Query Refactoring: Add RangeQueryBuilder and Parser refactoring and test.

Split the parse(QueryParseContext ctx) method into a parsing and a query building part,
adding Streamable support for serialization and hashCode(), equals() for better testing.

This PR also adds test setup for two mappes fields (integer, date) to the BaseQueryTestCase
and introduces helper methods for optional conversion of String fields to BytesRef representation
that is shared with the already refactored BaseTermQueryBuilder.

Relates to elastic#10217
Closes elastic#11108

Author: cbuescher

src/main/java/org/elasticsearch/index/query/BaseTermQueryBuilder.java

@@ -23,14 +23,13 @@
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.io.stream.Streamable;
-import org.elasticsearch.common.lucene.BytesRefs;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 
 import java.io.IOException;
 import java.util.Objects;
 
 public abstract class BaseTermQueryBuilder<QB extends BoostableQueryBuilder<QB>> extends QueryBuilder implements Streamable, BoostableQueryBuilder<QB> {
-    
+
     /** Name of field to match against. */
     protected String fieldName;
 
@@ -105,17 +104,16 @@ public BaseTermQueryBuilder(String fieldName, boolean value) {
 
     /**
      * Constructs a new base term query.
+     * In case value is assigned to a string, we internally convert it to a {@link BytesRef}
+     * because in {@link TermQueryParser} and {@link SpanTermQueryParser} string values are parsed to {@link BytesRef}
+     * and we want internal representation of query to be equal regardless of whether it was created from XContent or via Java API.
      *
      * @param fieldName  The name of the field
      * @param value The value of the term
      */
     public BaseTermQueryBuilder(String fieldName, Object value) {
         this.fieldName = fieldName;
-        if (value instanceof String) {
-            this.value = BytesRefs.toBytesRef(value);
-        } else {
-            this.value = value;
-        }
+        this.value = convertToBytesRefIfString(value);
     }
 
     BaseTermQueryBuilder() {
@@ -127,11 +125,14 @@ public String fieldName() {
         return this.fieldName;
     }
 
-    /** Returns the value used in this query. */
+    /**
+     *  Returns the value used in this query.
+     *  If necessary, converts internal {@link BytesRef} representation back to string.
+     */
     public Object value() {
-        return this.value;
+        return convertToStringIfBytesRef(this.value);
     }
-    
+
     /** Returns the query name for the query. */
     public String queryName() {
         return this.queryName;
@@ -144,7 +145,7 @@ public QB queryName(String queryName) {
         this.queryName = queryName;
         return (QB) this;
     }
-    
+
     /** Returns the boost for this query. */
     public float boost() {
         return this.boost;
@@ -163,16 +164,11 @@ public QB boost(float boost) {
     @Override
     protected void doXContent(XContentBuilder builder, Params params) throws IOException {
         builder.startObject(parserName());
-        Object valueToWrite = value;
-        if (value instanceof BytesRef) {
-            valueToWrite = ((BytesRef) value).utf8ToString();
-        }
-
         if (boost == 1.0f && queryName == null) {
-            builder.field(fieldName, valueToWrite);
+            builder.field(fieldName, convertToStringIfBytesRef(this.value));
         } else {
             builder.startObject(fieldName);
-            builder.field("value", valueToWrite);
+            builder.field("value", convertToStringIfBytesRef(this.value));
             if (boost != 1.0f) {
                 builder.field("boost", boost);
             }
@@ -183,7 +179,7 @@ protected void doXContent(XContentBuilder builder, Params params) throws IOExcep
         }
         builder.endObject();
     }
-    
+
     /** Returns a {@link QueryValidationException} if fieldName is null or empty, or if value is null. */
     @Override
     public QueryValidationException validate() {
@@ -194,7 +190,7 @@ public QueryValidationException validate() {
         if (value == null) {
             validationException = QueryValidationException.addValidationError("value cannot be null.", validationException);
         }
-        return validationException;        
+        return validationException;
     }
 
     @Override

src/main/java/org/elasticsearch/index/query/QueryBuilder.java

@@ -21,6 +21,8 @@
 
 import org.apache.lucene.search.Query;
 import org.elasticsearch.action.support.ToXContentToBytes;
+import org.apache.lucene.util.BytesRef;
+import org.elasticsearch.common.lucene.BytesRefs;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentType;
 
@@ -75,4 +77,30 @@ public QueryValidationException validate() {
     }
 
     protected abstract void doXContent(XContentBuilder builder, Params params) throws IOException;
+
+    /**
+     * This helper method checks if the object passed in is a string, if so it
+     * converts it to a {@link BytesRef}.
+     * @param obj the input object
+     * @return the same input object or a {@link BytesRef} representation if input was of type string
+     */
+    protected static Object convertToBytesRefIfString(Object obj) {
+        if (obj instanceof String) {
+            return BytesRefs.toBytesRef(obj);
+        }
+        return obj;
+    }
+
+    /**
+     * This helper method checks if the object passed in is a {@link BytesRef}, if so it
+     * converts it to a utf8 string.
+     * @param obj the input object
+     * @return the same input object or a utf8 string if input was of type {@link BytesRef}
+     */
+    protected static Object convertToStringIfBytesRef(Object obj) {
+        if (obj instanceof BytesRef) {
+            return ((BytesRef) obj).utf8ToString();
+        }
+        return obj;
+    }
 }