HttpSolrCall是solr底層發送http請求的中轉站，首先看一下它的構造函數
public HttpSolrCall(SolrDispatchFilter solrDispatchFilter, CoreContainer cores,
HttpServletRequest request, HttpServletResponse response, boolean retry) {
this.solrDispatchFilter = solrDispatchFilter;
this.cores = cores;
this.req = request;
this.response = response;
this.retry = retry;
this.requestType = RequestType.UNKNOWN;
queryParams = SolrRequestParsers.parseQueryString(req.getQueryString());
}
沒有什麼特別之處，主要是進行了一些賦值操作
接下來這個類裏面有個 private void init() throws Exception {}方法
主要是解析req從中獲取core名稱，並向req中寫入一些屬性，初始化一些core相關的參數，檢查core在不在corecontainer中，並做一些錯誤異常拋出的處理，以及得到當前url的action類型。在這個方法裏還調用了一個方法
extractHandlerFromURLPath(SolrRequestParsers parser) throws Exception {}
此方法從url中解析出當前請求需要用到的SolrRequestHandler，這個SolrRequestHandler在solr中很重要，每一種不同的request請求都對應着一個SolrRequestHandler，在後面的文章中我們將詳細介紹
solrReq = parser.parse(core, path, req);
invalidStates = checkStateIsValid(solrReq.getParams().get(CloudSolrClient.STATE_VERSION));
String qt = solrReq.getParams().get(CommonParams.QT);
handler = core.getRequestHandler(qt);
下面這個方法是這個類的核心
public Action call() throws IOException {
switch (action) {
case ADMIN:
handleAdminRequest();
return RETURN;
case REMOTEQUERY:
remoteQuery(coreUrl + path, resp);
return RETURN;
case PROCESS:
final Method reqMethod = Method.getMethod(req.getMethod());
HttpCacheHeaderUtil.setCacheControlHeader(config, resp, reqMethod);
// unless we have been explicitly told not to, do cache validation
// if we fail cache validation, execute the query
if (config.getHttpCachingConfig().isNever304() ||
!HttpCacheHeaderUtil.doCacheHeaderValidation(solrReq, req, reqMethod, resp)) {
SolrQueryResponse solrRsp = new SolrQueryResponse();
/* even for HEAD requests, we need to execute the handler to
* ensure we don't get an error (and to make sure the correct
* QueryResponseWriter is selected and we get the correct
* Content-Type)
*/
SolrRequestInfo.setRequestInfo(new SolrRequestInfo(solrReq, solrRsp));
execute(solrRsp);
HttpCacheHeaderUtil.checkHttpCachingVeto(solrRsp, resp, reqMethod);
Iterator<Map.Entry<String, String>> headers = solrRsp.httpHeaders();
while (headers.hasNext()) {
Map.Entry<String, String> entry = headers.next();
resp.addHeader(entry.getKey(), entry.getValue());
}
QueryResponseWriter responseWriter = core.getQueryResponseWriter(solrReq);
if (invalidStates != null) solrReq.getContext().put(CloudSolrClient.STATE_VERSION, invalidStates);
writeResponse(solrRsp, responseWriter, reqMethod);
}
return RETURN;
default: return action;
}
}
在這些代碼裏處理了ADMIN，REMOTEQUERY，PROCESS三種類型的請求，其他類型的action不做操作
ADMIN的請求在本機
這個類的分析到此結束，下一篇文章我們將分析CoreContainer這個類的作用