Updated for ES 1.7.0, added a better example

README.textile

@@ -1,21 +1,29 @@
 h1. A custom SimilarityProvider example for Elasticseach
 
-This plugin contains a custom @Similarity@ class that can be used in an index:
+This plugin contains a custom @Similarity@ class that can be used as follows.
+
+Build the plugin with maven, then put the jar file into @$ES_PATH/lib@.
+
+Then, declare it in the settings section of your index:
 
 <pre>
-curl -XPOST 'http://host:port/tweeter/' -d '
-{
-  "settings": {
-    "similarity": {
-      "index": {
-        "type": "org.elasticsearch.index.similarity.CustomSimilarityProvider"
-      },
-      "search": {
-        "type": "org.elasticsearch.index.similarity.CustomSimilarityProvider"
-      }
+"settings" : {
+  "similarity" : {
+    "my_similarity" : {
+      "type" : "org.elasticsearch.index.similarity.CustomSimilarityProvider"
     }
   }
-}'
+}
+</pre> 
+
+After that, you can refer to @my_similarity@ when defining fields:
+
+<pre>
+"book" : {
+  "properties" : {
+    "title" : { "type" : "string", "similarity" : "my_similarity" }
+  }
+}
 </pre> 
 
 Enjoy

pom.xml

@@ -3,15 +3,28 @@
 	<modelVersion>4.0.0</modelVersion>
 
 	<groupId>fr.tlrx</groupId>
-	<artifactId>elasticsearch-custom-similarity-provider</artifactId>
-	<version>1.0-SNAPSHOT</version>
+	<artifactId>elasticsearch-constant-similarity-provider</artifactId>
+	<version>1.0</version>
 	<packaging>jar</packaging>
-	<name>A custom SimilarityProvider example for Elasticsearch</name>
-	<url>https://github.com/tlrx/elasticsearch-custom-similarity-provider</url>
+	<name>A constant SimilarityProvider for Elasticsearch</name>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-compiler-plugin</artifactId>
+				<version>3.3</version>
+				<configuration>
+					<source>1.7</source>
+					<target>1.7</target>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
 
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<elasticsearch.version>0.20.0.Beta1-SNAPSHOT</elasticsearch.version>
+		<elasticsearch.version>1.7.0</elasticsearch.version>
 	</properties>
 
 	<dependencies>
@@ -27,5 +40,5 @@
 			<version>${elasticsearch.version}</version>
 		</dependency>
 	</dependencies>
-	
+
 </project>

src/main/java/org/elasticsearch/index/similarity/CustomSimilarity.java

@@ -1,6 +1,6 @@
 package org.elasticsearch.index.similarity;
 
-import org.apache.lucene.search.DefaultSimilarity;
+import org.apache.lucene.search.similarities.DefaultSimilarity;
 
 /**
  * Custom similarity class
@@ -12,7 +12,7 @@
 public class CustomSimilarity extends DefaultSimilarity {
 
 	@Override
-	public float idf(int docFreq, int numDocs) {
+	public float idf(long docFreq, long numDocs) {
 		return 1.0f;
 	}
 }

src/main/java/org/elasticsearch/index/similarity/CustomSimilarityProvider.java

@@ -12,18 +12,16 @@
  * @author tlrx
  *
  */
-public class CustomSimilarityProvider extends AbstractSimilarityProvider<CustomSimilarity> {
+public class CustomSimilarityProvider extends AbstractSimilarityProvider {
 
-	private CustomSimilarity similarity;
+	private final CustomSimilarity similarity = new CustomSimilarity();
 
 	@Inject
-	public CustomSimilarityProvider(Index index,
-			@IndexSettings Settings indexSettings, @Assisted String name,
-			@Assisted Settings settings) {
-		super(index, indexSettings, name);
-		this.similarity = new CustomSimilarity();
+	public CustomSimilarityProvider(@Assisted String name, @Assisted Settings settings) {
+		super(name);
 	}
 
+	@Override
 	public CustomSimilarity get() {
 		return similarity;
 	}