Parse the filters passed by controller and build Search Criteria

BaseService.java

/**
	 * Format search criteria.
	 *
	 * @param filter the filter
	 * @return the list
	 */
	public List<SearchCriteria> formatSearchCriteria(String[] filter) {
		List<SearchCriteria> criterias = new ArrayList<>();
		if (null != filter) {
			Collection<SearchCriteria> collect = Arrays.asList(filter).parallelStream().map(this::validateFilterPattern)
					.collect(Collectors.toList());
			criterias.addAll(collect);
		}
		return criterias;
	}

	/**
	 * Gets the and boolean expression.
	 *
	 * @param criterias the criterias
	 * @param t         the t
	 * @return the and boolean expression
	 */
	public BooleanExpression getAndBooleanExpression(List<SearchCriteria> criterias, Class<Post> t) {
		return new CommonPredicateBuilder<>(t).and(criterias).build();
	}

	/**
	 * Validate filter pattern.
	 *
	 * @param filter the filter
	 * @return the search criteria
	 */
	private SearchCriteria validateFilterPattern(String filter) {
		final Pattern pattern = Pattern.compile("([\\w.]+?)(:|<|>|<=|>=|%|-|\\(\\))([\\w\\s\\(\\),.:-]+?)\\|");
		Matcher m = pattern.matcher(filter + "|");
		if (m.find()) {
			return SearchCriteria.builder().key(m.group(1)).operator(m.group(2)).value(m.group(3)).build();
		} else {
			throw new RuntimeException("Invalid Filter format");
		}
	}