Add utility method to parse named XContent objects with typed prefix (#24240)

This commit adds a XContentParserUtils.parseTypedKeysObject() method
that can be used to parse named XContent objects identified by a field
name containing a type identifier, a delimiter and the name of the
object to parse.

1 files changed, 71 insertions, 0 deletions

diff --git a/core/src/test/java/org/elasticsearch/common/xcontent/XContentParserUtilsTests.java b/core/src/test/java/org/elasticsearch/common/xcontent/XContentParserUtilsTests.java
index 00edb25d5c..d0426e1e10 100644
--- a/core/src/test/java/org/elasticsearch/common/xcontent/XContentParserUtilsTests.java
+++ b/core/src/test/java/org/elasticsearch/common/xcontent/XContentParserUtilsTests.java
@@ -19,15 +19,22 @@
 
 package org.elasticsearch.common.xcontent;
 
+import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.ParsingException;
+import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.xcontent.json.JsonXContent;
 import org.elasticsearch.test.ESTestCase;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 
+import static org.elasticsearch.common.xcontent.XContentHelper.toXContent;
 import static org.elasticsearch.common.xcontent.XContentParserUtils.ensureExpectedToken;
+import static org.elasticsearch.common.xcontent.XContentParserUtils.parseTypedKeysObject;
 
 public class XContentParserUtilsTests extends ESTestCase {
+
     public void testEnsureExpectedToken() throws IOException {
         final XContentParser.Token randomToken = randomFrom(XContentParser.Token.values());
         try (XContentParser parser = createParser(JsonXContent.jsonXContent, "{}")) {
@@ -40,4 +47,68 @@ public class XContentParserUtilsTests extends ESTestCase {
             ensureExpectedToken(XContentParser.Token.END_OBJECT, parser.nextToken(), parser::getTokenLocation);
         }
     }
+
+    public void testParseTypedKeysObject() throws IOException {
+        final String delimiter = randomFrom("#", ":", "/", "-", "_", "|", "_delim_");
+        final XContentType xContentType = randomFrom(XContentType.values());
+
+        List<NamedXContentRegistry.Entry> namedXContents = new ArrayList<>();
+        namedXContents.add(new NamedXContentRegistry.Entry(Boolean.class, new ParseField("bool"), parser -> {
+            ensureExpectedToken(XContentParser.Token.VALUE_BOOLEAN, parser.nextToken(), parser::getTokenLocation);
+            return parser.booleanValue();
+        }));
+        namedXContents.add(new NamedXContentRegistry.Entry(Long.class, new ParseField("long"), parser -> {
+            ensureExpectedToken(XContentParser.Token.VALUE_NUMBER, parser.nextToken(), parser::getTokenLocation);
+            return parser.longValue();
+        }));
+        final NamedXContentRegistry namedXContentRegistry = new NamedXContentRegistry(namedXContents);
+
+        BytesReference bytes = toXContent((builder, params) -> builder.field("test", 0), xContentType, randomBoolean());
+        try (XContentParser parser = xContentType.xContent().createParser(namedXContentRegistry, bytes)) {
+            parser.nextToken();
+            ParsingException e = expectThrows(ParsingException.class, () -> parseTypedKeysObject(parser, delimiter, Boolean.class));
+            assertEquals("Failed to parse object: expecting token of type [FIELD_NAME] but found [START_OBJECT]", e.getMessage());
+
+            parser.nextToken();
+            e = expectThrows(ParsingException.class, () -> parseTypedKeysObject(parser, delimiter, Boolean.class));
+            assertEquals("Cannot parse object of class [Boolean] without type information. Set [typed_keys] parameter " +
+                    "on the request to ensure the type information is added to the response output", e.getMessage());
+        }
+
+        bytes = toXContent((builder, params) -> builder.field("type" + delimiter + "name", 0), xContentType, randomBoolean());
+        try (XContentParser parser = xContentType.xContent().createParser(namedXContentRegistry, bytes)) {
+            ensureExpectedToken(XContentParser.Token.START_OBJECT, parser.nextToken(), parser::getTokenLocation);
+            ensureExpectedToken(XContentParser.Token.FIELD_NAME, parser.nextToken(), parser::getTokenLocation);
+
+            NamedXContentRegistry.UnknownNamedObjectException e = expectThrows(NamedXContentRegistry.UnknownNamedObjectException.class,
+                    () -> parseTypedKeysObject(parser, delimiter, Boolean.class));
+            assertEquals("Unknown Boolean [type]", e.getMessage());
+            assertEquals("type", e.getName());
+            assertEquals("java.lang.Boolean", e.getCategoryClass());
+        }
+
+        final long longValue = randomLong();
+        final boolean boolValue = randomBoolean();
+        bytes = toXContent((builder, params) -> {
+            builder.field("long" + delimiter + "l", longValue);
+            builder.field("bool" + delimiter + "b", boolValue);
+            return builder;
+        }, xContentType, randomBoolean());
+
+        try (XContentParser parser = xContentType.xContent().createParser(namedXContentRegistry, bytes)) {
+            ensureExpectedToken(XContentParser.Token.START_OBJECT, parser.nextToken(), parser::getTokenLocation);
+
+            ensureExpectedToken(XContentParser.Token.FIELD_NAME, parser.nextToken(), parser::getTokenLocation);
+            Long parsedLong = parseTypedKeysObject(parser, delimiter, Long.class);
+            assertNotNull(parsedLong);
+            assertEquals(longValue, parsedLong.longValue());
+
+            ensureExpectedToken(XContentParser.Token.FIELD_NAME, parser.nextToken(), parser::getTokenLocation);
+            Boolean parsedBoolean = parseTypedKeysObject(parser, delimiter, Boolean.class);
+            assertNotNull(parsedBoolean);
+            assertEquals(boolValue, parsedBoolean);
+
+            ensureExpectedToken(XContentParser.Token.END_OBJECT, parser.nextToken(), parser::getTokenLocation);
+        }
+    }
 }