java - 如何在 Spring REST API 响应中连接 Elasticsearch 的结果

Question

我已经使用 Spring 开发了一个 REST API 条目，它在 Elasticsearch 中进行搜索，现在我想返回 ES 找到的任何结果作为响应。我不关心搜索结果，也不知道其中的 JSON 结构。我只是想把它退还给客户。

我希望这样的事情能起作用:

@RequestMapping(value = "/search/{index:.*}", method = RequestMethod.GET)public void search(@PathVariable String index, @RequestParam Map allRequestParams, HttpServletResponse response)    throws IOException{    BoolQueryBuilder query = QueryBuilders.boolQuery();    for (Map.Entry entry : allRequestParams.entrySet()) {        query.should(QueryBuilders.fuzzyQuery(entry.getKey(), entry.getValue()));    }    SearchResponse results = esClient.prepareSearch("nyc_visionzero")        .setTypes("logs")        .setQuery(query)        .execute()        .actionGet();    SearchHits hits = results.getHits();    hits.writeTo(response.getOutputStream());}

但是最后一行有编译错误，因为两个 OutputStream 不兼容。所以我的问题是，将 Elasticsearch 的结果连接到 Spring 的响应中的最简单方法是什么？

Answer 1

您可以更改搜索方法的签名以返回字符串，然后直接将结果作为有效 JSON 返回，而不是尝试写入响应输出流。像这样的东西:

@RequestMapping(value = "/search/{index:.*}", method = RequestMethod.GET)
public String search(@PathVariable String index, @RequestParam Map allRequestParams, HttpServletResponse response)
    throws IOException
{
    BoolQueryBuilder query = QueryBuilders.boolQuery();
    for (Map.Entry entry : allRequestParams.entrySet()) {
        query.should(QueryBuilders.fuzzyQuery(entry.getKey(), entry.getValue()));
    }

    SearchResponse results = esClient.prepareSearch("nyc_visionzero")
        .setTypes("logs")
        .setQuery(query)
        .execute()
        .actionGet();

    SearchHits hits = results.getHits();

    // Replacing hits.writeTo(response.getOutputStream()); below
    StringBuilder builder = new StringBuilder();
    SearchHit[] hitsDatas = hits.hits();
    int length = hitsDatas.length;
    builder.append("[");
    for (int i = 0; i < length; i++) {
       if (i == length - 1) {
          builder.append(hitsDatas[i].getSourceAsString());
       } else {
          builder.append(hitsDatas[i].getSourceAsString());
          builder.append(",");
       }
    }
    builder.append("]");
    return builder.toString();
}