ATLAS-2229: Added thread-safety for SimpleDateFormat.

repository/src/main/java/org/apache/atlas/discovery/EntityDiscoveryService.java

@@ -68,6 +68,7 @@ import javax.script.Bindings;
 import javax.script.ScriptEngine;
 import javax.script.ScriptException;
 import java.util.*;
+import java.util.stream.Stream;
 
 import static org.apache.atlas.AtlasErrorCode.CLASSIFICATION_NOT_FOUND;
 import static org.apache.atlas.AtlasErrorCode.DISCOVERY_QUERY_FAILED;
@@ -897,9 +898,7 @@ public class EntityDiscoveryService implements AtlasDiscoveryService {
     @Override
     public String getDslQueryUsingTypeNameClassification(String query, String typeName, String classification) {
         final String whereDSLKeyword = "where";
-        final String isaDSLKeyword = "isa";
-        final String isDSLKeyword = "is";
-        final String limitDSLKeyword = "limit";
+        final String[] keywords = new String[]{whereDSLKeyword, "isa", "is", "limit", "orderby", "has"};
         final String whereFormat = whereDSLKeyword + " %s";
 
         String queryStr = query == null ? "" : query;
@@ -907,10 +906,7 @@ public class EntityDiscoveryService implements AtlasDiscoveryService {
         if (StringUtils.isNotEmpty(typeName)) {
             if(StringUtils.isNotEmpty(query)) {
                 String s = query.toLowerCase();
-                if(!s.startsWith(whereDSLKeyword) &&
-                        !s.startsWith(limitDSLKeyword) &&
-                        !s.startsWith(isaDSLKeyword) &&
-                        !s.startsWith(isDSLKeyword)) {
+                if(!Stream.of(keywords).anyMatch(x -> s.startsWith(x))) {
                     queryStr = String.format(whereFormat, query);
                 }
             }
@@ -921,7 +917,7 @@ public class EntityDiscoveryService implements AtlasDiscoveryService {
         if (StringUtils.isNotEmpty(classification)) {
             // isa works with a type name only - like hive_column isa PII; it doesn't work with more complex query
             if (StringUtils.isEmpty(query)) {
-                queryStr += String.format("%s %s %s", queryStr, isaDSLKeyword, classification);
+                queryStr += String.format("%s %s %s", queryStr, "isa", classification);
             }
         }
         return queryStr;

repository/src/main/java/org/apache/atlas/query/GremlinQueryComposer.java

@@ -38,7 +38,7 @@ import java.util.stream.Stream;
 public class GremlinQueryComposer {
     private static final Logger LOG = LoggerFactory.getLogger(GremlinQueryComposer.class);
 
-    private final String DATE_FORMAT_ISO8601_FORMAT = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'";
+    private static final String ISO8601_FORMAT = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'";
     private final int DEFAULT_QUERY_RESULT_LIMIT = 25;
     private final int DEFAULT_QUERY_RESULT_OFFSET = 0;
 
@@ -50,13 +50,22 @@ public class GremlinQueryComposer {
     private       int                    providedLimit  = DEFAULT_QUERY_RESULT_LIMIT;
     private       int                    providedOffset = DEFAULT_QUERY_RESULT_OFFSET;
     private       Context                context;
-    private final DateFormat dateFormat = new SimpleDateFormat(DATE_FORMAT_ISO8601_FORMAT);
+
+    private static final ThreadLocal<DateFormat> DSL_DATE_FORMAT = new ThreadLocal<DateFormat>() {
+        @Override
+        public DateFormat initialValue() {
+            DateFormat ret = new SimpleDateFormat(ISO8601_FORMAT);
+
+            ret.setTimeZone(TimeZone.getTimeZone("UTC"));
+
+            return ret;
+        }
+    };
 
     public GremlinQueryComposer(Lookup registryLookup, final AtlasDSL.QueryMetadata qmd, boolean isNestedQuery) {
         this.isNestedQuery = isNestedQuery;
         this.lookup        = registryLookup;
         this.queryMetadata = qmd;
-        dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
 
         init();
     }
@@ -74,7 +83,6 @@ public class GremlinQueryComposer {
         this.lookup        = lookup;
         this.context       = context;
         this.queryMetadata = qmd;
-        dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
 
         init();
     }
@@ -351,7 +359,7 @@ public class GremlinQueryComposer {
 
     public long getDateFormat(String s) {
         try {
-            return dateFormat.parse(s).getTime();
+            return DSL_DATE_FORMAT.get().parse(s).getTime();
         } catch (ParseException ex) {
             errorList.add(ex.getMessage());
         }

repository/src/main/java/org/apache/atlas/query/antlr4/AtlasDSLLexer.g4

@@ -121,8 +121,6 @@ K_SUM: S U M ;
 
 K_COUNT: C O U N T ;
 
-K_LOOP: L O O P ;
-
 K_OFFSET: O F F S E T ;
 
 K_AS: A S ;
@@ -137,8 +135,6 @@ K_ASC: A S C ;
 
 K_DESC: D E S C ;
 
-K_WITHPATH: W I T H P A T H ;
-
 K_TRUE: T R U E ;
 
 K_FALSE: F A L S E ;
@@ -158,12 +154,10 @@ KEYWORD: K_LIKE
         | K_OR
         | K_GROUPBY
         | K_ORDERBY
-        | K_WITHPATH
         | K_SUM
         | K_MIN
         | K_MAX
         | K_OFFSET
-        | K_LOOP
         | K_FROM
         | K_DESC
         | K_ASC