fix coredump issue when client not successfully connected but need disconnect (#28)

* fix coredump issue when client not successfully connected but need disconnect

* use flag to indicate exception happened or not

Author: yma11

java/plasma/src/main/java/org/apache/arrow/plasma/PlasmaClient.java

@@ -23,6 +23,7 @@
 import java.util.List;
 
 import org.apache.arrow.plasma.exceptions.DuplicateObjectException;
+import org.apache.arrow.plasma.exceptions.PlasmaClientException;
 import org.apache.arrow.plasma.exceptions.PlasmaOutOfMemoryException;
 
 /**
@@ -35,13 +36,27 @@ public class PlasmaClient implements ObjectStoreLink {
 
   private final long conn;
 
+  private boolean hasConnectException = false;
+
   protected void finalize() {
-    PlasmaClientJNI.disconnect(this.conn);
+    if (!hasConnectException) {
+      PlasmaClientJNI.disconnect(this.conn);
+    }
   }
 
-  // use plasma client to initialize the underlying jni system as well via config and config-overwrites
+  /**
+   * use plasma client to initialize the underlying jni system as well via config and config-overwrites.
+   * @param storeSocketName Socket path of Plasma server
+   * @param managerSocketName managerSocketName
+   * @param releaseDelay releaseDelay
+   */
   public PlasmaClient(String storeSocketName, String managerSocketName, int releaseDelay) {
-    this.conn = PlasmaClientJNI.connect(storeSocketName, managerSocketName, releaseDelay);
+    try {
+      this.conn = PlasmaClientJNI.connect(storeSocketName, managerSocketName, releaseDelay);
+    } catch (PlasmaClientException e) {
+      hasConnectException = true;
+      throw e;
+    }
   }
 
   // interface methods --------------------