Use antlr4 for FQN instead of regex. (#4066)

catalog-rest-service/pom.xml

@@ -22,6 +22,10 @@
   </properties>
 
   <dependencies>
+    <dependency>
+      <groupId>org.antlr</groupId>
+      <artifactId>antlr4-runtime</artifactId>
+    </dependency>
     <dependency>
       <groupId>com.macasaet.fernet</groupId>
       <artifactId>fernet-java8</artifactId>
@@ -342,6 +346,18 @@
 
   <build>
     <plugins>
+      <plugin>
+        <groupId>org.antlr</groupId>
+        <artifactId>antlr4-maven-plugin</artifactId>
+        <version>${antlr.version}</version>
+        <executions>
+          <execution>
+            <goals>
+              <goal>antlr4</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
       <plugin>
         <groupId>com.theoryinpractise</groupId>
         <artifactId>googleformatter-maven-plugin</artifactId>

catalog-rest-service/src/main/antlr4/org/openmetadata/catalog/Fqn.g4

@@ -0,0 +1,30 @@
+grammar Fqn;
+
+fqn
+    : name ('.' name)* EOF
+    ;
+
+name
+    : NAME               # unquotedName
+    | NAME_WITH_RESERVED # quotedName
+    ;
+
+NAME
+    : NON_RESERVED+
+    ;
+
+NAME_WITH_RESERVED
+    : QUOTE NON_RESERVED* (RESERVED NON_RESERVED*)+ QUOTE
+    ;
+
+QUOTE
+    : '"'
+    ;
+
+NON_RESERVED
+    : ~[".]
+    ;
+
+RESERVED
+    : '.'
+    ;

catalog-rest-service/src/main/java/org/openmetadata/catalog/util/FullyQualifiedName.java

@@ -4,7 +4,17 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import org.antlr.v4.runtime.BailErrorStrategy;
+import org.antlr.v4.runtime.CharStreams;
+import org.antlr.v4.runtime.CommonTokenStream;
+import org.antlr.v4.runtime.tree.ParseTreeWalker;
 import org.openmetadata.catalog.Entity;
+import org.openmetadata.catalog.FqnBaseListener;
+import org.openmetadata.catalog.FqnLexer;
+import org.openmetadata.catalog.FqnParser;
+import org.openmetadata.catalog.FqnParser.FqnContext;
+import org.openmetadata.catalog.FqnParser.QuotedNameContext;
+import org.openmetadata.catalog.FqnParser.UnquotedNameContext;
 
 public class FullyQualifiedName {
   // Match the sub parts of fqn string "sss". or sss. or sss$
@@ -28,16 +38,37 @@ public class FullyQualifiedName {
   }
 
   public static String[] split(String string) {
+    SplitListener listener = new SplitListener();
+    walk(string, listener);
+    return listener.split();
+  }
+
+  private static <L extends FqnBaseListener> void walk(String string, L listener) {
+    FqnLexer fqnLexer = new FqnLexer(CharStreams.fromString(string));
+    CommonTokenStream tokens = new CommonTokenStream(fqnLexer);
+    FqnParser fqnParser = new FqnParser(tokens);
+    fqnParser.setErrorHandler(new BailErrorStrategy());
+    FqnContext fqn = fqnParser.fqn();
+    ParseTreeWalker walker = new ParseTreeWalker();
+    walker.walk(listener, fqn);
+  }
+
+  private static class SplitListener extends FqnBaseListener {
     List<String> list = new ArrayList<>();
-    Matcher matcher = partsPattern.matcher(string);
-    while (matcher.find()) {
-      if (matcher.group(1) != null) {
-        list.add(matcher.group(3).contains(".") ? matcher.group(1) : matcher.group(3));
-      } else {
-        list.add(matcher.group(5));
-      }
+
+    public String[] split() {
+      return list.toArray(new String[list.size()]);
+    }
+
+    @Override
+    public void enterQuotedName(QuotedNameContext ctx) {
+      list.add(ctx.getText());
+    }
+
+    @Override
+    public void enterUnquotedName(UnquotedNameContext ctx) {
+      list.add(ctx.getText());
     }
-    return list.toArray(new String[list.size()]);
   }
 
   /** Adds quotes to name as required */

pom.xml

@@ -79,6 +79,7 @@
     <org.junit.jupiter.version>5.8.2</org.junit.jupiter.version>
     <dropwizard-health.version>1.7.1</dropwizard-health.version>
     <fernet.version>1.5.0</fernet.version>
+    <antlr.version>4.9.3</antlr.version>
 
     <!--   sonar   -Dsonar.login=XXX  -->
     <sonar.projectKey>open-metadata_OpenMetadata</sonar.projectKey>
@@ -94,6 +95,11 @@
   </properties>
   <dependencyManagement>
     <dependencies>
+      <dependency>
+        <groupId>org.antlr</groupId>
+        <artifactId>antlr4-runtime</artifactId>
+        <version>${antlr.version}</version>
+      </dependency>
       <dependency>
         <groupId>org.glassfish.jersey</groupId>
         <artifactId>jersey-bom</artifactId>