org.apache.solr.request.SolrRequestHandler Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of solr-core Show documentation
Apache Solr (module: core)
There is a newer version: 9.7.0
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.solr.request;

import org.apache.solr.common.util.NamedList;
import org.apache.solr.core.SolrInfoBean;
import org.apache.solr.response.SolrQueryResponse;

/**
 * Implementations of SolrRequestHandler are called to handle query requests.
 *
 * Different SolrRequestHandlers are registered with the SolrCore. One
 * way to register a SolrRequestHandler with the core is through the solrconfig.xml
 * file.
 *
 * 
Example solrconfig.xml entry to register a SolrRequestHandler
 * implementation to handle all queries with a Request Handler of "/test":
 *
 * 

 *    <requestHandler name="/test" class="solr.tst.TestRequestHandler" />
 * 
 *
 * 
A single instance of any registered SolrRequestHandler is created via the default constructor
 * and is reused for all relevant queries.
 */
public interface SolrRequestHandler extends SolrInfoBean {

  /**
   * init will be called just once, immediately after creation.
   *
   * 
The args are user-level initialization parameters that may be specified when declaring a
   * request handler in solrconfig.xml
   */
  public void init(NamedList args);

  /**
   * Handles a query request, this method must be thread safe.
   *
   * 
Information about the request may be obtained from req and response information
   * may be set using rsp.
   *
   * There are no mandatory actions that handleRequest must perform. An empty handleRequest
   * implementation would fulfill all interface obligations.
   */
  public void handleRequest(SolrQueryRequest req, SolrQueryResponse rsp);

  public static final String TYPE = "requestHandler";
}