Allow parsing Content-Type and Accept headers with version

libs/x-content/src/main/java/org/elasticsearch/common/xcontent/XContentType.java

@@ -26,6 +26,8 @@
 
 import java.util.Locale;
 import java.util.Objects;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 /**
  * The content type of {@link org.elasticsearch.common.xcontent.XContent}.
@@ -114,13 +116,35 @@ public XContent xContent() {
         }
     };
 
+    /**
+     * A regexp to allow parsing media types. It covers two use cases.
+     * 1. Media type with a version - requires a custom vnd.elasticserach subtype and a compatible-with parameter
+     * i.e. application/vnd.elasticsearch+json;compatible-with
+     * 2. Media type without a version - for users not using compatible API i.e. application/json
+     */
+    private static final Pattern COMPATIBLE_API_HEADER_PATTERN = Pattern.compile(
+            //type
+        "^(application|text)/" +
+            // custom subtype and a version: vnd.elasticsearch+json;compatible-with=7
+            "((vnd\\.elasticsearch\\+([^;\\s]+)(\\s*;\\s*compatible-with=(\\d+)))" +
+            "|([^;\\s]+))" + //subtype: json,yaml,etc some of these are defined in x-pack so can't be enumerated
+            "(?:\\s*;\\s*(charset=UTF-8)?)?$",
+        Pattern.CASE_INSENSITIVE);
+
+
+    /*Pattern.compile(
+        "^(application|text)/(vnd\\.elasticsearch\\+)?([^;]+)(\\s*;\\s*compatible-with=(\\d+))?$",
+        Pattern.CASE_INSENSITIVE);
+*/
     /**
      * Accepts either a format string, which is equivalent to {@link XContentType#shortName()} or a media type that optionally has
      * parameters and attempts to match the value to an {@link XContentType}. The comparisons are done in lower case format and this method
      * also supports a wildcard accept for {@code application/*}. This method can be used to parse the {@code Accept} HTTP header or a
      * format query string parameter. This method will return {@code null} if no match is found
      */
-    public static XContentType fromMediaTypeOrFormat(String mediaType) {
+    public static XContentType fromMediaTypeOrFormat(String mediaTypeHeaderValue) {
+        String mediaType = parseMediaType(mediaTypeHeaderValue);
+
         if (mediaType == null) {
             return null;
         }
@@ -130,7 +154,7 @@ public static XContentType fromMediaTypeOrFormat(String mediaType) {
             }
         }
         final String lowercaseMediaType = mediaType.toLowerCase(Locale.ROOT);
-        if (lowercaseMediaType.startsWith("application/*")) {
+        if (lowercaseMediaType.startsWith("application/*") || lowercaseMediaType.equals("*/*")) {
             return JSON;
         }
 
@@ -142,7 +166,9 @@ public static XContentType fromMediaTypeOrFormat(String mediaType) {
      * The provided media type should not include any parameters. This method is suitable for parsing part of the {@code Content-Type}
      * HTTP header. This method will return {@code null} if no match is found
      */
-    public static XContentType fromMediaType(String mediaType) {
+    public static XContentType fromMediaType(String mediaTypeHeaderValue) {
+        String mediaType = parseMediaType(mediaTypeHeaderValue);
+
         final String lowercaseMediaType = Objects.requireNonNull(mediaType, "mediaType cannot be null").toLowerCase(Locale.ROOT);
         for (XContentType type : values()) {
             if (type.mediaTypeWithoutParameters().equals(lowercaseMediaType)) {
@@ -157,6 +183,31 @@ public static XContentType fromMediaType(String mediaType) {
         return null;
     }
 
+    // package private for testing
+    static String parseMediaType(String mediaType) {
+        if (mediaType != null) {
+            Matcher matcher = COMPATIBLE_API_HEADER_PATTERN.matcher(mediaType);
+            if (matcher.find()) {
+                if(matcher.group(2).toLowerCase(Locale.ROOT).startsWith("vnd.elasticsearch")){
+                    return (matcher.group(1) + "/" + matcher.group(4)).toLowerCase(Locale.ROOT);
+                }
+                return (matcher.group(1) + "/" + matcher.group(7)).toLowerCase(Locale.ROOT);
+            }
+        }
+
+        return null;
+    }
+
+    // package private for testing
+    static String parseVersion(String mediaType){
+        if(mediaType != null){
+            Matcher matcher = COMPATIBLE_API_HEADER_PATTERN.matcher(mediaType);
+            if (matcher.find() && matcher.group(2).toLowerCase(Locale.ROOT).startsWith("vnd.elasticsearch")) {
+                return matcher.group(6);
+            }
+        }
+        return null;
+    }
     private static boolean isSameMediaTypeOrFormatAs(String stringType, XContentType type) {
         return type.mediaTypeWithoutParameters().equalsIgnoreCase(stringType) ||
                 stringType.toLowerCase(Locale.ROOT).startsWith(type.mediaTypeWithoutParameters().toLowerCase(Locale.ROOT) + ";") ||

