Spring Boot 占位符Map工具类

一时失言乱红尘 2021-10-19 01:18 275阅读 0赞

## 占位符工具类 ##

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();
        }
    }

## 单元测试 ##

public class PlaceholderUtilTest { 
    
        @Test
        public void resolvePlaceholders() { 
    
            String aa = "${name}女士/先生，您好！今天是您的生日，${bankname}银行祝您生日快乐，愿您今天的回忆温馨，愿您今天的梦想甜美，愿您这一年称心如意。";
            Map<String, String> map = new HashMap<>();
            map.put("name", "阿豪");
            map.put("bankname", "中国");
            System.out.println(PlaceholderUtil.format(aa, map));
        }
    }

输出：

阿豪女士/先生，您好！今天是您的生日，中国银行祝您生日快乐，愿您今天的回忆温馨，愿您今天的梦想甜美，愿您这一年称心如意。