SolrJ: CloudSolrClient, HTTP StateProvider: Use EnvUtils to customize…

… a cache timeout (#2629)

New "solr.solrj.cache.timeout.sec" setting which will affect HttpClusterStateProvider caching of liveNodes and aliases.

solr/solrj/src/java/org/apache/solr/client/solrj/impl/BaseHttpClusterStateProvider.java

@@ -39,6 +39,7 @@
 import org.apache.solr.common.cloud.DocCollection;
 import org.apache.solr.common.cloud.PerReplicaStates;
 import org.apache.solr.common.params.ModifiableSolrParams;
+import org.apache.solr.common.util.EnvUtils;
 import org.apache.solr.common.util.NamedList;
 import org.apache.solr.common.util.SimpleOrderedMap;
 import org.apache.solr.common.util.Utils;
@@ -55,7 +56,8 @@ public abstract class BaseHttpClusterStateProvider implements ClusterStateProvid
   volatile Map<String, Map<String, String>> aliasProperties;
   long aliasesTimestamp = 0;
 
-  private int cacheTimeout = 5; // the liveNodes and aliases cache will be invalidated after 5 secs
+  // the liveNodes and aliases cache will be invalidated after 5 secs
+  private int cacheTimeout = EnvUtils.getPropertyAsInteger("solr.solrj.cache.timeout.sec", 5);
 
   public void init(List<String> solrUrls) throws Exception {
     for (String solrUrl : solrUrls) {
@@ -411,10 +413,6 @@ public int getCacheTimeout() {
     return cacheTimeout;
   }
 
-  public void setCacheTimeout(int cacheTimeout) {
-    this.cacheTimeout = cacheTimeout;
-  }
-
   // This exception is not meant to escape this class it should be caught and wrapped.
   private static class NotACollectionException extends Exception {}