server/src/test/java/org/elasticsearch/common/xcontent/XContentTypeTests.java

@@ -23,6 +23,7 @@
 import java.util.Locale;
 
 import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.nullValue;
 
 public class XContentTypeTests extends ESTestCase {
@@ -84,4 +85,75 @@ public void testFromRubbish() throws Exception {
         assertThat(XContentType.fromMediaTypeOrFormat("text/plain"), nullValue());
         assertThat(XContentType.fromMediaTypeOrFormat("gobbly;goop"), nullValue());
     }
+
+    public void testMediaType() {
+        String version = String.valueOf(Math.abs(randomByte()));
+        assertThat(XContentType.parseMediaType("application/vnd.elasticsearch+json;compatible-with=" + version),
+            equalTo("application/json"));
+        assertThat(XContentType.parseMediaType("application/vnd.elasticsearch+cbor;compatible-with=" + version),
+            equalTo("application/cbor"));
+        assertThat(XContentType.parseMediaType("application/vnd.elasticsearch+smile;compatible-with=" + version),
+            equalTo("application/smile"));
+        assertThat(XContentType.parseMediaType("application/vnd.elasticsearch+yaml;compatible-with=" + version),
+            equalTo("application/yaml"));
+        assertThat(XContentType.parseMediaType("application/json"),
+            equalTo("application/json"));
+
+
+        assertThat(XContentType.parseMediaType("APPLICATION/VND.ELASTICSEARCH+JSON;COMPATIBLE-WITH=" + version),
+            equalTo("application/json"));
+        assertThat(XContentType.parseMediaType("APPLICATION/JSON"),
+            equalTo("application/json"));
+    }
+
+    public void testVersionParsing() {
+        String version = String.valueOf(Math.abs(randomByte()));
+        assertThat(XContentType.parseVersion("application/vnd.elasticsearch+json;compatible-with=" + version),
+            equalTo(version));
+        assertThat(XContentType.parseVersion("application/vnd.elasticsearch+cbor;compatible-with=" + version),
+            equalTo(version));
+        assertThat(XContentType.parseVersion("application/vnd.elasticsearch+smile;compatible-with=" + version),
+            equalTo(version));
+        assertThat(XContentType.parseVersion("application/json"),
+            nullValue());
+
+
+        assertThat(XContentType.parseVersion("APPLICATION/VND.ELASTICSEARCH+JSON;COMPATIBLE-WITH=" + version),
+            equalTo(version));
+        assertThat(XContentType.parseVersion("APPLICATION/JSON"),
+            nullValue());
+
+        assertThat(XContentType.parseVersion("application/json;compatible-with=" + version+".0"),
+            is(nullValue()));
+    }
+
+    public void testMediaTypeWithoutESSubtype() {
+        String version = String.valueOf(Math.abs(randomByte()));
+        assertThat(XContentType.fromMediaTypeOrFormat("application/json;compatible-with=" + version), nullValue());
+    }
+
+    public void testAnchoring(){
+        String version = String.valueOf(Math.abs(randomByte()));
+        assertThat(XContentType.fromMediaTypeOrFormat("sth_application/json;compatible-with=" + version+".0"), nullValue());
+        assertThat(XContentType.fromMediaTypeOrFormat("sth_application/json;compatible-with=" + version+"_sth"), nullValue());
+        //incorrect parameter not validated at the moment, just ignored
+        assertThat(XContentType.fromMediaTypeOrFormat("application/json;compatible-with=" + version+"_sth"), nullValue());
+    }
+
+    public void testVersionParsingOnText() {
+        String version = String.valueOf(Math.abs(randomByte()));
+        assertThat(XContentType.parseVersion("text/vnd.elasticsearch+csv;compatible-with=" + version),
+            equalTo(version));
+        assertThat(XContentType.parseVersion("text/vnd.elasticsearch+text;compatible-with=" + version),
+            equalTo(version));
+        assertThat(XContentType.parseVersion("text/vnd.elasticsearch+tab-separated-values;compatible-with=" + version),
+            equalTo(version));
+        assertThat(XContentType.parseVersion("text/csv"),
+            nullValue());
+
+        assertThat(XContentType.parseVersion("TEXT/VND.ELASTICSEARCH+CSV;COMPATIBLE-WITH=" + version),
+            equalTo(version));
+        assertThat(XContentType.parseVersion("TEXT/csv"),
+            nullValue());
+    }
 }