java解析{{}}变量名以及文本内容替换操作

/**
 * 根据正则表达式获取文本中的变量名列表
 * @param pattern
 * @param content
 * @return
 */
public static List<String> getParams(String pattern, String content) {
 Pattern p = Pattern.compile(pattern);
 Matcher m = p.matcher(content);
 
 List<String> result = new ArrayList<String>();
 while (m.find()) {
  result.add(m.group(1));
 }
 return result;
}
 
/**
 * 根据正则表达式将文本中的变量使用实际的数据替换成无变量的文本
 * @param pattern
 * @param content
 * @param data
 * @return
 */
public static String parse(String pattern, String content, Map<String, String> data) {
 Pattern p = Pattern.compile(pattern);
 Matcher m = p.matcher(content);
 
 StringBuffer sb = new StringBuffer();
 while (m.find()) {
  String key = m.group(1);
  String value = data.get(key);
  m.appendReplacement(sb, value == null ? "" : value);
 }
 m.appendTail(sb);
 return sb.toString();
}
 
public static void main(String[] args) {
 String content = "恭喜{{姓名}}报名成功，请凭报名编号{[code]}到现场参加活动";
 String reg = "\\{\\{(.+?)\\}\\}";
 List<String> params = getParams(reg, content);
 System.out.println(params);
 
 Map<String, String> data = new HashMap<String, String>();
 data.put("姓名", "张三丰");
 data.put("code", "930118");
 String text = parse(reg, content, data);
 System.out.println(text);
}

/**
 * 占位符解析器
 *
 * @author meilin.huang
 * @version 1.0
 * @date 2018-11-13 1:42 PM
 */
public class PlaceholderResolver {
 /**
  * 默认前缀占位符
  */
 public static final String DEFAULT_PLACEHOLDER_PREFIX = "${";

 /**
  * 默认后缀占位符
  */
 public static final String DEFAULT_PLACEHOLDER_SUFFIX = "}";

 /**
  * 默认单例解析器
  */
 private static PlaceholderResolver defaultResolver = new PlaceholderResolver();

 /**
  * 占位符前缀
  */
 private String placeholderPrefix = DEFAULT_PLACEHOLDER_PREFIX;

 /**
  * 占位符后缀
  */
 private String placeholderSuffix = DEFAULT_PLACEHOLDER_SUFFIX;


 private PlaceholderResolver(){}

 private PlaceholderResolver(String placeholderPrefix, String placeholderSuffix) {
  this.placeholderPrefix = placeholderPrefix;
  this.placeholderSuffix = placeholderSuffix;
 }

 /**
  * 获取默认的占位符解析器，即占位符前缀为"${", 后缀为"}"
  * @return
  */
 public static PlaceholderResolver getDefaultResolver() {
  return defaultResolver;
 }

 public static PlaceholderResolver getResolver(String placeholderPrefix, String placeholderSuffix) {
  return new PlaceholderResolver(placeholderPrefix, placeholderSuffix);
 }

 /**
  * 解析带有指定占位符的模板字符串，默认占位符为前缀：${ 后缀：}<br/><br/>
  * 如：template = category:${}:product:${}<br/>
  * values = {"1", "2"}<br/>
  * 返回 category:1:product:2<br/>
  *
  * @param content 要解析的带有占位符的模板字符串
  * @param values 按照模板占位符索引位置设置对应的值
  * @return
  */
 public String resolve(String content, String... values) {
  int start = content.indexOf(this.placeholderPrefix);
  if (start == -1) {
   return content;
  }
  //值索引
  int valueIndex = 0;
  StringBuilder result = new StringBuilder(content);
  while (start != -1) {
   int end = result.indexOf(this.placeholderSuffix);
   String replaceContent = values[valueIndex++];
   result.replace(start, end + this.placeholderSuffix.length(), replaceContent);
   start = result.indexOf(this.placeholderPrefix, start + replaceContent.length());
  }
  return result.toString();
 }

 /**
  * 解析带有指定占位符的模板字符串，默认占位符为前缀：${ 后缀：}<br/><br/>
  * 如：template = category:${}:product:${}<br/>
  * values = {"1", "2"}<br/>
  * 返回 category:1:product:2<br/>
  *
  * @param content 要解析的带有占位符的模板字符串
  * @param values 按照模板占位符索引位置设置对应的值
  * @return
  */
 public String resolve(String content, Object[] values) {
  return resolve(content, Stream.of(values).map(String::valueOf).toArray(String[]::new));
 }

 /**
  * 根据替换规则来替换指定模板中的占位符值
  * @param content 要解析的字符串
  * @param rule 解析规则回调
  * @return
  */
 public String resolveByRule(String content, Function<String, String> rule) {
  int start = content.indexOf(this.placeholderPrefix);
  if (start == -1) {
   return content;
  }
  StringBuilder result = new StringBuilder(content);
  while (start != -1) {
   int end = result.indexOf(this.placeholderSuffix, start);
   //获取占位符属性值，如${id}, 即获取id
   String placeholder = result.substring(start + this.placeholderPrefix.length(), end);
   //替换整个占位符内容，即将${id}值替换为替换规则回调中的内容
   String replaceContent = placeholder.trim().isEmpty() ? "" : rule.apply(placeholder);
   result.replace(start, end + this.placeholderSuffix.length(), replaceContent);
   start = result.indexOf(this.placeholderPrefix, start + replaceContent.length());
  }
  return result.toString();
 }

 /**
  * 替换模板中占位符内容，占位符的内容即为map key对应的值，key为占位符中的内容。<br/><br/>
  * 如：content = product:${id}:detail:${did}<br/>
  * valueMap = id -> 1; pid -> 2<br/>
  * 经过解析返回 product:1:detail:2<br/>
  *
  * @param content 模板内容。
  * @param valueMap 值映射
  * @return 替换完成后的字符串。
  */
 public String resolveByMap(String content, final Map<String, Object> valueMap) {
  return resolveByRule(content, placeholderValue -> String.valueOf(valueMap.get(placeholderValue)));
 }

 /**
  * 根据properties文件替换占位符内容
  * @param content
  * @param properties
  * @return
  */
 public String resolveByProperties(String content, final Properties properties) {
  return resolveByRule(content, placeholderValue -> properties.getProperty(placeholderValue));
 }

 /**
  * 根据对象中字段路径(即类似js访问对象属性值)替换模板中的占位符 <br/><br/>
  * 如 content = product:${id}:detail:${detail.id} <br/>
  * obj = Product.builder().id(1).detail(Detail.builder().id(2).build()).build(); <br/>
  * 经过解析返回 product:1:detail:2 <br/>
  *
  * @param content 要解析的内容
  * @param obj 填充解析内容的对象(如果是基本类型，则所有占位符替换为相同的值)
  * @return
  */
 public String resolveByObject(String content, final Object obj) {
  if (obj instanceof Map) {
   return resolveByMap(content, (Map)obj);
  }
  return resolveByRule(content, placeholderValue -> String.valueOf(ReflectionUtils.getValueByFieldPath(obj, placeholderValue)));
 }
}