转自:
在搜索开发中，我们要修改打分机制，就需要自定义similarity。现在来简单说一下elasticsearch下的自定义similarity 插件开发。
网上的 仅仅支持0.20.0.Beta1-SNAPSHOT版本，现在我们用的版本是elasticsearch 0.90版本以上。那个例子现在不能用，我修改了一下。
1.继承DefaultSimilarity，实现自己的搜索打分机制。
package org.elasticsearch.index.similarity; import org.apache.lucene.search.similarities.DefaultSimilarity; /** * Custom similarity class * * @author xq * */public class CustomSimilarity extends DefaultSimilarity { @Override public float idf(long docFreq, long numDocs) { return 1.0f; } } |
2.继续AbstractSimilarityProvider，把自定义的打分机制类加载到elasticsearch中。
package org.elasticsearch.index.similarity; import org.elasticsearch.common.inject.Inject;import org.elasticsearch.common.inject.assistedinject.Assisted;import org.elasticsearch.common.settings.Settings; /** * Simple { @link SimilarityProvider} for a { @link CustomSimilarity} * * @author xq * */ public class CustomSimilarityProvider extends AbstractSimilarityProvider { private CustomSimilarity similarity; @Inject public CustomSimilarityProvider(@Assisted String name, @Assisted Settings settings) { super(name); this.similarity = new CustomSimilarity(); } public CustomSimilarity get() { return similarity; } } |
3.继承AbstractPlugin作为elasticsearch插件使用
public class CustomerSimilarityPlugin extends AbstractPlugin { @Override public String name() { return "customer-similarity"; } @Override public String description() { return "customer similarity"; } @Override public void processModule(Module module) { if (module instanceof SimilarityModule) { SimilarityModule similarityModule = (SimilarityModule) module; similarityModule.addSimilarity("customer-similarity", CustomSimilarityProvider.class); } } } |
4.使用
curl -XPOST 'http://host:port/tweeter/' -d '{ "settings": { "similarity": { "index": { "type": "org.elasticsearch.index.similarity.CustomSimilarityProvider" }, "search": { "type": "org.elasticsearch.index.similarity.CustomSimilarityProvider" } } }}' |
在创建mapping的使用自定义的打分规则：
{ "news" : { "properties" : { "title" : { "type" : "string", "similarity" : "my_similarity" } } } |
在elasticsearch.yml中配置自定义的打分规则类为默认规则。 index.similarity.default.type: my_similarity