由于现在使用拼音输入法较多，很可能输入同音字而无法搜索到结果，或者由于普通话不标准（前后鼻音不分）输入了错误的拼音。例如用户想搜索”牛奶“却输入了刘来（liulai），那我们可以对liulai进行模糊音扩展，然后一起放到搜索引擎中去搜索。为了避免过度扩展曲解了用户的意图，对于扩展词需要进行排序，越少改动越排在前面（原文排在最前），越多改动越排在后面。在搜索时按照顺序赋予不同的权重。

  类似这样：

 "query": {"bool":{"should":[{"match" : { "t.py":{"query": "lanqiuxie","analyzer":"whitespace","operator":"or"  ,"boost":3}}},         {"match" : { "t.py":{"query": "langqiuxie","analyzer":"whitespace","operator":"or"  ,"boost":3}}}, {"match" : { "t.py":{"query": "nangqiuxie","analyzer":"whitespace","operator":"or"  ,"boost":2}}}, {"match" : { "t.py":{"query": "nanqiuxie","analyzer":"whitespace","operator":"or"  ,"boost":1}}}]}}}

好，现在show一下模糊拼音扩展的算法：

1.声母l和n互换

2.韵母有g和没g互换。

3.变换少的排在前面。

例如 ["liulai"] => ["liulai","liunai","niulai","niunai"]

    //汉语拼音模糊音扩展static public List<String> expand(String[] ss) {int n = ss.length;List<String>[] lists = new ArrayList[n];List<Integer> changes = new ArrayList<>();for (int i = 0; i < n; i++) {lists[i] = expandOne(ss[i]);if (lists[i].size() > 1) changes.add(i);}int max = changes.size();if (max > 4) max = 4;List<String> ans = new ArrayList<>();for (int i = 0; i <= max; i++) {ans.addAll(miss(lists, changes, i, 0, 0));}return ans;}static private Map<String, String> confusingMap = new HashMap<String, String>() {{this.put("in", "ing");this.put("an", "ang");this.put("en", "eng");this.put("un", "ong");}};static private List<String> miss(List<String>[] lists, List<Integer> changes, int c, int b1, int b2) {List<String> list = new ArrayList<>();if (c > changes.size() - b2 || c < 0) return list;int n = lists.length;if (c == 0) {StringBuilder sb = new StringBuilder();for (int i = b1; i < n; i++) {sb.append(lists[i].get(0));}list.add(sb.toString());} else {int fc = changes.get(b2);StringBuilder sb = new StringBuilder();for (int i = b1; i < fc; i++) {sb.append(lists[i].get(0));}String pre = sb.toString();List<String> left = miss(lists, changes, c - 1, fc + 1, b2 + 1);for (int i = 1; i < lists[fc].size(); i++) {for (String s : left) {list.add(pre + lists[fc].get(i) + s);}}pre += lists[fc].get(0);left = miss(lists, changes, c, fc + 1, b2 + 1);for (String s : left) {list.add(pre + s);}}return list;}static private List<String> expandOne(String py) {List<String> list = new ArrayList<>();list.add(py);if (py.equals("yang") || py.equals("yan")) return list;if (py.startsWith("l") || py.startsWith("n")) {List<String> vs = changeVowel(py.substring(1));String[] ln = py.startsWith("l") ? new String[]{"l", "n"}: new String[]{"n", "l"};for (String sm : ln) {for (String s : vs) {String nw = sm + s;if (!nw.equals(py)) list.add(nw);}}} else {List<String> vs = changeVowel(py);return vs;}return list;}static private List<String> changeVowel(String s) {List<String> list = new ArrayList<>();list.add(s);if (s.endsWith("iang") || s.endsWith("ian")) return list;int len = s.length();for (Map.Entry<String, String> en : confusingMap.entrySet()) {String k = en.getKey(), v = en.getValue();if (s.endsWith(k)) {list.add(s.substring(0, len - k.length()) + v);break;} else if (s.endsWith(v)) {list.add(s.substring(0, len - v.length()) + k);break;}}return list;}public static void main(String[] args) {System.out.println(expand(new String[]{"niu","nai"}));}