diff --git a/runtime/Java/src/org/antlr/v4/runtime/BaseRecognizer.java b/runtime/Java/src/org/antlr/v4/runtime/BaseRecognizer.java
index e8e352dc0..451429456 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/BaseRecognizer.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/BaseRecognizer.java
@@ -688,6 +688,7 @@ public abstract class BaseRecognizer extends Recognizer<ParserATNSimulator> {
 	 *  parse trees as well.
 	 */
 	public void enterRule(int ruleIndex) {
+		_ctx.ruleIndex = ruleIndex;
 		if ( buildParseTrees ) {
 			if ( _ctx.parent!=null ) _ctx.parent.addChild(_ctx);
 		}
diff --git a/runtime/Java/src/org/antlr/v4/runtime/ParserRuleContext.java b/runtime/Java/src/org/antlr/v4/runtime/ParserRuleContext.java
index 3ff4ccfe6..8520c2dcd 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/ParserRuleContext.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/ParserRuleContext.java
@@ -49,6 +49,9 @@ import org.stringtemplate.v4.ST;
  *  satisfy the superclass interface.
  */
 public class ParserRuleContext extends RuleContext {
+	/** Set during parsing to identify which rule parser is in. */
+	public int ruleIndex;
+
 	public Token start, stop;
 	public Object tree;
 	public ST st;
diff --git a/tool/resources/org/antlr/v4/tool/templates/codegen/Java/Java.stg b/tool/resources/org/antlr/v4/tool/templates/codegen/Java/Java.stg
index 4ac8a7e4c..dc82d2d6e 100644
--- a/tool/resources/org/antlr/v4/tool/templates/codegen/Java/Java.stg
+++ b/tool/resources/org/antlr/v4/tool/templates/codegen/Java/Java.stg
@@ -44,6 +44,8 @@ public class <parser.name> extends Parser {
         "\<INVALID>", "\<INVALID>", "\<INVALID>",
         <parser.tokenNames:{k | "<k>"}; separator=", ", wrap, anchor>
     };
+    public static final int
+        <parser.rules:{r | RULE_<r.name> = <r.index>}; separator=", ", wrap, anchor>;
     public static final String[] ruleNames = {
         <parser.ruleNames:{r | "<r>"}; separator=", ", wrap, anchor>
     };
diff --git a/tool/src/org/antlr/v4/codegen/model/Parser.java b/tool/src/org/antlr/v4/codegen/model/Parser.java
index 78cf683db..5a6af826b 100644
--- a/tool/src/org/antlr/v4/codegen/model/Parser.java
+++ b/tool/src/org/antlr/v4/codegen/model/Parser.java
@@ -40,6 +40,7 @@ public class Parser extends OutputModelObject {
 	public Map<String,Integer> tokens;
 	public String[] tokenNames;
 	public Set<String> ruleNames;
+	public Collection<Rule> rules;
 	public ParserFile file;
 
 	@ModelElement public List<RuleFunction> funcs = new ArrayList<RuleFunction>();
@@ -59,6 +60,7 @@ public class Parser extends OutputModelObject {
 		}
 		tokenNames = g.getTokenDisplayNames();
 		ruleNames = g.rules.keySet();
+		rules = g.rules.values();
 		atn = new SerializedATN(factory, g.atn);
 	}
 }