fix for

"org.apache.solr.core.SolrCore Too many close [count:-1] on
org.apache.solr.core.SolrCore@51af7c57"
-error

source/net/yacy/cora/federate/solr/connector/CachedSolrConnector.java

@@ -73,6 +73,10 @@ public class CachedSolrConnector extends AbstractSolrConnector implements SolrCo
         this.documentCache.clear();
         if (this.solr != null) this.solr.commit(true);
     }
+    
+    protected void finalize() throws Throwable {
+        this.close();
+    }
 
     @Override
     public synchronized void close() {

source/net/yacy/cora/federate/solr/connector/EmbeddedSolrConnector.java

@@ -141,12 +141,18 @@ public class EmbeddedSolrConnector extends SolrServerConnector implements SolrCo
     public SolrConfig getConfig() {
         return this.core.getSolrConfig();
     }
+    
+    protected void finalize() throws Throwable {
+        this.close();
+    }
 
     @Override
     public synchronized void close() {
-        try {this.commit(false);} catch (final Throwable e) {ConcurrentLog.logException(e);}
+        if (this.core != null && !this.core.isClosed()) try {this.commit(false);} catch (final Throwable e) {ConcurrentLog.logException(e);}
         try {super.close();} catch (final Throwable e) {ConcurrentLog.logException(e);}
-        try {this.core.close();} catch (final Throwable e) {ConcurrentLog.logException(e);}
+        // we do NOT close the core here because that is closed if the enclosing instance is closed
+        // do NOT uncomment the following line, which caused a "org.apache.solr.core.SolrCore Too many close [count:-1] on org.apache.solr.core.SolrCore@51af7c57" error
+        // try {this.core.close();} catch (final Throwable e) {ConcurrentLog.logException(e);}
     }
 
     @Override

source/net/yacy/cora/federate/solr/instance/EmbeddedInstance.java

@@ -205,10 +205,17 @@ public class EmbeddedInstance implements SolrInstance {
         this.cores.put(name, c);
         return c;
     }
+    
+    protected void finalize() throws Throwable {
+        this.close();
+    }
 
     @Override
     public synchronized void close() {
-        try {this.coreContainer.shutdown();} catch (final Throwable e) {ConcurrentLog.logException(e);}
+        if (this.coreContainer != null) try {
+            this.coreContainer.shutdown();
+            this.coreContainer = null;
+        } catch (final Throwable e) {ConcurrentLog.logException(e);}
     }
     
 }