFalseAndActivationKeyIsNotNullAndCreatedDateBefore(Instant.now().minus(3, ChronoUnit.DAYS))
                    .forEach(user -> { 
                        log.debug("Deleting not activated user {}", user.getLogin());
                        userRepository.delete(user);
                        this.clearUserCaches(user);
                    });
        }

public void delete(List<Long> roleIds) { 
            roleRepository.findAllById(roleIds)
                    .forEach(role -> { 
                        roleRepository.delete(role);
                    });
        }

### 四、查询,需要在构造对象DTO的时候，合适的构造方法即可 ###

*  4.1

@Transactional(readOnly = true)
        public Page<UserDTO> getAllManagedUsers(Pageable pageable) { 
            return userRepository.findAllByLoginNot(pageable, Constants.ANONYMOUS_USER).map(UserDTO::new);
        }

*  4.2

public Optional<AuditEvent> find(Long id) {
            return Optional.ofNullable(persistenceAuditEventRepository.findById(id))
                .filter(Optional::isPresent)
                .map(Optional::get)
                .map(auditEventConverter::convertToAuditEvent);
        }