# Note For Thymeleaf
###### tags: `Shannon`,`SpringBoot`

資料來源:https://www.thymeleaf.org/doc/tutorials/2.1/thymeleafspring.html#checkbox-fields

補充資料:https://www.itread01.com/content/1547106606.html
30天學習Spring: https://ithelp.ithome.com.tw/users/20107812/ironman/1538

# th:object用法
before

    <p>Name: <span th:text="${user.name}">Jack</span>.</p>
    <p>Age: <span th:text="${user.age}">21</span>.</p>
    <p>friend: <span th:text="${user.friend.name}">Rose</span>.</p>
</h2>

after

<h2 th:object="${user}">
    <p>Name: <span th:text="*{name}">Jack</span>.</p>
    <p>Age: <span th:text="*{age}">21</span>.</p>
    <p>friend: <span th:text="*{friend.name}">Rose</span>.</p>
</h2>

# 02 關於ResponseEntity
* Download File時會使用到
* 可以透過ResponseEntity設置http response 內容、狀態與頭訊息

## 2.1 ResponseEntity
* ResponseEntity標示了整個http response 像是狀態碼、頭部訊息以及相應體內容。可以透過這個來對http response實現完整配置

## 03 Thymeleaf使用@Component裡面的方法
* 如果想要使用某個Service方法，那初始化會有問題，因此如果要使用方法就要選能夠不用初始化的Service

                                <button type="button" class="btn btn-success" onclick="showCredentialModal(this.getAttribute('data-credentialId'), this.getAttribute('data-url'), this.getAttribute('data-userName'), this.getAttribute('data-password'))"
                                 th:data-credentialId="${cred.credentialId}"
                                 th:data-url="${cred.url}"
                                 th:data-userName="${cred.userName}"
                                 th:data-password="${@EncryptionService.decryptValue(cred.password, cred.key)}"
                                >Edit</button>

> 不用初始化

@Service
public class EncryptionService {
    private Logger logger = LoggerFactory.getLogger(EncryptionService.class);

    public String decryptValue(String data, String key){
        byte[] decryptedValue = null;

        try {
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            SecretKey secretKey = new SecretKeySpec(key.getBytes(), "AES");
            cipher.init(Cipher.DECRYPT_MODE, secretKey);
            decryptedValue = cipher.doFinal(Base64.getDecoder().decode(data));
        } catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException | IllegalBlockSizeException | BadPaddingException e) {
            logger.error("這裡是Decrypt 發生錯誤喔" + e.getMessage());
        }
        return new String(decryptedValue);
    }
}

> 要初始化

@Service
public class CredentialService {
    private CredentialMapper credentialMapper;
    private EncryptionService encryptionService;

    public CredentialService(CredentialMapper credentialMapper,EncryptionService encryptionService){
        this.credentialMapper = credentialMapper;
        this.encryptionService = encryptionService;
    }

    public String Decrypt(String password, String key){
        return encryptionService.decryptValue(password, key);
    }
}