Spring Boot 佔位符Map工具類

佔位符工具類

PlaceholderUtil.java

@Slf4j
public class PlaceholderUtil {

    /**
     * Prefix for system property placeholders: "${"
     */
    public static final String PLACEHOLDER_PREFIX = "${";
    /**
     * Suffix for system property placeholders: "}"
     */
    public static final String PLACEHOLDER_SUFFIX = "}";

    public static String format(String text, Map<String, String> parameter) {
        if (parameter == null || parameter.isEmpty()) {
            return text;
        }
        StringBuffer buf = new StringBuffer(text);
        int startIndex = buf.indexOf(PLACEHOLDER_PREFIX);
        while (startIndex != -1) {
            int endIndex = buf.indexOf(PLACEHOLDER_SUFFIX, startIndex + PLACEHOLDER_PREFIX.length());
            if (endIndex != -1) {
                String placeholder = buf.substring(startIndex + PLACEHOLDER_PREFIX.length(), endIndex);
                int nextIndex = endIndex + PLACEHOLDER_SUFFIX.length();
                try {
                    String propVal = parameter.get(placeholder);
                    if (propVal != null) {
                        buf.replace(startIndex, endIndex + PLACEHOLDER_SUFFIX.length(), propVal);
                        nextIndex = startIndex + propVal.length();
                    } else {
                        log.warn("Could not resolve placeholder '" + placeholder + "' in [" + text + "] ");
                    }
                } catch (Exception ex) {
                    log.warn("Could not resolve placeholder '" + placeholder + "' in [" + text + "]: " + ex);
                }
                startIndex = buf.indexOf(PLACEHOLDER_PREFIX, nextIndex);
            } else {
                startIndex = -1;
            }
        }
        return buf.toString();
    }
}

單元測試

public class PlaceholderUtilTest {

    @Test
    public void resolvePlaceholders() {

        String aa = "${name}女士/先生，您好！今天是您的生日，${bankname}銀行祝您生日快樂，願您今天的回憶溫馨，願您今天的夢想甜美，願您這一年稱心如意。";
        Map<String, String> map = new HashMap<>();
        map.put("name", "阿豪");
        map.put("bankname", "中國");
        System.out.println(PlaceholderUtil.format(aa, map));
    }
}

輸出：

阿豪女士/先生，您好！今天是您的生日，中國銀行祝您生日快樂，願您今天的回憶溫馨，願您今天的夢想甜美，願您這一年稱心如意。